Activity-guided isolation of constituents of Cerbera manghas with antiproliferative and antiestrogenic activities

Two new cardenolides, (−)-14-hydroxy-3β-(3-O-methyl-6-deoxy-α- -rhamnosyl)-11α,12α-epoxy-(5β,14β,17βH)-card-20(22)-enolide (1), (−)-14-hydroxy-3β-(3-O-methyl-6-deoxy-α- -glucopyranosyl)-11α,12α-epoxy-(5β,14β,17βH)-card-20(22)-enolide (2), and a known cardenolide, (−)-17β-neriifolin ( 3), were isolated from the roots of Cerbera manghas as antiproliferative and antiestrogenic principles when evaluated against a human colon cancer cell line (Col2) and the Ishikawa cell line, respectively. Two known lignans, (−)-olivil (4) and (−)-cycloolivil (5), were also isolated but were inactive in the assay systems used.