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  • 1985-1989  (4,242)
  • 1940-1944  (1,512)
  • 1870-1879  (2,105)
  • 1840-1849  (4,620)
  • Organic Chemistry  (11,729)
  • Life Sciences  (596)
  • breast cancer
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Material
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Year
Keywords
  • 1
    Electronic Resource
    Electronic Resource
    The acceptable delay between biopsy and radical mastectomy in breast cancer patients (1989)
    Springer
    Surgery today 19 (1989), S. 679-683 
    Details
    ISSN: 1436-2813
    Keywords: biopsy ; breast cancer ; radical mastectomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effects on the prognosis of breast cancer, of the delay between biopsy and radical mastectomy were studied in 394 patients. No delay had been experienced by 148 cases (no delay group), no biopsy had been performed in 166 cases (no biopsy group) and 80 cases had experienced a delay of 1 day or longer after having had a biopsy taken at a different institution (delay group). The recurrence rate of the no delay group was 10.8 per cent (16/148), whereas that of the delay group was 18.8 per cent (15/80). The relapse free survival rate of the no delay group was superior to that of the delay group (Kaplan Meier’s method: p〈0.05). The delay group was further divided into two groups according to the duration of delay, namely: a group whose delay was less than 7 days and another whose delay was longer than 8 days. There was no significant difference between the relapse free survival rates of the no delay group and the less than 7 days group, however, a significant difference was observed between the no delay group and the longer than 8 days delay group (p〈0.05). The acceptable delay between biopsy and radical mastectomy may therefore be concluded as less than 7 days.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02471718
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  • 2
    Electronic Resource
    Electronic Resource
    Breast cancer arisingde novo in recipients of kidney allograft (1989)
    Springer
    Surgery today 19 (1989), S. 370-375 
    Details
    ISSN: 1436-2813
    Keywords: kidney transplantation ; breast cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Immunosuppressive therapy is not only an etiologic factor ofde novo malignant disease but it also accelerates progression of the already developed malignant disease in immunosuppressed recipients. Two cases ofde novo breast cancer arising in kidney transplant recipients are reported herein. A 25 year-old woman, transplanted one haploidentical kidney transplant 4 years and 9 months ago, developed a left breast tumor. Within one month the tumor had rapidly enlarged from 3.5 cm to 8 cm in diameter by the time she underwent a radical mastectomy. Nine axillary lymph nodes were positive for metastasis. Although her graft function had been poor due to chronic rejection, she was treated with standard immunosuppressive therapy, but not adjuvant therapy. Since local recurrent disease appeared two months postoperatively, the immunosuppressive therapy was ceased and60Co therapy started. Recurrent disease progressed rapidly, however, and she died 7 months after her operation. A 27 year-old woman, having allograft from an identical sibling, noted a right breast tumor, 8 years and 7 months later. Again the tumor had grown rapidly from 1.8 cm to 3 cm in diameter within one month. She underwent a standard radical mastectomy. One axillary lymph nodes was positive for metastasis. She has been treated with standard immunosuppressive therapy and adjuvant endocrinochemotherapy. Presently, she is alive with a well functioning graft and no disease.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02471416
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  • 3
    Electronic Resource
    Electronic Resource
    A new method of modified radical mastectomy for breast cancer (1989)
    Springer
    Surgery today 19 (1989), S. 684-690 
    Details
    ISSN: 1436-2813
    Keywords: breast cancer ; modified radical mastectomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract We have developed a new type of modified radical mastectomy, the method and clinical results of which are reported herein. In this operation, axillary dissection is performed by the following two approaches. Firstly, the axillary contents are dissected from the highest possible subclavicular point to the pectoralis minor muscle, after partially cutting the sternocostal origin of the pectoralis major muscle. The second approach is from the posterior aspect of the pectoralis minor muscle to the lateral portion of the latissimus dorsi muscle. Parasternal dissection can also be performed for stage II and IIIa cancers with a central or medial tumor. After lymph node dissection, the detached edge of the sternocostal origin of the pectoralis major muscle is resutured to cover the parasternal region. Thus, complete dissection of the axillary nodes is performed whilst preserving the pectoralis major and pectoralis minor muscles. Good clinical results were achieved with respect to radicality, cosmetic effects and function in 28 patients with stage I, II and IIIa breast cancers who were followed up for between 5 to 8 years. This new operation may therefore be adopted for the majority of patients with Stage I, II, or IIIa cancers, unless massive infiltration into the pectoralis major muscle has occurred. Preservation of both the pectoralis major and pectoralis minor muscles results in a good cosmetic appearance, good functioning of the arm and easy reconstruction of the breast following mastectomy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02471719
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  • 4
    Electronic Resource
    Electronic Resource
    The discrepancy between immunocytochemical and biochemical assay of estrogen receptor in breast cancer patients treated by endocrine therapy (1989)
    Springer
    Surgery today 19 (1989), S. 768-772 
    Details
    ISSN: 1436-2813
    Keywords: estrogen receptor ; breast cancer ; endocrine therapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Estrogen receptor (ER) expression was investigated by ER-immunocytochemical assay (ICA) and the dextran coated charcoal (DCC) method in 10 recurrent or primary-advanced breast cancer patients treated with endocrine or chmmo-endocrine therapy. In 6 of these 10 patients, ER was examined both before and after treatments by the 2 methods. ER contents measured by the DCC method were found to be decreased after treatments, however, no change in the immunoreactivities of ER-ICA was observed. In the remaining 4 patients, the ER of new lesions refractory to endocrine or chemo-endocrine therapy was examined. ER status was determined as negative in 3 of the 4 patients by the DCC method, whereas by ER-ICA, the proportion of ER stained cells was about 70 per cent, those cells being diffusely distributed in the section. A discrepancy between ER-ICA and the DCC method was thus demonstrated in breast cancer patients treated by endocrine therapy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02471732
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  • 5
    Electronic Resource
    Electronic Resource
    Cancer cell emboli in the pectoral lymphatics of patients with breast cancer (1989)
    Springer
    Surgery today 19 (1989), S. 392-397 
    Details
    ISSN: 1436-2813
    Keywords: cancer cell emboli ; pectoral lymphatics ; breast cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In order to investigate the possibility of local recurrence in the pectoral muscles of patients who undergo modified radical mastectomies, the cancer cell involvement of the lymphatics associated with the pectoralis major muscle was studied in 39 patients who underwent a standard radical mastectomy for Stage I–III breast cancer. Cancer cell emboli were found in the transpectoral lymphatics of 2 patients (2/39=5.1 per cent) and in the pectoral fascial lymphatics of 6 patients (6/39=15.4 per cent). Two patients with fascial lymphatic cancer cell emboli were from a group of 14 patients with intramammary lymphatic tumor emboli of a low degree (ly 1). The other 6 patients with cancer cell emboli in either the pectoral fascia or the transpectoral lymphatics were from a group of 11 patients with intramammary lymphatic tumor emboli of a moderate degree (ly 2). There was a significant relationship between the intramammary and the pectoral lymphatic cancer cell emboli (Chi square test: p〈0.05). The results of this study therefore indicate that lymphatic cancer cell emboli in the pectoral fascia and muscle are an important risk factor for patients who undergo a modified radical mastectomy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02471618
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  • 6
    Electronic Resource
    Electronic Resource
    The significance of regional lymph node dissection in the surgical management of breast cancer (1989)
    Springer
    Surgery today 19 (1989), S. 21-28 
    Details
    ISSN: 1436-2813
    Keywords: breast cancer ; regional lymph node dissection ; modified extended mastectomy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The results of an analysis done on the regional lymph node metastases of 300 patients with operable breast cancer, who were treated in the Department of Surgery (II), Kanazawa University Hospital from 1973 to early 1988 are reported herein. It was found that the metastases of the axillary and internal mammary lymph nodes were closely related to the survival of patients, but they were hardly diagnosed before the operation. Only the dissection of these lymph nodes proved useful for providing the prognostic information. Moreover, in a retrospective study comparing theen bloc extended radical mastectomyversus the other types of mastectomy, the extended radical mastectomy was seen to greatly improve the survival of patients with 3 or less than 3 metastatic axillary lymph nodes. Thus, the extended radical mastectomy provides the maximum diagnostic and prognostic information, and gives the best chance of loco-regional control of the disease. The anterior chest deformity created by the extended radical mastectomy, however, should be avoided in those patients without internal mammary involvement. We therefore propose the modified extended mastectomy as a staging operation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02471562
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  • 7
    Electronic Resource
    Electronic Resource
    Successful esophagectomy for metastatic carcinoma of the esophagus from breast cancer —A case report— (1989)
    Springer
    Surgery today 19 (1989), S. 82-85 
    Details
    ISSN: 1436-2813
    Keywords: metastatic carcinoma of the esophagus ; breast cancer ; surgical resection
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract A case of progressive dysphagia due to metastatic carcinoma of the esophagus from breast cancer is described herein. The patient was a 55 year-old Japanese woman who had undergone a right radical mastectomy for carcinoma of the right breast 9 years previously. We performed a subtotal esophagectomy and reconstruction, using the stomach. She is now well and working without any further symptoms, five years after surgery. Thus, palliative surgery for the complications caused by metastatic carcinoma of the esophagus may be worthwhile.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02471573
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  • 8
    Electronic Resource
    Electronic Resource
    The clinical value of serum CA15-3 assay postoperatively in breast cancer patients (1989)
    Springer
    Surgery today 19 (1989), S. 278-282 
    Details
    ISSN: 1436-2813
    Keywords: breast cancer ; tumor marker ; CA15-3 ; CEA
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Serum carbohydrate antigen (CA15-3) values were examined in 300 normal subjects in order to determine the standard value of this antigen. The clinical relevance of repeatedly assaying this marker in patients with or without recurrent breast cancer postoperatively was compared with assaying the serum carcinoembryonic antigen (CEA) values. The upper limit of CA15-3 was calculated as being 25.3 U/ml in the normal subjects and the distributions of CA15-3 values were not markedly different among the normal subjects, even if they had been selected according to sex or age. Moreover, no differences were observed among normal women who had been randomly selected according to the age distribution of the breast cancer patients. Thirty samples taken from the breast cancer patients postoperatively revealed values of higher than 25 U/ml and 73 samples showed lower levels. The serum CEA values were positive in 16 samples and negative in 85 samples. Although the accuracy of the CEA assay was about 10 per cent higher than that of the CA15-3 assay, its low positive rate was unsatisfactory for effective use in the breast clinic. The results of this study suggest that serum CA15-3 is not detectable unless there is a relatively large number of tumor cells. The higher false positive rate of the CA15-3 assay should therefore be considered as suggesting recurrence.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02471402
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  • 9
    Electronic Resource
    Electronic Resource
    Promoting mammography appointment making (1989)
    Springer
    Journal of behavioral medicine 12 (1989), S. 605-611 
    Details
    ISSN: 1573-3521
    Keywords: mammography ; compliance ; appointment keeping ; breast cancer ; incentives
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine , Psychology
    Notes: Abstract Compliance with screening mammography recommendations is low. Consequently, a community-wide program offering $50 mammograms at 29 radiology facilities was implemented. The program was promoted on a local TV news show and women 35 years and older were instructed to call a referral phone bank. If the caller met eligibility criteria, she received an information packet that assigned her to one of the facilities; it was her responsibility to schedule the appointment. At one facility, a strategy to increase compliance was piloted using a controlled design. Of the 96 subjects assigned to that clinic, 47 received an incentive coupon combined with a prompt in addition to the information packet and 49 received no coupon. The coupon was redeemable for a nutrition information kit when the subject appreared at her appointment. Results indicated that the incentive group had a significantly higher rate of appointment making than the control group (81 vs. 59%). Of subjects in both groups who made appointments, nearly 100% kept them. The intervention appeared to be cost-effective with a self-referred sample.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00844829
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  • 10
    Electronic Resource
    Electronic Resource
    Phase I clinical trial of doxorubicin and iproplatin combination chemotherapy in patients with breast cancer (1989)
    Springer
    Investigational new drugs 7 (1989), S. 189-193 
    Details
    ISSN: 1573-0646
    Keywords: doxorubicin ; iproplatin ; breast cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology , Medicine
    Notes: Summary Forty-eight patients with advanced breast cancer were treated in a disease-specific phase I trial of doxorubicin and iproplatin combination chemotherapy. The doses of doxorubicin ranged between 30 and 50 mg/m2, and the doses of iproplatin ranged between 150 and 250 mg/m2. Myelosuppression was observed at all levels, but was dose-limiting at the highest level. In addition, nausea, diarrhea and malaise were prominent toxicities. Neither cardiac nor renal toxicity was encountered. Nine of 26 (35%) of previously untreated patients, and 5 of 22 (23%) previously treated patients demonstrated partial or complete responses. Although this combination possesses therapeutic activity, given its toxicities, further evaluation of doxorubicin in combination with iproplatin is not recommended.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00170856
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  • 11
    Electronic Resource
    Electronic Resource
    Racial and age differences in multiple primary cancers after breast cancer: A population-based analysis (1989)
    Springer
    Breast cancer research and treatment 14 (1989), S. 245-254 
    Details
    ISSN: 1573-7217
    Keywords: age ; breast cancer ; multiple primary cancers ; race
