4-methylumbelliferyl-α-D-xylopyranoside

• 分子结构分类: 有机化合物 - 苯丙烷和聚酮 - 香豆素及其衍生物
• 英文名称: 4-methylumbelliferyl-α-D-xylopyranoside
• 英文别名: 4-Methylumbelliferyl alpha-d-xylopyranoside；4-methyl-7-[(2R,3R,4S,5R)-3,4,5-trihydroxyoxan-2-yl]oxychromen-2-one
• 化学式: C₁₅H₁₆O₇
• 分子量: 308.288
• InChiKey: JWIYLOHVJDJZOQ-AQNFWKISSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -0.7
• 重原子数：
  22
• 可旋转键数：
  2
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.4
• 拓扑面积：
  105
• 氢给体数：
  3
• 氢受体数：
  7

反应信息

• 作为产物：
  描述：

  羟甲香豆素 、 α-D-xylopyranosyl fluoride 在 α-thioglycoligase YicI-D482A mutant 作用下， 以 aq. phosphate buffer 为溶剂， 反应 4.0h， 以96%的产率得到4-methylumbelliferyl-α-D-xylopyranoside
  参考文献：
  名称：

  α-Thioglycoligase-based synthesis of O-aryl α-glycosides as chromogenic substrates for α-glycosidases

  摘要：

  alpha-Thioglycoligases are retaining alpha-glycosidase mutants, with modification of their general acid/base catalytic residue to an inactive amino acid residue, catalyzing the formation of S-glycosidic linkages using a sugar donor with an excellent leaving group and suitable sugar acceptors with a thiol group as the substrate. In this study, we describe the enzymatic synthesis of O-aryl alpha-glycosides catalyzed by alpha-thioglycoligases. An alpha-xylosidase mutant (Yicl-D482A) efficiently catalyzed the synthesis of O-aryl alpha-xylosides in near-quantitative yields (up to 99%) using 4-methylumbelliferone and nitrophenols. Synthesis did not occur with those acceptors having a nitro group at the ortho-position. The conversion yields of 3-nitrophenol markedly increased at pH 8.0, whereas those of other aryl compounds were nearly independent of pH, ranging from pH 6.0 to 8.0. The O-aryl alpha-xylosides were prepared on a preparative scale with yields of up to 96%. Upon employing the O-aryl alpha-xylosides as the substrate for the wild-type Yicl, Bronsted relationships of log k(cat) versus pK(a) and log (k(cat)/K-M) versus pK(a) both showed a linear monotonic dependence on the leaving group pK(a) with low beta(lg) values of 0.39 and 0.38, respectively. In addition, synthesis of O-aryl alpha-glucosides was successfully conducted by an alpha-glucosidase mutant (MalA-D416A) in the same fashion with high yields. Therefore, this strategy can be used for the synthesis of O-aryl alpha-glycosides using an acid/base mutant of retaining alpha-glycosidases that hydrolyze the glycosides. (c) 2012 Elsevier B.V. All rights reserved.

  DOI：

  10.1016/j.molcatb.2012.10.008

文献信息

• α-Thioglycoligase-based synthesis of O-aryl α-glycosides as chromogenic substrates for α-glycosidases
  作者：Chao Li、Jin-Hyo Kim、Young-Wan Kim

  DOI：10.1016/j.molcatb.2012.10.008

  日期：2013.3

  alpha-Thioglycoligases are retaining alpha-glycosidase mutants, with modification of their general acid/base catalytic residue to an inactive amino acid residue, catalyzing the formation of S-glycosidic linkages using a sugar donor with an excellent leaving group and suitable sugar acceptors with a thiol group as the substrate. In this study, we describe the enzymatic synthesis of O-aryl alpha-glycosides catalyzed by alpha-thioglycoligases. An alpha-xylosidase mutant (Yicl-D482A) efficiently catalyzed the synthesis of O-aryl alpha-xylosides in near-quantitative yields (up to 99%) using 4-methylumbelliferone and nitrophenols. Synthesis did not occur with those acceptors having a nitro group at the ortho-position. The conversion yields of 3-nitrophenol markedly increased at pH 8.0, whereas those of other aryl compounds were nearly independent of pH, ranging from pH 6.0 to 8.0. The O-aryl alpha-xylosides were prepared on a preparative scale with yields of up to 96%. Upon employing the O-aryl alpha-xylosides as the substrate for the wild-type Yicl, Bronsted relationships of log k(cat) versus pK(a) and log (k(cat)/K-M) versus pK(a) both showed a linear monotonic dependence on the leaving group pK(a) with low beta(lg) values of 0.39 and 0.38, respectively. In addition, synthesis of O-aryl alpha-glucosides was successfully conducted by an alpha-glucosidase mutant (MalA-D416A) in the same fashion with high yields. Therefore, this strategy can be used for the synthesis of O-aryl alpha-glycosides using an acid/base mutant of retaining alpha-glycosidases that hydrolyze the glycosides. (c) 2012 Elsevier B.V. All rights reserved.