Synthesis of piperine–amino acid ester conjugates and study of their cytotoxic activities against human cancer cell lines

Abstract

A series of piperine–amino acid ester conjugates (4a–4r) were synthesized under mild conditions and screened for their cytotoxic activities against a panel of human cancer cell lines (IMR-32, MCF-7, PC-3, DU-145, Colo-205, and Hep-2). The parent compound piperine lacked significant activity but the analogues were effective to in all tested human cancer cell lines. The introduction of d- and l-amino acid side chain to piperine through peptide linkage significantly increased cytotoxic activity. Among the tested conjugates, 4p showed significant cytotoxic activity against DU-145 cell lines with IC50 of 21 μM. The synthetic protocol is suitable for generating piperine derivatives with various structural motifs for exploring the desired activity. A series of piperine–amino acid ester conjugates (4a–4r) were synthesized under mild conditions and screened for their cytotoxic activities against a panel of human cancer cell lines (IMR-32, MCF-7, PC-3, DU-145, Colo-205, and Hep-2).