二苯乙烯苷特性及DPPH自由基清除活性

Property and activity of DPPH radical scavenging of stilbene glucosides

讨论何首乌中二苯乙烯苷晶体的理化性质及清除DPPH自由基活性.从何首乌中分离结晶得到二苯乙烯苷晶体,并运用液-质(LC-MS)、核磁(NMR)、X-射线衍射、差示扫描量热分析(DSC)、热重分析(TGA)等技术分析晶体性质及稳定性,对照Vc、BHT、白藜芦醇测定了其清除DPPH自由基的活性.试验表明二苯乙烯苷晶体不存在同质多晶现象,仅有一种针状晶体存在形式,且不含结晶水,熔点为151.33℃.且其晶体具有良好的稳定性.其清除自由基活性依次为:Vc IC505.38μg/mL,BHT IC506.20μg/m l,二苯乙烯苷IC508.06μg/mL,白藜芦醇IC509.21μg/mL.从何首乌提取物中可以通过结晶得到单一针状、稳定的二苯乙烯苷晶体,且该晶体具有良好的清除DPPH自由基功能.

The physics property and the activity of DPPH radical scavenging of the stilbene glycoside crystals extracted from Polygonum multiflorum Thunb were studied. The crystals of stilbene glycoside were verified by X-ray diffraction analysis, and the physical property of crystals was determined by DSC and TGA, the chemical stability and the capability of DPPH radical scavenging were also determined using resveratrol, BHT and Vc as control. The results show that there exists no polymorphism with only one acicular crystal of SG. The melting point of SG is 151.33 ℃. The crystal is stable at room temperature. The order of antioxidant activity is Vc IC50of 5.38μg/ml, BHT IC50 of 6.20 μg/ml, stilbene glycosides IC50 of 8.06 μg/ml, and resveratrol IC50 of 9. 21 μg/ml. It is indicated that stilbene glycoside with acieular crystals is stable, and its radical scavenging effect is good.