Interaction of oxovanadium(IV)-salphen complexes with bovine serum albumin and their cytotoxicity against cancer

Vanadyl compounds of clinical significance are recommended as drugs against diseases such as tuberculosis, diabetes, cancer, etc. In order to check the potential of the salphen ligands and oxovanadium(IV)-salphen complexes as drugs their binding with bovine serum albumin (BSA) is investigated. The binding constants measured at pH 7.4 using UV-vis absorption and fluorescence techniques are in the range of 10(3)-10(5) M(-1). The quenching of the fluorescence of BSA and appearance of enhanced luminescence of the salphen ligand/vanadium(IV) complex at the increased [quencher] show efficient FRET from the protein to the quencher and the distance of energy transfer estimated using Forster's theory is in the range of 1.4-3.5 nm. Molecular docking studies (DFT) utilizing oxovanadium(IV)-salphen derivatives show strong binding with BSA and give insight into the binding modes, interaction pattern and stability of synthesized complexes in the target site. The cytotoxicity study shows the ability of these V(IV) complexes to inhibit the growth of AGS gastric cell lines.