Glycosidase-catalyzed Deoxy Oligosaccharide Synthesis. Practical Synthesis of Monodeoxy Analogs of Ethyl β-Thioisomaltoside Using<i>Aspergillus niger</i>α-Glucosidase
作者:Toshiyuki NISHIO、Chika KANAI、Wataru HAKAMATA、Masahiro OGAWA、Kousuke NAKAJIMA、Shigeki HOSHINO、Akari MATSUISHI、Ryu KAWACHI、Tadatake OKU
DOI:10.1271/bbb.67.1024
日期:2003.1
Enzymatic transglycosylation using four possible monodeoxy analogs of p-nitrophenyl α-D-glucopyranoside (Glcα-O-pNP), modified at the C-2, C-3, C-4, and C-6 positions (2D-, 3D-, 4D-, and 6D-Glcα-O-pNP, respectively), as glycosyl donors and six equivalents of ethyl β-D-thioglucopyranoside (Glcβ-S-Et) as a glycosyl acceptor, to yield the monodeoxy derivatives of glucooligosaccharides were done. The reaction was catalyzed using purified Aspergillus niger α-glucosidase in a mixture of 50 mM sodium acetate buffer (pH 4.0)/CH3CN (1: 1 v/v) at 37°C. High activity of the enzyme was observed in the reaction between 2D-Glcα-O-pNP and Glcβ-S-Et to afford the monodeoxy analogs of ethyl β-thiomaltoside and ethyl β-thioisomaltoside that contain a 2-deoxy α-D-glucopyranose moiety at their glycon portions, namely ethyl 2-deoxy-α-D-arabino-hexopyranosyl-(1,4)-β-D-thioglucopyranoside and ethyl 2-deoxy-α-D-arabino-hexopyranosyl-(1,6)-β-D-thioglucopyranoside, in 6.72% and 46.6% isolated yields (based on 2D-Glcα-O-pNP), respectively. Moreover, from 3D-Glcα-O-pNP and Glcβ-S-Et, the enzyme also catalyzed the synthesis of the 3-deoxy analog of ethyl β-thioisomaltoside that was modified at the glycon α-D-glucopyranose moiety, namely ethyl 3-deoxy-α-D-ribo-hexopyranosyl-(1,6)-β-D-thioglucopyranoside, in 23.0% isolated yield (based on 3D-Glcα-O-pNP). Products were not obtained from the enzymatic reactions between 4D- or 6D-Glcα-O-pNP and Glcβ-S-Et.
使用对硝基苯α-D-吡喃葡萄糖苷(Glcα-O-pNP)的四种可能的单脱氧类似物(分别在 C-2、C-3、C-4 和 C-6 位置进行修饰)(2D-、3D-、4D- 和 6D-Glcα-O-pNP)作为糖基供体,以及六种等量的乙基β-D-硫代吡喃葡萄糖苷(Glcβ-S-Et)作为糖基受体,进行酶促转糖基化、分别)作为糖基供体,六当量的乙基 β-D-硫代吡喃葡萄糖苷(Glcβ-S-Et)作为糖基受体,生成葡萄糖寡糖的单脱氧衍生物。该反应是在 50 mM 醋酸钠缓冲液(pH 4.0)/CH3CN(1: 1 v/v)的混合物中,于 37°C 下使用纯化的黑曲霉 α-葡萄糖苷酶催化的。在 2D-Glcα-O-pNP 和 Glcβ-S-Et 的反应中观察到该酶的高活性,从而得到乙基 β-硫代异麦芽糖苷和乙基 β-硫代异麦芽糖苷的单脱氧类似物、即乙基 2-脱氧-α-D-阿拉伯-六吡喃糖基-(1,4)-β-D-硫代吡喃葡萄糖苷和乙基 2-脱氧-α-D-阿拉伯-六吡喃糖基-(1,6)-β-D-硫代吡喃葡萄糖苷,分离率分别为 6.72% 和 46.6% 的分离收率(基于 2D-Glcα-O-pNP )。此外,从三维-Glcα-O-pNP 和 Glcβ-S-Et 中,该酶还催化合成了乙基 β-硫代异麦芽糖苷的 3-脱氧类似物,即乙基 3-脱氧-α-D-核糖基-己吡喃糖基-(1,6)-β-D-硫代吡喃葡萄糖苷,分离产率为 23.0%(基于三维-Glcα-O-pNP)。4D- 或 6D-Glcα-O-pNP 与 Glcβ-S-Et 的酶促反应没有得到产物。