枇杷菜抗食用油脂氧化活性及其成分研究

Study on Antioxidant Effects and Medchanism of Extracts from Jussiaea repens on Edible Oil and Fat

用1:2(V/V)的氯仿:甲醇超声提取,并用石油醚、乙酸乙酯和正丁醇依次对提取物进行萃取,利用Schaal烘箱法进行抗氧化实验,同时与合成抗氧化剂BHT进行对照。结果显示乙酸乙酯提取物(EAF)具有最高的抗氧化活性,其活性大于人工合成抗氧化剂BHT。利用硅胶、RP-18和Sephadex LH-20对其进行活性追踪分离,得到3种纯的抗氧化成分。利用现代波谱技术对其化学结构进行了鉴定,结果显示其为迷迭香酸、槲皮素-3-O-葡萄糖甙和山奈酚-3-O-葡萄糖甙。抗氧化活性大小顺序为迷迭香酸>槲皮素-3-O-葡萄糖甙>山奈酚-3-O-葡萄糖甙>EAF>BHT。含酚羟基化合物的抗氧化活性与其结构密切相关。活性大小主要取决于酚羟基的数目。

Jussiaea repens L. （JRL） was extracted with chloroform-methanol （1：2,V/V） in a ultrasonator, and the extract was then partitioned with petroleum ether, EtOAc and BuOH successively. Antioxidant activities （AA） of the three corresponding extracts were evaluated by Schaal method, and compared with that of BHT. The ethyl acetate-soluble fraction （EAF） exhibits the highest AA among the three fractions, which is higher than that of BHT. Furthermore, bioactivity-guided chromatographic fractionation of the EAF was conducted by repeated column chromatography of silica gel, RP-18 and S ephadex LH-20, and three pure antioxidant compounds were obtained. Their structures were determined by interpretation of the 1D and 2D NMR, as well as mass spectral data. The results showed that rosmarinic acid, quercetin 3-O- β -D-glucopyranoside and kaempferol 3-0- β - D-glucopyranoside are the major antioxidant constituents in JRL. The antioxidant activities of the compounds decrease in the following order： rosmarinic acid 〉 quercetin 3-O- β-D-glucopyranosid 〉 kaempferol 3-O- β -D-glucopyranoside 〉 EAF 〉 BHT. The antioxidant activities of phenolic compounds are closely correlated to their chemical structures. In general, the antioxidant activities of phenolics depend mainly on the number of hydrogen-donating hydroxyl groups on the aromatic ring of the phenolic molecules.