Triterpenoids From The Bark Of Ailanthus Altissima And Their Bioactivities

The bark of Ailanthus altissima (Miller) Swingle (family Simaroubaceae), called ’chu-bai-pi’in Mandarin, has been used for centuries as an astringent traditional Chinese medicine for treatment of diarrhea and bleeding. By focusing one of our research efforts on the discovery of bioactive terpenoids from plants, the terpenoids from’chu-bai-pi’were therefore reinvestigated. The isolation and structure elucidation of the new compounds and their cytotoxicities were reported in this thesis.Six new (1-6) and sixteen known (7-22) compounds were isolated by column chromatography (CC) over silica gel. RP-silica gel, MCI gel, Sephadex LH-20, and semi-preparative HPLC. The structures of the new compounds were established by spectroscopic methods (especially1D,2D-NMR, IR, UV, CD spectra and LR/HR-MS) and chemical transformations.In this study, seven tirucallane-type (1,2.7-11) and seven dammarane-type (3,12-17) triterpenoids together with two triterpene dimers (4,5) were identified. In addition, three terpenylated coumarins (6,18.19), one quassinoid (20), and two steroids (21,22) were also encountered. Altissimanin A (1) is a tirucallane-type triterpenoid bearing an uncommon oxetane ring in the side chain, while altissimanins D (4) and E (5) are two unprecedented dimers each consisting of one tirucallane-type and one dammarane-type triterpenoid moiety.All the isolates (except for21,22) were evaluated for their cytotoxic effects against a small panel of human cancer cell lines. Compound8and9were found to exhibit considerable cytotoxicities against the BGC-823, KE-97, KB, Huh-7and jurkat cancer cell lines.