title: Cytotoxic Tirucallane and Apotirucallane Triterpenoids from the Stems of Picrasma quassioides.
abstract: Phytochemical investigation on the stems of Picrasma quassioides led to the isolation of a novel compound, picraquassin A (1), with an unprecedented 21,24-cycloapotirucallane skeleton, and four new apotirucallane-type triterpenoids (2-5), together with 15 new tirucallane-type triterpenoids (6-20) and 10 known tirucallane-type triterpenoids (21-30). To our knowledge, this is the first report demonstrating the presence of apotirucallane-type triterpenoids in the genus Picrasma. The structures of the new compounds were determined based on spectroscopic data interpretation. Cytotoxicities of the isolated compounds were evaluated using three human cancer cell lines, MKN-28, A-549, and MCF-7. Compound 2 exhibited the most potent activity against MKN-28 cells with an IC50 value of 2.5 μM. Flow cytometry and Western blot analysis revealed that 2 induces the apoptosis of MKN-28 cells via activating caspase-3/-9, while increasing Bax and Bad and decreasing Bcl-2 expression levels.
authors: Jian
authors: J
authors: Xu
authors: Di
authors: D
authors: Xiao
authors: Qing-Hua
authors: QH
authors: Lin
authors: Jing-Feng
authors: JF
authors: He
authors: Wen-Yuan
authors: WY
authors: Liu
authors: Jiangxi Qingfeng Pharmaceutical Corporation , Ganzhou 341000, People's Republic of China.
authors: Ning
authors: N
authors: Xie
authors: Key Laboratory of Biomedical Functional Materials, China Pharmaceutical University , Nanjing 211198, People's Republic of China.
authors: Feng
authors: F
authors: Feng
authors: Key Laboratory of Biomedical Functional Materials, China Pharmaceutical University , Nanjing 211198, People's Republic of China.
authors: Wei
authors: W
authors: Qu
mesh_terms: D000972:Antineoplastic Agents, Phytogenic / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification / Q000494:pharmacology; D004354:Drug Screening Assays, Antitumor; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D020128:Inhibitory Concentration 50; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D032270:Picrasma / Q000737:chemistry*; D018547:Plant Stems / Q000737:chemistry*; D014315:Triterpenes / Q000737:chemistry / Q000145:classification / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D004365:Drugs, Chinese Herbal; D014315:Triterpenes; C000617675:picraquassin A; C000617676:picraquassin B