毛药忍冬花蕾抗氧化活性部位化学成分研究

毛药忍冬(Lonicera serreana)为忍冬属(Lonicera)植物,其花和果实入药,具有清热解毒、凉散风热之功效,但至今缺乏系统化学成分及药理活性研究。为了寻找毛药忍冬中天然抗氧化活性成分,进一步开发利用忍冬属药用植物资源,该研究以DPPH自由基清除法为活性指导,首次对毛药忍冬干燥花蕾75%乙醇提取物的不同极性萃取部位进行抗氧化活性测试,结果发现乙酸乙酯萃取物表现出最强的抗氧化活性(平均清除率为89.45%)。进一步应用现代色谱手段(硅胶柱色谱、Sephadex LH-20凝胶柱色谱等),从毛药忍冬花蕾的乙酸乙酯萃取物中分离单体化合物,运用现代光谱分析技术(MS、1 H-NMR、13 C-NMR、COSY、HSQC、HMBC、ROESY),并结合文献数据鉴定化合物的化学结构。结果表明:从毛药忍冬干燥花蕾75%乙醇提取物中共分离得到9个化合物,分别鉴定为4个酚酸类化合物:绿原酸(1)、绿原酸甲酯(2)、绿原酸乙酯(3)、咖啡酸(4);4个黄酮类化合物:木犀草素(5)、木犀草素-7-O-β-D-葡萄糖苷(6)、槲皮素(7)、槲皮素-3-O-β-D-葡萄糖苷(8);1个甾醇类化合物:β-谷甾醇(9)。所有化合物均为从毛药忍冬花蕾中首次分离得到。研究结果可为抗氧化类相关产品的开发提供科学依据。

Chemical constituents with antioxidative activity from the flower buds of Lonicera serreana

Lonicera serreana is the endemic species in China from the genus Lonicera. The flowers and fruits of L. serreana were commonly used in the traditional Chinese medicine for the treatment of various diseases, but there was no study on the chemical constituents of L. serreana. To study the chemical constituents with antioxidative activity from the flower buds of L. serreana, DPPH radical scavenging assay was used for screening the active fractions of 75% ethanol extract. The highest antioxidant activity(89.45%)was observed in the ethyl acetate layer of the extract. Further chemical investigation led to the isolation of nine compounds by modern chromatographic method(chromatography on silica gel and Sephadex LH-20 columns). Their structures were elucidated by modern spectrum analysis(MS, ¹H-NMR, ¹³C-NMR, COSY, HSQC, HMBC, ROESY). As a result, four chlorogenic acids, four flavonoids and one sterol compound were identified from the ethyl acetate layer of the extract. All of these compounds were isolated from the flower buds of L. serreana for the first time. The chemical constituent of the flower buds of L. serreana was deeply studied under the active guidance of DPPH radical scavenging assay, therefore this study would accumulate the fundamental data for antioxidant related products development.