Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Electronic Resource
    Electronic Resource
    s.l. : American Chemical Society
    Journal of the American Chemical Society 110 (1988), S. 3393-3396 
    ISSN: 1520-5126
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    ISSN: 1520-4804
    Source: ACS Legacy Archives
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    ISSN: 1439-099X
    Keywords: Key Words: Rectal cancer ; Radiotherapy ; Amifostine ; Radioprotection ; Acute toxicity ; Schlüsselwörter: Rektumkarzinom ; Radiotherapie ; Amifostin ; Radioprotektion ; Akute Nebenwirkungen
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Hintergrund: Amifostin ist in den letzten Jahren in mehreren Phase-II/III-Studien als Radioprotektor eingesetzt worden. Dabei zeigte sich eine Verringerung der Xerostomie bei Bestrahlungen im Kopf-Hals-Bereich. Ein Effekt auf Mukositis wurde bisher nicht belegt. Wir haben Amifostin in einer Phase-II-Studie bei Patienten mit Rektumkarzinomen während der postoperativen Radiochemotherapie eingesetzt, aber das Präparat nur in den zwei Chemotherapiewochen gegeben. Es sollte geprüft werden, ob dieser intermittierende Applikationsmodus klinisch wirksam sein könnte. Patienten und Methodik: Zwischen September 1997 und Oktober 1998 wurden 15 Patienten mit postoperativer Radiochemotherapie wegen eines Rektumkarzinoms in die offene Phase-II-Studie eingebracht. Die Radiochemotherapie erfolgte nach den Empfehlungen der Deutschen Krebsgesellschaft (28 Fraktionen großvolumig mit 1,8 Gy in Drei-Felder-Technik, drei Fraktionen Boost auf Sakrum und Präsakralregion, zwei Kurse 5-FU mit 1000 mg/m2 pro Tag als 120-Stunden-Dauerinfusion in Woche 1 und 5). Amifostin wurde nur an den Chemotherapietagen (Tage 1 bis 5 und 29 bis 33) in einer Dosis von jeweils 500 mg direkt vor der täglichen Bestrahlungsfraktion intravenös appliziert. Die Zustimmung der Ethikkommission der Martin-Luther-Universität lag vor. Während des Studienzeitraums wurden weitere 15 Patienten mit Rektumkarzinom, die die Einschlusskriterien erfüllten, aber an der Studie nicht teilnehmen wollten, mit einer identischen Radiochemotherapie ohne Amifostin behandelt; diese dienten als nicht randomisierte Kontrollgruppe. Ergebnisse: Alle Patienten beendeten die Therapie ohne Komplikationen oder ungeplante Unterbrechungen. Die Toxizität von Amifostin war mild (Hypotension Grad I in 53% und Grad II in 7%, Nausea Grad I in 47% und Grad II in 13%). Patienten mit Amifostin hatten im Vergleich zur nicht randomisierten Kontrollgruppe signifikant weniger akute Nebenwirkungen an der Haut und am Darm (maximaler Erythem-Score 1,47±0.64 ohne vs. 0,87±0,52 mit Amifostin, p = 0,009 und maximaler Diarrhö-Score 1,07±1,03 ohne vs. 0,40±0,63 mit Amifostin, p = 0,044). Hämatologische Toxizität und orale 5-FU-Mukositis waren nicht signifikant verschieden. Schlussfolgerungen: In dieser Phase-II-Studie ergeben sich Hinweise für eine mögliche klinische Effektivität von Amifostin auch bei intermittierender Gabe während einer Radiochemotherapie bei Patienten mit Rektumkarzinom.
