title: Protolimonoids from Melia toosendan.
abstract: Toosendanone A (1), a new euphane (tirucallane)-type triterpene bearing a five-membered ring in the side chain and the first cyclopentanyl protolimonoid, was isolated from the bark of Melia toosendan, along with two new tirucallanes, toosendanic acids A (2) and B (3). The structure and absolute configuration of compound 1 was elucidated by spectroscopic data interpretation and X-ray diffraction analysis. Compounds 1-3 were evaluated for cytotoxicity against a small panel of cancer cell lines.
authors.affiliation: Laboratory of Natural Products, Jiangsu Simcere Pharmaceutical R&D Company, Ltd, 699-18 Xuanwu Road, Xuanwu District, Nanjing 210042, People's Republic of China.
authors.forename: Yi Shu
authors.initials: YS
authors.lastname: Sang
authors.forename: Chun Yan
authors.initials: CY
authors.lastname: Zhou
authors.forename: Ai Jun
authors.initials: AJ
authors.lastname: Lu
authors.forename: Xiao Jin
authors.initials: XJ
authors.lastname: Yin
authors.forename: Zhi Da
authors.initials: ZD
authors.lastname: Min
authors.forename: Ren Xiang
authors.initials: RX
authors.lastname: Tan