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The occurrence of multiple primary cancers was evaluated among 17,944 white and black female residents of Metropolitan Detroit diagnosed with breast cancer between 1973 and 1983. Invasive second primary cancers were diagnosed among 1106 of these women, almost twice the expected number. Subsequentin situ cancers were detected four times more often than expected. Fifty-six percent of the subsequent invasive cancers were of the breast (Standardized Incidence Ratio, SIR = 3.80). Black women experienced higher risk of subsequent breast cancers (SIR = 5.30) than white women (SIR = 3.62). Highest risk was seen among women first diagnosed before age 40 (SIR for black women = 26.15, SIR for white women = 10.87) and within five years of initial diagnosis. These findings suggest that young breast cancer patients, especially black women, are at high risk of developing a second primary breast cancer soon after their initial diagnosis and should be under continued medical surveillance. The occurrence of multiple primary breast cancers among young women suggests a genetic component to risk. Identification of this subpopulation would be useful in the study of molecular and genetic markers for cancer. Subsequent colon (SIR = 1.24) and cervical (SIR = 1.54) cancers also were diagnosed significantly more often than expected, as were ovarian cancers among white women (SIR = 1.45). These findings are consistent with common etiologic factors associated with these cancers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01810741
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  • 12
    Electronic Resource
    Electronic Resource
    Progesterone receptor determination in human breast tumors by immunocytochemical and biochemical techniques (1989)
    Springer
    Breast cancer research and treatment 14 (1989), S. 217-225 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; enzyme immunoassay ; immunocytochemical assay ; progesterone receptor ; radioligand binding assay
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Progesterone receptors were determined on frozen sections from 74 primary human breast tumors by an immunocytochemical assay using an indirect avidin-biotin peroxidase method. In the same tumors, cytosol estrogen (ERc) and progesterone receptors (PgRc) were determined by ligand binding assay, and nuclear estrogen (ERn) and progesterone receptors (PgRn) were determined by an immunoassay. Immunocytochemical staining was seen in 36% of tumors. It was predominantly nuclear and there was extensive cell to cell heterogeneity. When the immunocytochemical results were compared to PgRc the agreement rate was 63%, but it was 77% when compared to PgRn. About one third (38%) of PgRc positive tumors were immunocytochemically defined as negative. Thus a significant discordance exists between this immunocytochemical assay for PgR and both the conventional radioligand assay (used for PgRc) and the relatively new enzyme immunoassay (used for PgRn). However discordance rates were critically influenced by the arbitrary cutoff levels that were used to define receptor positivity in the biochemical assays. Our studies support the addition to, rather than the substitution of, immunocytochemical methods, to the conventional biochemical assays for PgR, until long-term follow-up studies of patients with PgRn and immunocytochemical PgR determinations become available.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01810738
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  • 13
    Electronic Resource
    Electronic Resource
    Prognostic value of epidermal growth factor receptor in node-positive breast cancer (1989)
    Springer
    Breast cancer research and treatment 14 (1989), S. 77-90 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; epidermal growth factor receptor ; estrogen receptor ; prognosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The prognostic significance of EGFR (epidermal growth factor receptor) was studied in a cohort of 68 node-positive patients with breast cancer, who entered a controlled protocol of adjuvant therapy between February 1980 and June 1984. EGFR radioligand binding assay was carried out on frozen stored samples. Twenty five (37%) of 68 primary sites and 9 (41%) of 19 lymph node metastases assayed were EGFR-positive with a cut off value of 5 fmol/mg membrane protein; there is no statistical difference between the two distributions. EGFR was significantly correlated to ER and histological grade. EGFR-positive tumors and high levels of EGFR were mainly found in the ER-negative group of tumors (p = 0.008) and in histological grade III (p = 0.007). Fifty five patients could be followed for 40 to 92 months. EGFR was an independent prognostic factor for survival after 40 months (p = 0.05). EGFR+/ER− patients had the lowest survival probability, but statistical significance was not reached (p = 0.06). The EGFR phenotype appeared as a prognostic parameter in node-positive patients, individualizing subgroups of patients with different early outcome, with potential therapeutic implication especially in the group of ER-negative patients. These results emphasize the need for a standardized assay methodology and for further clinical studies, particularly in protocols where adjuvant hormonal therapy is prescribed on the basis of steroid hormone receptor status, in order to assess the respective prognostic worth of EGFR and ER (or PR).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01805978
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  • 14
    Electronic Resource
    Electronic Resource
    Growth kinetics of four human breast carcinomas grown in nude mice (1989)
    Springer
    Breast cancer research and treatment 14 (1989), S. 235-243 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; cell kinetics ; flow cytometry ; growth curves ; nude mice ; xenografts
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The immune-deficient nude mouse with human tumor xenografts is an appropriate model system for performing detailed growth kinetic examinations. In the present study one estrogen and progesterone receptor-negative (T60) and three receptor-positive (Br-10, MCF-7, T61) human breast cancer xenografts in nude mice were investigated. The proliferative tumor characteristics were examined by growth curves, thymidine labelling technique, and flow cytometric DNA analysis performed on fine-needle aspirations. The results showed that the tumors had growth kinetics comparable to other human tumor types with cell generation times of 42 to 60 hours. The three receptor-positive tumors had slower growth rate, larger tumor volume doubling time, and smaller growth fraction and labelling index than the receptor-negative tumor. However, no single proliferation parameter was sufficient to characterize the growth kinetics of individual tumors or to describe proliferative differences between the tumors.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01810740
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  • 15
    Electronic Resource
    Electronic Resource
    Circulating CA 15-3 levels in the postsurgical follow-up of breast cancer patients and in non-malignant diseases (1989)
    Springer
    Breast cancer research and treatment 13 (1989), S. 123-133 
    Details
    ISSN: 1573-7217
    Keywords: antigens ; breast cancer ; CA 15–3 ; CEA ; markers ; relapse
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Circulating CA 15-3 antigen levels were evaluated in patients with benign diseases and breast cancer patients with no clinical evidence of disease after surgery (NED). Patients with breast cancer NED were followed for tumor recurrence or death during a median of 12.9 months (range 1 to 25 months). CA 15-3 and carcinoembryonic antigen (CEA) were compared in the same breast cancer NED patient population. Elevated CA 15-3 levels (〉40 U/ml) were observed in 38 of 1220 patients with benign diseases (3.1%) and in 25 of 350 breast cancer NED patients (7.1%). Elevations of CEA (〉5ng/ml) were observed in 23 patients with breast cancer NED (6.5%). Benign diseases that produced significant elevations of CA 15-3 were chronic hepatitis (42.9%), liver cirrhosis (13.3%), sarcoidosis (16.7%), tuberculosis (9.7%), and systemic lupus erythematosous (6.7%). In breast cancer NED, initial elevations of CA 15-3 were observed in 12 of the 297 patients that remained free of disease during the follow-up, and in 13 of the 40 patients that relapsed (4.0% vs. 32.5%, p〈0.001). Initial CEA levels were elevated in 16 patients that remained NED and in 7 patients that relapsed (5.3% vs. 17.5%, p〈0.001). Serial determinations of CA 15-3 in patients continuously NED showed persistent elevations in 4 cases. Three of these exhibited concomitant benign diseases. In relapsing patients, serial tumor marker determinations showed that elevations of CA 15-3 before any other clinical evidence of recurrence occurred significantly more frequently than elevations of CEA (45% vs. 25%, p〈0.001). Overall, two or more serial elevated values of CA 15-3 were observed in 7 cases, and 6 of them (85%) eventually relapsed. Median survival from study entry was 18.3 months in patients with breast cancer NED that had initial elevated CA 15-3, compared to 25+ months in those with negative CA 15-3 (p〈0.0001). We conclude that circulating levels of CA 15-3 antigen can be elevated in some patients with nonmalignant diseases, and that serial determinations of CA 15-3 may be useful in the postsurgical follow-up of patients with breast cancer when specific types of benign diseases that may cause elevations of the antigen are excluded. Additionally, CA 15-3 is more sensitive than CEA in the early diagnosis of breast cancer recurrences, and the simultaneous assay of CEA does not add information to that of CA 15-3 alone.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01806524
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  • 16
    Electronic Resource
    Electronic Resource
    Influence of radiotherapy on the dose of adjuvant chemotherapy in early breast cancer (1989)
    Springer
    Breast cancer research and treatment 13 (1989), S. 237-241 
    Details
    ISSN: 1573-7217
    Keywords: adjuvant chemotherapy ; breast cancer ; conservative treatment ; lumpectomy ; mastectomy ; radiotherapy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 399 patients with early breast cancer were randomly allocated to treatment by either modified radical mastectomy or lumpectomy and radiotherapy. 169 had histologically involved axillary nodes and were randomised to receive either adjuvant cytotoxic chemotherapy (76 patients) or no systemic adjuvant treatment (93 patients). Chemotherapy comprised a combination of oral cyclophosphamide and intravenous methotrexate and 5-fluorouracil (CMF) for 12 cycles over one year. Patients in the mastectomy group received a significantly higher percentage of the planned chemotherapy dose compared with those in the radiotherapy group (median 85% v. 71% p 〈 0.05). Patients treated with radiotherapy were more frequently nauseated and developed more severe alopecia, but these differences were not statistically significant. At median follow-up of 37 months the relapse-rate and pattern of relapse were similar in both groups of patients receiving CMF.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02106573
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  • 17
    Electronic Resource
    Electronic Resource
    Inter- and intraobserver variability in the histopathological diagnosis of medullary carcinoma of the breast, and its prognostic implications (1989)
    Springer
    Breast cancer research and treatment 14 (1989), S. 91-99 
    Details
    ISSN: 1573-7217
    Keywords: observer variability ; medullary carcinoma of the breast ; breast cancer ; histopathology ; diagnosis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary One hundred thirty-one breast carcinomas with medullary features, registered in the Danish Breast Cancer Cooperative Group from 1977–1982, have been histopathologically reviewed by two senior pathologists and classified as typical medullary carcinoma (TMC), atypical medullary carcinoma (AMC), and non-medullary carcinoma (NMC). Diagnostic criteria were based on those put forward by Ridolfiet al. and Fisheret al. The procedure was repeated with an interval of about one year by both pathologists. The diagnostic interobserver agreement was 72% with a Kappa of 0.55. The intraobserver agreement was 77% and 63% with Kappa values of 0.64 and 0.44, respectively. To see whether the observed inter- and intraobserver variability had any prognostic implications, diagnostic subgroups for both pathologists were analyzed with Kaplan Meier plots for recurrence-free survival (RFS) and with log rank tests. In the first evaluation pathologist 1 segregated a group of TMC with a significantly better RFS than for the NMC group, and pathologist 2 segregated a group of TMC with a corresponding strong trend. These findings could not, however, be reproduced in the second evaluation. The study indicates that the criteria of TMC and AMC as proposed by Ridolfiet al. need to be sharpened and simplified in order to reduce inter-and intraobserver variability. Larger studies with a control group of infiltrating ductal carcinomas are mandatory to elucidate the clinical importance of the diagnoses of Typical and Atypical Medullary Carcinoma of the breast.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01805979
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  • 18
    Electronic Resource
    Electronic Resource
    Antiestrogenic properties of keoxifene,trans-4-hydroxytamoxifen, and ICI 164384, a new steroidal antiestrogen, in ZR-75-1 human breast cancer cells (1989)
    Springer
    Breast cancer research and treatment 14 (1989), S. 65-76 
    Details
    ISSN: 1573-7217
    Keywords: antiestrogens ; estrogen receptor ; ICI 164384 ; keoxifene ; tamoxifen ; breast cancer ; mixed agonist-antagonist
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The agonistic/antagonistic properties of two non-steroidal antiestrogens, namelytrans-4-monohydroxy-tamoxifen (OH-TAM) and keoxifene (LY156758), and the new steroidal antiestrogen ICI164384, a 7β-alkylamide derivative of estradiol (E2), were assessed by measuring their effect on the proliferation of ZR·75-1 cells, an estrogen-responsive human breast cancer cell line. While subnanomolar concentrations of both OH-TAM and LY156758 had significant estrogenic stimulatory activity on cell growth in the absence of estrogens and higher concentrations were inhibitory, ICI164384 behaved exclusively as a growth inhibitor and more potently so than the two other compounds. The three antiestrogens had similar potency to inhibit the mitogenic effect of E2 and at 300 nM, all antiproliferative effects were completely reversible by the estrogen. ICI164384 was a weaker competitor of3H-labeled E2 or R2858 (moxestrol) uptake in intact ZR-75-1 cells in a 1-hour assay, partly because of a slower intracellular access to estrogen specific binding sites. Moreover, ICI164384 interacted in a rapidly (~ 6 h) reversible manner with estrogen-specific binding sites, while the non-steroidal antiestrogens induced a longer-acting (〉 24 h) down-regulation of specific [3H]R2858 uptake. The present data indicate that, among the antiestrogens studied, ICI164384 is the only compound acting as a pure antiestrogen in ZR-75-1 breast cancer cells, while LY156758 and OH-TAM behave as antiestrogens endowed with partial agonistic activity in this system.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01805977
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  • 19
    Electronic Resource
    Electronic Resource
    Antitumor activity of the antiprogestins ZK 98.299 and RU 38.486 in hormone dependent rat and mouse mammary tumors: Mechanistic studies (1989)
    Springer
    Breast cancer research and treatment 14 (1989), S. 275-288 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; antiprogesterones ; tumor models ; rats ; mice ; differentiation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In the transplantable MXT mammary tumor model of the mouse and in the DMBA- and MNU-induced mammary tumor models of the rat, the progesterone antagonists ZK 98.299 and RU 38.468 were shown to have potent antitumor activity. The weight and/or morphology of the ovaries, uterus, and vagina, as well as the effects on serum hormone levels, indicate that the antitumor activity of both antiprogesterones in these models does not depend on a blockade of the ovarian and pituitary functions and does not depend on a non receptor-mediated cytotoxic effect. On the other hand, the morpholoy of the MXT and the DMBA-induced mammary tumors after treatment with the progesterone antagonists is completely different from that observed after ovariectomy. Treatment with the antiprogesterones seems to trigger differentiation of the mitotically active polygonal tumor cells towards glandular structures and acini with a massive sequestering of secretory products, as well as towards spindle-shaped necrobiotic subpopulations. By contrast, the induction of tumor cell degeneration and cytolysis is the predominant feature of the mammary tumors after ovariectomy. In conclusion, our results indicate that the main mechanism of the antitumor action of antiprogesterones in these models is a direct progesterone receptor-mediated antiproliferative effect at the level of the mammary tumor cells, most probably via the induction of terminal differentiation associated with terminal cell death. This antiproliferative effect seems to be dissociated from the antihormone (antiprogestational) activity of these progesterone antagonists.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01806299
