Longipedlactones A–I, nine novel triterpene dilactones possessing a unique skeleton from Kadsura longipedunculata》.pdfVIP

Tetrahedron 62 (2006) 6073–6081 Longipedlactones A–I, nine novel triterpene dilactones possessing a unique skeleton from Kadsura longipedunculata Jian-Xin Pu,a Rong-Tao Li,a Wei-Lie Xiao,a Ning-Bo Gong,b Sheng-Xiong Huang,a Yang Lu,b Qi-Tai Zheng,b Li-Guang Louc and Han-Dong Suna,* aState Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, Yunnan, PR China bInstitute of Materia Medica, Chinese Academy of Medical Sciences and Peking union Medical College, Peking 100050, PR China cShanghai Institute of Materia Medica, Shanghai Institutes for Biological Science, Chinese Academy of Sciences, Shanghai 200032, PR China Received 5 February 2006; revised 29 March 2006; accepted 31 March 2006 Available online 2 May 2006 Abstract—Nine novel triterpene dilactones with an unprecedented rearranged pentacyclic skeleton, longipedlactones A–I (1–9), have been isolated from the leaves and stems of Kadsura longipedunculata Finet et Gagnep (Schisandraceae). Their structures were determined on the basis of comprehensive spectroscopic analysis and single-crystal X-ray structure determination. A biogenetic pathway for longipedlactone A (1) was also proposed. Compounds 1–3, 6, and 8 showed significant cytotoxicity against A549, with HT-29 and K562 cell lines having IC50 values of 0.84–11.38 mM in vitro. 2006 Elsevier Ltd. All rights reserved. 1. Introduction stems of K. longipedunculata.13 In the continuous search for