4-Hydroxymandelate

• 分子结构分类: 有机化合物 - 苯类化合物 - 酚类
• 英文名称: 4-Hydroxymandelate
• 英文别名: 2-hydroxy-2-(4-hydroxyphenyl)acetate
• 化学式: C8H7O4-
• 分子量: 167.14
• InChiKey: YHXHKYRQLYQUIH-UHFFFAOYSA-M

计算性质

• 辛醇/水分配系数(LogP)：
  1.1
• 重原子数：
  12
• 可旋转键数：
  1
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.12
• 拓扑面积：
  80.6
• 氢给体数：
  2
• 氢受体数：
  4

反应信息

• 作为反应物：
  描述：

  4-Hydroxymandelate 、 氢(+1)阳离子 生成 对羟基苯甲醇 、 二氧化碳
  参考文献：
  名称：

  p-Hydroxyphenylacetate decarboxylase from Clostridium difficile

  摘要：

  The human pathogenic bacterium Clostridium difficile is a versatile organism concerning its ability to ferment amino acids. The formation of p‐cresol as the main fermentation product of tyrosine by C. difficile is unique among clostridial species. The enzyme responsible for p‐cresol formation is p‐hydroxyphenylacetate decarboxylase. The enzyme was purified from C. difficile strain DMSZ 1296T and initially characterized. The N‐terminal amino‐acid sequence was 100% identical to an open reading frame in the unfinished genome of C. difficile strain 630. The ORF encoded a protein of the same size as the purified decarboxylase and was very similar to pyruvate formate‐lyase‐like proteins from Escherichia coli and Archaeoglobus fulgidus. The enzyme decarboxylated p‐hydroxyphenylacetate (Km = 2.8 mm) and 3,4‐dihydroxyphenylacetate (Km = 0.5 mm). It was competitively inhibited by the substrate analogues p‐hydroxyphenylacetylamide and p‐hydroxymandelate with Ki values of 0.7 mm and 0.48 mm, respectively. The protein was readily and irreversibly inactivated by molecular oxygen. Although the purified enzyme was active in the presence of sodium sulfide, there are some indications for an as yet unidentified low molecular mass cofactor that is required for catalytic activity in vivo. Based on the identification of p‐hydroxyphenylacetate decarboxylase as a novel glycyl radical enzyme and the substrate specificity of the enzyme, a catalytic mechanism involving ketyl radicals as intermediates is proposed.

  DOI：

  10.1046/j.1432-1327.2001.02001.x