Synthesis and evaluation of anticancer and antiobesity activity of 1-ethoxy carbonyl-3,5-bis (3'-indolyl methylene)-4-pyperidone analogs.

A series of eleven novel bisindole derivatives were synthesized and screened for anticancer and antiobesity potentials in in vitro mode. The reaction of 1-ethoxy carbonyl 4-pyperidone 1a with indole-3-carboxaldehyde 1b in presence of catalytic amount of piperidine gave 2 which was N-alkylated with different benzyl halides in the presence of potassium carbonate to afford compounds 3a-3k in quantitative yields. Among the compounds tested for anticancer activity against different human cancer cell lines, 3f significantly inhibited HepG2 cell line (IC50 7.33 μM) when compared with standard doxorubicin (IC50 10.15 μM). Compounds 3e (IC50 2.75 μM), 3f (IC50 4.21 μM) and 3i (IC50 15.98 μM) showed better activity than the standard curcumin (IC50 23.54 μM) against A549 cell line. Also, among the synthesized compounds, 3g (IC50 14.89 μM), 3c (IC50 56.41 μM) and 3i (IC50 30.88 μM) have potentially inhibited enzyme lipase when compared to standard Orlistat (IC50 62.25 μM). In in silico docking assays, piperidones 3e, 3f, 3i, 3c and 3a showed higher binding affinity towards anti-cancer target of A549 (3e: -11.1, 3f: -10.3, 3c: -11.3, 3i: -11.2 kcal/mol), HepG2 (3f: -10.5 kcal/mol), HeLa (3d: -10.0 kcal/mol) and SKOV3 (3f: -8.4 kcal/mol) cell lines better than standard drug doxorubicin. Docking to lipase protein for compounds 3i, 3g and 3c showed scores of -11.1, -10.7 and -10.5 kcal/mol when compared to that of standard drug Orlistat with -6.9 kcal/mol.
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