【摘要】 本文探讨了益智(Alpinia oxyphylla Miquel)超临界CO2提取物及其渣的水提物、正丙醇提取物和乙酸乙酯提取物的抗氧化作用,测定了总酚含量、黄酮含量、抗氧化力、还原能力、DPPH清除率。结果表明,益智超临界CO2提取物和正丙醇提取物的总酚含量最高,均为5.53%,乙酸乙酯提取物的总酚含量为4.04%,水提物总酚含量最低,为0.89%。抗氧化力与酚含量相关(R2=0.703)。四种提取物中黄酮含量顺序为:乙酸乙酯提取物(6.29%)>丙醇提取物(5.81%)>水提取物(4.85%)>超临界CO2提取物(4.70%)。在还原能力、清除DPPH自由基和羟自由基方面,乙酸乙酯提取物表现出了很强的抗氧化能力,呈现剂量依赖关系。更多还原

【Abstract】 The antioxidant activities of extracts and residuum of Alpinia oxyphylla Miquel fruits from supercritical CO₂ extraction were determined in vitro.The residuum was extracted in turn with water,propyl alcohol and ethyl acetate.The total phenolic contents and flavonoid contents of the extracts were evaluated and the antioxidant activities of the extracts were assayed with antioxidant capacity in linoleic acid model system,reducing powers,radical scavenging activity using 1,1-diphenyl-2-picrylhydrazyl（DPPH） method.The total phenolic contents of the fruit extracts as gallic acid equivalents by the Folin–Ciocalteu method were found to be highest in propyl extracts（5.53%） and supercritical CO₂ extracts（5.53%）,a little lower in ethyl acetate extracts（4.04%） and lowest in water extracts（0.89%）.The phenolic constituents appeared to be responsible,at least in part,for the antioxidant capacity of extracts（R²=0.703）.At the same time,flavonoid content is in the following order:ethyl acetate extract（6.29%）,propyl alcohol extract（5.81%）,water extract（4.85%） and supercritical CO₂ extract（4.70%）.The results show that the ethyl acetate extract of Alpinia oxyphylla Miquel possesses strongest DPPH radical scavenging activity and reducing power in a concentration-dependent manner.更多还原