(Z)-2,3,6-tri-O-benzyl-4-O-(2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl)-D-glucono hydroximo-1,5-lactone | 201736-68-7

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: (Z)-2,3,6-tri-O-benzyl-4-O-(2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl)-D-glucono hydroximo-1,5-lactone
• CAS: 201736-68-7
• 化学式: C₆₁H₆₃NO₁₁
• 分子量: 986.171
• InChiKey: NQQBQDKDKKAHCP-AXNPVWOPSA-N

反应信息

• 作为反应物：
  描述：

  (Z)-2,3,6-tri-O-benzyl-4-O-(2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl)-D-glucono hydroximo-1,5-lactone 在 氨 、 碘 、 三乙胺 、 三甲胺 作用下， 以 二氯甲烷 为溶剂， 反应 51.83h， 生成 1,5-anhydro-1-azi-2,3,6-tri-O-benzyl-4-O-(2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl)-D-glucitol
  参考文献：
  名称：

  The Active Site of Cellobiohydrolase Cel6A from Trichoderma reesei:  The Roles of Aspartic Acids D221 and D175

  摘要：

  Trichoderma reesei cellobiohydrolase Cel6A is an inverting glycosidase. Structural studies have established that the tunnel-shaped active site of Cel6A contains two aspartic acids, D221 and D175, that are close to the glycosidic oxygen of the scissile bond and at hydrogen-bonding distance from each other. Here, site-directed mutagenesis, X-ray crystallography, and enzyme kinetic studies have been used to confirm the role of residue D221 as the catalytic acid. D175 is shown to affect protonation of D221 and to contribute to the electrostatic stabilization of the partial positive charge in the transition state. Structural and modeling studies suggest that the single-displacement mechanism of Cel6A may not directly involve a catalytic base. The value of (D2O)(V) of 1.16 +/- 0.14 for hydrolysis of cellotriose suggests that the large direct effect expected for proton transfer from the nucleophilic water through a water chain (Grotthus mechanism) is offset by an inverse effect arising from reversibly breaking the short, tight hydrogen bond between D221 and D175 before catalysis.

  DOI：

  10.1021/ja012659q
• 作为产物：
  描述：

  2,3,6,2',3',4',6'-hepta-O-benzyl-α,β-D-cellobiose 在 盐酸羟胺 、 sodium methylate 、 N-氯代丁二酰亚胺 、 1,8-二氮杂双环[5.4.0]十一碳-7-烯 作用下， 以 甲醇 、 二氯甲烷 为溶剂， 反应 1.7h， 以62%的产率得到(Z)-2,3,6-tri-O-benzyl-4-O-(2,3,4,6-tetra-O-benzyl-β-D-glucopyranosyl)-D-glucono hydroximo-1,5-lactone
  参考文献：
  名称：

  The Active Site of Cellobiohydrolase Cel6A from Trichoderma reesei:  The Roles of Aspartic Acids D221 and D175

  摘要：

  Trichoderma reesei cellobiohydrolase Cel6A is an inverting glycosidase. Structural studies have established that the tunnel-shaped active site of Cel6A contains two aspartic acids, D221 and D175, that are close to the glycosidic oxygen of the scissile bond and at hydrogen-bonding distance from each other. Here, site-directed mutagenesis, X-ray crystallography, and enzyme kinetic studies have been used to confirm the role of residue D221 as the catalytic acid. D175 is shown to affect protonation of D221 and to contribute to the electrostatic stabilization of the partial positive charge in the transition state. Structural and modeling studies suggest that the single-displacement mechanism of Cel6A may not directly involve a catalytic base. The value of (D2O)(V) of 1.16 +/- 0.14 for hydrolysis of cellotriose suggests that the large direct effect expected for proton transfer from the nucleophilic water through a water chain (Grotthus mechanism) is offset by an inverse effect arising from reversibly breaking the short, tight hydrogen bond between D221 and D175 before catalysis.

  DOI：

  10.1021/ja012659q