Glucose-lowering properties of vanadium compounds: Comparison of coordination complexes with maltol or kojic acid as ligands

• Published in: Journal of inorganic biochemistry 1997-11, Vol.68 (2), p.109-116
• Main Authors: Yuen, Violet G., Caravan, P., Gelmini, Lucio, Glover, Nicholas, McNeill, John H., Setyawati, Ika A., Zhou, Ying, Orvig, Chris
• Format: Article
• Language: English
• Subjects: Animals; Blood Glucose - drug effects; Diabetes Mellitus, Experimental - drug therapy; Dose-Response Relationship, Drug; Hypoglycemic Agents - pharmacology; Male; Organometallic Compounds - chemistry; Organometallic Compounds - pharmacology; Pyrones - chemistry; Pyrones - pharmacology; Rats; Rats, Wistar; Solutions; Structure-Activity Relationship; Time Factors
• ISSN: 0162-0134; 1873-3344
• DOI: 10.1016/S0162-0134(97)00082-2

Bis(kojato)oxovanadium(IV) [abbreviated VO(ka) 2], a close chemical analog of the insulin-mimetic lead compound bis(maltolato)oxovanadium(IV)—abbreviated BMOV or VO(ma) 2—is reported and its reaction chemistry and insulin-mimetic properties are presented. VO( ka) 2 [ log K 1 = 7.61 (10), log K 2 = 6.89(6), log β 2 = 14.50 (16)] has a reaction chemistry which directly parallels that of VO(ma) 2. In aqueous solution it is more slowly oxidized by molecular oxygen to [VO 2 (ka) 2] − than is VO(ma) 2 to [VO 2(ma) 2] −. Variable pH electrochemistry and variable pH 51 V NMR of solutions of VO(ka) 2 are presented and contrasted with the corresponding results for VO(ma) 2. Time course studies (24 hr) in STZ-diabetic rats following the oral or ip administration of VO(ka) 2, VO(ma) 2, VO 2+ (vanadyl) as vanadyl sulfate (VOSO 4), and [VO 2(ma) 2] − as its [NH 4] + salt have been performed, as have chronic oral studies comparing VO(ka) 2 and VO(ma) 2 over a six week period. In all studies, the most potent form of vanadium was the neutrally charged, water soluble, complex VO(ma) 2.