Isolation and structure elucidation of kadlongilactones C-F from Kadsura longipedunculata by NMR spectroscopy and DFT computational methods

  • J Nat Prod. 2007 Nov;70(11):1706-11. doi: 10.1021/np070247a.
Jian-Xin Pu  1 ,  Sheng-Xiong Huang ,  Jie Ren ,  Wei-Lie Xiao ,  Li-Mei Li ,  Rong-Tao Li ,  Liang-Bo Li ,  Tou-Gen Liao ,  Li-Guang Lou ,  Hua-Jie Zhu ,  Han-Dong Sun
Affiliations
  • 1. State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650204, People's Republic of China.
PMID: 17970593 DOI: 10.1021/np070247a
Abstract

Four new triterpenoids, kadlongilactones C-F (2-5), containing a consecutive hexacyclic [7,7,5,6,6,6] ring system, were isolated from the leaves and stems of Kadsura longipedunculata. In comparison with the NMR data of kadlongilactones A (1) and D (3), a significant phenomena was discovered that ring D of 3 inverted from a half-chair in 1 to a half-boat conformation when the HO-16 group changed from alpha- to beta-orientation. The structures of 2-5 were established on the basis of detailed spectroscopic analysis, and DFT computational methods were applied in the structural validation of compounds 3 and 5. Compounds 1-4 showed significant cytotoxicity against A549, HT-29, and K562 cell lines with IC50 values of 0.49-3.61 microM in vitro.