Efficient Synthesis of Aurone Mannich Bases and Evaluation of their Antineoplastic Activity in PC-3 Prostate Cancer Cells.

An efficient method for regioselective synthesis of C-7 Mannich bases of 6-hydroxyaurones was accomplished by the -dialkylaminomethylation using aminals prepared from dimethylamine, dipropylamine, bis(2-methoxyethyl)amine, -methylbutylamine, -methylbenzylamine, morpholine, piperidine, and 1-methylpiperazine. Further transformation of 7-(-dialkylamino)methyl group in these aurones led to formation of C-7 acetoxymethyl and methoxymethyl derivatives of 6-hydroxyaurones, some of which showed promising inhibition of PC-3 prostate cancer cell proliferation in the high nanomolar to low micromolar range that exceeded that of cisplatin.