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  • 20
    Electronic Resource
    Electronic Resource
    Influence of S-phase fraction on metastatic pattern and post-recurrence survival in a randomized mammography screening trial (1989)
    Springer
    Breast cancer research and treatment 14 (1989), S. 321-327 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; recurrence ; prognosis ; post-recurrence survival ; metastasis ; S-phase ; mammography screening ; static cytofluorometry
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Using static cytofluorometry, S-phase was determined on the primary tumors of 421 patients with breast carcinomas in stages I–III diagnosed 1981–85 during the second and third screening rounds of a randomized trial evaluating the effect of mammographic screening. Through December 1988, 82 patients had developed local and/or distant recurrence, 51 of whom had died of cancer during the same period. The distribution among sites of recurrence differed between patients with tumors detected by mammography screening and cancers diagnosed due to clinical symptoms. The mean S-phase fraction was highest in patients with liver or brain metastases and lowest in patients with metastases in subcutaneous and cutaneous tissue and lymph nodes only. In univariate analysis, survival after first recurrence was significantly associated with the site of primary recurrence, the disease-free interval, and node status and tumor size at diagnosis, as well as the S-phase level. The median survival period was 31.3. months for patients with a S-phase fraction below 6%, and 10.7 months in cases with S-phase exceeding 10%. Neither ploidy nor the estrogen receptor content had significant influence on post-recurrence survival. In Cox's multiple regression analysis, only metastatic site, disease-free interval, and S-phase fraction showed significantly independent prognostic value.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01806304
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  • 21
    Electronic Resource
    Electronic Resource
    Cell dissociation techniques in human breast cancer — Variations in tumor cell viability and DNA ploidy (1989)
    Springer
    Breast cancer research and treatment 13 (1989), S. 153-159 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; DNA ploidy ; viability ; enzymatic dissociation ; mechanical dissociation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Approximately 70% of breast cancers contain cell populations with hyperdiploid (〉G0/G1) DNA content; however, cells cultured from breast cancers have only diploid DNA contents and karyotypes. Mechanically dissociated cells rarely, if ever, grow in culture, while enzymatically dissociated cells do grow in most cases. To determine if cell dissociation techniques used to prepare cells for culture and other laboratory procedures select for cells with specific features, and if tumor cells are killed in the process, breast cancer cells obtained by mechanical dissociation and by enzymatic dissociation were examined for DNA content and cell viability (measured by dye exclusion). Mechanical dissociation yielded more dead cells and cells with hyperdiploid (〉G0/G1) DNA than did enzymatic dissociation. Hyperdiploid cells were also found in the dye-excluding population with each dissociation technique, suggesting that the hyperdiploid cells were not always dead. We conclude that,in vivo, tumors contain cellular subpopulations with low viability and hyperdiploid (〉G0/G1) DNA patterns. The extent to which these subpopulations are present in a sample depends on the dissociation technique employed. That only diploid cells are found in cultures of primary breast cancers may be because enzymatic dissociation, used to prepare cells for culture, yields predominantly diploid cells. These observations also have important implications for interpreting measurements made on dispersed cells,e.g., viability, DNA content, and other cytochemical markers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01806527
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  • 22
    Electronic Resource
    Electronic Resource
    Androgen and glucocorticoid receptor-mediated inhibition of cell proliferation by medroxyprogesterone acetate in ZR-75-1 human breast cancer cells (1989)
    Springer
    Breast cancer research and treatment 13 (1989), S. 161-172 
    Details
    ISSN: 1573-7217
    Keywords: androgens ; breast cancer ; glucocorticoids ; hydroxyflutamide ; medroxyprogesterone acetate ; progestins
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Medroxyprogesterone acetate (MPA) is a synthetic progestin, currently used in the adjuvant treatment of advanced breast cancer, which induces remission rates (30–40%) comparable to those obtained with other types of endocrine therapies. Since, in addition to its progestin-like action, MPA exhibits androgen- and glucocorticoid-like activities in other tissues, the present study was designed to assess the relative contribution of the different steroid receptor systems in the direct action of MPA on breast cancer cell growth, using the ZR-75-1 human mammary carcinoma cell line as anin vitro model. Unlike pure progestins, MPA potently inhibited the proliferation of ZR-75-1 cells in a concentrationdependent manner either in the presence or in the absence of estrogens, and the addition of insulin had only marginal effects on its growth-inhibitory activity. On the other hand, both hydroxyflutamide (OHF, a non-steroidal monospecific antiandrogen) and RU486 (a potent antiglucocorticoid and antiprogestin also endowed with antiandrogenic activity) competitively reversed MPA antiproliferative effects. MPA further decreased the growth of ZR-75-1 cells co-incubated with maximally inhibitory concentrations of either 5α-dihydrotestosterone (DHT) or dexamethasone (DEX), although at about 300-fold higher MPA concentrations with DHT-treated than with DEX-treated ZR-75-1 cells, thus demonstrating a highly predominant androgenic effect. However, MPA had no effect on the growth of ZR-75-1 cells co-incubated with DHT and DEX simultaneously, thus supporting the predominant role of androgen and glucocorticoid receptors in MPA action. A 12-day preincubation of ZR-75-1 cells with increasing concentrations of MPA (10−12 to 3 × 10−6M) decreased the specific uptake of [3H]estradiol (E2) by intact cell monolayers to the same extent as 10 nM DHT, an effect which was competitively blocked by the addition of OHF (3 µM). MPA action on ZR-75-1 cell growth also significantly differed from that of progestins in being additive to the inhibition of E2-stimulated growth by the steroidal antiestrogen ICI164384. The present data indicate that the main action of MPA on ZR-75-1 human breast cancer cell growth is due to its androgen receptor-mediated inhibitory action, while its glucocorticoid-like activity could play an additional role at high concentrations.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01806528
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  • 23
    Electronic Resource
    Electronic Resource
    Inhibitory effect of androgens on DMBA-induced mammary carcinoma in the rat (1989)
    Springer
    Breast cancer research and treatment 14 (1989), S. 299-306 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; androgens ; dihydrotestosterone ; androgen receptor ; dimethylbenz[a]anthracene ; estrogens ; hormone-sensitive ; antiandrogen ; Flutamide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Constant release of the androgen 5α-dihydrotestosterone (DHT) in ovariectomized rats bearing DMBA-induced mammary carcinoma caused a marked inhibition of tumor growth induced by 17β-estradiol (E2). That DHT acts through interaction with the androgen receptor is supported by the finding that simultaneous treatment with the antiandrogen Flutamide completely prevents DHT action. Particularly illustrative of the potent inhibitory effect of DHT on tumor growth are the decrease by DHT of the number of progressing tumors from 69.2% to 29.2% in E2-treated animals and the increase by DHT of the number of complete responses (disappearance of palpable tumors) from 11.5% to 33.3% in the same groups of animals. The number of new tumors appearing during the 28-day observation period in E2-treated animals decreased from 1.5 ± 0.3 to 0.7 ± 0.2 per rat during treatment with DHT, an effect which was also reversed by the antiandrogen Flutamide. The present data demonstrate, for the first time, that androgens are potent inhibitors of DMBA-induced mammary carcinoma growth by an action independent of inhibition of gonadotropin secretion, and suggest an action exerted directly at the tumor level.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01806301
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  • 24
    Electronic Resource
    Electronic Resource
    Polypeptide composition of normal and neoplastic human breast tissues and cells analyzed by two-dimensional gel electrophoresis (1989)
    Springer
    Breast cancer research and treatment 14 (1989), S. 337-348 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; cell lines ; image analysis ; infiltrating ductal carcinoma ; polypeptides ; two-dimensional polyacrylamide gel electrophoresis
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The protein populations of epithelial cells cultured from two neoplastic and five non-neoplastic human breast tissues were resolved and displayed by two-dimensional polyacrylamide gel electrophoresis and silverstaining. With a computer-based image analysis system, we identified eight polypeptides which are present in both of the neoplastic cell lines, but absent from all five of the cultures of non-neoplastic breast cells. The eight polypeptides are not unique to cells cultured from neoplastic breast, because they are also found in cells cultured from non-breast tissues, both neoplastic and non-neoplastic. Two of the eight polypeptides (∼ Mr 25,000/pI 4.4 and ∼ Mr 31,000/pI 5.5) are present in the patterns of whole tissue samples from infiltrating ductal carcinomas and absent in most normal breast tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01806306
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  • 25
    Electronic Resource
    Electronic Resource
    Beta-adrenergic receptors in DMBA-induced rat mammary tumors: Correlation with progesterone receptor and tumor growth (1989)
    Springer
    Breast cancer research and treatment 13 (1989), S. 251-263 
    Details
    ISSN: 1573-7217
    Keywords: beta-adrenergic receptor ; catecholamines ; DMBA-induced rat mammary carcinoma ; spontaneous mammary tumors ; estrogen-sensitive cancer ; progesterone receptor ; breast cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In order to gain further knowledge about the potential role of catecholamines in mammary carcinoma, we have used the potent β-adrenergic antagonist cyanopindolol (CYP) as iodinated ligand to characterize β-adrenergic receptors in membranes prepared from mammary tumors induced by dimethylbenz(a)anthraene (DMBA) administration in the rat. The binding of [125I]CYP to membrane preparations of DMBA-induced rat mammary tumors is rapid at room temperature, reaching half maximal specific binding at 30 min of incubation. Scatchard analysis of the data indicates that [125I]CYP binds to a single class of high affinity sites (114 ± 2.1 fmoles/mg protein) at an apparent KD value of 38.0 ± 0.3 pM. The order of potency of a series of agonists to compete for [125I]CYP binding is consistent with interaction with a β2-subtype receptor: zinterol 〉 (−)isoproterenol 〉 (−)epinephrine» (−)norepinephrine. In addition, the potency of a series of specific β1, and β2 synthetic compounds to displace [125I]CYP in mammary tumors is similar to their potency in typical β2-adrenergic tissues. The binding of [125I]CYP to DMBA-induced rat mammary tumors shows a marked stereoselectivity, the (−)isomers of isoproterenol and propranolol being 150 and 80 times more potent, respectively, than their respective enantiomers. The autoradiographic localization of [125I]CYP performed on frozen sections revealed the presence of specific β-adrenergic receptors in all the malignant cells. Spontaneous mammary tumors of aging (18–22 months) female rats have high levels of β-adrenergic receptors. Castration decreased the concentration of [125I]CYP binding sites in DMBA-induced mammary tumors. A close correlation was observed between progressing, static, and regressing tumors after ovariectomy and β-adrenergic receptor concentration. The presence of β-adrenergic receptors in mammary tumors as well as the modulation of their level by ovarian hormones provides a mechanism for catecholaminergic influence in mammary cancer tissue.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02106575
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  • 26
    Electronic Resource
    Electronic Resource
    The Stockholm breast cancer screening trial — 5-year results and stage at discovery (1989)
    Springer
    Breast cancer research and treatment 13 (1989), S. 79-87 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; mammography ; screening ; stage ; advanced cancer
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In screening programmes it is important to assess a preliminary effectiveness of the screening method as soon as possible in order to forecast survival figures. In March 1981 a controlled single-view mammographic screening trial for breast cancer was started in the south of Stockholm. The population invited for screening mammography consisted of 40,000 women aged 40–64 years, and 20,000 women served as a well-defined control group. The main aim of the trial was to determine whether repeated mammographic screening could reduce the mortality in the study population (SP) compared to the control population (CP). The cumulative number of advanced mammary carcinomas in the screening and the control populations from the first five years of screening have shown a tendency towards more favourable stages in the screened population aged 40–64 years. A breakdown by age suggests an effect in age group 50–59 years, but not yet in age groups 40–49 and 60–64 years. When comparing the rates of stage II+ cancer, an increased number is found in the study group. As the total rate of breast cancer is higher in SP than in CP, there ought to be a concealed group of stage II+ cancers in the CP which makes the comparison biased. A new approach has been designed, where an estimation of the ‘hidden’ number of stage II+ cancers in CP is added to the clinically detected cases, and in this respect a comparison has shown a decrease in the cumulative number of advanced cancers in the SP in relation to the CP (p〈0.05). According to this it could be important to add the estimated number of undetected, hidden cases in the control group in order to utilize the difference in detection rate in the screening- and control group respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01806553
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  • 27
    Electronic Resource
    Electronic Resource
    Risk factors and 10-year breast cancer survival in Northern Alberta (1989)
    Springer
    Breast cancer research and treatment 13 (1989), S. 143-151 
    Details
    ISSN: 1573-7217
    Keywords: age ; breast cancer ; menopausal status ; obesity ; oral contraceptives ; prognosis ; risk factors ; survival ; weight
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary 1,121 women in northern Alberta diagnosed as having breast cancer between 1971–74 were followed for 10 years. Risk factors for breast cancer were studied with respect to their possiblé influence on survival by comparing survival curves, using both Logrank and Cox's regression model, and controlling for intercurrent death, stage and axillary node status. A complex interaction was found between age and menopausal status and survival rates. Premenopausal women aged 45–55 had a better survival rate than postmenopausal women of the same age. However, one subgroup of premenopausal women aged 35–39 had a significantly worse prognosis than those aged 40–44 as did a group of post menopausal women aged 70–74. No cause was found other than the effect of age. There was a significant trend to worsening survival with heavier weight at time of diagnosis and with breast feeding. Parity of five or more and family history of breast cancer were less consistently associated with worse survival. Oral contraceptive use was only associated with worsened prognosis significantly when stage was controlled for; there was no overall effect. Age at menarche and age at first birth did not influence prognosis. Theories to explain the findings are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01806526
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  • 28
    Electronic Resource
    Electronic Resource
    Genetic alterations in primary breast cancer (1989)
    Springer
    Breast cancer research and treatment 13 (1989), S. 191-203 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; frequent mutations ; loss of heterozygosity ; prognostic indicators ; tumor biology
