Abstrakt

Isolation and crystal structure of 11á-hydroxy-â-amyrin from the shell of Celastrus orbiculatus

Chuan-JinWang, Guang-Jun Zhu, Bai-Hui Shi

ABSTRACT KEYWORDS The title compound, 11á-hydroxy-â-amyrin is a pentacyclic triterpenes which was first isolated from the acetyl acetate fraction of Celastrus Orbiculatus shell and characterized by 1H-NMR and 13C-NMR. Besides, the crystal of the compound was acquired, and the relative configuration of 11á-hydroxy-â-amyrin was determined by single-crystal X-ray diffraction analysis. It crystallizes in orthorhombic system, space group P212121, a=13.280(3),b=32.096(6), c=6.7260(13)Å, á=90°, â=90°, ã=90°, Z=4,C30H50O2, Mr=442.73, Dc=1.100g/cm3, V=2866.9(10)Å3, ì(MoKa)=0.068mm|1, F(000)=1056, the final R=0.0696 and wR=0.1745 for 5242 independent reflections(Rint=0.0825) and 2793 observed ones (I>2ó(I)). The bond lengths, bond angles, partial values of torsional angles, atomic coordinates and isotropic equivalent displacement parameters of the molecule are also given. Intramolecuar van der waals force contribute to the stability of the structure.