3-O-α-maltosyl-L-ascorbate

• 分子结构分类: 有机化合物 - 有机氧化合物
• 英文名称: 3-O-α-maltosyl-L-ascorbate
• 英文别名: (2R)-2-[(1S)-1,2-dihydroxyethyl]-3-[(2R,3R,4R,5S,6R)-3,4-dihydroxy-6-(hydroxymethyl)-5-[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxyoxan-2-yl]oxy-4-hydroxy-2H-furan-5-one
• 化学式: C₁₈H₂₈O₁₆
• 分子量: 500.411
• InChiKey: QVPYRWBLTPROJX-NRHPUQJGSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  -5.8
• 重原子数：
  34
• 可旋转键数：
  8
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.83
• 拓扑面积：
  266
• 氢给体数：
  10
• 氢受体数：
  16

反应信息

• 作为产物：
  描述：

  4-O-(α-D-glucopyranosyl)-α-D-glucopyranosyl fluoride 、 维生素 C 在 cyclodextrin glucantransferase mutant E₂₈₄A 作用下， 以 aq. phosphate buffer 为溶剂， 反应 24.0h， 以29%的产率得到3-O-α-maltosyl-L-ascorbate
  参考文献：
  名称：

  Enzymatic synthesis of 3-O-α-maltosyl-l-ascorbate using an engineered cyclodextrin glucanotransferase

  摘要：

  A mutant derived from a cyclodextrin glucantransferase with an alanine residue as its acid/base catalyst residue (CGT-E284A) catalyzed regioselective glycosylation at 3-OH of L-ascorbic acid using a-maltosyl fluoride (alpha G2F) and L-ascorbic acid as the donor and acceptor, respectively, yielding 3-O-alpha-maltosyl-L-ascorbate (AA3 alpha G2). The optimum conditions were determined by high-performance liquid chromatography analysis with 20 mM alpha G2F and 40 mM L-ascorbic acid as the substrates at pH 7.5 and 25 degrees C with 1 mg/ml of the enzyme for 24 h. Calcium ions bound in CGT-E284A played an important role in the transglycosylation. CGT-E284A exhibited typical saturation kinetic behaviour for aG2F at a fixed acceptor concentration (40 mM), and substrate inhibition by L-ascorbic acid was observed at high L-ascorbic acid concentrations (>60 mM). AA3 alpha G2 was isolated from a preparative scale reaction with a yield of 29%, and it showed extremely high stability under oxidative conditions. (C) 2014 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.foodchem.2014.07.110