Synthesis, structural characterization and in vitro antiproliferative effects of novel organotin( iv ) compounds with nicotinate and isonicotinate moieties on carcinoma cells

In recent decades, organotin( iv ) chemistry has seen a rapid growth owing to the biological, pharmaceutical and medicinal applications found for different compounds. The aim of this study was the evaluation of the antiproliferative activity of several organotin( iv ) compounds for a better understanding of the structure–activity relationship (SAR). The synthesis and structural features of the new organotin( iv ) species are also presented. Thus, the treatment of [2-{(CH 2 O) 2 CH}C 6 H 4 ]Me 2 SnCl ( 1 ) and [2-(OCH)C 6 H 4 ]Me 2 SnCl ( 2 ) with potassium salts of isonicotinic and nicotinic acids resulted in the isolation of [2-{(CH 2 O) 2 CH}C 6 H 4 ]Me 2 Sn[O(O)CC 5 H 4 N-4] ( 3 ), [2-{(CH 2 O) 2 CH}C 6 H 4 ]Me 2 Sn[O(O)CC 5 H 4 N-3] ( 4 ), [2-(OCH)C 6 H 4 ]Me 2 Sn[O(O)CC 5 H 4 N-4] ( 5 ) and [2-(OCH)C 6 H 4 ]Me 2 Sn[O(O)CC 5 H 4 N-3] ( 6 ), respectively, in high yields. The one pot reaction between compound 2 , isonicotinic acid and sodium hydroxide allows the formation of [2-(EtOOC)C 6 H 4 ]Me 2 Sn[O(O)(CC 5 H 4 N-4)] ( 7 ) in a moderate yield. The novel compounds were characterized by multinuclear NMR spectroscopy, mass spectrometry and IR spectroscopy. The molecular structures of compounds 3 – 5 and 7 were established via single crystal X-ray diffraction; in all cases a distorted trigonal bipyramidal coordination geometry was found around the metal center, as a result of the strong intramolecular O→Sn coordination. Compounds 1–6 were investigated for their in vitro antiproliferative activity towards the mouse colon carcinoma C26 cell line with the preliminary results showing a better activity than that of 5-fluorouracil.