2-氧-α-D-葡萄糖基-L-抗坏血酸酶法合成工艺优化

Optimization of enzymatic transformation of 2-O-α-D-glucopyranosyl-L-ascorbic acid

以L-抗坏血酸和β-环糊精为底物,利用海洋微生物Y112所产的环糊精葡萄糖基转移酶(CGTase)催化合成2-氧-α-D-葡萄糖基-L-抗坏血酸(AA-2G)。在单因素试验的基础上应用Plackett-Burman试验设计筛选出3个对AA-2G产量有显著影响的因素(pH、底物浓度、加酶量),然后应用Box-Behnken方法进行三因素三水平的试验设计优化AA-2G酶法合成工艺。结果表明,最佳工艺条件为:加酶量90.78U/g·β-环糊精,pH 9.07,底物浓度56.81g/L,底物配比11(体积比),转化时间24h,温度45℃。该条件下,AA-2G的产量为10.62g/L。

2-O-α-D-glucopyranosyl L-ascorbic acid(AA-2 G)was transformed by marine microorganism cyclodextrin glucanotransferase(CGTase)using L-ascorbic acid andβ-cyclodextrin(β-CD)as substrate.The qualitative and quantitative analyses of AA-2 G were undertaken by LC-MS and HPLC.On the basis of single factor experiment Plackett-Burman design was carried out to determine three main effective factors(pH,substrate concentration,enzyme concentration).Then Box-Behnken design using three factors and three levels was applied to optimize synthesis conditions of AA-2 G.The results indicated that the optimum conditions were pH 9.07,enzyme concentration 90.78 U/g·β-CD,substrate concentration 56.81 g/L,the ratio of substrate 1:1(volume ratio),reacting for 24 h,at45℃.Under this condition the yield of AA-2 Gwas 10.62 g/L.