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
    ISSN: 1520-6041
    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
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inorganic and organometallic polymers and materials 7 (1997), S. 71-91 
    ISSN: 1572-8870
    Keywords: Ferrocene polymers ; polyaspartamide carriers ; poly(ethylene oxide)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract In continuation of earlier investigations of polymer–ferrocene conjugates for biomedical applications, this article deals with conjugates prepared by N-acylation of linear, amine-functionalized polyaspartamide carriers with 4-ferrocenylbutanoic acid. Acylation is brought about both by mediation of HBTU coupling agent and by the N-hydroxysuccinimide active ester method. The polymeric carriers contain oligo- or poly(ethylene oxide) side chains introduced here for enhancement of water solubility. The longer side chains, in addition, are to impart such biomedically important properties as increased resistance to uptake by the reticuloendothelial system and to protein binding, extended circulation life time, and lowered immunogenicity. The conjugates comprise from 10 to 25 mol% ferrocenylated subunits, corresponding to ca. 2–5% Fe by mass. Freshly prepared and isolated in the solid state, they dissolve smoothly in aqueous media, with upper concentration limits (〉0.2g/ml) dictated solely by their viscosity behavior. The conjugates are of interest in biomedical applications.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inorganic and organometallic polymers and materials 8 (1998), S. 225-236 
    ISSN: 1572-8870
    Keywords: Polymer–ferrocene conjugates ; N-succinimidyl 4-ferrocenylbutanoate ; polyamide carriers ; intrachain anchoring sites
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract It is the objective of this project to synthesize polymer–ferrocene conjugates from macromolecular carriers in which the “anchoring” sites are main-chain constituents, thus contrasting with previously described conjugates featuring side-chain terminals as anchoring sites. To this end, earlier-developed polyamide carriers containing secondary amino groups in the main chain are treated with the active N-succinimidyl ester of 4-ferrocenylbutanoic acid in DMF solution. Molar feed ratios are chosen so as to favor the incorporation of a single ferrocenyl group per recurring unit. The water-soluble, microanalytically and spectroscopically characterized conjugates are of interest as antiproliferative agents in cancer research.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    ISSN: 1572-8870
    Keywords: antiproliferative activity ; water-soluble polymer–platinum complexes ; LNCaP human metastatic prostate adenocarcinoma
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract The chemotherapeutic treatment of secondary, i.e., disseminated cancers, has until now remained an unsatisfactory modality. The LNCaP human metastatic prostate adenocarcinoma cell line lends itself as a useful tool to probe the efficaciousness of novel antineoplastic agents for the control of metastatic cell growth. In this paper we report on a series of cell culture tests assessing the antiproliferative activity of several water-soluble polymer–platinum conjugates in which the metal is tied (anchored) to various polymeric carriers through coordination by a single carrier-attached primary amine ligand. The conjugates are based on polyaspartamide carriers composed, within the backbone, of a majority fraction of subunits bearing water-solubilizing tertiary amine side-group functions and a minority fraction of subunits featuring side chain-terminating primary amino groups for metal binding. Two similarly structured conjugates in which the platinum center is coordinated by two amine ligands in cisoid orientation mimicking the structural skeleton of cisplatin are included in the study for comparison. In all structures cleavage of a side-chain segment is required for release of the monomeric bioactive platinum complex. The growth of LNCaP human metastatic prostate adenocarcinoma cells in RPMI 1640 medium in the presence and absence of the conjugates in a range of concentrations is assessed by a protein assay, and the IC50 values, representing the drug concentrations required for 50% cell growth inhibition relative to untreated control, are determined. The results show both classes of conjugates, those comprising monoamine-coordinated platinum and those featuring cis-diamine-coordinated metal, to be well comparable in antiproliferative activity. A major program of synthesis and evaluation of polymer-bound monoamineplatinum complexes, prompted by these findings, is forthcoming in this laboratory.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    ISSN: 1572-8870
