A 62 Antioxidant and antimutagenic activity of N-(2-carboxyethyl)chitosan [Text] / G. Kogan, Yu. A. Skorik, I. Zitnanova, L. Krizkova, Z. Durackova, C. A. R. Gomes, Yu. G. Yatluk, J. Krajcovic // Toxicology and Applied Pharmacology . - 2004. - Vol. 201, № 3. - P303-310 : ил. - Библиогр.: с. 309-310 (49 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): CARBOXYETHYLATION -- CHITOSAN -- EUGLENA GRACILIS -- OFLOXACIN -- ANTIOXIDANT -- ANTIMUTAGENICITY Аннотация: The antioxidant and antimutagenic activities of the novel carboxyethyl derivatives of chitosan with three different degrees of substitution have been assayed in vitro in the unicellular flagellate Euglena gracilis subjected to the action of genotoxic agents acridine orange and ofloxacin. It has been demonstrated that chitosan derivatives exhibit concentration-dependent protective antigenotoxic activity against both mutagens. It is suggested that different mechanisms may be involved in its protective action—antioxidant activity in case of ofloxacin-induced DNA damage, as well as possible interaction with the cell membrane that prevents acridine orange from reaching the genetic compartments and subsequent damaging DNA through intercalative binding. Direct adsorption of acridine orange on chitosan derivatives was ruled out as a possible mechanism of protection on the basis of spectrophotometric measurements. Dependence of the antimutagenic properties of the studied chitosan derivatives on the degree of substitution was reversed in experiments involving acridine orange and ofloxacin, which also indicated different mechanisms of protection involved in these two cases.???? |
1,3,4-Oxa(thia)diazino [i,j]-annelated quinolines: a new type of key intermediate in the synthesis of tricyclic fluoroquinolones [Electronic resource] / G. N. Lipunova, E. V. Nosova, V. N. Charushin, L. P. Sidorova, O. M. Chasovskikh // Mendeleev Communications. - 1998. - Vol. 8, № 4. - P131-132 Рубрики: ХИМИЧЕСКИЕ НАУКИ Аннотация: The synthesis of new derivatives of 1,3,4-oxa(thia)diazino[6,5,4-i,j]quinolines, which have a structure that is very similar to the ofloxacin skeleton, by intramolecular cyclizations of ethyl 3-(R-carbonylhydrazino)- and 3-(R-thiocarbonylhydrazino)-substituted 2-polyfluorobenzoyl acrylates, is described?????? \\\\expert2\\nbo\\Mendeleev Communications\\1998, v.8, N 4. p.131.pdf |
F 33 Features of synthesis and structure of ethyl (2Z)-3-hydroxy-(2,3,4,5-tetrafluorophenyl)-propyl-2-enoate / D. N. Bazhin, E. V. Shchegol'kov, Yu. S. Kudyakova, K. V. Scherbakov, Ya. V. Burgart, V. I. Saloutin // Russian Journal of General Chemistry. - 2012. - Vol. 82, № 1. - С. 116-121. - Bibliogr. : p. 121 (22 ref.) Рубрики: ХИМИЧЕСКИЕ НАУКИ Кл.слова (ненормированные): ANTIBACTERIAL AGENTS -- DERIVATIVES -- OFLOXACIN -- ESTERS Аннотация: The structure of key intermediates in the synthesis of fluoroquinolone antibiotics: diethyl (2,3,4,5-tetrafluorobenzoyl)malonate and ethyl (2Z)-3-hydroxy-(2,3,4,5-tetrafluorophenyl)prop-2-enoate was for first time studied using X-ray diffraction (XRD) and H-1, F-19 NMR spectroscopy. In solution both the esters were shown to exist as a mixture of enol and ketone tautomeric forms with predominance of the latter. According to the XRD analysis, ethyl (2Z)-3-hydroxy-(2,3,4,5-tetrafluorophenyl)prop-2-enoate in the solid state exists entirely in the enol form \\\\Expert2\\nbo\\Russian Journal of General Chemistry\\2012, V. 82, N 8, p. 1444–1450.pdf |