Chemistry and insulin-like properties of vanadium(IV) and vanadium(V) compounds

The chemistry of vanadium compounds that can be taken orally is very timely since a vanadium(IV) compound, KP-102, is currently in clinical trials in humans, and the fact that human studies with inorganic salts have recently been reported. VO(acac)(2) and VO(Et-acac)(2) (where acac is acetylacetonato and Et-acac is 3-ethyl-2,4-pentanedionato) have long-term in vivo insulin mimetic effects in streptozotocin induced diabetic Wistar rats. Structural characterization of VO(acac)(2) and two derivatives, VO(Me-acac)(2) and VO(Et-acac)(2), in the solid state and solution have begun to delineate the size limits of the insulin-like active species. Oral ammonium dipicolinatooxovanadium (V) is a clinically useful hypoglycemic agent in cats with naturally occurring diabetes mellitus. This compound is particularly interesting since it represents the first time that a well-characterized organic vanadium compound with the vanadium in oxidation state five has been found to be an orally effective hypoglycemic agent in animals. (C) 2000 Elsevier Science Inc. All rights reserved.