Synthesis and Characterization of Serendipitous Dioxovanadates and Their DNA/BSA Interaction Studies and In Vitro Cytotoxic activity

Abstract

In the current study, we have synthesized and characterized two, hitherto unreported, bis (N,N) donor dioxovanadium(V) complexes based on 1,10-phenanthroline (complex 1) and 2,2′-bipyridyl (complex 2) ligands with 3,5-dinitrosalicylic acid counter anion. The structure of the complexes are confirmed by single crystal X-ray crystallography. The binding interactions of the metal complexes with deoxyribonucleic acid (DNA) and bovine serum albumin (BSA) have been investigated by UV absorption titration and tryptophan emission quenching methods respectively. The complexes quench the intrinsic fluorescence of BSA with increasing amount of the complex concentration. Furthermore, the cytotoxic effect of the complexes against cervical cancer cell lines (HeLa) has been ascertained by MTT assay. The complexes are found to show good DNA/BSA binding ability. Based on the results obtained, it has been observed that the complexes bind preferably to groove as implicated by hyperchromic effect with increasing amount of the DNA. The binding constants (Kb) of the complexes 1 and 2 are 9.02 × 103 M−1 and 2.13 × 103 M−1 respectively. The quenching constants (KBSA) and quenching rate constant (Kq) of the complexes 1 & 2 are 0.1075 × 106 M−1 & 0.076 × 106 M−1 and 1.075 × 1013 M−1S−1 and 0.76 × 1013 M−1S−1, respectively.