辽东楤木芽多糖乙酰化修饰工艺及其抗氧化活性研究

Optimization of acetylated modification of polysaccharide extracted from Aralia elata(Miq.)Seem.bud and its antioxidant activity

以辽东楤木芽为原料,采用超声波辅助提取法提取辽东楤木芽多糖,制备辽东楤木芽乙酰化多糖(Ac-AEBP)。以乙酰基取代度为指标,研究反应温度、反应时间和液料比(mL/g)对AEBP乙酰化修饰取代的影响。在单因素实验的基础上,运用Box-Behnken设计响应面实验对乙酰化工艺参数进行优化,并比较乙酰化修饰前后的辽东楤木芽多糖对·OH、·O^(2-)、DPPH·、ABTS+·的清除作用以及还原能力,探讨其抗氧化活性。结果表明辽东楤木芽多糖乙酰化最佳工艺条件为:反应温度52℃,反应时间4 h,液料比43∶1(mL/g),在此条件下,乙酰化辽东楤木芽多糖的取代度为0.4596。抗氧化研究表明,与未经修饰的AEBP相比,Ac-AEBP的抗氧化活性有较大的增强。该研究可为进一步开发利用辽东楤木芽提供科学依据。

Using Aralia elata(Miq.)Seem.bud(AEBP)as raw material,Polysaccharides from AEBP was extracted by ultrasonic assisted extraction,and acetylation of polysaccharides from Aralia elata(Miq.)Seem.bud(Ac-AEBP)was prepared.The degree of acetylation substitution was used as index,the effects of reaction temperature,reaction time and liquid-material ratio(mL/g)on AEBP acetylation modification substitution were studied.On the basis of single factor experiment,parameters of the acetylation process were optimized using Box-Behnken design response surface experiment.The scavenging effect and reducing ability of AEBP and Ac-AEBP on·OH,·O^(2-)DPPH·and ABTS+·were compared to study their antioxidant activities.The optimal preparation conditions of Ac-AEBP were as follows:reaction temperature 52℃,reaction time 4 h and liquid-material ratio 43∶1(mL/g).Under the optimized conditions,the degree of Ac-AEBP substitution was 0.4596.Antioxidant results showed that,compared with unmodified AEBP,Ac-AEBP antioxidant capacity were greatly enhanced.The study provides a scientific basis for the further development and utilization of Aralia elata(Miq.)Seem.bud.