Two-Step Enzymatic Conversion of Rebaudioside A into a Mono-α-1,4-Glucosylated Rebaudioside A Derivative
Two-Step Enzymatic Conversion of Rebaudioside A into a Mono-α-1,4-Glucosylated Rebaudioside A Derivative
复制标题
将莱鲍迪甙 A 两步酶促转化为单-α-1,4-葡萄糖基化莱鲍迪甙 A 衍生物。
DOI：
10.1021/acs.jafc.0c07452
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发表时间：
2021-02-23
影响因子：
6.1
通讯作者：
Xiao, Min
中科院分区：
文献类型：
--
作者：
Wang, Wenzheng;Sun, Yajing;Xiao, Min
建立了一种新的两步酶促转化工艺，通过转糖基化和水解反应合成了一种新的单α-1，4-葡萄糖化甜菊糖苷A衍生物(RA1G)。在环糊精糖基转移酶催化下的转糖基化反应中，白藜芦醇苷A(RA)被转化为糖基化的RA衍生物(RAGS)，当酶浓度为2U/mL、β-环糊精浓度为82.5 mg/mL、RA浓度为82.5 mg/mL、反应温度为60℃、反应时间为5h时，最大转化率为87.8%，所得RAG溶液可直接用于水解液的水解。对四种淀粉酶进行了筛选，以缩短RAG中新合成的α-葡聚糖。在60℃的RAG溶液中加入1.5U/mL糖淀粉酶3h，RA1G的产率最高，达53.3%，经MS和核磁共振鉴定为13-[(2-O-beta-D-glucopyranosyl-3-O-beta-D-glucopyranosyl-beta-D-glucopyranosyl)oxy-Kaur-16-en-19-OIC acid-[(4-O-alpha-D-glucopyranosyl-beta-D-glucopyranosyl)酯，感官品质较RA有所改善。
A new two-step enzymatic conversion process for the production of a novel mono-alpha-1,4-glucosylated rebaudioside A derivative (RA1G) was established via transglycosylation followed by hydrolyzation. In the transglycosylation reaction catalyzed by cyclodextrin glycosyltransferase, rebaudioside A (RA) was converted into glucosylated RA derivatives (RAGs), and the maximum conversion of 87.8% was obtained with the optimal conditions of 2 U/mL enzyme, 82.5 mg/mL beta-cyclodextrin, and 82.5 mg/mL RA at 60 degrees C for 5 h. The obtained RAG solution was then directly used in hydrolyzation. Four amylases were screened for shortening the newly synthesized alpha-glucans of RAGs. A glucoamylase was found to produce RA1G as the single glucosylated product, and the maximum yield of 53.3% was achieved with the optimal conditions of adding 1.5 U/mL glucoamylase into RAG solution at 60 degrees C for 3 h. RA1G was identified as 13-[(2-O-beta-D-glucopyranosyl-3-O-beta-D-glucopyranosyl-beta-D-glucopyranosyl) oxy] ent-kaur-16-en-19-oic acid-[(4-O-alpha-D-glucopyranosyl-beta-D-glucopyranosyl) ester] by MS and NMR analysis and showed an improved sensory quality compared to RA.