title: Complexes of vanadium(III) with L-alanine and L-aspartic acid.
abstract: The equilibria of the complexation processes of V(3+) with L-alanine and L-aspartic acid in aqueous solution over a wide pH range (2-10) were studied by potentiometric and spectroscopic (UV-Vis, CD) methods. The results show that alanine forms complexes with V(3+) in the metal ion concentration range and at the ligand-to-metal ratios investigated, giving mononuclear species only. In ML(2) species, which dominate in the range pH 4-8, alanine acts as a bidendate ligand through O and N atoms. The complexation processes of V(3+) with aspartic acid are more complicated. In acidic solution (up to pH approximately 4) they are similar to those for alanine. In the higher pH region, however, there are complicated equilibria among mono- and various dinuclear species. These dinuclear species consist of carboxylic or mu-oxo bridges and differ from each other by the number of coordinated ligands and OH(-) groups. The solid phase of the V(III) complex with aspartic acid could be isolated from nonaqueous solution only. Spectroscopic (UV-Vis-IR) measurements and magnetic susceptibility data confirm the coordination of vanadium(III) by two carboxylic groups. Both V(III)-L-aspartic acid and V(III)-L-alanine complexes have a significant apoptotic effect on Hepatoma Morris 5123 cells.
authors.affiliation: Faculty of Chemistry, University of Wroclaw, 14 F Joliot-Curie St, 50-383 Wrocław, Poland.
authors.forename: Krystyna
authors.initials: K
authors.lastname: Bukietyńska
authors.forename: Halina
authors.initials: H
authors.lastname: Podsiadly
authors.forename: Zofia
authors.initials: Z
authors.lastname: Karwecka
mesh_terms: D000409:Alanine / Q000737:chemistry* / Q000494:pharmacology; D000818:Animals; D000970:Antineoplastic Agents / Q000737:chemistry / Q000494:pharmacology; D017209:Apoptosis / Q000187:drug effects; D001224:Aspartic Acid / Q000737:chemistry* / Q000494:pharmacology; D002942:Circular Dichroism; D006863:Hydrogen-Ion Concentration; D006878:Hydroxides / Q000737:chemistry; D008024:Ligands; D008114:Liver Neoplasms, Experimental / Q000188:drug therapy; D008958:Models, Molecular; D009942:Organometallic Compounds / Q000737:chemistry* / Q000494:pharmacology; D011199:Potentiometry; D051381:Rats; D013053:Spectrophotometry / Q000379:methods; D013056:Spectrophotometry, Ultraviolet; D014407:Tumor Cells, Cultured; D014639:Vanadium / Q000737:chemistry* / Q000494:pharmacology; D014867:Water / Q000737:chemistry
chemical_list: D000970:Antineoplastic Agents; D006878:Hydroxides; D008024:Ligands; D009942:Organometallic Compounds; D014639:Vanadium; D014867:Water; D001224:Aspartic Acid; C031356:hydroxide ion; D000409:Alanine