The Synthesis and Biological Activity of Organotin Complexes with Thio-Schiff Bases Bearing Phenol Fragments.

A number of novel di- and triorganotin(IV) complexes 1 - 5 (Ph 2 SnL 1 , Ph 2 SnL 2 , Et 2 SnL 2 , Ph 3 SnL 3 , Ph 3 SnL 4 ) with mono- or dianionic forms of thio-Schiff bases containing antioxidant sterically hindered phenol or catechol fragments were synthesized. Compounds 1 - 5 were characterized by 1 H, 13 C NMR, IR spectroscopy, and elemental analysis. The molecular structures of complexes 1 and 2 in the crystal state were established by single-crystal X-ray analysis. The antioxidant activity of new complexes as radical scavengers was estimated in DPPH and ABTS assays. It was found that compounds 4 and 5 with free phenol or catechol fragments are more active in these tests than complexes 1 - 3 with tridentate O,N,S-coordinated ligands. The effect of compounds 1 - 5 on the promoted oxidative damage of the DNA by 2,2'-azobis(2-amidinopropane) dihydrochloride and in the process of rat liver (Wistar) homogenate lipid peroxidation in vitro was determined. Complexes 4 and 5 were characterized by more pronounced antioxidant activity in the reaction of lipid peroxidation in vitro than compounds 1 - 3 . The antiproliferative activity of compounds 1 - 5 was investigated against MCF-7, HTC-116, and A-549 cell lines by an MTT test. The values of IC 50 are significantly affected by the presence of free antioxidant fragments and the coordination site for binding.