Design and microwave-assisted synthesis of tri- and dialkyltin(IV) hippurates, characterization, in vitro anti-cancer and in vivo anti-inflammatory activities

Microwave-assisted reactions of triorganotin(IV)/diorganotin(IV) chlorides/oxides with hippuric acid (HHA), in 1:1 or 1:2 molar ratio resulted R3Sn(HA) (R = Ph (1b), n-Bu (2b), and Me (3b))/R2Sn(HA)2 (R = n-Oct (4b),n-Bu (5b), and Me (6b)); (HA = anion of hippuric acid). However, all complexes (1a–6a) were also synthesized under conventional thermal conditions for comparison. IR, ESI–MS, and NMR (1H, 13C and 119Sn) spectroscopic studies revealed that R3Sn(HA) (1–3) and R2Sn(HA)2 (4, 5) exhibit trigonal–bipyramidal and tetrahedral geometry, respectively (except dimethyltin(IV) hippurate (6) exhibiting octahedral geometry). All complexes (1b–6b) have been screened in vitro against five cancer cell lines of human origin, viz. MCF-7 (mammary cancer), HEK-293 (kidney cancer), PC-3 (prostate cancer), HCT-15 (colon cancer), and HepG-2 (liver cancer). Compounds 1b and 3b exhibited good anti-cancer activity against MCF-7, HEK-293, and PC-3 cell lines, while 6b showed better activity against PC-3 and HepG-2 cell lines. Toxicity and in vivo anti-inflammatory activity of all (1b–6b) complexes in Swiss albino mice have also been carried out. Compound 1b exhibited the highest anti-inflammatory activity among the studied complexes.