1,721,065 research outputs found
Isolation and structure elucidation of the main UV-A photoproducts of vandetanib
No full textExposure of aqueous solutions of the antitumor drug vandetanib to UV-A light results in the photochemical degradation. Two main photodegradation products were identified by HPLC-MS analysis and their structures were elucidated, after their isolation by HPLC, on the basis of LC-MS and NMR spectra. The photoproducts derived from a simple debromination (N-(2-fluorophenyl)-6-methoxy-7-((1-methylpiperidin-4 yl)methoxy)quinazolin-4-amine, FP3) or from the loss of the bromide atom followed by the solvent addition (N-(4-hydroxy-2-fluorophenyl)-6-methoxy-7-((1-methylpiperidin-4 yl)methoxy)quinazolin-4-amine, FP2). At our knowledge this is the first report about the photodegradation of vandetanib. © 2013 Elsevier B.V
Tetrahydrobenzo-4,6-dimethylangelicin: a new angular furocoumarin forming interstrand photo-cross-links.
No full textNew studies on the interaction between 8-methoxypsoralen and DNA in vitro.
No full textSome aspects of the interactions between DNA and 8-methoxypsoralen (8-MOP) in its ground state (complex formation) or in its excited state (photobinding) have been investigated. 8-MOP shows a low affinity towards DNA in the complex formation; this fact minimizes the possible biological consequences deriving from this interaction, when it occurs in vivo. In covalent photobinding to DNA, 8-MOP forms mainly monofunctional adducts, and to a lesser extent bifunctional adducts, showing a behavior similar to that of other linearly condensed furocoumarins (psoralens); the ratio between mono-and bifunctional adducts was found to be 9:1. The covalent photobinding to DNA does not occur at random along the macromolecule, but preferentially at the level of specific receptor sites. The regions having an alternate sequence of A-T seem to be the best receptor sites for the formation of monoadducts while the regions containing an alternate sequence of A-T and C-G appeared to be the preferential sites for the cross-linkage formation
Studies on the mechanism of action of mitomycin C.
No full textThe in vitro formation and properties of the molecular complex between mitomycin C and native DNA were examined by means of various experimental methods; the data obtained indicate that the complex is extremely weak and that the chromophoric moiety of the antibiotic is not involved in its formation. The alkylating activity of mitomycin C was also studied using 3H-mitomycin C; while monofunctional alkylation increases almost in parallel with the concentration of the antibiotic, the difunctional alkylation, causing inter-strand cross-linkages in DNA, rapidly reaches a maximum and then remains constant even when increasing the concentration of the antibiotic and monofunctional alkylation. On the basis of these results, the currently accepted molecular model of the mitomycin--DNA interaction must be revised; a new model of this interaction is presented, which is in better agreement with the properties of mitomycin C and with the latest findings on the subject
Some photochemical and photobiological properties of 8,8-desmethylxanthyletine (homopsoralen), a potential photochemotherapeutic agent.
No full text
Antimicrobial properties of some 3-acyl-4,7-disubstituted indoles.
No full textThe compounds tested were 4,7 dimethoxy, 4 hydroxy 7 methoxy and 4,7 dihydroxyindoles and indole 4,7 quinones. Only the dihydroxy compounds were active against certain bacterial strains. To test whether the action mechanism was analogous to that of mitomycin, experiments were carried out to study the formation of complexes with DNA. Only the substances with antimicrobial activity formed complexes, and it is therefore suggested that the action mechanism involves interference with cellular DNA
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