烷基木糖苷的酶法合成及其纯化

Enzymatic Synthesis and Purification of Alkyl Xylosides and Xylobiosides

用海栖热袍菌的极耐高温木聚糖酶B(XynB)水解木聚糖,通过转糖苷化反应合成了β-(1,4)烷基木单苷和木二苷.XynB能够水解对硝基木单苷(p-nitrophenyl-β-D-xylopyranoside, pNP-X)和对硝基木二苷(p-nitrophenyl-β-D-xylobioside, pNP-X2),同时以不同长度碳链(C1-C4)的醇及其异构醇和二级结构醇作为转糖苷化反应的受体,生成烷基木单苷和木二苷.另外XynB还可以水解天然木聚糖,同时合成产量很高的烷基木单苷和烷基木二苷.反应生成物采用活性碳层析柱进行分离纯化,用40-的乙醇梯度洗脱,洗脱液流速为1.5 mL/min,得到纯的β-(1,4)烷基木单苷和木二苷.

Enzymatic synthesis of b-(1,4)-alkyl xylosides and xylobiosides via the transglycosylation reaction wascarried out using the recombinant xylanase B (XynB) from Thermotoga maritima. p-nitrophenyl-xylopyranoside, p-nitrophenylxylobioside and xylan from birchwood were the donors, and alcohols with different carbon chainlengths (C1~C4), including iso-alcohol and sec-alcohol, were the acceptors. The yields of alkyl xylosides andxylobiosides were high when xylan was used in the presence of various alcohols. The alkyl xylosides andxylobiosides were purified from the reaction mixture by charcoal column chromatography using ethanol-water solution (with concentration of the ethanol ranging from 0 to 40%, j) at the flow rate of 1.5 mL/min.