摘要
采用硅胶柱色谱、Sephadex LH-20柱色谱和制备型高效液相色谱法,从八角莲乙醇提取物中分离得到5个双黄酮类化合物.通过波谱数据分析(MS、UV、IR、NMR)与电子圆二色谱(ECD)技术,分别鉴定为(+)-八角莲双黄酮H(1a)、(-)-八角莲双黄酮H(1b)、(+)-八角莲双黄酮Ⅰ(2a)、(-)-八角莲双黄酮Ⅰ(2b)、podoverine F(3),其中,1a与1b、2a与2b为2对新的双黄酮对应异构体.DPPH自由基清除实验结果显示,化合物2、2a、2b对DPPH自由基具有较强的清除能力,IC50值分别为8.87、10.18、11.35 µmol/L,且强于阳性药trolox(14.95 µmol/L).化合物2、2a、2b对DPPH自由基的清除能力分别强于化合物1、1a、1b,进一步的构效关系研究表明,B环上邻二酚羟基是黄酮类化合物具有DPPH自由基清除活性的必需结构基团.
Abstract
Five biflavonoids were isolated and purified from the ethanol extract of Dysosma versipellis by silica gel column chromatography,Sephadex LH-20 column chromatography,and preparative HPLC.Their structures were identified as(+)-dysosmabiflavonoid H(1a),(-)-dysosmabiflavonoid H(1b),(+)-dysosmabiflavonoid Ⅰ(2a),(-)-dysosmabiflavonoid Ⅰ(2b),podoverine F(3)by extensive spectroscopic analysis(MS,UV,IR,NMR)and electronic circular dichroism(ECD)calculations.Compounds 1a and 1b,2a and 2b are two pairs of new biflavonoid enantiomers.Compounds 2,2a,and 2b showed significant DPPH scavenging capacity with IC50 values of 8.87,10.18,11.35 μmol/L,respectively,in comparison with trolox(IC50,14.95 μmol/L).Compounds 2,2a,and 2b displayed more potent DPPH radical scavenging activity than compounds 1,1a,1b,and trolox,respectively.The preliminary structure-activity relationship exhibited that the catechol hy-droxyl group in B ring of flavonoids is essential for DPPH radical scavenging activity.
基金项目
河南中医药大学省属高校基本科研业务专项(2014KYY WF-QN26)
河南中医药大学科技创新人才项目(2016XCXRC01)
河南省中医药科学研究专项(20-21ZY1039)
河南省高等学校科技创新团队支持计划(24IRTSTHN039)
维普
万方数据