Two new triterpene caffeates have been isolated from the root bark of Hibis
cus syriacus. Their structures were established through various spectral st
udies as 3 beta,23,28-trihydroxy-12-oleanene 23-caffeate (1) and 3 beta,23,
28-trihydroxy-12-oleanene 3 beta-caffeate (2). Compounds 1 and 2 showed lip
id peroxidation inhibitory activity and significant cytotoxicity against a
panel of human cancer cell lines.