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冬凌草甲素是从抗癌中草药冬凌草中提取的一种有效成分。它的乙酰衍生物的晶体结构和分子结构已由X—射线衍射法中直接法解出,R因子被修正到0.067。其晶体属单斜晶系,空问群为P2_1,晶胞参数是:a=8.923(3),b=6.551(2),c=20.102(3),β=99.77(2)°晶胞中含有两个C_(22)H_(30)O_7分子和两个乙醇(溶剂)分子。 晶体结构分析表明,分子中含有部分共轭的α—亚甲基环戊酮的五员环。其内角均分别地远小于各自碳原子SP~2或SP~3杂化所要求的数值,而含有较大的内应力。
Oridonin is an effective component extracted from the anti-cancer herbal medicine Rubescens. The crystal structure and molecular structure of its acetyl derivative have been solved directly by X-ray diffractometry with the R factor corrected to 0.067. The crystal belongs to the monoclinic system, the space group P2_1, unit cell parameters are: a = 8.923 (3), b = 6.551 (2), c = 20.102 (3), β = 99.77 Containing two C_ (22) H_ (30) O_7 molecules and two ethanol (solvent) molecules. Crystal structure analysis showed that the molecule contains a partially conjugated five-membered ring of α-methylenecyclopentanone. Their internal angles are far less than the respective carbon atoms SP ~ 2 or SP ~ 3 hybrid required value, and contains a large internal stress.