Novel diphenyltin(IV) complexes with carboxylato N-functionalized 2-quinolone ligands: Synthesis, characterization and in vitro anticancer studies

Three new diphenyltin(IV) complexes, bis(3-(4-methyl-2-oxoquinolinyl-1(2H)-yl)propanoato)diphenyltin(IV) (1), bis(2-(4-methyl-2-oxoquinolin-1(2H)-yl)ethanoato)diphenyltin(IV) (2), and bis(2-(4-hydroxy-2-oxoquinolin-1(2H)-yl)ethanoato)diphenyltin(IV) (3), were synthesized and characterized by elemental microanalysis, FT-IR spectroscopy, and multinuclear (1H, 13C and 119Sn) NMR spectroscopy. Crystal structure of ligand precursor, 2-(4-methyl-2-oxoquinolinyl-1-(2H)-yl)acetic acid (HL2), has been determined by X-ray diffraction studies. Asymmetric bidentate coordination of the carboxylato ligands and skew trapezoidal structures are assumed for the synthesized complexes. In vitro anticancer activity of the synthesized diphenyltin(IV) complexes was evaluated against three human: MCF-7 (breast adenocarcinoma), A375 (melanoma), HCT116 (colorectal carcinoma), and three mouse tumor cell lines: 4T1 (breast carcinoma), B16 (melanoma), CT26 (colon carcinoma) using MTT and CV assays. The IC50 values fall in the range from 0.1 to 3.7 μM. Flow cytometric analysis and fluorescent microscopy suggest that complex 1 induces caspase-dependent apoptosis followed with strong blockade of cell division in HCT116 cells. Since complex 1 showed ROS/RNS scavenging potential mentioned cytotoxicity was not connected with oxidative stress. Three new (carboxylato)diphenyltin(IV) complexes with N-functionalized 2-quinolone ligands were synthesized and characterized by IR and NMR spectroscopy. The structure of 2-(4-methyl-2-oxoquinolin-1(2H)-yl)acetic acid (HL2) was solved. In vitro cytotoxicity was evaluated against three human and three mouse cancer cell lines. The modes of action of Ph2SnL12 (1) were investigated. [Display omitted] •Three new bis(carboxylato)diphenyltin(IV) complexes were synthesized and characterized.•Structure of 2-(4-methyl-2-oxoquinolin-1(2H)-yl)acetic acid (HL2) was determined.•Complexes showed high antiproliferative activity.•Ph2SnL12 (1) induced caspase-dependent apoptosis in HTC116 cells.•Ph2SnL12 showed scavenging potential on ROS/RNS production in HTC116 cells.