Synthesis and molecular modeling studies of indole-based antitumor agents

Indole-based compounds 30-63 were synthesized by the multi-component 1,3-dipolar cycloaddition reaction of 1-alkyl-3,5-bis(arylidene)-4-piperidones 11-25 with azomethine ylides (generated by the condensation of isatins 26-28 with sarcosine 29). The single crystal X-ray studies of 46 and 48 supported the regio- and stereoselectivity of the reaction. Most of the synthesized spiro-indoles exhibited potent antitumor properties against the HeLa (cervical cancer) cell line through in vitro sulfo-rhodamine-B bioassay, higher than that of cisplatin. Only compound 54 showed bio-potency against the HepG2 (hepatocellular cancer) cell line, comparable to that of doxorubicin hydrochloride (standard reference). 3D-Pharmacophore and 2D-QSAR studies were used to validate the observed biological data and determine the most important parameters controlling activity. The estimated bio-properties from the computational studies showed high approximations to the experimental data.