蒙古黄芪中黄酮类成分抗超氧阴离子活性研究及构效关系分析

 目的研究蒙古黄芪Astragalus membranaceus(Fish.)Bge.var.mongholicus(Bge.)Hsiao]中有效成分对超氧阴离子(O^2-)的清除能力,并探讨黄酮类物质抗氧化能力与结构之间的关系。方法对蒙古黄芪中的黄酮类成分进行分离,通过化学发光法测定这些成分对邻苯三酚-鲁米诺-碳酸缓冲液(pH10.2)体系产生的超氧阴离子的清除能力。结果从蒙古黄芪中分离出12个黄酮类单体,分别为:槲皮素(Ⅰ),异槲皮苷(Ⅱ),芦丁(Ⅲ),山柰酚(Ⅳ)和异鼠李素(Ⅴ),芒柄花素(Ⅵ),芒柄花苷(Ⅶ),毛蕊异黄酮(Ⅷ),(3R)-8,2′-二羟基-7,4′-二甲氧基异黄烷(Ⅸ),2′,4′-二甲氧基-3′-羟基异黄烷-6-O-β-葡萄糖苷(Ⅹ),(6aR,11aR)-10-羟基-3,9-二甲氧基紫檀烷(Ⅺ),(6aR,11aR)9,10-二甲氧基紫檀烷-3-O-β-D-葡萄糖苷(Ⅻ)。结果表明,所有成分在一定浓度范围内(此浓度范围所对应的清除率在10%～90%之间),量效呈对数关系(y=alogx+b)。构效关系结果显示,化合物的分子结构决定其抗氧化活性。结论黄芪中的黄酮类成分具有明显的清除超氧阴离子活性,是黄芪抗氧化作用的主要活性成分,且黄酮类成分的清除超氧阴离子活性与其结构有明显的相关性。

Study on Scavenging Activities for Superoxide Anion Radicals and Structure-Activity Relationship of Flavonoids from Astragalus membranaceus (Fish.) Bge. var. mongholicus (Bge.) Hsiao

OBJECTIVE To study the scavenging activities of the flavonoids for superoxide anion radicals from Astragalus membranaceus(Fish.) Bge.var.mongholicus(Bge.) Hsiao,and to analyze the structure-activity relationship of the compounds.METHODS The flavonoids were isolated from Astragalus membranaceus(Fish.) Bge.var.mongholicus(Bge.) Hsiao,Their antioxidant activities were compared by scavenging the superoxide anion radicals generated by the Pyrogallic acid 3-Amino-Phthalhy-drazid(Luminol)-Na₂CO₃/NaHCO₃ buffer(pH 10.2)system.RESULTS Twelve compounds were isolated from Astragalus membranaceus(Fish.) Bge.var.mongholicus(Bge.) Hsiao,they were quercetin(Ⅰ),isoquercitrin(Ⅱ),rutin(Ⅲ),kaempferol(Ⅳ),isorhamnetin(Ⅴ),formononetin(Ⅵ),formononetin-7-O-β-D-glucoside(Ⅶ),calycosin(Ⅷ),(3R)8,2'-dihydroxy-7,4'-dimethoxyisoflavan(Ⅸ),2',4'-dimethoxy-3'-hydroxy-isoflavan-6-O-β-glucopyranoside(Ⅹ),(6aR,11aR)3,9-dimethoxy-10-hydroxypterocarpan(Ⅺ) and(6aR,11aR)9,10-dimethoxypterocarpan-3-O-β-D-glucoside(Ⅻ).The concentration effect relationships were all logarithmic(y=alogx+b) over the range of 10%~90% of the scavenging activities.The scavenging activities of the flavonoids for superoxide anion were decided by their structures.CONCLUSION The flavonoids from Astragalus membranaceus(Fish.) Bge.var.mongholicus(Bge.) Hsiao have strong scavenging activities of the superoxide anion,and they are the main antioxidants in the herb.