Zhan Zha-Jun, Bian Hong-Ling, Shan Wei-Guang
College of Pharmaceutical Science, Zhejiang University of Technology, Hangzhou 310014, People's Republic of China.
Acta Crystallogr Sect E Struct Rep Online. 2008 Oct 31;64(Pt 11):o2231. doi: 10.1107/S1600536808032959.
THE TITLE COMPOUND [SYSTEMATIC NAME: 11β-hydr-oxy-24,25-ep-oxy-3,16-oxo-protost-13 (17)-en-23-yl acetate], C(32)H(48)O(6), a protostane-type triterpenoid, was isolated from the Chinese herbal medicine alismatis rhizoma (the rhizome of Alisma orientalis Juzep). The mol-ecule contains four trans-fused rings, viz. three six-membered and one five-membered ring. Two of the six-membered rings have slightly distorted half-chair conformations, while the third exhibits a chair conformation. The five-membered ring is almost planar. An inter-molecular O-H⋯O hydrogen bond between the hydr-oxy and ep-oxy groups and intra- and intermolecular C-H⋯O hydrogen bonds are observed.
标题化合物[系统名称：11β-羟基-24,25-环氧-3,16-氧代-原萜-13(17)-烯-23-基乙酸酯]，C(32)H(48)O(6)，一种原萜烷型三萜类化合物，是从中药材泽泻（东方泽泻的根茎）中分离得到的。该分子包含四个反式稠合环，即三个六元环和一个五元环。其中两个六元环具有轻微扭曲的半椅构象，而第三个呈现椅式构象。五元环几乎是平面的。观察到羟基和环氧基之间的分子间O-H⋯O氢键以及分子内和分子间的C-H⋯O氢键。
