Antiproliferative constituents in plants 9. Aerial parts of Lippia dulcis and Lippia canescens.

The antiproliferative constituents in the MeOH extracts of the aerial parts of Lippia dulcis Trev. and Lippia canescens Kunth (Verbenaceae) were investigated. Activity-guided chemical investigation of the MeOH extracts resulted in the isolation of the three bisabolane-type sesquiterpenes [(+)-hernandulcin (1), (-)-epihernandulcin (2), and (+)-anymol (3)] and four phenylethanoid glycosides [acteoside (4), isoacteoside (5), martynoside (6), and a new diacetylmartynoside (7)] from the former, and four phenylethanoid glycosides [acteoside (4), isoacteoside (5), arenarioside (8), and leucosceptoside A (9)] and three flavones [desmethoxycentaureidin (10), eupafolin (11), and 6-hydroxyluteolin (12)] from the latter. Antiproliferative activity of the isolated compounds against murine melanoma (B16F10), human gastric adenocarcinoma (MK-1), and human uterine carcinoma (HeLa) cells was estimated. (+)-Anymol (3), acteoside (4), isoacteoside (5), arenarioside (8), eupafolin (11), and 6-hydroxyluteolin (12) had GI50 values of 10-16 microM against B16F10 cell. Desmethoxycentaureidin (10) and eupafolin (11) showed high inhibitory activity against HeLa cell growth (GI50 9 microM, and 6 microM, respectively).