莲子心中黄酮苷类化合物分离鉴定及其抗氧化活性研究

Isolation and Identification of Flavonoid Glycoside from Lianzixin(Plumula nelumbinis)and Their Antioxidant Activity

研究莲子心(plumula nelumbinis)中黄酮苷类大极性成分及其抗氧化活性。选择80%乙醇进行初步提取分离,得到莲子心粗提物。先后选用D001阳离子交换树脂和AB-8大孔树脂对粗提物进行柱层析得到莲子心总黄酮部分。进一步选择硅胶柱、Sephadex LH-20柱、ODS反向柱、制备型HPLC等对莲子心总黄酮部分进行分离纯化,并利用波谱解析和理化性质对黄酮苷类化合物的结构进行鉴定,最终确定了11个化合物为:异牡荆素(isovitexin,1)、牡荆素(vitexin,2)、异夏佛托苷(isoshaftoside,3)、夏佛托苷(shaftoside,4)、金丝桃苷(hypericin,5)、芦丁(rutin,6)、芹菜素-6(apigenin-6),8-二吡喃葡萄糖苷(8-glucopyranoside,7)、4-羟基苯乙醇-O-β-D-吡喃葡萄糖苷(icariside D2,8)、忍冬苦苷(lonicerin,9)、荭草苷(orientin,10)、异荭草苷(isoorientin,11);并对7种黄酮苷类化合物进行了DPPH自由基清除活性测试。化合物8为首次从莲属植物中分离得到;活性测试结果表明,化合物5、6的抗氧化活性较好,当浓度为120μmol·L-1时,其DPPH自由基清除率达到了和Vc相当的效果。

It is to study the flavonoids glycosides in Lianzixin(Plumula nelumbinis)and its antioxidant activity.Choosing 80%ethanol as a solvent for extraction to obtain crude extraction,macroporous resins(D001 and AB-8)were used to perform column chromatography on the crude extraction to obtain the total flavonoids of Lianzixin(Plumula nelumbinis).Silica gel col⁃umn,Sephadex LH-20 column,ODS column,prep-HPLC and other methods were selected to purify the total flavonoids.The structures of 11 compounds were determined as follows:Isovitexin(1),Vitexin(2),Isoshaftoside(3),Shaftoside(4),Hypericin(5),Rutin(6),Apigenin-6,8-glucopyranoside(7),Icariside D2(8),Lonicerin(9),orientin(10),isoorientin(11).The DP⁃PH free radical scavenging assay of flavonoids were tested on 7 flavonoid glycoside compounds.Compound 8 was obtained from Lianzixin(Plumula nelumbinis)for the first time.The results showed that Compound 5 and 6 had good DPPH radical scavenging ability,and when the concentration was 120μmol·L-1,its DPPH radical scavenging rate was equivalent to that of Vc.