title: Lactam Triterpenoids from the Bark of Toona sinensis.
abstract: Three new limonoid-type triterpenoids, namely toonasins A-C (1-3) with a rare lactam E ring, along with six known compounds (4-9) were isolated from the barks of Toona sinensis. The structures of new compounds were elucidated by interpretation of spectroscopic data, and the relative configuration of compound 1 was further characterized by X-ray crystallographic analyses. The isolated compounds were evaluated for their cytotoxic activities against five human tumor cell lines (HL-60, SMMC-7721, A-549, MCF-7 and SW480), and compounds 3 and 5 showed weak cytotoxicities.
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China.|University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
authors.forename: Qian-Qian
authors.initials: QQ
authors.lastname: Meng
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China.|Yunnan University of Traditional Chinese Medicine, Kunming, 650500, People's Republic of China.
authors.forename: Xing-Rong
authors.initials: XR
authors.lastname: Peng
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China.|University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
authors.forename: Shuang-Yang
authors.initials: SY
authors.lastname: Lu
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China.|Yunnan University of Traditional Chinese Medicine, Kunming, 650500, People's Republic of China.
authors.forename: Luo-Sheng
authors.initials: LS
authors.lastname: Wan
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China.|University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
authors.forename: Xia
authors.initials: X
authors.lastname: Wang
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China.|University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
authors.forename: Jin-Run
authors.initials: JR
authors.lastname: Dong
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China.|University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.
authors.forename: Rui
authors.initials: R
authors.lastname: Chu
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China.|Yunnan University of Traditional Chinese Medicine, Kunming, 650500, People's Republic of China.
authors.forename: Lin
authors.initials: L
authors.lastname: Zhou
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China.|Yunnan University of Traditional Chinese Medicine, Kunming, 650500, People's Republic of China.
authors.forename: Xiao-Nian
authors.initials: XN
authors.lastname: Li
authors.affiliation: State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming, 650201, People's Republic of China. mhchiu@mail.kib.ac.cn.|University of the Chinese Academy of Sciences, Beijing, 100049, People's Republic of China. mhchiu@mail.kib.ac.cn.|Yunnan University of Traditional Chinese Medicine, Kunming, 650500, People's Republic of China. mhchiu@mail.kib.ac.cn.
authors.forename: Ming-Hua
authors.initials: MH
authors.lastname: Qiu
keywords: Cytotoxicity; Lactam triterpenoids; Limonoids; Toona sinensis