目的 研究钩藤Uncaria rhynchophylla叶的化学成分及抗氧化活性。方法 采用多种色谱技术对其进行分离纯化，应用¹H-NMR、¹³C-NMR、MS、HR-MS等波谱学方法进行结构鉴定；利用DPPH法进行抗氧化活性测定。结果 从钩藤叶95%乙醇提取物中分离得到17个化合物，分别鉴定为18，19-hydroxyvincosamide（1）、α-生育酚（2）、α-tocospiro A（3）、二氢猕猴桃内酯（4）、乌苏酸内酯（5）、3，4-dehydrotheaspirone（6）、chakyunglupulin A（7）、乌苏酸（8）、原儿茶酸（9）、槲皮素（10）、表儿茶素（11）、绿原酸乙酯（12）、槲皮素-3-O-洋槐糖苷（13）、芦丁（14）、咖啡酸甲酯（15）、strictosamide（16）、vincosamide（17）；其中化合物10、11、13～15抗氧化活性IC₅₀值分别为7.52、8.21、8.14、2.13、5.35 μmol/L，优于阳性药维生素E（IC₅₀值为9.53 μmol/L）。结论 化合物1为新化合物，命名为喜果苷A；化合物2～7、9、12、13、15为首次从该属植物中分离得到；并且化合物10、11、13～15抗氧化活性良好。

Objective To study the chemical constituents from the leaves of Uncaria rhynchophylla and their antioxidant activities. Methods The compounds were isolated by various column chromatography. Their structures were identified by spectroscopic methods including ¹H-NMR, ¹³C-NMR, MS, HR-MS, etc. The antioxidant activities were evaluated by DPPH radical scavenging assay. Results Seventeen compounds were isolated from the leaves of U. rhynchophylla, and identified as 18,19-hydroxy- vincosamide (1), α-tocopherol (2), α-tocospiro A (3), dihydroactinidiolide (4), ursolic acid lactone (5), 3,4-dehydrotheaspirone (6), chakyunglupulin A (7), ursolic acid (8), protocatechuic acid (9), quercetin (10), epicatechin (11), chlorogenic acid ethyl ester (12), quercetin-3-O-robinobioside (13), rutin (14), methyl caffeate (15), strictosamide (16), and vincosamide (17). The anti-oxidative IC₅₀ values of compounds 10, 11, and 13—15 were 7.52, 8.21, 8.14, 2.13, and 5.35 μmol/L, respectively, which were better than the positive control Vit E (IC₅₀ value was 9.53 μmol/L). Conclusion Compound 1 is a new compound named as vincosamide A, and compounds 2—7, 9, 12, 13, and 15 are isolated from genus Uncaria Schreber nom. cons. for the first time. Moreover, compounds 10, 11, and 13—15 have the certain prospects in the development of natural anti-oxidative agents.

国家“重大新药创制”科技重大专项（2014ZX09304307-001）；中国中医科学院自主选题研究项目（ZXKT15032）