Formation and structure in aqueous solution of complexes between vanadium(V) and aminohydroxamic acids that potentiates vanadium’s insulinomimetic activity: l-glutamic γ-hydroxamic and l-aspartic-β-hydroxamic acids

A thermodynamic model for vanadate in aqueous solution – equilibria and reaction enthalpies

“…1 Vanadates have been investigated for purposes as diverse as polymerisation catalysts, 2,3 nanofibres, 4,5 pH probes 6 and insulin mimetics. [7][8][9] In particular, the medicinal applications of vanadates have attracted a substantial amount of interest. In recent years, attention has been focused on vanadate complexes as insulin mimetics in the treatment of diabetes.…”

“…In recent years, attention has been focused on vanadate complexes as insulin mimetics in the treatment of diabetes. [7][8][9][10][11][12] Several vanadium chemistry reviews have been published in the last decade describing these investigations. [13][14][15][16] For the application and/or investigation of vanadates and vanadate complexes in aqueous solution, a thorough understanding of the solution chemistry is essential.…”

Vanadium, niobium and tantalum

“…For instance, [V(ma) 2 (N-N)][ClO 4 ] (N-N = bpy, phen, dpq, dppz) and vanadium(V) complexes bearing aspartic-b-and glutamic-g-hydroxamic acid as ligands, were examined for insulin mimetic activity. 76,77 The antidiabetic characteristics of [VO(dmpp) 2 ], [VO(pimin) 2 ], [VO(Etpimin) 2 ] and [VO(EtOHpimin) 2 ] were assessed (dmpp = bis(1,2-dimethyl-3-hydroxy-4pyridinonate), piminH = 2-(2 0 -hydroxyphenyl)-1H-imidazoline, EtpiminH = 2-(2 0 -hydroxyphenyl)-1-ethylimidazoline, EtOHpimin = 2-(2 0 -hydroxyphenyl)-1-ethanolimidazoline). 78,79 The biotransformation of insulin-enhancing vanadium complexes, [VO(6-mepci) 2 ], [cis-{VO(pic) 2 (H 2 O)], [VO(acac) 2 ] and [VO(dhp) 2 ], were examined (6-mepci-H = 6-methylpicolinic acid, dhp-H = 1,2-dimethyl-3-hydroxy-4(1H)-pyridinone).…”

Carbonate complexes of vanadate

“…Indeed, vanadate and vanadate complexes have been found to both activate and inhibit phosphate metabolising enzymes [8]. In recent years, attention has been focused on the medicinal applications of vanadates [9], particularly their potential as insulin mimetics in the treatment of diabetes [10][11][12].…”

“…A wide range of different types of vanadate complexes have been investigated to date, including those with amino alcohols, alcohols and amino acids, amongst others [10,[13][14][15][16][17][18][19][20]. These studies focused primarily on the determination of equilibrium constants under biologically relevant conditions and the identification of structural features which influence the stability of the complexes.…”