    Notes: Purpose: Amifostine has been shown to be able to reduce acute radiation toxicity of administered daily prior to radiation during a course of a conventionally fractionated radiotherapy. A disadvantage is the necessity of daily intravenous injection. We have used amifostin in patients undergoing adjuvant radiochemotherapy for rectal cancer. Amifostine was administered only in the first and fifth week of radiotherapy together with 5-FU chemotherapy. The objective was to determine whether the intermittent use of amifostine may be effective in reducing acute radiation toxicity. Patients and Methods: From September 1997 through October 1998, 30 patients with stage II/III rectal cancer underwent postoperative radiochemotherapy at our department. All patients had undergone curative (R0) resection and received 50.4 Gy to the pelvis with a 3-field technique using a belly board followed by a boost of 5.4 Gy to the presacral space in conventional frationation with 1.8 Gy per fraction. 5-FU chemotherapy was administered as 120-hours continuous infusion in the first and fifth radiation week via a central venous catheter in a daily dosage of 1 000 mg/m2. All patients were offered to participate in a phase-II study using additional amifostine. Fifteen patients participated and received 500 mg amifostine daily on chemotherapy days (days 1 to 5 and 29 to 33) immediately prior to the daily radiation fraction. Fifteen patients did not participate and served as non-randomized control. The study was approved by the ethical committee of the Martin-Luther-University and informed consent was obtained from all patients. Results: The distribution of patients' characteristics and prognostic parameters was comparable in both groups. Side effects of amifostine were mild and included hypotension (53% grade I, 7% grade II) and nausea (47% grade I, 13% grade II). Antiemetics were not routinely used. All patients completed radiochemotherapy plus amifostine without unplanned breaks or dose reductions. One patient developed a cerebral infarction which was considered to be not related to the use of amifostine. As compared to the non-randomized control group, patients with additional amifostine had less acute skin and bowel toxicity (maximum erythema score 1.47±0.64 without vs. 0.87±0.52 with amifostine, p = 0.009 and maximum diarrhea score 1.07±1.03 vs 0.40±0.63, p = 0.044). Oral 5-FU-related mucositis and hematological toxicity were not significantly different. Conclusions: In this phase-II study, amifostine significantly reduced acute skin and bowel toxicity of adjuvant chemoradiation in patients with rectal cancer even if the drug was administered only intermittently and not during the whole course of radiotherapy. This finding might be important with regard to intense combined regimes and should be further investigated.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1986 (1986), S. 1687-1704 
    ISSN: 0170-2041
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Peptide Conformations, 41. - A Unique Conformation of the Cyclic Pentapeptide cyclo-(-Pro-Pro-Phe-Phe-Gly-) in DMSOThe title compound 1 was obtained on two different ways by cyclization between Gly5 and Pro1 as well as between Phe4 and Gly5. Investigations by 1H-, 13C-, and 15N-NMR spectroscopy show that one single conformation of the peptide dominates in DMSO solution. From the temperature dependence of the NH-proton signals and the changes of their chemical shifts on adding chloroform we conclude that only the glycine NH is intramolecularly oriented. The chemical shifts of the proline β- and γ-carbons indicate both Xaa - Pro peptide bonds to be cis configurated. The evaluation of interproton distances, which were obtained by one- and two-dimensional NOE measurements, and NH-CαH coupling constants, combined with model studies lead to a βII- conformation with phenylalanine in positions (i + 1) and (i + 2). This result is in contradiction to the βI conformation which is expected for both Phe's with L-configuration. The occurrence of two cis peptide bonds in a cyclic pentapeptide is unique.
