以松树蕈多糖为原料,采用乙酸酐法制备乙酰化松树蕈多糖,以乙酰化取代度为指标,通过单因素实验考察料液比、反应温度和反应时间对取代度的影响,在单因素的基础上,采用响应面Box-Benhnken试验设计乙酰化工艺进行优化,并通过乙酰化松树蕈多糖对·OH、DPPH自由基和O2-·的清除作用探讨其抗氧化活性.结果表明:松树蕈多糖乙酰化最佳工艺为,料液比1:34.07(g∶ mL),反应时间为2.8h,反应温度为42.42℃.在该优化条件下,乙酰化松树蕈多糖取代度达0.587.抗氧化研究表明,与未修饰多糖相比,乙酰化松树蕈多糖对·OH和DPPH自由基的清除能力减弱,但对O2-·的清除能力有较大的增强.

Polysaccharides from Tricholoma matsutake (TMP) was actylated by acetic anhydride,and its acetylated modification was studied.Effect of polysaccharides-to-acetic anhydride ratio,reaction time and reaction temperature on the substitution degree of actylated polysaccharides from Tricholoma matsutake (Ac-TMP) were investigated through the single factor experiment.The optimization of acetylation was obtained by response surface experiments with BoxBehnken design.Antioxidant activity in vitro of Ac-TMP was assessed by DPPH,hydroxyl and superoxide anion free radical scavenging assays.The optimal conditions were:polysaccharides-to-acetic anhydride ratio 1∶34.07 (g ∶ mL),reaction time 2.8 h and reaction temperature 42.42 ℃.Under the above conditions,the degree of substitution was 0.587.Compared with TMP,scavenging capacities of Ac-TMP against hydroxyl free radicals and DPPH free radicals were reduced,but the scavenging capacity against superoxide anion free radicals was improved.