Abstract

Two novel vanadium complexes, [V^IVO(bp-O)(HSO₄)] (1) and [V^IVO(bp-OH)Cl₂]•CH₃OH (2•CH₃OH), where bp-OH is 2-{[bis(pyrid-2-yl)methyl]amine}methylphenol, were prepared and structurally characterised. EPR spectra of methanol solutions of 2 suggest exchange of Cl^- for CH₃OH and partial conversion to [VO(bp-OH)(CH₃OH)₃]²⁺. Speciation studies on the VO²⁺-bpOH system in a water/dmso mixture (4:1 v/v) revealed [VO(bp-O)(H₂O)_n]+ as the dominating species in the pH range 2–7. The insulin-mimetic properties of 1 and 2, [V^IVO(SO₄)tpa] (3), [V^IVO(pic-trpMe)₂] (5) and the new mixed-ligand complexes [V^VO(pic-trpH)tpa]Cl₂ (4Cl₂) and [V^VO(pic-OEt)tpa]Cl₂ (6Cl₂), tpa = tris(pyrid-2-yl)methylamine, picH-trpH = 2-carboxypyridine-5-(L-tryptophan)carboxamide (picH-trpMe is the respective tryptophanmethyl ester), pic-OEt = 5-carboethoxypyridine-2-carboxylic acid, were evaluated with rat adipocytes, employing two lipolysis assays (release of glycerol and free fatty acids (FFA)), respectively and a lipogenesis assay (incorporation of glucose into lipids). The IC₅₀ values for the inhibition of lipolysis in the FFA assay vary between 0.41 (±0.03) (5) and 21.2 (±0.6) mM (2), as compared to 0.81 (±0.2) mM for VOSO₄.

I documenti depositati in UnissResearch sono protetti dalle leggi che regolano il diritto d'autore