Microwave-Assisted Synthesis of Novel Pyrazole Clubbed Polyhydroquinolines in an Ionic-Liquid and their Biological Perspective

A series of diarylpyrazole clubbed polyhydroquinoline derivatives (6a-j, 7a-j, 8a-j) were synthesized by one pot multicomponent methodology using ionic liquid (Bbpy)(HSO4)(2) as solvent as well as catalyst under microwave irradiation as energy source. The synthesized entities were further screened invitro for their preliminary biocidal potency against group of pathogenic bacterial as well as fungal strains; against M. tuberculosis H(37)Rv strain for antituberculosis activity and against P. falciparum to evaluate antimalarial potency. A number of compounds were found to render antibacterial activity against bacterial strains as compared to standard drugs. Compounds 6b, 6f, 8e and 8j were found to possess higher antibacterial potency as compared to ampicillin as well as comparable to ciprofloxacin and chloramphenicol. The compounds 6e, 6j, 7e, 7j and 8j (MIC: 100 mu g/mL) were found to be highly potent as antifungal candidates against C. albicans as compared to griseofulvin. For antituberculosis activity, compounds 8e, 8h and 8j were found to be potent candidates against M. tuberculosis H(37)Rv strain as compared to rifampicin. Compounds 7a, 7c, 7d, 7f, 7h, 8d and 8i were found to be highly potent as compared to quinine (0.268 mu g/mL) and comparable activity as to chloroquine (0.020 mu g/mL). The cytotoxicity of the synthesized compounds was evaluated against Vero cell proving their non-toxic behavior.