Oxovanadium complexes of N-substituted 3-hydroxy-2-methyl-4(1H)-pyridinones: synthesis, spectroscopic characterization, and the insulin-mimetic activity

摘要

Five kinds of N-substituted 3-hydroxy-2-methyl-4(1H)-pyridinones, and two kinds of tetradentate ligands, N, N'-[bis(3-hydroxy-1,4-dihydro-2-methyl-4-oxo-1-pyridyl)hexanoyl-and octanoyl]-1,5-diamino-3-oxapentanes, were synthesized. Treatment of these ligands with VO(acac)_2 in CH_3OH exclusively gave CH_3OH-coordinated oxovanadium(V) complexes. On the other hand, treatment with VOSO_4 in H_2O at around pH 10 afforded oxovanadium(IV) complexes. On the basis of the inhibitory effect of oxovanadium(IV) complexes on free fatty acid (FFA) release from rat adipocytes treated with epinephrine in the presence of 0.1% glucose in vitro, it was revealed that some of oxovanadium(IV) complexes show the insulin-mimetic activity.