DNA interaction, docking, molecular modelling and biological studies of o-Vanillin derived Schiff base metal complexes

Abstract

In the present studies, [Cu(ABOVL)]1, [Co(ABOVL)]2, [Cr (ABOVL)]3, and [Zn (ABOVL)]4 complexes were prepared where ABOVL is the condensation product of 2-hydroxy-3-methoxybenzaldehyde (o-Vanillin) and (2-aminophenyl)methanol (2-aminobenzylalcohol). To characterize ABOVL and its metal complexes standard analytical and spectral techniques were employed. From the spectral data, ABOVL acts as a bi-dentate ligand with O, N as donor atoms and complex I exhibited square planar geometry and complexes 2, 3, and 4 exhibited octahedral geometries respectively. DNA binding studies were performed using fluorescence, viscosity and absorption studies. The binding constant from absorption studies was 6.23 ± 0.04 × 104 M−1, 5.76 ± 0.03 × 104 M−1, 4.95 ± 0.07 × 104 M−1 and 4.12 ± 0.06 × 104 M−1 for 1, 2, 3 and 4 complexes respectively, and Stern-Volmer quenching constant, KSV from fluorescence studies was 3.99 × 103 M−1, 3.21 × 103 M−1, 2.78 × 103 M−1 and 2.53 × 103 M−1 for 1, 2, 3 and 4 complexes respectively. The above data signifies intercalative mode of binding of complexes to CT-DNA. Viscosity studies further revealed the binding of complexes to CT-DNA through intercalation. Nuclease studies of the complexes were carried out using supercoiled pUC19 DNA with hydrogen peroxide as an oxidant and the results were discussed. GOLO 3.1 programme (software) was used for docking studies and the results showed that complexes can effective bind with active receptor protein of DNA topoisomerase I involving hydrogen bonding interactions and the results were discussed. Antimicrobial studies performed by disc diffusion method showed that the complexes possess higher anti-microbial activity than compared to ABOVL. In-vitro cytotoxic studies were performed for the synthesized complexes against selected cell lines by MTT assay where Complex I showed potential inhibitory efficiency with an IC50 of 49.13 μg/mL as compared to other complexes. Molecular modelling studies were carried out using Argus lab.