Synthesis, structure and in vitro cytostatic activity study of the novel organotin(IV) derivatives of p-aminobenzenesulfonic acid

Abstract

Four new p-aminobenzenesulfonate organotin complexes, [(n-Bu3Sn)(O3SC6H3-NH2-4)]n (1), [(n-Bu2Sn)4(O)2(OH)2(O3SC6H4-NH2-4)2] (2), [(Me2Sn)4(O)2(OH)2(O3SC6H4-NH2-4)2] (3) and [{(n-BuSn)12O14(OH)6}(O3SC6H4-NH2-4)2·3C4H8O2] (4·diox), were synthesized by reaction of p-aminobenzenesulfonic acid with tributyltin oxide, dibutyltin oxide, dimethyltin oxide and monobutyltin oxide, respectively. These complexes were characterized by elemental analysis, FT-IR, NMR (1H, 13C, 119Sn) spectroscopy as well as single-crystal X-ray diffraction. The crystal structure of complex 1 reveals that it is a 1D zig-zag chain structure and further interlinked into a 2D network by intermolecular interaction (N-H⋯O). The structure analysis indicates that complexes 2 and 3 are the ladder-like structure including three alternate Sn2O2 rings, and further result in the formation of a 3D supramolecular architecture for 2 and a 2D supramolecular network for 3 by extensive hydrogen-bonding interactions (O-H⋯O, N-H⋯O). Complex 4 exhibits a dodecanuclear organooxotin cages, which are connected into a hydrogen-bonded 2D structure. Furthermore, complexes 1-4 were evaluated for their in vitro cytostatic activity against the human lung cancer cells (A549) and the human hepatocellular carcinoma cells (HepG-2). The preliminary screen shows that organotin derivatives with increasing number n-butyl group exhibitsignificantly higher cytostatic activity, and much higher than methyl group.