Microwave-assisted Synthesis of Polymethoxychalcone Mannich Bases and Their Antiproliferative Activity

A series of eight polymethoxychalcone Mannich base derivatives 2a-2h was synthesized via the microwave-assisted Mannich reaction of natural product 2'-hydroxy-3,4,4',5,6'-pentamethoxychalcone (1) with various secondary amines and formaldehyde. Compared to conventional heating method (80°C), the microwave-assisted method (700W, 65°C) is efficient with short reaction time (0.5-1 h) and good yields (74-88%). The antiproliferative activities of eight Mannich base derivatives were evaluated in vitro on a panel of three human cancer cell lines (Hela, HCC1954 and SK-OV-3) by CCK-8 assay. The results showed that all of the Mannich base derivatives exhibited potential antiproliferative activities on tested cancer cell lines with the IC50 values of 9.13-48.51 μM. Some active compounds exhibited more activity as compared to positive control cis-Platin. Among them, compound 2b revealed to have the strongest antiproliferative activity against all the three cancer cell lines with IC50 values ranging from 9.13 to 11.24 μM.