DFT predictions, synthesis, stoichiometric structures and anti-diabetic activity of Cu (II) and Fe (III) complexes of quercetin, morin, and primuletin

Abstract

The current study is aimed at the synthesis of Cu (II) and Fe (III) complexes of three flavonoids {morin (mor), quercetin (quer) and primuletin (prim)} and characterization through UV–Vis spectroscopy, cyclic voltammetry, FTIR, and thermal analysis. Structure prediction through DFT calculation was supported by experimental data. Benesi-Hildebrand equation was modified to function for 1:2 Cu-flavonoid and 1:3 Fe-flavonoid complexes. DFT predictions revealed that out of poly chelation sites present in morin and quercetin, 3-OH site was utilized as preferable chelation site while primuletin chelated through 5-OH position. In-vivo trials revealed the complexes to have better anti-diabetic potential than respective flavonoid. Fls/M-Fls proved as antagonistic to Alloxan induced diabetes and also retained anti-diabetic activity even in the presence of (2-hydroxypropyl)-β-cyclodextrin (HPβCD).