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A serious effort has been made to identify and characterize mutations that frequently occur during the evolution of primary human breast cancer. Some of these mutations involve amplification of protooncogenes (c -myc, c-erbB-2, andint-2) that have been shown to contribute to experimentally induced breast cancer in mouse model systems. Tumor development in mice containing the c -myc or c -erbB-2 transgene suggests that the cellular and developmental contexts in which the genes are expressed define their relative contribution to tumorigenesis. Homozygous deletions or loss of heterozygosity (LOH) represent another type of mutation that has been frequently observed on four chromosomes (1q, 3p, 11p, and 13q) in tumor DNA. They are thought to unmask recessive mutations (LOH) that inactivate or remove (homozygous deletion) suppressor genes that regulate normal cell proliferation. Attempts to determine whether specific mutations are associated with certain clinical parameters have led to the controversial hypothesis that some mutations may be useful prognostic indicators of the post-surgical course of the disease. The current results underscore the necessity for much larger, better control studies to unambiguously define the potential of such mutations as clinical markers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02106570
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  • 29
    Electronic Resource
    Electronic Resource
    Phytohaemagglutinin responsiveness of peripheral lymphocytes and survival in patients with primary breast cancer (1989)
    Springer
    Breast cancer research and treatment 13 (1989), S. 243-250 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; adjuvant therapy ; prognosis ; lymphocytes ; phytohaemagglutinin responsiveness
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The response of peripheral blood lymphocytes from 153 breast cancer patients to the T-cell mitogen phytohaemagglutinin (PHA) was measured prior to surgery and patients assigned to either high (Hi/PHA) or low (Lo/PHA) PHA response groups. Patients were followed up for between 8 and 12 years, or until death. Clinical characteristics were similar in Hi/PHA and Lo/PHA groups. In the 96 patients who received no postoperative adjuvant therapy, overall and relapse-free survival was significantly longer in Hi/PHA than in Lo/PHA patients (p 〈 0.005, and p 〈 0.025 respectively); relative risk of death within 12 years was 0.52 and of relapse was 0.64. In 47 patients who were treated with radiotherapy postoperatively, there was no correlation between the PHA response and overall or relapse-free survival. The implications of these findings for the selection of breast cancer patients for adjuvant treatment following surgery are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02106574
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  • 30
    Electronic Resource
    Electronic Resource
    Progestin inhibition of estrogen-dependent proliferation in ZR-75-1 human breast cancer cells: Antagonism by insulin (1989)
    Springer
    Breast cancer research and treatment 13 (1989), S. 265-276 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; progestins ; progesterone receptor ; antiprogestin ; insulin ; estrogens ; antiestrogens
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The effect of R5020 [17,21-dimethyl-19-nor-4,9-pregnadiene-3,20-dione], a synthetic progestin, was studied in the hormone-responsive ZR-75-1 human breast cancer cell line. Following a 12-day incubation with increasing concentrations of R5020, the mitogenic effect of 17β-estradiol (E2,1 nM) was partially (60–80%) antagonized by the progestin, with a half-maximal effective concentration measured at about 30 pM. This effect of R5020 was completely reversed by the addition of physiological concentrations of bovine insulin, as well as by the potent antiprogestin RU486 [17β-hydroxy-11β-(4-dimethylaminophenyl)-17α-(1-propynyl)-4,9-estradien-3-one], but not by the antiandrogen hydroxyflutamide (α,α,α-trifluoro-2-methyl-4′-nitro-m-lactotoluidide). Moreover, the effect of R5020 required the presence of estrogens, thus further indicating a progesterone receptor (PgR)-mediated effect. Low (〈100 nM) concentrations of R5020 increased the specific binding of [125I]-insulin up to 2- to 2.5-fold in intact ZR-75-1 cells, an effect which was reversed by RU486. The effect was rapid, being nearly maximal after 24 h of incubation with R5020. The PgR-mediated effect of R5020 on cell proliferation was abolished by the addition of a pure steroidal antiestrogen. The present results suggest a physiological role for progestins in increasing the responsiveness to insulin, which could, in turn, reverse the antiproliferative effect of progestins on estrogen action and thus decrease the efficacy of progestins in the treatment of breast cancer.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02106576
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  • 31
    Electronic Resource
    Electronic Resource
    Chemoprevention of breast cancer (1989)
    Springer
    Breast cancer research and treatment 14 (1989), S. 23-31 
    Details
    ISSN: 1573-7217
    Keywords: anti-oestrogens ; breast cancer ; prevention ; tamoxifen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The hypothesis that oestrogen is an important promotor of human breast cancer raises the possibility that endrocrine intervention could prevent the disease. Various methods of reducing oestrogenic activity have been proposed including dietary control, progestin therapy, and ovarian ablation. Tamoxifen is a synthetic anti-oestrogen of low toxicity with proven anti-proliferative activity in endocrine sensitive breast cancer which makes it an attractive alternative for a trial of endocrine prevention. We have undertaken a doubleblind placebo-controlled pilot study to assess the feasibility of mounting a large multicentre study of tamoxifen in the prevention of breast cancer in high risk women. Two hundred women were randomised to tamoxifen or placebo during an 18 month accrual period. Acute toxicity was mild and serial studies of blood lipids, clotting factors, and bone mineral density suggested that no long-term deleterious effects are likely to be seen. It is estimated that 10,000 women would be required with a 10–15 year follow up in order to detect a 25% prevention effect.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01805972
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  • 32
    Electronic Resource
    Electronic Resource
    Genomic DNA analysis of the estrogen receptor gene in breast cancer (1989)
    Springer
    Breast cancer research and treatment 14 (1989), S. 57-64 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; estrogen receptor ; RFLP ; alleles
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary A human estrogen receptor (ER) cDNA probe was used to examine genomic DNA extracted from 59 primary invasive breast cancers. The tumors were also studied histopathologically, and their ER status was assessed by hormone-binding assay and immunohistochemical analysis. Southern blots of genomic DNA samples digested with restriction endonucleases (BamHI, EcoRI, HindIII, PvuII, XbaI) revealed identical restriction fragments for each tumor, indicating preservation of gross ER gene integrity regardless of ER status, clinical stage, or histopathologic appearance. Digestion with PvuII identified a single, two-allele polymorphism with band(s) at 1.6 and/or 0.7 kb. The homozygous 1.6 kb pattern was present in 14 (24%) patients, the heterozygous 1.6/0.7 kb pattern in 29 (49%) patients and the homozygous 0.7 kb pattern in 16 (27%) patients. The PvuII restriction fragment length polymorphism (RFLP) within the ER gene showed no correlation with the results of the ER binding assay, the immunohistochemical analysis, clinical stage, or histopathologic appearance. A significant correlation was found between the genotypes and patient age at the time of tumor diagnosis. Tumors with the homozygous 1.6 kb and the heterozygous 1.6/0.7 kb patterns were observed in older women with mean ages of 64.6 and 64.4 years, respectively. In contrast, patients with tumors containing the homozygous 0.7 kb pattern were significantly younger, with a mean age of 50.4 years (p-value = 0.0024). The mechanism by which the homozygous 0.7 kb genotype is associated with breast cancer in the premenopausal age group is unknown.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01805976
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  • 33
    Electronic Resource
    Electronic Resource
    Mitoxantrone use in breast cancer patients with elevated bilirubin (1989)
    Springer
    Breast cancer research and treatment 14 (1989), S. 267-274 
    Details
    ISSN: 1573-7217
    Keywords: mitoxantrone ; liver dysfunction ; breast cancer ; performance status ; bilirubin elevation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract To determine the safety and efficacy of mitoxantrone use in hyperbilirubinemic breast cancer patients, a prospectively determined dosage schedule was evaluated in a multi-center trial. Pretreatment bilirubin prospectively defined three groups: Controls (with normal bilirubin) and two Study groups (with either moderate or severe bilirubin increase). Bilirubin determined initial mitoxantrone dose as well: bilirubin 〈 3.5 mg/dl, 14 mg/m2; and bilirubin ≥ 3.5 mg/dl, 8 mg/m2. Mitoxantrone at 14 mg/m2 was well tolerated in patients with moderate hepatic dysfunction. Patients with severe hepatic dysfunction demonstrated a mixed toxicity picture, with performance status (ECOG level 3) defining a population with limiting myelosuppression and/or early death. The survival of Study patients with severe hepatic dysfunction (median 17 days) was significantly worse than both Control (p 〈 0.01) and Study (p 〈 0.05) patients with lower bilirubin. Entry performance status (ECOG level 0–2 versus level 3) profoundly influenced survival (median survival 222 days versus 25 days, respectively, p 〈 0.0001). Objective responses were seen in patients with both normal and elevated bilirubin. Bilirubin reduction following mitoxantrone commonly occurred, representing at least an indicator of favorable prognosis. Recommendations for mitoxantrone use include: 1. Patients with moderate bilirubinemia tolerate 14 mg/m2 mitoxantrone with reasonable chance for benefit. 2. Patients with severe hepatic dysfunction and poor performance status should not be given mitoxantrone. A definitive recommendation regarding use of reduced 8 mg/m2 mitoxantrone in patients with severe hyperbilirubinemia and favorable performance status requires further study.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01806298
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  • 34
    Electronic Resource
    Electronic Resource
    Prognostic value of nuclear DNA content in breast cancer in relation to tumor size, nodal status, and estrogen receptor content (1989)
    Springer
    Breast cancer research and treatment 13 (1989), S. 23-32 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; DNA ploidy ; estrogen receptor ; prognosis ; microspectrophotometry ; nodal status ; tumor size
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The prognostic value of nuclear DNA distribution pattern in relation to tumor size, axillary lymph node status, and estrogen receptor (ER) content was studied in 464 patients with primary, operable mammary adenocarcinoma. The median follow-up time was 3 1/2 years. Slide cytophotometric DNA analysis was performed on morphologically identified Feulgen-stained tumor cells. The tumors were classified into four subgroups according to their DNA histogram type. DNA content was significantly related to tumor size and ER level but not to nodal status. When all variables were stimultaneously introduced into Cox's proportional hazards model, tumor size, nodal status, and DNA profile remained as significant predictors of recurrence. Restricting the analysis to node-negative patients, both DNA profile and tumor size showed a significant prognostic value. DNA did not contribute significant prognostic information in node-positive patients. However, the trends in recurrence-free survival were similar to those in the node-negative subgroup: patients with aneuploid tumors tended to fare worse than those with euploid carcinomas.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01806547
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  • 35
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    Androstenedione and androst-5-ene-3β,17β-diol stimulate DMBA-induced rat mammary tumors — role of aromatase (1989)
    Springer
    Breast cancer research and treatment 13 (1989), S. 61-69 
    Details
    ISSN: 1573-7217
    Keywords: breast cancer ; adrenal steroids ; androst-5-ene-3β ; 17β-diol ; androstenedione ; aminoglutethimide ; aromatase inhibitors ; antiandrogens ; flutamide ; dimethylbenz[a]anthracene (DMBA)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary The effect of the adrenal steroids androst-5-ene-3β,17β-diol (Δ5-diol) and androstenedione (Δ4-dione) was studied on the growth of mammary carcinoma induced in the rat by dimethylbenz[a]anthracene (DMBA). The plasma levels of the two steroids were maintained at values within the range of those found in the circulation of post-menopausal women by constant release from osmotic pumps in ovariectomized animals. Δ5-diol and Δ4-dione, at the daily release rate of 500µg, led to plasma levels of 1.26±0.19 and 1.72 ± 0.75 ng/ml, respectively. At these physiologically relevant plasma concentrations, both Δ5-diol and Δ4-dione caused a marked stimulation of tumor growth while having minimal or no effect on uterine weight or on plasma prolactin and LH levels. Concomitant treatment with the aromatase inhibitor aminoglutethimide completely blocked the stimulatory effect of Δ4-dione released from silastic implants on tumor growth, while simultaneous administration of the antiandrogen flutamide had no significant effect. On the other hand, when aminoglutethimide was administered with Δ5-diol, the stimulatory effect of the adrenal steroid on tumor growth was not affected. Such data indicate that, under the present experimental conditions, transformation of Δ4-dione into androgens plays a minor role, the predominant effect of the adrenal steroid being stimulation of tumor growth through conversion into estrogens, while Δ5-diol exerts a direct estrogenic effect independent from aromatase activity. The minimal or absent effect of the same treatment on uterine weight and on plasma prolactin and LH levels indicates the tissue specificity of the effects observed, the mammary tissue being most sensitive to the action of adrenal steroids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01806551
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    Masthead (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989) 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720101
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  • 37
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    The Conformation of Cycloartenol Investigated by NMR and Molecular Mechanics (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 1-13 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Cycloartenol (4), a natural plant sterol, was shown to be an effective membrane reinforcer; this was attributed to its conformation. We now present a conformational analysis of 4 by molecular modeling and NMR. Molecular modeling suggests that two conformations I and II coexist, differing mainly at the level of ring C, and of nearly equal energy, I and II each having ring A and B in a chair and half-chair conformation, respectively, with ring C 1,3-diplanar in I (solid-state structure as determined by X-ray crystallography) and in chair conformation in II. A complete assignment of the 1H- and 13C-NMR spectra of 4 and the entire coupling network in rings A and B is determined by various modern NMR techniques. The conformation of rings A and B thus determined is in agreement with conformations I and II. Low-temperature NMR experiments show a fast equilibrium between two conformations, presumably I and II. It is concluded, therefore, that the cyclopropane ring of 4 produces a flexibility at the level of ring C which may be important for the membrane properties.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720102
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  • 38
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    Palladium(0)-Catalyzed Cyclizations of Simple 1-Aryl-1,7-octadien-3-yl Acetates. Preliminary communicationPresented (W.O.) at the ‘3e Congrès national de la Société Française de Chimie’, Nice, September 5, 1988. (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 14-16 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Dienyl acetates 2 lacking a geminal disulfone or a malonate group cyclize selectively to (E)-l-methylidene-2-styrylcyclopentanes 4 in the presence of 7 mol-% of [Pd(PPh3)4].
