摘要:
研究不同溶剂对洋葱皮总多酚、总黄酮和槲皮素的提取效果及其提取物的抗氧化、抑制α-糖苷酶活性。以紫色洋葱皮为原料,分别以水、40%~100%乙醇溶液、乙酸乙酯、石油醚为溶剂提取洋葱皮活性成分,分析不同溶剂对总多酚、总黄酮及槲皮素的提取效果,测定不同溶剂提取物的总还原能力、清除DPPH·、ABTS+·、O2-·能力及抑制α-糖苷酶活性,并分析提取物中总多酚、总黄酮及槲皮素含量与其生物活性的相关性。结果表明:60%乙醇对总多酚、总黄酮、槲皮素的提取效果最好,三种活性成分的提取率分别为5.5%、9.87%、3.25%,纯度分别达(33.12%±0.39%)、(59.44%±0.38%)、(19.56%±0.14%)。40%、60%乙醇提取物均具有较强总还原能力、清除DPPH·、ABTS+·、O2-·能力和抑制α-糖苷酶活性能力。洋葱皮提取物总黄酮、槲皮素含量与其抗氧化、抑制α-糖苷酶活性的相关系数均达显著或极显著水平,其中,提取物的槲皮素含量与自由基清除活性、抑制α-糖苷酶活性相关性最高。
Abstract:
This study investigated extraction effect of different solvents on total polyphenols, total flavonoids and quercetin and the antioxidant and inhibition of α-glucosidase activities of extracts from onion skin (Allium cepa L.). The active ingredients of purple onion skin as raw material were extracted with water, 40%~100% ethanol solution, ethyl acetate and petroleum ether respectively. The effects of different solvents on total polyphenols, total flavonoids and quercetin were analyzed. The total reducing power, scavenging DPPH·, ABTS+·, O2-·and inhibition of α-glucosidase activities of different solvent extracts, which were compared with contents of total polyphenols, total flavonoids and quercetin were determined. Results showed that the highest extraction rate and contents or purity of total phenols, flavonoids and quercetin were determined in 60% ethanol extracts, which were respectively up to 5.5%, 9.87%, 3.25% and (33.12%±0.39%), (59.44%±0.38%), (19.56%±0.14%). The high reducing power, scavenging activities on DPPH·, ABTS+·, O2-·and inhibition of α-glucosidase activities were determined in 40% and 60% ethanol extracts. The correlation between total flavonoids and quercetin contents in onion skin extracts and antioxidant and inhibition of α-glucosidase activities all reached significant or extremely significant level. Actually, the correlation between quercetin contents in extracts and scavenging activities, inhibition of α-glucosidase activities reached the highest level.
百度学术
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