高抗氧化性小分子阿胶的研究

用碱性蛋白酶对阿胶进行酶解，并采用超滤技术分离制备了平均分子量小于1 kDa的小分子阿胶（CCAH-Ⅱ）。通过多种抗氧化评价方法分析发现制备的CCAH-Ⅱ具有较高的抗氧化活性，质量浓度2 mg/mL的CCAH-Ⅱ对1，1-二苯基-2-三硝基苯肼（DPPH）自由基、2，2-联氮基-双-（3-乙基苯并噻唑啉-6-磺酸）二铵盐（ABTS）自由基和羟基自由基的清除率分别可以达到（53.79±1.18）%、（70.53±0.65）%、（80.00±0.45）%。通过氨基酸组成和圆二色谱分析，发现CCAH-Ⅱ中疏水性氨基酸的摩尔分数高达42.40%，β-转角和无规卷曲结构的摩尔分数分别为30.4%、46.8%；推测高占比的疏水性氨基酸、β-转角和无规卷曲结构与小分子阿胶的高抗氧化性密切相关。

Preparation of a high-antioxidant hydrolysate from Colla Corii Asini

Colla Corii Asini was hydrolyzed with alkaline protease,and the enzymatic hydrolysate was ultrafiltered with a 3k ultrafiltration membrane to afford a Colla Corii Asini hydrolysate (CCAH-Ⅱ). DPPH, ABTS and OH radical scavenging activities of CCAH-Ⅱ at a concentration of 2 mg/mL were (53.79±1.18)%, (70.53±0.65)% and (80.00±0.45)%, respectively. By means of amino acid composition analysis and circular dichroism chromatography, it was found that the content of hydrophobic amino acids in CCAH-Ⅱ was as high as 42.40%. The proportions of β-turn and random coil moieties were 30.4% and 46.8%, respectively, and this high proportion of β-turn and random coil may be responsible for the high antioxidant activity of CCAH-Ⅱ.