Abstrait

Isolation, characterization and crystal structure of natural â-sitosterol from the shell of Celastrus orbiculatus thunb

Chuan-JinWang, Guang-Jun Zhu

The title compound, â-sitosterol is a phytosterol which was first isolated from the acetyl acetate fraction of Celastrus Orbiculatus Theunb shell and characterized by 1H-NMR and 13C-NMR. Besides, the crystal of the compound was acquired, and the relative configuration of â-sitosterol was determined by single-crystal X-ray diffraction analysis. It crystallizes in monoclinic system, space group P21, a=10.311(2), b=7.6050(15), c=35.257(7)Å, á=90°, â=94.66°, ã=90°, Z=4, C29H50O, Mr=414.0, Dc=1.043g/cm3, V=2755.5(10)Å3, ì(MoKa)=0.063mm-1, F(000)=968, the final R=0.0760 and wR=0.1894 for 5442 independent reflections (Rint=0.0988) and 2525 observed ones (I>2ó(I)). The bond lengths, bond angles, partial values of torsional angles are also given. Intramolecuar van der waals force contribute to the stability of the structure.