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本文研究了番石榴叶乙酸乙酯萃取物的体外抗氧化活性及活性物质基础。采用95%乙醇溶液浸泡提取、正己烷和乙酸乙酯萃取后得到粗提物,首先分析了乙酸乙酯萃取物的体外抗氧化活性,然后通过硅胶柱色谱、Sephadex LH-20凝胶柱色谱、质谱和核磁共振等技术对乙酸乙酯萃取物的化学成分进行了分离和鉴定。结果表明,乙酸乙酯萃取物对DPPH自由基、超氧阴离子、羟自由基具有较强的体外抗氧化活性,清除能力随着浓度的增大而增强,当浓度为1 mg/m L时,对DPPH自由基、超氧阴离子和羟自由基的清除率分别达94.15%、87.88%和67.3%,清除效果接近或强于同浓度的Vc。通过硅胶柱色普、Sephadex LH-20凝胶柱色谱等技术从番石榴叶乙酸乙酯萃取部位中分离纯化得到5个化合物,通过MS和NMR等波谱数据和结合文献,最终确定了4个化合物,分别为:去甲氧基荚果蕨(1)、胶藤素(2)、槲皮素(3)和异槲皮苷(4),其中化合物2为首次从番石榴属植物中分离得到的二氢黄酮类化合物。
In this paper, the anti-oxidative activity and active substance basis of the ethyl acetate extract of Guava leaves were studied. The crude extracts were extracted by extraction with 95% ethanol and extracted with n-hexane and ethyl acetate. The antioxidant activity of the ethyl acetate extract was analyzed firstly, then the residue was purified by silica gel column chromatography, Sephadex LH-20 gel column chromatography, The chemical constituents of ethyl acetate extract were separated and identified by mass spectrometry and nuclear magnetic resonance. The results showed that ethyl acetate extract had strong antioxidant activity against DPPH, superoxide anion and hydroxyl radical in vitro. The scavenging ability of ethyl acetate extract increased with the increase of concentration. When the concentration was 1 mg / m L, The scavenging rates of DPPH, superoxide anion and hydroxyl radical were 94.15%, 87.88% and 67.3%, respectively. The scavenging effect was close to or stronger than that of Vc at the same concentration. Five compounds were isolated and purified from the ethyl acetate extract of Guava leaf by silica gel column chromatography and Sephadex LH-20 gel column chromatography. Through the spectral data of MS and NMR and the binding literature, four compounds (1), emmentin (2), quercetin (3) and isoquercitrin (4). Among them, compound 2 was isolated from Guava for the first time Flavonoids.