Oxidovanadium (IV) and iron (III) complexes with O2N2 donor linkage as plausible antidiabetic candidates: Synthesis, structural characterizations, glucose uptake and model biological media studies

Abstract

With the upsurging cases of type II diabetic patients, the demand for safe and effective oral antidiabetic drugs is also increasing. Coordination complexes have proven their mettle as efficient oral drug candidates, which thereby motivated us in this work to design new transition metal complexes as plausible candidates for the treatment of diabetes. A reduced salen ligand, {H2(hpdbal)2‐an} (1) derived vanadium (IV) and iron (III) complexes, namely, [VIVO{(hpdbal)2‐an}] (2) and [{FeIII (OH2)((hpdbal)2‐an)}2 μ2‐SO4] (3) were synthesized in this study. The newly obtained ligand and complexes were characterized using usual analytical and spectroscopic techniques. The potential of these compounds in inducing increased glucose uptake by diabetic cells were studied by using insulin resistant HepG2 cells as model diabetic cells and 2‐NBDG molecule as a D‐glucose analogue and fluorescent tracker. The cells added with the vanadium (IV) complex 3 induced significant NBDG uptake of 95.4% which was higher than that induced by metformin, the standard antidiabetic drug. To elucidate the behavior of the complexes in biological media, model solution studies were conducted with a wide range of pH conditions and protein bovine serum albumin (BSA). The complexes demonstrated effective binding with BSA which was concluded through spectroscopic titration studies and were also found to be sufficiently stable over physiological pH conditions. The study can thus prove to be beneficial in the quest for new antidiabetic drugs.