Chemical constituents of Mallotus macrostachyus growing in Vietnam and cytotoxic activity of some cycloartane derivatives

► Two new cycloartanes macrostachyosides A (1) and B (2) were isolated and elucidated from Mallotus macrostachyus. ► Compounds 1 and 2 showed significant cytotoxicity on KB and LU-1 human cancer cell lines. ► This is the first report of cycloartanes from Mallotus species.