Bioactive Pentacyclic Triterpenoids from the Leaves of Cleistocalyx operculatus

  • J Nat Prod. 2016 Nov 23;79(11):2912-2923. doi: 10.1021/acs.jnatprod.6b00715.
Chen Wang  1  2 ,  Ping Wu  1 ,  Shuai Tian  1 ,  Jinghua Xue  1 ,  Liangxiong Xu  1 ,  Hanxiang Li  1 ,  Xiaoyi Wei  1
Affiliations
  • 1. Key Laboratory of Plant Resources Conservation and Sustainable Utilization and Guangdong Provincial Key Laboratory of Applied Botany, South China Botanical Garden, Chinese Academy of Sciences , Xingke Road 723, Tianhe District, Guangzhou 510650, People's Republic of China.
  • 2. University of Chinese Academy of Sciences , Yuquanlu 19A, Beijing 100049, People's Republic of China.
PMID: 27797185 DOI: 10.1021/acs.jnatprod.6b00715
Abstract

Thirteen new Pentacyclic Triterpenoids, cleistocalyxic acids A-K (1, 2, 4, 5, and 7-13) and cleistocalyxolides A (3) and B (6), and 15 known analogues (14-28), based on taraxastane, oleanane, ursane, multiflorane, and lupane skeletons, were isolated from the leaves of Cleistocalyx operculatus. The structures of 1-13 were elucidated by analysis of their spectroscopic data and ECD/TDDFT computations. Cleistocalyxolide A (3), presumed to be derived from the known taraxastane-type compound 14, has a rare rearranged triterpenoid backbone. Cleistocalyxic acid B (2) displayed cytotoxicity against HepG2, NCI-N87, and MCF-7 Cancer cell lines with IC50 values ranging from 3.2 to 6.5 μM, and cleistocalyxic acid D (5) was active against HepG2 and NCI-N87 cells with values around 5.0 μM. The noncytotoxic cleistocalyxic acid E (7) inhibited production of IL-6 by 68.1% and TNF-α by 53.7% in LPS-induced RAW 264.7 macrophages at a concentration of 2 μM.