新疆药桑叶中黄酮类化合物的分离及其抗氧化活性评价

以自由基清除率为评价指标，利用制备液相从药桑叶醇提物的乙酸乙酯萃取部分中分离黄酮单体化合物，并采用1,1-二苯基- 2-硝基苯肼（DPPH）自由基和2,2-联氮基-双-（3-乙基苯并噻唑啉-6-磺酸）二氨盐（ABTS）自由基清除法对单体化合物进行抗氧化活性评价。结果表明，从乙酸乙酯萃取部分分离得到4个单体化合物，分别为化合物Ⅰ、化合物Ⅱ、化合物Ⅲ、化合物Ⅳ，对DPPH自由基清除率的半数抑制浓度（IC50）分别为0.004 4 mg/mL、0.003 7 mg/mL、0.003 0 mg/mL、0.078 0 mg/mL，对ABTS自由基清除率IC50分别为0.021 mg/mL、0.014 mg/mL、0.012 mg/mL、0.087 mg/mL。4个单体化合物均具有很强的抗氧化活性，且抗氧化活性顺序化合物Ⅲ＞化合物Ⅱ＞化合物Ⅰ＞化合物Ⅳ。

Isolation of flavonoids compounds in Morus nigra leaves from Xinjiang and their antioxidant activity

With the free radical scavenging rate as the evaluation index, the flavonoids monomer compounds were separated from ethyl acetate extraction phase of alcohol extract of Morus nigra leaves by preparative liquid chromatograph. The antioxidant activity of flavonoids monomer compounds was evaluated using the DPPH and ABTS free radical scavenging method. The results showed that four monomer compounds including compound Ⅰ, Ⅱ, Ⅲ, and IV were separated from ethyl acetate extraction phase. The compound Ⅰ, Ⅱ, Ⅲ, and IV on IC50 of DPPH free radical scavenging rate were 0.004 4 mg/ml, 0.003 7 mg/ml, 0.003 0 mg/ml and 0.078 0 mg/ml, respectively, and on IC50 of ABTS free radical scavenging rate were 0.021 mg/ml, 0.014 mg/ml, 0.012 mg/ml, 0.087 mg/ml, respectively. All four monomer compounds had a strong antioxidant activity, and the antioxidant activity in order was compound Ⅲ, compound Ⅱ, compound Ⅰand compound Ⅳ.