An ultrasound assisted green protocol for the synthesis of quinoxaline based bisspirooxindoles: Crystal structure analysis, enone umpolung, DFT calculations, anti-cancer activity, and molecular docking studies.

A series of novel quinoxaline based bisspirooxindolo-pyrrolizidines were synthesized through 1,3-dipolar cycloaddition under ultrasonication with shorter reaction time and good yields. The compounds were well characterized by various spectroscopic methods and finally single crystal X-ray diffraction method (4c, 4d). DFT energy calculations confirm the regioselectivity due to enone umpolung effect. The in vitro anti-cancer activity of the synthesized compounds (4a–s) shows that the compounds 4g and 4q exhibited good anti-cancer activity with IC₅₀ values14.51 ± 1.1 and 11.36 ± 0.23 µM against DU-145 prostate cancer cell line; and 16.78 ± 0.95 and 14.28 ± 0.64 µM against Hela cervical cancer cell lines when compared to the standard anti-cancer drug doxorubicin (1.75 ± 0.06 and 1.35 ± 0.09 µM). In silico molecular docking studies indicated that the synthesized compounds may serve as a potential lead for the further development of novel anti-cancer agents. [ABSTRACT FROM AUTHOR]