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/hlca.19890720103
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  • 39
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    Über den Einfluss des Akzeptor-Teilchromophors bei Dimethin-merocyanin-Farbstoffen auf das Aggregationsverhalten in wässriger Lösung (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 17-28 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: On the Influence of the Acceptor Part of the Chromophor of Dimethinemerocyanine Dyes upon the Aggregation Tendency in Aqueous SolutionA series of novel long-chain alkyl-dimethinemerocyanine dyes containing sulfonate groups is synthesized in good yield and their aggregation tendency in H2O and in organic solvent/H2O mixtures investigated. The merocyanine dyes 11 and 15 only exhibit an intense, red-shifted absorption band due to J-aggregation in H2O without addition of salt. The influence of cationic and anionic tensides and other compounds as urea, glucose, and polysaccharides upon the J-aggregation tendency is investigated.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720104
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  • 40
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    Generation and Trapping of TriafulveneFulvene, Fulvalenes, Part 55; Part 54: [1].Short communication: [2]. (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 29-40 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Substituted methylidenecyclopropanes 12a-d, being easily available from 1,1-dibromo-2-(phenylthio)-cyclopropane (9a), are attractive precursors of triafulvene (2-methylidene-1-cyclopropene; 1). Both the sulfoxide 12b and the sulfone 12c react with an excess of alkoxides (t-BuOK and NaOMe) to give 12e and 12f, respectively, while the sulfinyl group of 12b may be replaced by the PhCH2S substituent in the presence of PhCH2SH/t-BuOK. These reactions (Scheme 4) may be explained by assuming 1 as a reactive intermediate, although an alternative sequence including carbene 20 (Scheme 6) is not completely ruled out. D-labelling experiments (Scheme 5) do not give conclusive evidence due to D scrambling, but deprotonation/methylation sequences show that H—C(2) of 12a-c is the most acidic proton. Final evidence for 1 results from the reaction of 12d with cyclopentadienide (Scheme 7): the reaction of 1 with cyclopentadiene produces the expected [4 + 2]-cycloaddition product 23, while some mechanistic insight results from the sequence 12d → 24 → 25.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720105
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  • 41
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    A Nonconcerted Intramolecular Diels-Alder Reaction of Chiral Allenic-Acid Derivatives (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 59-64 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The reaction between the chiral allenic acid (+)-(S)-1 and the carbodiimides 2a-d and the keten-imine 6 gives, under mild conditions, the tricyclic compounds 3-5, 7, and 8. Low diastereoselectivity and a partial loss of optical activity are observed. A stepwise mechanistic pathway via a biradical intermediate is postulated.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720108
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  • 42
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    Konkurrenz von Endoperoxid- und Hydroperoxid-Bildung bei der Umsetzung von Singulett-Sauerstoff mit cyclischen, konjugierten Dienen. Teil I (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 51-58 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Competition of Endoperoxide and Hydroperoxide Formation in the Reaction of Singlet Oxygen with Cyclic, Conjugated DienesRose-bengal-sensitized photooxygenation of (-)-(R)-α-phellandrene (1) in MeOH at room temperature yielded a complex mixture of products, contrary to previous reports describing cis-(3S, 6R)-epidioxy-p-menthene (2) and trans-(3R, 6S)-epidioxy-p-menthene (3) as the only products. The mixture was separated by prep. HPLC (silica gel, pentane/Et2O 9:1). Besides the known endoperoxides 2 (yield 39%) and 3 (26%), all those hydroper-oxides, which can be deduced from an ene reaction of 1O2 with 1, were isolated, i.e. 4β-p-mentha-2,5-dien-1β-yl hydroperoxide (4) (14%), 4β-p-mentha-2,5-dien-1α-yl hydroperoxide (5) (9%), (2R, 4R)-p-mentha-1(7), 5-dien-2-yl hydroperoxide (6) (2,1%), (2S, 4R)-p-mentha-1(7),5-dien-2-yl hydroperoxide (7) (1,5%) and (1R)-p-mentha-3,6-dien-yl hydroperoxide (8; 1,5%; Scheme 1). Furthermore, the constant cis/trans ratio for all diastereoisomeric pairs (2/2, 4/2, 6/2) was striking. With the help of the two possible conformers 1a and 1b of the starting material a model of a common first step for endoperoxide as well as for hydroperoxide formation is developed. A photooxygenation at -50° supports this model. The absolute value of the cis/trans ratio changes in the same way for the endoperoxides and the hydroperoxides.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720107
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    Versuche zur Synthese von Calicen aus trisubstituierten Cyclopropanen und Cyclopentenon56. Mitt. über Fulvene, Fulvalene; 55. Mitt. [1]: Kurzmitt. (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 41-50 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Attempted Synthesis of Calicene from Trisubstitued Cyclopropanes and CyclopentenoneThe Li carbenoids 4, prepared by treatment of substituted 1,1-dihalocyclopropanes with BuLi, are reacted with cyclopent-2-enone under thermodynamic and kinetic control (Scheme 1). In general, the latter procedure gives better yields of cyclopropylcyclopentenols 5a-e, but the reaction seems to be controlled mainly by the steric and electronic properties of the substituent Y. So, with 4b and 4e, the main reaction is the attack of the carbenoid at C(1) of cyclopent-2-enone, while 4a (Y = PhS) predominantly deprotonates the ketone (Scheme 4). Whereas 5d and 5e can easily be converted to the dihydrocalicenes 6d and 6e (Scheme 6), the attempted elimination of H2O from 5a-c leads to the rearranged products 13-2 due to the opening of the cyclopropane ring (Scheme 5). Finally, the generation of the parent compound 2 from the silylated precursor 6d is attempted: treatment with MeO- gives the addition products 18A/18B, while the reaction with Br2 provides 19 by a bromination/dehydrobromination sequence (Scheme 7).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720106
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    Locoselective [4 + 2] Cycloadditions of Vinylindoles with Inverse Electron Demand: A new access of indolyl-substituted and annellated pyridazinesDedicated to Prof. Dr. C. H. Brieskorn (Würzburg, FRG) on the occasion of his 75th birthday (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 65-72 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 2-Vinylindole (1a) and its donor- and acceptor-substituted (E)-derivatives 1b-e react highly locoselectively with dimethyl 1,2,4,5-tetrazine-3,6-dicarboxylate (3) to form the novel (indol-2-yl)-1,4-dihydropyridazines 4a and 7 as well as the heterocyclic annellated pyridazines 4b, 5, and 6. The reactions of the structurally related 3-vinylindoles 2a-e with 3 also gave rise to new indol-3-ylpyridazines 8, 9, and 10. The locoselectivities of these Diels-Alder reactions were controlled mainly by steric effects.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720109
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  • 45
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    Photochemistry of Thiophen-2(5H)-onesDedicated to Prof. Dr. O. E. Polansky on the occasion of his 70th birthday (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 83-92 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Mechanistic evidence for the light-induced ring opening of thiophen-2(5H)-ones 1 in alcohols affording α, β-unsaturated mercapto esters 2 is presented. Regio-and stereochemical aspects of the ring closure of alkenylthio (type 3) radicals 15 and 17 to S-heterocycles 16 and 18, of 3-thiahex-5-enyl radicals 4 to (tetrahydrothien-3-yl)methyl radicals 6 and of (2,3-dihydrothien-3-yl)methyl radicals 30 (type 7, but-3-enyl radicals) to cyclopropane-methyl radicals 29 are discussed. Irradiation (λ 350 nm) of 1 in cyclohexane in the presence of 2,3-dimethylbut-2-ene affords [2 + 2] cycloadducts 14 albeit in very low yields.
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/hlca.19890720111
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  • 46
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    Electronic and Molecular Structure of the C8H10+· Valence Isomers 1,3,5-Cyclooctatriene+· and Bicyclo[4.2.0]octa-2,4-diene+· from their Electronic absorption Spectra in Freon (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 73-82 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The molecular cations of 1,3,5-cyclooctatriene (COT+·) and bicyclo[4.2.0]octa-2,4-diene (BCO+·) can be observed intact in γ-irradiated Freon glasses, as opposed to Ar matrices where ionization is accompanied by extensive rearrangements. This proves the superiority of the Freon-glass method for the generation of metastable primary cations. The electronic absorption (EA) spectra reveal a) that a previous analysis of the BCO+· electronic structure on the basis of the ultraviolet photoelectron (UP( spectrum of BCO was incomplete, and b) that COT undergoes planarization upon ionization, in accord with qualitative expectations and MNDO calculations. A previously proposed LCBO model was used to assess the influence of the above geometry change on the electronic structure of COT+·.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720110
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  • 47
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    Cyclization Studies with N-Mannich bases of 2-substituted indoles (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 93-100 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of the indoles 7, 15, 16 with a 3-methoxyphenyl group, attached via an α-side chain of 1,2,or 3 CH2 units, is reported. These compounds, after appropriate protection at C(3), were transformed into the N-[(dimethylamino)methyl]indoles 22, 23, and 24, respectively. When treated with AcCl, these N-Mannich bases gave, in two cases, stable N-(chloromethyl)indoles 25 and 26. In the presence of SnCl4, ring closure occurred via electrophilic attack of 1-methylideneindolium ions on the methoxyphenyl group. Formation of seven-membered rings (→ 27, 28) and eight-membered rings (→ 29) was found to be a favorable process. Cyclization to six-membered rings did not occur within this series.
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    URL: http://dx.doi.org/10.1002/hlca.19890720112
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  • 48
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    Template-Dependent Incorporation of Spin-Labeled Thymidine Analogs into Viral DNA (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 110-116 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of novel pppUd analogs substituted at position C(5) with tethered nitroxide radicals is reported. It is shown that these analogs can serve as good substrates for E. coli DNA polymerase (Pol I) and T-4 DNA polymerase using lambda-phage DNA as template. The template-dependent incorporation of the substrates was established by radio-labeling and ESR experiments.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720114
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  • 49
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    Stereoselektive Synthesen von Taxan-Derivaten (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 101-109 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Stereoselective Synthesis of Taxane DerivativesSubstituted racemic 4,8,12-trinortaxanes were prepared stereoselectively in several steps from the dienone 10. A variant of the de Mayo reaction with bicyclononenones 4 and cyclohexen produced the desired configuration at C(8) of the taxane framework. Retro-aldol cleavage of the tetracycle 5 led to the taxane skeleton 6. Stereoselective reduction followed by treatment with base afforded 7b. Hydrolysis of the acetal group and further reduction yielded 9 in which the relative configuration corresponds to the one of the natural products.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720113
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  • 50
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    Asymmetric Diels-Alder reactions: X-Ray crystal-structure analysis of [N-((E)-But-2-enoyl)bornane-10,2-sultam]tetrachlorotitaniumPresented (WO) at the Annual Congress of the Royal Society of Chemistry, Canterbury, April, 1988. (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 123-130 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: An X-ray diffraction analysis of the crystalline complex 2b (MLn — TiCl4) shows a chelation of the carbonyl O-atom and the upper SO2 O-atom by TiCl4, a slightly pyramidal N-atom, and a π -face-stereoselective shielding of the C(α)-Si face by the CH2(3) group. The Ti-atom is in a pseudo-octahedral environment.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720116
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  • 51
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    Metal Complexes with Macrocyclic Ligands. Part XXVIIPart XXVI. Cu2+-promoted hydrolysis of carboxylic- and phosphonic-acid esters in the side chain of tetraazamacrocycles (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 131-138 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The X-ray structures of the Cu2+ complexes of 1,4,8,11-tetraazacyclotetradecane derivatives with an ethylpro-pionate and diethylphosphonate group, 5 and 6, respectively, indicate that the metal ion is pentacoordinated by the four N-atoms of the macrocycle and one O-atom. In the case of 5, it is the carbonyl O-atom of the carboxylate group, whereas for 6 it is the phosphonyl O-atom of the phosphonate group. The hydrolysis kinetics of the functional group in the Cu2+ complexes with the 1,4,8,11-tetraazacyclotetradecanes 3-6 have been measured by pH-stat and stopped-flow techniques. The rate law for the hydrolysis of the carboxylates 3-5 is proportional to the complex concentration and to [OH-] up to pH 13, whereas that of the phosphonate 6 is proportional to [OH-] up to pH 11.5, becoming independent of [OH-] at pH 〉 11.5. The mechanisms of these two reactions are discussed, considering the possibility of an intra- or an intermolecular OH- attack and the results of the X-ray structure analyses.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720117
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  • 52
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    A New Method for the Preparation of (E)-3-Acylprop-2-enoic AcidsPresented in part at the autumn meeting of the Swiss Chemical Society in Bern on October 21, 1988.Dedicated to Prof. R. E. Ireland on the occasion of his 60th birthday (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 117-122 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A new method for the preparation of (E)-3-acylprop-2-enoic acids ( = (E)-3-acylacrylic acids) of type II via acid-catalyzed isomerization of the corresponding 3-acylprop-2-ynal acetals of type I (Scheme 1) has been found. The described reaction gives a rapid and quite general access to these compounds known to exhibit a number of interesting biological activities. Some studies toward the elucidation of the reaction mechanism have been made, and a hypothetical mechanism is proposed.
    Additional Material: 2 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720115
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    6-Thia-1-aza-5λ5-phosphabicyclo[3.2.0]hept-3-ene und Isothiocyanatophosphin-sulfide aus (Methylidenamino)phosphinen, Schwefelkohlenstoff und Acetylen- oder Ethylen-Derivaten (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 139-146 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 6-Thia-l-aza-5λ5-phosphabicyclo[3.2.0]hept-3-enes and Isothiocyanatophosphine-sulfides from (Methylidenamino)phosphines, Carbon Disulfide, and Acetylene- or Ethylene Derivatives(Methylidenamino)phosphines react with carbon disulfide to 1,3,2-thiazaphosphete derivatives 2. Acetylenedicarboxylates give with 2 6-thia-l-aza-5λ5-phosphabicyclo[3.2.0]hept-3-enes 4a, b, and acrylates yield isothio-cyanatophosphin-sulfides 5a-c. The structures of 4a and 5a are proven by an X-ray diffraction analysis.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720118
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    C45 und C50-Carotinoide. 6. Mitteilung5. Mitteilung, s. [1]. Synthese eines optisch aktiven cyclischen C20-Bausteins und von Decaprenoxanthin (= (2R, 6R, 2′R, 6′R)-2,2′-Bis(4-hydroxy-3-methylbut-2-enyl)-∊, ∊-carotin) (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 151-157 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: C45- and C50-Carotenoids: Synthesis of an Optically Active Cyclic C20-Building Block and of Decaprenoxanthin ( = (2R, 6R, 2′R, 6′R)-2,2′-Bis(4-hydroxy-3-methylbut-2-enyl)-∊, ∊-carotene)The synthesis of the optically active cyclic C20-building block (R, R)-15 and of the optically active C50-carotenoid (2R, 6R, 2′R, 6′R)-decaprenoxanthin (1) starting from (-)-β-pinene ((S)-2) is reported.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720120
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  • 55
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    Formation of the First Trimeric Monoterpenoid Indole Alkaloids (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 147-150 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Under O2, the Aspidosperma alkaloid tabersonine (1) was converted by a crude enzyme preparation from leaves of mature plants of Catharanthus roseus G DON into the trimeric 3-hydroxy-14′-(3α″-tabersonyl)voafrine B (4) which was easily reduced by NaBH4 to 14′-(3α″-tabersonyl)voafrine B ( = tertabersonine; 5). Compounds such as 4 and 5 are the first trimeric alkaloids in the series of monoterpenoid indole alkaloids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720119
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  • 56
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    Polynuclear Iron and Rhodium Complexes of 7-Oxa[2.2.1]hericene (2,3,5,6-tetramethylidenebicyclo[2.2.1]heptan-7-one) (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 158-164 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: μ-Carbonyl(Rh—Rh)di(η5-indenyl)[(2R,3S)-C,2,3,C-η-(2,3,4,5-tetramethylidenebicyclo[2.2.1]heptan-7-one)]]-dirhodium(I)(Rh—Rh) (7) and cis-μ-[(2R,3S,5R,6S))-C,2,3,C-η:C,5,6,C-η-(2,3,5,6-tetramethylidenebicyclo[2.2.1]heptan-7-one)]bis[μ-carbonyldi(η5-indenyl)dirhodium(I)(Rh—Rh)] (8) have been prepared. Complex 7 reacts with Fe2(CO)9 in hexane/MeOH and gives cis-μ-[(2R,3S,5R,6S] (9), trans-μ-[(2R,3S,5S,6R)-C,2,3,C-η: C,5,6, C-η-(2,3,5,6-tetramethylidenebicyclo[2.2.1]heptan-7-one)-μ-carbonyldi(η5-indenyl)dirhodium(I)(Rh—Rh)-(tricarbonyliron) (10), and, μ-carbonyl(Rh—Rh)[(2R,3S)-C,2,3,C-η-(2,3-dimethyl-5,6-dimethylidenebicyclo-[2.2.1]hept-2-en-7-one)]di(η5-indenyl)dirhodium(I)(Rh—Rh) (11). Treatment of 7-oxa[2.2.1]hericene (4) with Fe2(CO)9 or (cyclooctene)2Fe(CO)3 gave a 1:2 mixture of cis-μ-[(2R,3S,5R,6S)-] (12) and trans-μ-[(2R,3S,5S,6R)-C,2,3,C-η:C,5,6,C-η-(2,3,5,6-tetramethylidenebicyclo[2.2.1]heptan-7-one)]bis(tricarbonyliron)(13).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720121
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  • 57
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    Eine neue Aminoazirin-Reaktion. Bildung von 3,6-Dihydropyrazin-2(1H)-onen (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 172-179 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A New Aminoazirine Reaction. Formation of 3,6-Dihydropyrazin-2(1H)-onesThe reaction of 3-(dimethylamino)-2H-azirines 1 and 2-(trifluoromethyl)-1,3-oxazol-5(2H)-ones 5 in MeCN or THF at 50-80° leads to 5-(dimethylamino)-3,6-dihydropyrazin-2(1H)-ones 6 (Scheme 3). Reaction mechanisms for the formation of 6 are discussed: either the oxazolones 5 react as CH-acidic heterocycles with 1 (Scheme 4), or the azirines 1 undergo a nucleophilic attack onto the carbonyl group of 5 (Scheme 6). The reaction via intermediate formation of N-(trifluoroacetyl)dipeptide amide 8 (Scheme 5) is excluded.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720123
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  • 58
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    Synthesis of the Oviposition-Deterring Pheromone (ODP) in Rhagoletis cerasi L. Preliminary communication (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 165-171 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: For the assignment of the configuration at C(8) and C(15) of the natural oviposition-deterring pheromone 1 in Rhagoletis cerasi L., the four possible stereoisomers of 1 are synthesized. By condensing the C6 building blocks (5R)-4 and (5S)-4 with the boron enolates of the C10 building blocks (4S)-13 and (4R)-13, followed by decarboxylative dehydration, all stereoisomers of 16 are available (Scheme 5). Glucosylation of 16 followed by formation of the taurin amide gives, after deprotection, the four stereoisomers (8R,15S)-1, (8R,15R)-1, (8R,15S)-1, and (8S,15S)-1 (Scheme 6).
