Two new triterpenoids from the leaves and stems of Lantana camara

Two new oleanane-type triterpenoids with an epoxy bridge between C-3 and C-25, named lantacamaric acids A and B, were isolated from the leaves and stems of Lantana camara L. (Verbenaceae). In addition, seven known triterpenoids, two known iridoid glycosides, four known phenylethanoid glycosides, one known flavonoid glycoside, and one known cyanogenic glycoside were isolated. Their structures were determined based on the spectroscopic data. Furthermore, the cytotoxic activities of the isolated triterpenoids toward HL-60 cells were examined. The IC50 values of all compounds were obtained and ranged from 1.16 to 68.4 mu M, with three compounds exhibiting stronger activities than the positive control, cisplatin. In addition, the structure-activity relationship was investigated.