Abstract B87: In vitro DNA binding studies of S‐ and R‐enantiomers of organotin complexes: Antitumor activity of S‐enantiomer against human tumor cell lines Free

New organotin modulated antitumor drug candidates 1 and 2 derived from R‐ and S‐ enantiomer of [4‐hydroxy‐1‐phenylethylimino)pent‐2‐ol] and 2‐amino‐2‐phenylethanol, respectively were synthesized by de novo synthetic strategy and thoroughly characterized by analytical and various spectroscopic methods. The complexes (S) / (R)−1 and 2 display trigonal bipyramidal and tetrahedral environment, respectively around the tin center. Preliminary complex‐DNA interaction studies employing UV‐Visible, fluorescence, and viscosity revealed that S‐enantiomer displayed more propensities towards the ultimate drug target double helix DNA. This was quantified by K_b and K_sv values of (S)‐ and (R)‐1 and 2, their ligands L and L′ which demonstrated multifold increase in case of S‐ enantiomer in comparison to their R‐ enantiomeric form. Nevertheless, both isomers displayed higher K_b values than that of cisplatin. This clearly demonstrates the chiral preference of S‐ enatiomer over R‐ enantiomer. Therefore, the in vitro antitumor activity of S‐enantiomer of 1 and 2 was evaluated by the Sulforhodamine‐B (SRB) assays to assess cellular proliferation against five human cell lines viz, Hop62 (human lung), DWD (human oral), K562 (human leukemia), DU145 (human prostrate) and MCF‐7 (human breast). The complex (S)‐1 displayed remarkably pronounced and specific activity for K562 (human leukemia) while complex (S)‐2 exhibited significant activity towards Hop62 (human lung), DWD(Human oral), DU145 (human prostrate) and MCF‐7 (human breast).

Citation Information: Cancer Prev Res 2010;3(1 Suppl):B87.