    Keywords: ferrocene polymers ; polyaspartamide carriers ; carboxamide ; LNCaP cell line
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract In continuation of earlier studies probing the cytotoxic properties of polymer-bound ferrocene against the HeLa cell line, the present communication presents the results of cell culture tests performed on a number of polymer–ferrocene conjugates against the LNCaP human metastatic prostate adenocarcinoma line. The water-soluble substrates are polyaspartamide carriers containing primary amine functions as side-group terminals to which the ferrocenylation agent, 4-ferrocenylbutanoic acid, is covalently bound (anchored) through N-acylation, the carboxamide groups so generated in the tether acting as the biofissionable links for release of the monomeric ferrocene compound from the conjugate in the lysosomal compartment. The carrier backbone structures are of the α, β-DL-peptide type preferred in our ongoing work, as this structural configuration allows ultimate chain degradation for efficacious excretion yet prevents fast and premature, α-peptidase-mediated “unzipping” of the peptidic chain. The screens are performed by exposing the selected conjugates 1–7 at various concentrations to cultured LNCaP cells in RPMI medium over a period of 7 days and assessing cell viability by a protein assay. From cell growth data relative to control, plotted against conjugate concentration, the IC50 values, expressed as metal concentrations required for 50% cell growth inhibition, are found to be in the narrow range of 1–10 μg Fe/ml. This compares well with earlier results obtained on selected ferrocene conjugates against the HeLa cell line and, more strikingly still, on analogous, previously tested conjugates containing the square-planar structural skeleton of the cisplatin-type anticancer drug system as the bioactive agent. The present findings, hence, should provide a healthy motivation for more extended studies of polymer-anchored ferrocenes in the biomedical realm.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Electronic Resource
    Electronic Resource
    Springer
    Journal of inorganic and organometallic polymers and materials 9 (1999), S. 221-230 
    ISSN: 1572-8870
    Keywords: Polymer–ferrocene conjugates ; ester link ; bioactivity
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Ferrocene, the parent of the metallocene family of organotransition metal compounds, has come to occupy a significant niche in cancer research. Developmental work in the authors' laboratory has been focused on the synthesis of antiproliferative ferrocene conjugates in which the bioactive ferrocene unit is covalently, yet bioreversibly bound (anchored) to water-soluble carrier polymers designed in accordance with requisite biomedical specifications. The anchoring link in most of these conjugates has been an aliphatic spacer containing the biofissionable amide group. In this communication the synthesis of a class of ferrocene conjugates is reported in which the ferrocene group is carrier-anchored through spacers containing an ester link, of interest here because of potentially different drug release behavior. The carriers are polyamides equipped with variously spaced hydroxyl side groups, to which the ferrocenylation agent, 4-ferrocenylbutanoic acid, is connected through esterification. The coupling reactions, mediated by carbodiimide agent and catalyzed by 4-(dimethylamino)pyridine, are carried out in DMF at temperatures not exceeding 65°C, and the water-soluble product polymers are isolated in yields of typically 70–85% by precipitation, aqueous dialysis, and freeze-drying. With the molar feed ratios chosen in these coupling experiments, the incorporation of ferrocene, assessed by 1H NMR spectroscopy, corresponds to iron contents of roughly 2.5–5.5%, by mass. The conjugates will be included in a forthcoming bioactivity screening program.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    ISSN: 1572-901X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Di-(η5-cyclopentadienyl)dichlorotitanium(IV) reacts with salicylic acid or some of its ring-substituted derivatives in aqueous medium in the presence of alkali carbonate, giving (substituted) di-(η5-cyclopentadienyl)-salicylatotitanium(IV) complexes(3). Analogously, although less efficaciously, the dichlorotitanium compound reacts with phthalic acid to give the phthalato complex(5), and with dipicolinic acid to yield the pyridinedicarboxylato compound(7). Meticulous control of the experimental conditions is necessary to minimize hydrolytic side reactions. The product complexes(3) and(5) can be recrystallized from chloroform, in which they dissolve completely when freshly prepared; prolonged storage at ambient temperature causes reductions in solubility. I.r. and n.m.r. spectroscopic features of the product complexes are presented.