Organotin(IV) complexes of 3-(2-chlorobenzoylamino) benzoic acid; Synthesis, characterization, cytotoxicity, enzyme inhibition, DNA binding, and molecular docking studies

An amide-based carboxylic acid, 3-(2-chlorobenzoylamino) benzoic acid (HL), was synthesized. The reactions of the sodium carboxylate salt (NaL) of HL with di- and triorganotin(IV) chlorides yielded (n-C4H9)2SnL2 (1), (CH3)2SnL2 (2), (n-C4H9)3SnL (3), and (CH3)3SnL (4). Spectral analysis confirmed coordination of the ligand via its carboxylate functional group. FTIR spectra indicated a chelating and bridging bidentate coordination mode for the carboxylate ligand in di- and tri-organotin(IV) complexes, respectively. NMR spectra indicated higher (5/6) and lower (4) coordination numbers for tin in di- and tri-organotin(IV) complexes, respectively. The compounds 1–4 exhibited dose-dependent biological activity and were more potent than the HL. The compounds were more effective against U-87 cancer cell lines than against the normal HEK-293 cell line. The highest cytotoxicity was observed with 3 (IC50 = 8.83 ± 0.43 µg/mL). Complex 1 was identified as the most active inhibitor of α-amylase and α-glucosidase, with IC50 values of 121.54 ± 10.48 μM and 130.32 ± 8.62 μM, respectively. Complex 1 was also the most efficient DNA binder, with a binding constant of 5.9 × 104 M−1. Docking analysis has also shown 1 as the most potent DNA binder (docking score = −10.605), as well as an α-amylase (docking score = −684) and α-glucosidase (docking score = −36) inhibitor, thereby confirming the experimental results.