Catechin-Bound Ceanothane-Type Triterpenoid Derivatives from the Roots of Zizyphus jujuba.

Three unprecedented ceanothane-type triterpenoids, ent-epicatechinoceanothic acid A (1), ent-epicatechinoceanothic acid B (2), and epicatechino-3-deoxyceanothetric acid A (3), containing C-C bond linkages with catechin moieties, were isolated from the roots of Zizyphus jujuba. Their chemical structures, including absolute configurations, were established by spectroscopic analysis and calculation of their ECD spectra. A possible biogenetic pathway for C-C bond formation between the catechin and the triterpenoid moieties is presented. Compound 1 was evaluated for its antiproliferative activity on HSC-T6 hepatic stellate cells.