枇杷叶中三萜酸类成分及其抗炎、镇咳活性研究

 目的 对常用中药枇杷叶［Eriobotrya japonica(Thunb.) Lindl.］ 的化学和药效学进行研究，寻找与其功能主治相吻合的有效成分。方法 利用溶剂提取、萃取、柱色谱和化学衍生化方法进行分离，根据化合物的光谱数据(IR,MS,1H-NMR,13C-NMR)和理化性质鉴定其结构；根据其功能主治设计抗炎、镇咳药效学模型，对其萃取部位和所得单体成分进行抗炎、镇咳活性研究。结果枇杷叶乙醇提取物的醋酸乙酯和正丁醇萃取物对二甲苯引起的小鼠耳肿胀有明显抑制作用，对枸橼酸喷雾引起的豚鼠咳嗽有明显的止咳作用。从正丁醇萃取物中分离得到6个三萜酸类化合物，分别鉴定为齐墩果酸(oleanolic acid,Ⅰ)，2α-羟基齐墩果酸(maslinic acid,Ⅱ)，乌苏酸(ursolic acid,Ⅲ)，2α-羟基乌苏酸(2α-hydroxyursolic acid,Ⅳ)，坡模酸(pomolic acid,Ⅴ)和蔷薇酸(euscaphic acid,Ⅵ)，其中坡模酸系首次从该植物中分离得到。乌苏酸、2α-羟基齐墩果酸和总三萜酸对二甲苯引起的小鼠耳肿胀显示很强的抗炎活性；乌苏酸和总三萜酸还对枸橼酸喷雾引起的豚鼠咳嗽有止咳作用。结论枇杷叶中的三萜酸类成分是与其功能主治相吻合的活性成分，其中含量较高的乌苏酸可作为评价枇杷叶药材质量的指标性成分。

Studies on constituents of triterpene acids from Eriobotrya japonica and their anti-inflammatory and antitussive effects

OBJECTIVE To investigate the effective chemical constituents of traditional Chinese medicine Eriobotrya japonica. METHODS The plant material was extracted with ethanol,the extract was suspended in water,partitioned successively with petroleum ether,EtOAc,and n BuOH.The compounds were isolated by various column chromatography and identified by their spectral data (IR,MS,1H-NMR,13C-NMR) and physicochemical properties respectively.According to the clinical efficacy of E.japonica,both anti inflammatory and antitussive models were established for pharmacological evaluation of its fractionated extracts and constituents isolated. RESULTS The EtOAc and n-BuOH soluble fractions were found to show an anti inflammatory effect on xylene induced edema in mice as well as an antitussive effect on citric acid induced cough on guinea pigs.Phytochemical investigation of the effective n-BuOH soluble fraction resulted in isolation of six triterpene acids,identified as oleanolic acid (Ⅰ),maslinic acid (Ⅱ),ursolic acid (Ⅲ),2α-hydroxyursolic acid (Ⅳ).Pomolic acid (Ⅴ),and euscaphic acid (Ⅵ) respectively.Pomolic acid was isolated from this plant for the first time.Ursolic acid,maslinic acid,and the total triterpene acids exhibited strong anti inflammatory activity.Further more,Ursolic acid and the total triterpene acids also displayed antitussive activity. CONCLUSION Triterpene acid components appeared to be responsible for the pharmacological activity and clinical efficacy of E.japonica.Ursolic acid,which has a large amount,could be suitable as a significant constituent for quality control of E.japonica.