    Notes: Die Titelverbindung 1 wurde auf zwei verschiedenen Synthesewegen durch Cyclisierung zwischen Gly5 und Pro1 bzw. zwischen Phe4 und Gly5 erhalten. 1H-, 13C- und 15N-NMR-spektroskopische Untersuchungen in DMSO zeigen, daß das Peptidgerüst eine einzige Konformation bevorzugt. Aus der Temperaturabhängigkeit der chemischen Verschiebung der NH-Signale sowie deren Veränderung bei Zugabe von Chloroform wird auf nur ein intramolekular orientiertes Amidproton, nämlich das NH-Proton des Glycins, geschlossen. Die chemischen Verschiebungen der β- und γ-Prolinkohlenstoffe zeigen, daß beide Xaa - Pro-Amidbindungen cis-konfiguriert sind. Die Interpretation der Protonenabstände, ermittelt durch ein- und zweidimensionale NOE-Messungen, in Verbindung mit NH-CαH-Kopplungen läßt im Zusammenhang mit Modellbetrachtungen nur eine βII′-Konformation mit Phenylalanin in den Positionen (i + 1) und (i + 2) zu. Dieses Ergebnis steht im Gegensatz zu den bisher beobachteten Regelmäßigkeiten, denenzufolge wegen der L-Konfiguration beider Phe-Reste für 1 eine βI-Konformation zu erwarten wäre. Ungewöhnlich ist auch das Auftreten von zwei cis-Peptidbindungen in einem Pentapeptid.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1989 (1989), S. 903-912 
    ISSN: 0170-2041
    Keywords: Antamanide, NMR ; Peptides ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Zuordnung aller Wasserstoff-, Kohlenstoff- und Stickstoff-NMR-Signale von Antamanid in ChloroformlösungDie 1H-, 13C- und 15N-NMR-Spektren des cyclischen Decapeptids Antamanid (1) in CDCl3-Lösung wurden mit ein- und zweidimensionalen NMR-Techniken untersucht und zugeordnet. Die Zuordnung umfaßt auch die aromatischen Resonanzen der Phenylalanin- sowie die tertiären Stickstoffe der Prolin-Bausteine. Mit Hilfe eines COLOC-Experiments wurden die Subspektren der in Antamanid jeweils viermal vorkommenden Aminosäuren Phenylalanin und Prolin sequenziert. Die Spektren von drei neuen Thiazolidin-Analogen des Antamanids bestätigen die Sequenzanalyse im Hinblick auf Prolin und machen weitere spektrale Parameter zugänglich. NOE-Daten, die bei tiefer Temperatur und hoher Meßfrequenz aus ein- und zweidimensionalen Spektren erhalten wurden, zeigen, daß die Auswertung von NOE-Effekten zwischen NH- und α-Protonen zur Sequenzierung eines Peptides unter bestimmten Umständen zu Fehlinterpretationen führen kann.
    Notes: Homo- and heteronuclear one- and two-dimensional techniques have been used to assign the 1H, 13C, and 15N NMR spectra of the cyclic decapeptide antamanide (1) in CDCl3. The assignment includes the aromatic resonances of phenylalanine and the non-protonated nitrogen atoms of proline by means of heteronuclear two-dimensional NMR spectroscopy. Sequence analysis of the four phenylalanine and four proline amino acid residues was performed by heteronuclear proton - carbon long-range couplings using the COLOC sequence. Three new thiazolidine analogues of antamanide confirm the sequence analysis of prolines and open the possibility for the extraction of extended spectral parameters. The interpretation of NOE data, obtained from one- and two-dimensional spectra at high field and low temperatures, demonstrate possible misinterpretations of this effect respecting sequence assignment, if only NOEs between NH protons and α-protons are considered.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Liebigs Annalen 1989 (1989), S. 913-928 
    ISSN: 0170-2041
    Keywords: Antamanide, conformation, NMR, MD, X-ray ; Peptides ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Die Konformation von AntamanidDie Konformation des cyclischen Decapeptids Antamanid (1) in CDCl3-Lösung wurde NMR-spektroskopisch ermittelt. Zur Bestimmung der stabilsten Gerüstkonformation wurden 40 intra-molekulare Protonenabstände als „constraints“ für das GROMOS molecular dynamics Computerprogramm herangezogen. Die Kernabstände wurden aus NOE-Spektren, die bei 500 MHz und tiefer Temperatur aufgenommen wurden, erhalten. Die MD-Rechnungen zeigten, daß 1 in Lösung bis zu vier verschiedene Konformationen annimmt, die durch Rotation um die Winkel ϕ und ψ der beiden Peptidbindungen zwischen Ala4-Phe5 und Phe9-Phe10 im schnellen Gleichgewicht sind. Die Seitenketten-konformationen wurden mit Hilfe homo- und heteronuklearer Kopplungskonstanten bestimmt. Kohlenstoff-Relaxationszeiten lieferten Informationen über Beweglichkeiten. Drei neue Antamanid-Analoge, in denen jeweils Pro3, Pro7 oder Pro8 durch γ-Thiaprolin (Thz) ersetzt wurde, wurden synthetisiert und aus Aceton/Wasser kristallisiert. Die Röntgenstrukturanalysen dieser Thz-Derivate zeigen kompakte Strukturen, die durch intramolekulare Wasserstoffbrücken zu je vier H2O-Molekülen stabilisiert werden. Die Kristallstrukturen unterscheiden sich von der Antamanid-Konformation in Lösung.
