Machocho Alex K, Kiprono Paul C, Grinberg Sarina, Bittner Shmuel
Department of Chemistry, Kenyatta University, PO Box 43844, Nairobi, Kenya.
Phytochemistry. 2003 Feb;62(4):573-7. doi: 10.1016/s0031-9422(02)00619-2.
Five oleanane-type pentacyclic triterpenoids were isolated by chromatographic separation of a chloroform extract of the stem bark of Embelia schimperi. Three of these compounds have a methyleneoxy bridge. Two compounds, embelinone and schimperinone, are reported here for the first time from a natural source (they have been synthesized previously during chemical transformations). Their structures were determined by spectroscopic techniques, among which 2-D NMR was useful for complete characterization. Three of the triterpenoids exhibited mild antibacterial properties against the gram-positive bacterial strain Rhodococcus sp.
通过对希氏酸藤子茎皮氯仿提取物进行色谱分离，分离出了五种齐墩果烷型五环三萜。其中三种化合物具有亚甲氧基桥。两种化合物，即紫金牛醌和希氏醌，首次从天然来源报道（它们先前在化学转化过程中已被合成）。它们的结构通过光谱技术确定，其中二维核磁共振对完整表征很有用。三种三萜对革兰氏阳性细菌菌株红球菌表现出轻微的抗菌特性。
