灵菊七抗氧化成分研究

Antioxidant Constituents of Gynura medica

目的:研究灵菊七中抗氧化活性部位酚类成分。方法:采用系统溶剂萃取,1,1-二苯基苦基苯肼(DPPH)抗氧化模型筛选灵菊七抗氧化活性部位;运用硅胶柱色谱、SephadexLH-20凝胶和RP-ODS柱色谱分离纯化灵菊七抗氧化活性部位酚类化学成分,根据化合物的理化性质和波谱数据并与文献对照鉴定其结构。结果:灵菊七乙酸乙酯萃取物为其抗氧化活性部位,从乙酸乙酯萃取物中分离得到4个酚类化学成分,分别鉴定为山柰酚(1)、紫云英苷(2)、咖啡酸(3)、3,4-二咖啡酰奎宁酸(4)。化合物1～4均为首次从灵菊七中分离得到,化合物3和4为首次从三七草属中分离得到。结论:本研究可对进一步开发利用灵菊七植物资源提供科学依据。

OBJECTIVE： To study the antioxidant constituents phenol extracts of Gynura medica. METHODS： The antioxidant part of G. medica was successively isolated by DPPH antioxidant model using systematic solvent extraction. The chemical constituents of antioxidant fraction were isolated and purified by silica gel, Sephadex LH-20 and RP-ODS column chromatography. Their chemical structures were identified by physicochemical properties and spectral analysis. RESULTS： The ethyl acetate fraction exhibited the strongest antioxidant activity compared with other fractions of G. medica extract. 4 phenolic constituents were isolated and identified as kaempferol （ 1 ）, astragalin （2）, caffeic acid （ 3 ） and 3, 4-dicaffeoylquinicacid. All of the phenolic constituents were isolated from this plant for the first time and compounds 3 and 4 were isolated from the genus of Gynura for the first time. CONCLUSION： The results provide the scientific basis for further exploitation of G. medica plant.