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.