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/hlca.19890720122
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  • 59
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    Mitteilungen (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 185-192 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720125
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  • 60
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    New Spermine Alkaloids from Aphelandra tetragona (VAHL) NEESDedicated to Prof. Dr. D. Gröger on the occasion of his 60th birthday (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 180-184 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 18-O-Methylchaenorpine (1a) and iso-18-O-methylchaenorpine (1b) two novel stereoisomeric spermine alkaloids were isolated from the roots of Aphelandra tetragona (VAHL) NEES. Their structures were established by chemical and spectroscopic studies.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720124
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    Masthead (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989) 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720201
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  • 62
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    1,5,7-Triazabicyclo[4.4.0]dec-5-en als Reaktionsmedium: Präparativ ergiebige einstufige Herstellung von Etioporphyrin aus Protoporphyrin (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 185-195 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 1,5,7-Triazabicyclo[4.4.0]dec-5-ene as Reaction Medium: An Efficient One-Step Formation of Etioporphyrine from ProtoporphyrineHeating the commercially available protoporphyrine (4) in molten 1,5,7-triazabicyclo[4.4.0]dec-5-ene (TBD) at 200° for 4 h under exclusion of O2 produces etioporphyrine (6) in 60-70% yield by bisdecarboxylation and concomitant reduction of the two vinyl groups. Mesoporphyrine (5) is bisdecarboxylated to 6 in over 80% yield under these conditions in TBD as well as in DBU as the reaction medium.
    Additional Material: 7 Ill.
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  • 63
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    The Chemistry of Thujone. Part XIV.Part XIII [1]. Synthesis of biologically active aryl terpenoid analogues (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 205-212 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Employing thujone-derived intermediates, a series of achiral (9a-d; Scheme 1) and chiral (11b and 11d; Scheme 2) terpene analogues related to the biologically active ‘terpenoid’ hybrids have been prepared. The stereochemistry of the key epoxidation reaction was established by correlation of the product 11b with the previously reported alcohol (R)-20 of known absolute configuration (Scheme 3).
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720204
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  • 64
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    Vinyl Carbanions. Part 36.Part 35: [9]. Synthesis of 3-deoxy-D-manno-2-octulosonic acid (KDO) and derivatives (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 213-223 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The β-C-lithiated acrylamide 3A has been proven to be an ideal pyruvate β-carbanion equivalent useful in a highly diastereoselective KDO synthesis. The starting material 3 was prepared from pyruvate diethyl acetal in four convenient steps. Direct lithiation with 2 equiv. of LDA generated the dilithiated species 3A quantitatively. Reaction with 2,3:4,5-di-O-isopropylidene-D-arabinose (11) was highly D-manno-selective. The product 12 was obtained readily from the reaction mixture via crystallization. Ring closure to the butenolide 13, subsequent PhS-group removal with Bu3SnH and pyridinium bromide, and hydrogenolytic debenzylation afforded the known butenolide 19; this KDO precursor gives KDO in two convenient steps. Butenolide 19 was also transformed via two high-yielding steps into the 4,5:7,8-di-O-cyclohexylidene-KDO derivative 22, a valuable starting material for KDO α-glycoside syntheses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720205
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  • 65
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    Colchicine models: Synthesis and Antitubulin Activity of 2′-Monosubstituted and 2′, 5-Disubstituted 2,3,4,4′-Tetramethoxy-1,1′-biphenyls. Synthesis of 4,4′, 5′, 6′-tetramethoxy-1,1′-biphenyl-2,3′-dicarboxylic acidThis paper is dedicated to our friend and colleague Dr. Tetsuji Kametani, Hoshi College of Pharmacy, Tokyo, Japan, who died on October 11, 1988 (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 196-204 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reductive amination of 2,3,4,4′-tetramethoxtybiphenyl-2-carbaldehyde (4) with MeNH2 afforded methylamine 5 (Scheme 1), Hydroxymethylation of amine 8, prepared similarly from 4 by reductive amination with benzylamine followed by N-methylation, afforded alcohol 12 which was converted the 5-methyl-substituted methylamine 14 by conventional chemical reactions (Scheme 2), Methylamine 14 was also obtained from ester 16 after hydroxymethylation to alcohol 17 and conventional manipulation of alcohol and ester functions (Scheme 2). Both amines 5 and 14 as well as the 2′, 5-dimethyl-substituted biphenyl 26 prepared from the dialdehyde 25 by a Wolff-Kishner reduction, did not show noteworthy activity in the tubulin binding assay or as inhibitors of tubulin polymerization (Table). However, the 2′ethyl-substituted biphebyl 11 prepared from 4 by reaction with MeLi followed by dehyderation and catalytic reduction of styrene 10 (Scheme 1) showed appreciable activity in both assays, coming close to that of known phenyltropolone models. The X-ray analysis of 14·HCl and 11 showed significant difference in the orientation of the rings with respect to one another (Fig.).
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720203
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  • 66
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    Biosynthesis of Homoterpenes in Higher Plants (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 247-253 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: In higher plants, the two homoterpenes 4,8-dimethyinona-1,3,7-triene (1) and 4,8,12-trimethyltrideca-1,3,7,11-tetraene (2) are synthesized from the regular terpene alcohols nerolidol and geranyllinalool by fragmentation into the homoterpene and butenone. The biosynthetic pathway is evidenced by conversion of (2H)nerolidol in Hoya purpureo-fusca, Magnolia liliiflora nigra, Robinia pseudoacacia, and Philadelphus coronarius.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720208
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  • 67
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    Sphinxolide, a 26-Membered Antitumoral Macrolide Isolated from an Unidentified Pacific Nudibranch (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 237-246 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: It is shown that an unidentified nudibranch of Hawaiian waters contains a 26-membered macrolide, sphinxolide ((-)-1) with potent activity against the KB cell line. The structure of sphinxolide, a 2:1 mixture of (E/Z)-isomers at the formamide moiety, is established to be (-)-1 on the basis of extensive NMR and FAB-MS analysis, in combination with data for the products of mono- (→(-)-2) and diacetylation (→(+)-3).
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720207
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  • 68
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    Synthesis of Aristotelia-Type Alkaloids.Part III: [1]. Part IV. Synthesis of (±)-aristoserratineDedicated to Prof. D. Arigoni on the occasion of his 60th birthday (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 254-263 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A convergent diastereoselective synthesis of racemic aristoserratine ((±)-24) via an intramolecular iminium-ion cyclization is described. The pivotal imine (±)-19 was prepared by condensation of the two building blocks (± )-trans-8-amino-3-(2,6-difluorobenzyloxy)-1-p-menthene ((±)-11) and N-(p-methoxybenzenesulfonyl)-3-indo-leacetaldehyde (18) which were synthesized from (±)-trans-1-p-menthene-3,8-diol ((±)-7) and 3-indoleacetic acid, respectively. On the route to the target (±)-24, two previously unknown indole alkaloids have been characterized, namely (±)-‘anti’-hobartin-15-ol ((±)-22) and (±)-‘anti’-aristotelin-15-ol ((±)-23).
    Additional Material: 1 Tab.
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    URL: http://dx.doi.org/10.1002/hlca.19890720209
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  • 69
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    Syntheses of α, β-Epoxy Silyl Ketones (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 264-270 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis of the α, β-epoxy-acylsilanes 1 and 2 starting from the allylic silyl alcohols (E)- and (Z)-3, respectively, by epoxidation with t-BuOOH/VO(acac)2 followed by oxidation with Collins reagent (CrO3/pyridine) in up to 70% overall yields, is described. The acid-catalyzed rearrangement of the epoxy-silyl alcohols 4A + B und 5A + B led to the novel unstable diastereoisomeric α-silyl-β-hydroxy-aldehydes 9 and 10, respectively. The structure of 10 was established by X-ray crystal-structure analysis of the corresponding alcohol 11.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720210
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    Spectroscopic Studies of Cyclometallated Pd(II) and Pt(II) Complexes: Optical absorption and emission of single crystals of [Pd(thpy)2] and [Pt(thpy)2] (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 224-236 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The polarized optical absorption and emission (spectra, decay times) of single crystals of [Pd(thpy)2] and [Pt(thpy)2] (thpy ≡ C(3′)-deprotonated form of 2-(2-thienyl)pyridine) at temperatures 1.9 K ≤ T ≤ 80 K are reported. The emission of [Pt(thpy)2] can be influenced strongly by applied magnetic fields (0 ≤ H ≤ 6 T). Depending on the central ions Pd and Pt, the lowest excited electronic states of the single complexes are ligand-centered (LC) states and metal-to-ligand charge transfer (MLCT) states, respectively. This difference leads to distinctly dissimilar properties of the emission of both compounds. The experimental data show that the emission of single crystals of [Pd(thpy)2] and [Pt(thpy)2] at T ≤ 30 K originates from several types of traps (defect states of symmetry 3B2-stabilized below the exciton band) with LC and MLCT character, respectively. In the Pt compound, the 3B2 is split by spin-orbit coupling into three states. The states B1′ and A2′, which determine the emission properties, are separated by Δv ∼ 13 cm-1. Both states can mix under the influence of an applied magnetic field yielding an increase of the emission intensity by a factor of ∼ 1.5 at H = 6 T.
    Additional Material: 14 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720206
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    Total Synthesis of L-Allose, L-Talose, and derivatives.Enantiomerically pure 7-oxabicyclo[2.2.1]hept-5-en-2-yl derivatives (‘naked sugars’ [2]) as synthetic intermediates, Part IV. Part III, see [1]. (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 278-286 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (1S, 4R, 5S, 6S)-5-exo, 6-exo-(Isopropylidenedioxy)-7-oxabicyclo[2.2.1]heptan-2-one ((-)-1) was transformed with high stereoselectivity to L-allose. Similarly, enantiomer (+)-1 was transformed into L-talose. The ketones (+)-1 and (-)-1 were derived from furan and 1-cyanovinyl (1S)-camphanate and 1-cyanovinyl (1R)-camphanate, respectively.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720212
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  • 72
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    Highly Stereoselective Total Syntheses of 2,5-Anhydro-4-deoxy-D-ribo-hexonic Acid and of (1S)-1-C-(6-amino-7H-purin-8-yl)-1,4-anhydro-3-deoxy-D-erythro-pentitol (= cordycepin C)Enantiomerically pure 7-oxabicyclo[2.2.1]hept-5-en-2-yl derivatives (‘naked sugars’) as synthetic intermediates, Part V. Part III: [1]. Part IV: [2].Part of the planned Ph. D. thesis of F. G., University of Lausanne.Dedicated to Prof. Hans Dahn on the occasion of his 70th birthday (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 271-277 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Highly regio- and stereoselective monohydroxylation of the C=C bond of (+)-7-oxabicyclo[2.2.1]hept-5-en-2-one (8) was achieved via LiAlH4 reduction of the corresponding 5,6-exo-epoxy dimethyl acetal 9. The reaction gave exclusively (-)-(1R, 2R, 4S)-6,6-dimethoxy-7-oxabicyclo[2.2.1]heptan-2-exo-ol (10) which was transformed into 2,5-anhydro-3-O-benzyl-4-deoxy-D-ribo-hexonic acid (15) and 2,5-anhydro-4-deoxy-D-ribo-hexonic acid (6) via ozonolysis of (-)-(1R, 4S, 6R)-6-exo-benzyloxy-2-{[(tert-butyl)dimethylsilyl]oxy}-7-oxabicyclo[2.2.1]hept-2-ene (14). Cordycepin C (5) was derived from 6 and 4,5,6-triaminopyrimidine using CsF/DMF to generate the adenine heterocycle.
