Abstract
A series of VO2+ complexes of Schiff-bases of metformin with each of salicylaldehyde (HL1); 2,3-dihydroxybenzaldehyde (H2L2); 2,4-dihydroxybenzaldehyde (H2L3); 2,5-dihydroxybenzaldehyde (H2L4); 3,4-dihydroxybenzaldehyde (H2L5); and 2-hydroxynaphthaldehyde (HL6) were synthesized by template reaction. The new compounds are characterized through elemental analysis, conductivity measurements, magnetic moment, IR, UV-Vis, ESR and mass spectroscopy. The complexes have square pyramidal structure with mu values of pentacoordinated vanadyl ion. TG, DTG and DTA confirm the proposed stereochemistry, and a mechanism of thermal decomposition was suggested. Mice treated with the complexes [(VOLH2O)-H-1]center dot 1A 1/2H(2)O and [(VOHLH2O)-H-4]center dot 2H(2)O showed glucose-lowering effect of 59.31, 58.79% (20 mg kg(-1)) and 64.98, 74.8% (40 mg kg(-1)) compared to metformin.