黄花倒水莲花中黄酮苷类成分的分离、鉴定及抗氧化活性研究

Isolation, identification and antioxidant activity of the flavonoid glycosides from Polygala fallax flower

关键词:  黄花倒水莲, 化学成分, 黄酮苷, 结构鉴定, 抗氧化活性

Key words:  Polygala fallax, chemical constituents, flavonoid glycosides, structure identification, antioxidant activity

摘要:

该研究采用硅胶、Sephadex LH-20柱色谱和HPLC进行分离纯化,并结合1D-NMR波谱数据和文献比对,研究了黄花倒水莲花中黄酮类成分及抗氧化活性。结果表明:(1)从黄花倒水莲花95%乙醇提取物的乙酸乙酯部位中分离鉴定出6个黄酮苷类化合物,即紫云英苷(1)、槲皮素-3-O-β-D-葡萄糖苷(2)、槲皮素-3-O-β-吡喃木糖苷(3)、槲皮素-3-O-α-L-吡喃阿拉伯糖苷(4)、异鼠李素-3-O-β-葡萄糖苷(5)、芦丁(6),其中化合物1-6均为首次从该植物中分离得到。(2)分别采用DPPH·自由基清除法及FRAP法对花的不同极性部位和所获得化合物进行总抗氧化能力评价,结果显示化合物1-6均表现出较好的抗氧化作用,其中化合物4的总抗氧化能力达到(4.533±0.13)mmol·g^-1(Vc为5.951±0.25 mmol·g^-1)。该研究结果不仅丰富了黄花倒水莲花的物质基础,而且为其今后的综合开发利用提供了科学依据。

Abstract:

To study the chemical constituents and antioxidant activity of the flavones in flowers from the Polygala fallax. Six compounds were isolated and purified by silica gel, Sephadex LH-20 column chromatography and preparative high performance liquid chromatography(HPLC)from the ethyl acetate fraction of 95% ethanol extract of P. fallax. Combined with the 1D-NMR spectral data and literature comparison. The results were as follows:(1)Their structures were identified as kaempferol-3-glucoside(1), quercetin-3-O-β-D-galactoside(2), quercetin-3-O-β-xylopyranoside(3), quercetin-3-O-α-L-arabinoside(4), isorhamnetin-3-O-β-glucopyranoside(5), rutin(6), respectively. Compounds 1-6 were obtained from the plant for the first time.(2)The antioxidant activities of different polar parts and compounds were evaluated by using DPPH· and FRAP methods. The results showed that all compounds had antioxidant capacity, of which the total antioxidant activity of Compound 4 was up to(4.533±0.13)mmol·g^-1(vitamin C value was of 5.951±0.25 mmol·g^-1). Thus, the overall results not only enrich the material basis of flowers of P. fallax, but also provide scientific basis for its future development and utilization.