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    ISSN: 1572-901X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary The two μ-oxo-bis(trichloroferrate) salts (1) and (3) with diamagnetic ammonium cations are prepared as prototype compounds possessing an oxo-bridged dimer anion structure in which each iron(III) centre coordinates tetrahedrally to the three Cl ligands in addition to the bridging ligand. Antiferromagnetic coupling between the two iron centres in the anion complex is indicated by the low room-temperature effective magnetic moments (1.71–1.74 μB). The i.r. and electronic absorption spectra are in accord with the proposed anionic oxygen bridge structure.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Electronic Resource
    Electronic Resource
    Springer
    Transition metal chemistry 9 (1984), S. 337-338 
    ISSN: 1572-901X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Summary Titanocene derivatives of the dichlorodicyclopentadienyltitanium type(1) are known to possess antineoplastic activity against Ehrlich ascites and other tumor systems in mice. Good solubility in water is generally a prerequisite for biomedical applications of this kind. A titanocene derivative possessing excellent cold water solubility (being converted into an aquated species in the process of dissolution) is the complex(2), acetonitrilechlorodicyclopentadienyltitanium tetrachloroferrate, readily obtained from(1) and iron(III) chloride in acetonitrile. Some spectroscopic properties of(2) are presented.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Electronic Resource
    Electronic Resource
    Weinheim : Wiley-Blackwell
    Angewandte Makromolekulare Chemie 175 (1990), S. 141-156 
    ISSN: 0003-3146
    Keywords: Chemistry ; Polymer and Materials Science
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology , Physics
    Description / Table of Contents: Bei der Polycondensation von d,l-Asparaginsäure mit Nδ-phthaloyl-L-ornithin in Phosphorsäure bei 185°C entstehen statisticsche Copolymere (Ausbeute 60  -  70%) aus Poly(d,l-succinimid-co-Nδ-phthaloyl-d,l-ornithin), Formel 6, mit inhärenten Viskositäten (DMF) von 5 bis 15 ml g-1. Copolyimide der selben Zusammensetzung 6 und vergleichbarer Kettenlänge werden aus Asparaginsäure und dem Kupferchelat des Phthaloylornithins erhalten. Die Behandlung des Copolymeren 6 mit Hydrazinhydrat fuhrt zur Öffnung der Succinimid-Kettenglieder unter Bildung von Hydrazid-Seitengruppen. Die resultierenden Polyamide sind Poly(α,β-d,l-asparaginsäurehydrazid-co-d,l-ornithin), Formel 7. Kürzere Reaktionszeiten bedingen unvollständige Ringöffnung, und die verbleibenden Succinimid-Gruppen werden bei der folgenden Aufarbeitung hydrolytisch gespalten unter Bildung von Asparaginsaüre-Gruppen; die sogebildeten Polyamide besitzen die Struktur 8. Beide Polymere, 7 und 8, sind in Wasser loslich und zeigen in Wasser inharente Viskositiiten von 5 bis 14 ml g-l. Die Fahigkeit dieser Polyamide zur Arzneimittelverankerung wird durch Ankoppeln von Carbonsau- ren als Modellsubstanzen gezeigt.
    Notes: The polycondensation of d,l-aspartic acid with Nδ-phthaloyl-l-ornithine in phosphoric acid at 185°C gives rise to the formation, in 60  -  75% yield, of random copolymers of the poly(d,l-succinimide-co-Nδ-phthaloyl-D,L-ornithine) type 6 possessing inherent viscosities (DMF) in the range of 5  -  15 ml g-1. Copolyimides of the same compositions 6 and comparable chain lengths are obtained from aspartic acid and the copper chelate of the phthaloylornithine. Treatment of copolymers 6 with hydrazine hydrate in DMF leads to N-deprotection and opening of the intrachain succinimide rings with formation of hydrazide side groups. The resultant polyamides are of the poly(α,β-d,l-asparthydrazide-co-d,l-ornithine) type 7. Shorter reaction periods give incomplete hydrazinolytic ring opening, and the remaining succinimide units are cleaved hydrolytically during the subsequent aqueous workup, thereby transforming into aspartic acid units. The polyamides so formed possess the general poly(α,β-d,l-asparthydrazide-co-α,β-d,l-aspartic acid-co-d,l-ornithine) structure 8 Both types 7 and 8 are soluble in water and, in this medium, give inherent viscosities of 5  -  14 ml g-1. The potential drug-anchoring capabilities of these amine-functionalized polyamides are demonstrated by coupling reactions with model carboxylic acids.
    Additional Material: 2 Tab.
    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...