利用乙酸乙酯在中性和酸性条件下萃取EGCG氧化产物,得到级分A(EOPA)和级分B（EOPB）,用化学发光法比较EGCG与EOPA、EOPB的抗氧化活性及其对DNA损伤的保护作用,并通过HPLC-MS分析两级分中的氧化产物。结果表明EGCG及EOPA、EOPB均有较好的清除活性氧和保护DNA损伤的活性,其中EOPA的活性强于未氧化的EGCG。HPLC-MS分析表明,EOPA、EOPB级分中的氧化产物均为二聚体。
(-)-Epigallocatechin gallate (EGCG) was oxidized chemically and extracted under neutral, acidic condition value to obtain two extracts: fraction A (EOPA) and fraction B (EOPB). The antioxidant activities of EOP A, EOP B and EGCG were determined using a chemiluminescence technique. The components of two fractions were analyzed by HPLC-ESI-MS. Results showed that the EOP A possessed the strongest antioxidant activity in all test system followed by EGCG, EOP B in a decreasing order. HPLC-ESI-MS analysis showed that the oxidation products of EOP A and EOPB were all dimmers.
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