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    URL: http://dx.doi.org/10.1002/hlca.19890720211
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    Die absolute Konfiguration der Iridale und Cycloiridale unterschiedlicher HerkunftDr. G. Ohloff zum 65. Geburtstag mit den besten Wünschen gewidmet (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 287-294 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The Absolute Configuration of Iridals and Cycloiridals of Different OriginNatural irones are known to occur in enantiomeric forms within Iris oils of different origin. They are formed by oxidative degradation of the cycloiridals (C31-triterpenoids) found in rhizomes of various Iris species. The absolute configuration of iridals from different varieties is determined by ozonolysis of the triterpenoids and comparison of their degradation products with authentic samples of known configuration. It is shown that the initial cyclization of squalene resulting in the formation of a monocyclic seco-ring-A iridal has the same stereo-chemical course throughout all Iris species studied. The subsequent cyclization of the homofarnesyl side chain of the iridals, however, produces cycloiridals with enantiomeric irone moieties within different subspecies of the sword lilies.
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    URL: http://dx.doi.org/10.1002/hlca.19890720213
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    Metal Complexes with Macrocyclic Ligands. Part XXVIII.Part XXVII: [1]. Structures and stabilities of the Cu2+ complexes with 1,4,7-triazacyclononane-1-acetic acid (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 307-312 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The potentiometric study of the complexation of 1,4,7-triazacyclononane-l-acetic acid (1) with Cu2+ (I = 0.5 (KNO3), T = 25°) indicates the presence of the species [Cu(1)], [Cu(1)OH], [Cu(1)2], and [(Cu(1))2OH], the stability constants of which are determined. The two complexes [Cu(1)]ClO4 and [(Cu(1)2)OH]ClO4 were also characterized by X-ray structure analysis. In both cases, the Cu2+ ion is in a distorted square-pyramidal arrangement, penta-coordinated by the three N-atoms of the macrocycle, an O-atom of the carboxylate, and an additional O-atom either from a second carboxylate or from an OH-, acting as a bridge between two metal centres.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720215
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  • 75
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    Metal Complexes with Macrocyclic Ligands. Part XXIX.Part XXVIII: [1]. Structural and kinetic studies of two isomeric Cu2+ complexes with 1,4-dimethyl-8-[2-(2-pyridyl)ethyl]-1,4,8,11-tetraazacyclotetradecane (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 313-319 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The synthesis and complexation properties of 1,4-dimethyl-8-[2-(2-pyridyl)ethyl]-1,4,8,11-tetraazacyclotetra-decane (2) are described. This ligand forms with Cu2+ two complexes, one of which has been characterized by X-ray structure analysis. The structural, spectral, and kinetic studies indicate that the two Cu2+ complexes are isomers with the macrocycle in the trans-III and trans-I configuration. The rate of the interconversion of the trans-I isomer to the thermodynamically more stable trans-III species is proportional to [OH-]. A mechanism for this reaction is proposed.
    Additional Material: 2 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720216
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    Stereochemical Criteria Providing Unambiguous Experimental Evidence for the intermediacy of ion/molecule complexes in the generation of enolates from gaseous alkoxides. Short communicationDedicated to Prof. Josef Seibl on the occasion of his 65th birthday (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 320-322 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The epimeric alkoxides 6a and 6b, generated in the gas phase by deprotonation of the stereospecifically deuterated isoborneols 5a and 5b, undergo loss of H2 and HD in a 1:1 ratio. This result, ruling out a concerted one-step process, establishes the intermediacy of an ion/molecular complex (‘solvated’ hydride ion) in the course of formation of enolates from the alkoxide anions in the gas phase.
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    URL: http://dx.doi.org/10.1002/hlca.19890720217
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  • 77
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    Neue Dimethinmerocyanin-Farbstoffe mit der (Sulfobutyl)benzothiazol-Gruppe als Donor-Teilchromophor und deren Aggregationsverhalten in wässriger Lösung (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 295-306 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Novel Dimethinemerocyanine Dyes with the (Sulfobutyl)benzothiazole Group as Donor Part of the Chromophor and their Aggregation Tendency in Aqueous SolutionA series of novel dimethinemerocyanine dyes with the (sulfobutyl)benzothiazole group as the donor part of the chromophor is synthesized in good yield and their aggregation tendency in H2O without addition of salt investigated. The merocyanine dye 2b only gives J-aggregation in H2O. The dyes 1a-f and 2a exhibit an intense, red-shifted absorption band due to J-aggregation in H2O in the presence of Me4NCl. In contrast, the dyes 1g and 2c-f show a slightly red-shifted absorption band. The degree of aggregation in H2O is investigated by ultracentrifugation of the representative 2e. Indeed, the slightly red-shifted absorption band in H2O is due to aggregation of ‘oligomers’ of the dye. Contrary to the aggregation of ‘polymers’ of dyes (J-aggregation), we suggest the term ‘K’ band for the slightly red-shifted absorption band. The hemicyanine dye 5 gives the same absorption band in MeOH and in MeOH/H2O 1:3. The dye 11 shows an absorption band in H2O that is probably blue-shifted because of negative solvatochromism. The merocyanine dye 13 gives H-aggregation in H2O.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720214
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  • 78
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    Models for Copper-Dioxygen Complexes: The chemistry of copper(II) with some planar tridentate nitrogen ligands (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 323-337 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The solution chemistry of Cu(II) with a series of five planar tridentate nitrogen ligands, 2,6-bis(benzimidazol-2-yl)pyridine (bzimpy, 1), 2,6-bis(l-methylbenzimidazol-2-yl)pyridine (mbzimpy, 2) 2,6-bis(benzothiazol-2-yl) pyridine (bzthpy, 3), 2,6-bis(benzoxazol-2-yl)pyridine (bzoxpy, 4), and 2,2′, 6′, 2″-terpyridyl (terpy, 5) is reported. Electronic and EPR spectra are consistent with the complexes [CuL]2+ having essentially tetragonal structure in solution, with the fourth coordination site in the plane of the ligand occupied by solvent. bzthpy and bzoxpy show smaller ligand-field splittings than bzimpy, mbzimpy, and terpy, and are easily decomplexed from the copper. Substitution of the coordinated solvent molecule in the plane of the ligand is observed with Cl- and OH- (provided that the ligand has no acidic protons) for all ligands except terpy. The reaction between [Cu(mbzimpy)]2+ and imidazole has been studied by potentiometric titration in MeCN/H2O 1:1 and shows strong binding of the imidazole in the plane (log K = 4.5 at 25°), and also the formation of an imidazolate-bridged dinuclear species.
    Additional Material: 3 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720218
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  • 79
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    Synthesis of (-)-Conduritol C (1L-Cyclohex-5-ene-1,2,3/4-tetrol)Enantiomerically pure 7-oxabicyclo[2.2.1]hept-5en-2-yl derivatives (‘naked sugars’ [1]) as synthetic intermediates, Part VI; Part V:[2]. (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 338-347 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: (1R, 2R, 4R)-2-endo-Cyano-7-oxabicyclo[2.2.1]hept-5-en-2-yl acetate ((-)-7) has been transformed into the all-cis-configurated 4L-4,5,6/0-trihydroxycyclohex-2-en-1-one derivatives (-)-12 and (-)-19. (-)-Conduritol C ((-)-3) was derived in a stereospecific manner from (-)-12.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720219
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  • 80
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    Diels-Alder-Reaktionen mit 3-Cyclopropylidenprop-1-enyl-ethyl-ether als 1,3-Dien (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 348-352 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Diels-Alder Reactions with 3-Cyclopropylideneprop-1-enyl Ethyl Ether as 1,3-DieneThe title compound undergoes readily Diels-Alder reactions with various dienophiles, especially with quinones. The resulting adducts constitute key intermediates in the synthesis of labdane diterpenoids.
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    URL: http://dx.doi.org/10.1002/hlca.19890720220
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    Synthese von (+)-Abscisinsäure (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 361-364 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of (+)-Abscisic Acid.Starting from (4S)-4-hydroxy-2,6,6-trimethylcyclohex-2-enone (2), a short synthesis of the natural (+)-abscisic acid ((+)-1) has been accomplished.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720222
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  • 82
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    Ein neuer Zugang zu 2,6,6-Trimethylcyclohexa-2,4-dienon aus 4-Oxoisophoron (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 365-369 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A New Access to 2,6,6-Trimethylcyclohexa-2,4-dienone from 4-Oxoisophorone2,6,6-Trimethylcyclohexa-2,4-dienone (1), a versatile starting material for the preparation of some carotenoids and several natural products, was efficiently (73% yield) prepared from oxoisophorone 3. After conversion of 3 to the alcohol 4 or the acetate 5, H2O was eliminated (4→1) under acidic distillative conditions, whereas AcOH could be eliminated (5→l) under Pd(O) catalysis.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720223
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  • 83
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    Neue Zugänge zu einigen aromatischen Retinoiden (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 370-376 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New Approaches to Some Aromatic RetinoidsStarting from 2,3,5-trimethylphenol (2), two pathways to ethyl (all-E)-9-(4-methoxy-2,3,6-trimethylphenyl)-3,7-dimethylnona-2,4,6,8-tetraenoate (1) and to some of its (Z)-isomers have been developed. The first one is based on a Pd(O)-catalyzed arylation of (Z)-3-methylpent-2-en-4-yn-l-ol (6) with 4-bromo-2,3,5-trimethylanisol (5). The acetylenic C15-alcohol 9 was transformed into the corresponding acetylenic phosphonium salt 10, which was catalytically hydrogenated to the olefinic Wittig salt. Wittig olefination led, then, to the (6Z, 8Z)- and (4Z, 6Z, 8Z)-isomers, 7 and 8, respectively. In a second approach, Friedel-Crafts reaction of 3-methylpent-l-en-4-yn-3-ol with the 2,3,5-trimethylanisol gave a C15-intermediate with a terminal C=C bond in the side chain. After deprotonation and reaction with a C5 aldehyd, the corresponding C20-intermediate could be isolated in high yield. Finally, further conversion led predominantly to the (all-E)-retinoid, accompanied by its (9Z)- and (13Z)-isomers.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720224
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    Synthesis of Gossypol AnaloguesDedicated to the memory of Professor Dr. Pierre Crabbé (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 353-360 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Two gossypol analogues 2a and 2b were synthesized for biological evaluation as male contraceptive agents. The naphthol 8c was prepared by analogy with a known procedure starling from 3-isopropylcatechol (3). (t-Bu)2O2-Mediated phenolic coupling of 8c furnished the binaphthol 9c which, after pyrane ring closure, deprotection. and selective bisformylation with SnCl4/Cl2CHOCH3, gave the target compound 2a. The corresponding tetrahydroxy analogue 2b was prepared in a similar way.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720221
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  • 85
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    Cyclometalated Compounds of Platinum(II) with two different C, N-aromatic ligands (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 377-382 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: A synthetic route leading to bis-heteroleptic cyclometalated complexes is described. The complexes [2-(2′-thienyl)pyridinato-N, C-3′]{2-[3′-(trimethylsilyl)2′-thienyl]pyridinato-N, C3′}platinum(II) ([Pt(thpy) (TMS-thpy)]; I) and (l-phenylpyrazolato-N2, C2′)[2-(2′-thienyl)pyridinato-N, C3′]platinum ([Pt(Phpz)(thpy)]; II) are characterized by UV/VIS, NMR, and mass spectroscopy. Thermal and photochemical oxidative addition reactions yield two out of the 10 possible pairs of enantiomers of octahedral Pt(IV) compounds.
    Additional Material: 1 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720225
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    Masthead (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989) 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720301
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  • 87
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    Mitteilungen (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 401-402 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720228
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  • 88
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    The Radical Cations of Bicyclo[2.2.1]hepta-2,5-diene (8,9,10-Trinorborna-2,5-diene) and bicyclo[2.2.2]octa-2,5-diene (2,3-Dihydrobarrelene). An ESR and ENDOR studyPart 5 of ‘Applications of ENDOR Spectroscopy to Radical cations in Freon matrices’. Part-4: [1]. (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 383-390 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The radical cation of bicyclo[2-2.1]hepta-2,5-diene (8,9,10-trinorborna-2,5-diene; 1) in CF2ClCFCl2, and CF3CCl3 matrices and that of bicyclo[2.2.2]octa-2,5-diene (2,3-dihydrobarrelene; 2) in CFCl3 and CF3CCl3 matrices have been studied by ESR and ENDOR spectroscopy. For \documentclass{article}\pagestyle{empty}\begin{document}${\bf 1}^{+ \atop \dot{}}$\end{document}, the coupling constants of the olefinic, methano-bridge, and bridgehead protons are -0.780 ±0.005, +0.304±0.002, and -0.049±0.002 mT, respectively. The hyperfine tensor for the methano-bridge protons is axial, Ax = +0.263 ± 0.002 and Ay = +0.386 ± 0.002 mT, while that for the olefinic protons is orthorhombic, Ax = -0.594 ± 0.005, Ay= -0.913 ± 0.005, and Az = -0.834 ± 0.005 mT (x parallel to C—H- z parallel to 2pπ axis). For \documentclass{article}\pagestyle{empty}\begin{document}${\bf 2}^{+ \atop \dot{}}$\end{document}, the coupling constants of the olefinic, ethano-bridge, and bridgehead protons are -0.68 ± 0.01, +0.162 ± 0.005, and -0.108 ± 0.005 mT, respectively. The hyperfine data for \documentclass{article}\pagestyle{empty}\begin{document}${\bf 1}^{+ \atop \dot{}}$\end{document} and \documentclass{article}\pagestyle{empty}\begin{document}${\bf 2}^{+ \atop \dot{}}$\end{document} fully support the presentation of their singly occupied orbitals as antisymmetric combinations, b2(π), of the two bonding ethene π-MO's.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/hlca.19890720226
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  • 89
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    The Allylic Oxidation of Geraniol Catalyzed by Cytochrome P-450Cath., Proceeding with retention of configurationPresented in part at the ‘22nd Reaction Mechanisms Conference’, Pittsburgh, 12.6-16.6.88, at the ‘6th International Conference on Biochemistry and Biophysics of Cytochrome P-450’, Vienna, 3.7.-8.7.88, and at the meeting on the ‘Biocatalytic synthesis of Organic Compounds’, Saratoga Springs, NY, 8.-12.8.88.Dedicated to Prof. D. Arigoni on the occasion of his 60th birthday (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 391-400 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Incubation of the geraniols (R)-(8-2H1)[8-3H1]-1 and (S)-(8-2H1)[8-3H1]-1 with microsomal cytochrome P-450Cath. from the subtropical plant Catharanthus roseus (L.)G. DON resulted in the formation of the chiral 8-hydroxygeraniols (S)-(8-2H1)[8-3H1]-2 and (R)-(8-2H1)[8-3H1]-2. Their absolute configuration was assigned on the basis of the 1H-decoupled 3H-NMR Spectra of the corresponding dicamphanates (S)-(8-2H1)[8-3H1]-9 and (R)-(8-2H1)[8-3H1]-9, of which the configurations are established in relation to the synthetic reference samples. The results clearly indicate retention of configuration during the allylic oxidation of 1.
