| Abstrakt: |
The synthesis of dinuclear oxidovanadiumIV and dioxidovanadiumV complexes of two hydrazones [CH2H2salnah2I and CH2H2salinh2II] derived from 5,5′methylenebissalicylaldehyde [CH2Hsal2] and nicotinic acid hydrazide nah or isonicotinic acid hydrazide inh is described. The compounds were characterised in the solid state and in solution, namely by spectroscopic techniques IR, UVVis, EPR, 1H, 13C and 51V NMR. It has been demonstrated that the dioxidovanadiumV complexes K2[CH2{VVO2salnah}2]·2H2O 3, Cs2[CH2{VVO2salnah}2]·2H2O 4 and Cs2[CH2{VVO2salinh}2]·2H2O 5 of Iand IIare active in the oxidative bromination of salicylaldehyde by H2O2, therefore acting as functional models of vanadiumdependenthaloperoxidases, and it has also been shown that the corresponding oxidovanadiumIV complexes [CH2{VIVOsalnahH2O}2] 1 and [CH2{VIVOsalinhH2O}2] 2 are catalyst precursors for the catalytic oxidation, by peroxide, of methyl phenyl sulfide and diphenyl sulfide, yielding the corresponding sulfoxide and sulfone. Plausible intermediates involved in these catalytic processes are established by UVVis, EPR and 51V NMR studies. The dioxidovanadiumV complexes along with ligands Iand IIwere also screened against HM1:1MSS strains of Entamoeba histolytica. The results showed that the IC50values of compounds 3and 5are lower than the IC50value of metronidazole. The toxicity studies against human cervical HeLa cell lines showed that compounds 3and 5are not much toxic but are more toxic than metronidazole. © WileyVCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009 |
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