Lewis base-catalyzed synthesis of highly functionalized spirooxindole-pyranopyrazoles and their in vitro anticancer studies

Herein, the one-step, multi-component reaction (MCR) of a series of spirooxindole-pyranopyrazole derivatives (5a-g), via a Knoevenagel condensation and Michael addition cascade, under mild and green reaction conditions, is reported. The newly synthesized derivatives were screened for in vitro anti-cancer activity against 60 human cancer cell lines at the National Cancer Institute (NCI), USA. We found that compounds 5c, 5d, and 5g showed good activity against the HOP-92 (lung cancer), UO-31 (renal cancer), KM-12, SW-620 (colon cancer), and HS578T (breast cancer) cell lines. Compound 5c showed 43.19 and 21.18% growth inhibition at 10 mu M for HOP-92 and UO-31 cell lines, respectively, while compound 5g showed 82.02% growth inhibition for the KM12 cell line at the same concentration. Therefore, the compound 5g could be further derivatized as a futuristic lead molecule for colorectal cancer.