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    URL: http://dx.doi.org/10.1002/hlca.19890720227
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  • 90
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    Elektrochemische Decarboxylierung von L.-Threonin- und Oligopeptid-Derivaten unter Bildung von N-Acyl-N, O-acetalen: Herstellung von Oligopeptiden mit Carboxamid-oder Phosphonat-C-TerminusTeilweise in einer Kurzmitteilung erwähnt (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 401-425 
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    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Electrochemical Decarboxylation of L-Threonine and Oligopeptide Derivatives with Formation of N-Acyl-N, O-acetals: Preparation of Oligopeptides with Amide or Phophonate C-TerminusDerivatives of α-amino acids with two stereogenic centers (cf. L-threonine) and of di-, tri-, and tetrapeptides are electrolyzed in MeOH or AcOH, with formation of N-acyl-N, O-acetals (1b-15b, 20b), in an anodic oxidative substitution of the COOH by an OR group. The amine ends of the oligopeptides may be benzyloxycarbonyl(Z)- or (tert-butoxy)carbonyl(Boc)-protected. With unprotected dipeptides, an electrolytic decarboxylative cyclization to imidazolidinones (18c, 19c) may also occur (in H2O/NH4OAc). The electrolyses are carried out in simple flasks with cooling jackets (‘undivided cell’), using constant current conditions and anodes of Pt or glassy C. The electrolyte is generated in situ by adding 10-20 mol-% of a tertiary amine. Mild acidic hydrolysis of electrolysis products thus obtained may lead to amino-acid amides or peptide amides (10c, 11c, 12c, 17c) with one amino acid less than the starting material. The N, O-acetals from L-threonine and the oligopeptides also react with organometallic nucleophiles such as Grignard compounds (→21-26, 29), with formation of products in which the original COOH group has been replaced by alkyl or allyl (sometimes even with moderate stereoselectivity). By treatment of the peptide-derived (open-chain) N, O-acetals with trialkyl or triaryl phosphites/TiCl4 the RO group is replaced by a phosphodiester group in a (non-diastereoselective) Michaelis-Arbuzov-type reaction (1d, 1e, 2d-9d, 5e). Thus, the two-step sequence of electrolysis and phosphonation converts an oligopeptide derivative to an analogue with a phosphonic-acid end group. The diastereoisomeric N-protected dimethyl and diethyl dipeptidephosphonates (also prepared from the corresponding diaryl esters by Ti(OR)4-mediated transesterification) could be separated by preparative HPLC (SiO2, Lichrosorb Si 60, 10 μm); the dextrorotatory isomers of 1d-3d were assigned L, D-, the laevoratory ones L, L-configuration by hydrolysis to and identification of the known amino and aminophosphonic acids. The results described demonstrate a new simple route leading, from a given oligopeptide, to pure peptide analogues of known configuration.
    Notes: No abstract.
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    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720302
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  • 91
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    Acid-Catalyzed Cyclization Reactions of Substituted Acetylenic Ketones: A new Approach for the Synthesis of 3-Halofurans, Flavones, and StyrylchromonesPresented in part at the autumn meeting of the Swiss Chemical Society in Bern on October 21, 1988. (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 447-456 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Acetylenic acetals of type I (Scheme 1) and acetylenic ketones of type III (Scheme 1), 37 and 38 (Scheme 7) are versatile synthetic precursors for the synthesis of various heterocycles by acid-catalyzed cyclization reactions. By this way, substituted 3-halofurans of type II and IV (Scheme 1) and flavones and styrylchromones (Scheme 7) can be synthesized in good-to-excellent yields. The high degree of regioselectivity in the synthesis of the 3-halofurans (Scheme 4) is the result of the regioselective β-addition of HX (X = Cl, Br, I) to the acetylenic aldehyde and acetylenic ketone moieties. A possible mechanism is depicted in Scheme 5. Since 3-halofurans can easily be metalated and substituted, this approach constitutes a new synthesis of highly substituted furans.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/hlca.19890720305
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  • 92
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    Stoffwechselprodukte von Mikroorganismen. 253. Mitteilung252, Mitteilung. Hormaomycin, ein neues Peptid-lacton mit morphogener Aktivität auf Streptomyceten (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 426-437 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hormaomycin, a Novel Peptide Lactone with Morphogenetic Activity on StreptomycesA culture identified as Streptomyces griseoflavus (strain W-384) has been found to produce a novel peptide-lactone antibiotic designated hormaomycin (6). The empirical molecular formula of the compound is established to be C55H69ClN10O14. The constituent amino acids of the antibiotic are suggested to be allothreonine (1; 1), isoleucine (2; 1), 3-methyl-phenylalanine (3; 2), and, for the first time identified from a natural source, 4-[(Z)-prop-1-enyl]-proline (4; 1) and 3-(2-nitrocyclopropyl)-alanine (5; 2). The amino acids were delivered by acidic hydrolysis and assigned by high-resolution- GC/MS analysis (after transformation to derivatives) in combination with extended 2D-NMR experiments of the antibiotic itself. From the latter, it became plausible that the N-terminus of the peptide chain is acylated by a Cl-containing derivative of 1H-pyrrol-2-carboxylic acid. Hormaomycin is active against some Gram-positive bacteria. In addition, the antibiotic exhibits potent aerial mycelium-inducing activity and effects the production of antibiotics.
    Notes: No abstract.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720303
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    Novel Trinor-eremophilanes (Dendryphiellin B, C, and D), Eremophilanes (Dendryphiellin E, F, and G), and Branched C9-Carboxylic Acids (Dendryphiellic Acid A and B) from the Marine Deuteromycete Dendryphiella salina (SUTHERLAND) PUGHet NICOT (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 438-446 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Further investigation of global extracts from cultures of the marine deuteromycete Dendryphiella salina leads to the isolation of three novel trinor-eremophilanes esterified by branched C9-carboxylic acids, dendryphiellin B(= (+)-(1R*,2S*,7R*,8aR*)-1,2,6,7,8,8a-hexahydro-7-hydroxy-1,8a-dimethyl-6-oxonaphthalen-2-yl (6R*, 2E, 4E)-6-hydroxy-6-methylocta-2,4-dienoate; (+)-2), dendryphiellin C (=(+)-(1R*, 2S*, 7R*, 8aR*)-1,2,6,7,8,8a-hexa-hydro-7-hydroxy-1,8a-dimethyl-6-oxonaphthalen-2-yl (6S, 2E, 4E)-6-methylocta-2,4-dienoate; (+)-3)), and dendryphiellin D (=(+)-(1R*, 2S*, 7R*, 8aR*)-1,2,6,7(8,8a-hexahydro-7-hydroxy-1,8a-dimethyl-6-oxonaphthalen-2-yl (6R*,2E,4E)-6-(hydroxymethyl)octa-2,4-dienoate; (+)-4). An intact eremophilane, dendryphiellin E (5), and its ethanolysis product dendryphiellin F whose absolute configuration is represented by structural formula (+)-6 are also isolated from the above extracts. Dendryphiellin E exists as an open form 5a in equilibrium with a closed form 5b. A similar equilibrium exists between the open form 8a and the closed form 8b of a non-esterified eremophilane, dendryphiellin G (8), which is isolated too from the above extracts and proves structurally related to the cyclic portion of 5. Finally, the free, branched C9-carboxylic acids dendryphiellic acid A ((+)-9) and B ((+)-10) which correspond to side chains of the above esterified terpenes are also isolated from the above extracts.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720304
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  • 94
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    Eine neue Azepinring-Synthese (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 457-463 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: A New Azepine-Ring SynthesisA new one-step synthesis of an azepine ring is described. The 2H-pyran-2-one ring of methyl cumalate (8) or cumalaldehyde (2) upon reaction with an 1-aminoacryl derivative, e.g. 1 or 6, is opened with subsequent decarboxylation to give a 1-aminobutadiene derivative that undergoes an electrocyclic ring closure to the azepine ring (Schemes 1 and 2).
    Notes: No abstract.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720306
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  • 95
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    New Hyperforin Derivatives from Hypericum revolutum VAHL with Growth-Inhibitory Activity against a Human Colon Carcinoma Cell LinePresented in part at the 36th Annual Congress on Medicinal Plant Research, Freiburg im Breisgau, FRG, 12-16th September, 1988, and at the Meeting of the Swiss Chemical Society, Bern, 21st October, 1988. (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 464-471 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The crude petroleum-ether extract of the root bark of Hypericum revolutum VAHL (Guttiferae) exhibited in vitro growth-inhibitory activity against the Co-115 human colon carcinoma cell line. Activity-guided fractionation of this extract resulted in the isolation of two new hyperforin derivatives 1 and 2. The structure of 1 (hyperevolutin A) was established by X-ray analysis as the 4-hydroxy-8-exo-methyl-5,7-exo-bis(3-methylbut-2-enyl)-1-(2-methyl-1-oxopropyl)-8-endo-(4-methylpent-3-enyl)bicyclo[3.3.1]non-3-ene-2,9-dione. The structure of the homologue 2 was deduced by comparison of its UV and 1H- and 13C-NMR spectra with those of 1.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720307
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  • 96
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    Asymmetric Diels-Alder Reaction of 1-Methoxybuta-1,3-diene with (2R)-N-Glyoxyloylbornane-10,2-sultam (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 482-486 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Starting from sultam 1, the chiral dienophile (2R)-N-glyoxyloylbornane-10,2-sultam (4) was readily prepared. Non-catalyzed atmospheric- and high-pressure as well as [Eu(fod)3]-promoted [4 + 2] cycloadditions of 1-methoxy-buta-1,3-diene (5) to chiral dienophile 4, leading with high asymmetric induction to 6-methoxy-3,6-dihydro-2H-pyran-2-yl derivatives 6-9, are described. The extent and direction of asymmetric induction in these reactions were established by 1H-NMR analysis and chemical correlation, respectively. Stereochemical models for both non-catalyzed and [Eu(fod)3]-promoted reactions are proposed.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720310
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  • 97
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    5,10:8,9-Disecosteroids (= Steroklastanes): A new type of modified steroidsDr. Günther Ohloff on the occasion of his 65th birthday (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 608-623 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Thermolysis of steroidal 5α, 8α- peroxides of type 3a-d generates as major products the corresponding diseco compounds containing a 14-membered ring instead of the standard A-B-C-ring skeleton. Depending on the reaction conditions, either the primary products of type 9 or the α, β-unsaturated ketones of type 4, formed by subsequent elimination of AcOH, are isolated. The latter, configurationally uniform compounds undergo epoxidation of the C(9)=C(10) bond followed by a Baeyer-Villiger oxidation to give, as final products, the 15-membered cyclic epoxyenol lactones of type 20 and 21. The structures of the various products were determined by 1H- and 13C-NMR spectroscopy. The conformations of the 14- and 15-membered rings were established by X-ray structure analyses of 7 and 21a. A reaction mechanism for the above transformations is discussed.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720320
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  • 98
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    Thermal and Photochemical Reactions of 1,2-Annelated Barrelenes and Hydrobarrelenes in the presence of transition-metal carbonyls (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 648-652 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The [Co2(CO)8]-mediated retro-Diels-Alder reaction of the annelated barrelenes 1 afforded the 1H-indol-2(3H)-one derivatives 3 (Scheme 1), while the hydrobarrelene 4a, under the same conditions, was converted to the anilide 6 (Scheme 2); 4b remained unaffected. The direct irradiation of 1 led to the annelated cyclooctatetraenes 7 (Scheme 3). On irradiation in the presence of excess of [Fe(CO)5], 1a, 1b, and 4a gave the tricarbonyliron complexes 8, 9, and 11, respectively (Schemes 3 and 4); under these conditions, 4b was inert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720404
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  • 99
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    A Simple and Efficient Method for the Preparation of Binaltrorphimine and Derivatives and determination of their K opioid antagonist selectivity (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 675-677 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The bimorphinans 1 (binaltrorphimine), 3, and 7 have been prepared by treatment of the parent morphinan-6-ones naltrexone (5), naloxone (4), and dihydrocodeinone (6), respectively, with N-methylhydrazine sulfate in AcOH at room temperature. Compound 3 showed opioid antagonist potency and selectivity for K receptors which were somewhat lower in comparison to 1.
    Additional Material: 1 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720408
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  • 100
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    Synthèse d'une sonde biotinylée à bras clivable allongé pour l'isolement des récepteurs de l'angiotensine II (1989)
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 678-689 
    Details
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Synthesis of a Biotinylated Probe with an Extended Cleavable Arm for Angiotensin II Receptors PurificationWe have synthesized a new biotinylated probe for angiotensin II receptors studies: biotinyl-NH(CH2)2—SS—(CH2)2—CO-Gly-∊ Ahx-[Ala1, Phe(4N3)8]angiotensin II (5). This molecule can be photoactivated through an arylazido group. 1H-NMR studies suggest that it adopts an extended conformation which should allow a simultaneous recognition of both streptavidin and hormone receptor. It has a good affinity for receptors (Kd = 1 nM) and hence is a promising tool in their detection (autoradiography, gold-, ferritin-, enzyme-, or fluorescent streptavidin derivatives) and separation (cell sorting, affinity chromatography). It can be monoiodinated (°6) at its tyrosine residue without a significant loss of affinity. Its extended cleavable arm allows an easy recovery of the ‘probe-receptor’ complex from streptavidin. An HPLC monitoring of the synthesis is described, particularly of the segment coupling 1 + 2 in presence of (benzotriazol-1-yloxy)tris(dimethylamino)phosphonium hexafluorophosphate (BOP). This method can be used as well for synthesis of the D-Phe8 derivative that has antagonist properties.
    Additional Material: 4 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/hlca.19890720409
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