Structural characterization, DNA binding study, antioxidant potential and antitumor activity of diorganotin(IV) complexes against human breast cancer cell line MDA-MB-231

Five new organotin(IV) complexes, Me2SnL ( 1 ), n-Bu2SnL ( 2 ), tert-Bu2SnL ( 3 ), Ph2SnL ( 4 ) and n-Oct2SnL ( 5 ), have been synthesized from the reaction of R2SnCl2 (R = Me, Bu, tert-Bu, Ph, Oct) with N'-(3-ethoxy-2-hydroxybenzylidene)formohydrazide (H2L). The structural elucidation of synthesized compounds was done by FT-IR, 1H-NMR, 13C-NMR spectroscopy and single-crystal X-ray analysis. Crystallographic data of complex ( 1 ) showed seven coordinated central tin atom with distorted pentagonal bipyramidal geome-try. Where in solution the Sn atom of synthesized complexes exhibit five coordination, confirmed from 1H-NMR. The results from DNA interaction studies via UV-visible spectroscopy, viscosity, cyclic voltam-metry, and differential pulse voltammetry (DPV) suggested an intercalative mode of interaction between the synthesized compounds and SS-DNA. Furthermore, the complexes interact more significantly than ligand. Electrochemical and thermodynamic parameters, including diffusion coefficient, AH, AG, and AS, were calculated using cyclic voltammetry data. The linear plot of peak current (I) vs. square root of the scan rate (upsilon 1/2) indicated the electrochemical processes to be diffusion controlled. The DPPH free radical scavenging assay results showed that complex ( 4) is an active antioxidant. In-vitro cytotoxicity of the syn-thesized compounds was determined on human breast cancer cell line MDA-MB-231 using tetrazolium-based MTT assay, and complexes ( 2) , ( 3) and ( 4) showed significant cytotoxic activity. The structure -activity relationships may be utilised to direct the optimization of the activity of agents from this class of compounds by comparing the specifics of the compound structures, their DNA binding, and toxicity.(c) 2023 Elsevier B.V. All rights reserved.