    Notes: The conformation of the cyclic decapeptide antamanide (1) in CDCl3 solution was determined by means of NMR-spectroscopic methods. Distances obtained from 40 negative NOE values at 500 MHz at low temperature were used as constraints in calculations with the GROMOS molecular dynamics program package to elucidate the most stable backbone conformation in solution. It turned out that there is a fast conformational equilibrium between up to four conformations which differ in a flip about ϕ and ψ around the two amide bonds Ala4-Phe5 and Phe9-Phe10. Side chain conformations were determined using homo- and heteronuclear coupling constants. Carbon relaxation times provide information about the internal flexibility of 1. Three new antamanide derivatives in which Pro3, Pro7, or Pro8 have been substituted by γ-thiaproline (Thz) were synthesized and crystallized from acetone/water. The X-ray analyses of these Thz derivatives demonstrate that in the presence of water antamanide adopts a preferred structure which includes four water molecules for building up a compact hydrogen-bonded structure, which differs from the conformation in chloroform sulution.
    Additional Material: 12 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Electronic Resource
    Electronic Resource
    New York, NY : Wiley-Blackwell
    Helvetica Chimica Acta 72 (1989), S. 1597-1607 
    ISSN: 0018-019X
    Keywords: Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Structure Determination of N6-, 9-and 7-Acyladenines by 1H- and 13C-NMR Spectroscopy of Solids and in Solution.Adenine (1) reacts with carboxylic acid anhydrides or chlorides 2 to yield the acyladenine isomers 3-5. The isomeric structures were determined by 33C- and 1H-NMR spectroscopy in solution and by solid-state 13C-NMR spectroscopy.
    Additional Material: 6 Tab.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 0170-2041
    Keywords: Azachalcone ; Aldol reaction ; Michael addition ; Inverse 2D-NMR ; Chemistry ; Organic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 4-Acetylpyridine reacts stereoselectively with benzaldehyde under basic conditions to afford rac-1. The constitution of 1 was determined by the long-range connectivities revealed by the H, C-COLOC spectrum. The relative stereochemistry of the chiral centers C-2 to C-6 was obtained from 3JHH couplings. The stereochemistry at the non-proton bearing C-1 was established by through-space connectivities from ROESY and semiquantitative analysis of 3JCH from an inverse 2D-NMR spectrum (HMBC). The NMR findings were confirmed by single crystal X-ray diffraction.
    Additional Material: 5 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    ISSN: 0570-0833
    Keywords: Chemistry ; General Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Chichester : Wiley-Blackwell
    Organic Magnetic Resonance 29 (1991), S. 18-21 
    ISSN: 0749-1581
    Keywords: 1H and 13C NMR ; 2D NMR ; Spectral assignment ; Cardiosteroids ; Bufadienolides ; Acrihellin ; Hellebrigenin ; Chemistry ; Analytical Chemistry and Spectroscopy
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: The complete assignment of all 1H and 13C NMR signals of acrihellin in chloroform solution is presented. The analysis of the 1H and 13C NMR spectra was performed using the heteronuclear 2D NMR techniques H,C-COSY and H,C-COLOC. For an unambiguous assignment of the 13C NMR spectrum the elucidation of carbon-carbon connectivities via 2D-INADEQUATE was most important. The INADEQUATE experiment was also applied to hellebrigenin in DMSO-d6 solution. This experiment confirmed a recently published carbon assignment.
    Additional Material: 2 Ill.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...