Influence of chirality of V(V) Schiff base complexes on DNA, BSA binding and cleavage activity

New chiral V(V) Schiff base complexes (S)-[VO(OMe)L] and (R)-[VO(OMe)L] were synthesized and characterized by microanalysis, infrared (IR), UV–Visible, Circular dichroism (CD) spectroscopy and single crystal X-ray studies. The interaction of these complexes with calf thymus (CT) DNA and bovine serum albumin (BSA) protein showed chiral expression DNA/protein binding strength. The influence of chirality was also observed in cytotoxicity assay of Hep 2 cells. (R)-[VO(OMe)L] enantiomer exhibited higher binding constant (5 ± 1 × 105 M−1) as compared to (S)-[VO(OMe)L] (8 ± 1 × 104 M−1). The fluorescence quenching, thermal melting and viscosity data suggest DNA surface and/or groove binding nature of the complexes and electrophoresis studies also showed greater activity for (R)-[VO(OMe)L] in cleaving DNA and protein as against (S)-[VO(OMe)L].

Graphical abstractThe interaction of chiral Schiff base complexes with DNA and protein was investigated with a goal to examine the effect of chirality in metal complex vis-à-vis DNA/protein binding strength.Figure optionsDownload full-size imageDownload as PowerPoint slideHighlights► The novel chiral vanadium (V) Schiff base complexes were synthesized. ► Influence of chirality on DNA interaction and anticancer activity were evaluated. ► R enantiomer of complex interacted more strongly with DNA. ► R enantiomer of complex cleave DNA and protein stronger than S enantiomer. ► Chiral vanadium complexes showed anticancer activity against Hep2 cell line.