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.