4-Hydroxy-6-nonadecylpyran-2-one | 866474-31-9

• 分子结构分类: 有机化合物 - 有机杂环化合物 - 吡喃
• 英文名称: 4-Hydroxy-6-nonadecylpyran-2-one
• 英文别名: 4-hydroxy-6-nonadecylpyran-2-one
• CAS: 866474-31-9
• 化学式: C₂₄H₄₂O₃
• 分子量: 378.596
• InChiKey: YIANZBYTXWNKKM-UHFFFAOYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  10
• 重原子数：
  27
• 可旋转键数：
  18
• 环数：
  1.0
• sp3杂化的碳原子比例：
  0.79
• 拓扑面积：
  46.5
• 氢给体数：
  1
• 氢受体数：
  3

反应信息

• 作为产物：
  描述：

  (C20:0)辅酶A 、 丙二酰辅酶A-钠盐 在 alkylresorcylic acid synthase, ARAS₁ 作用下， 反应 0.33h， 生成 4-Hydroxy-6-nonadecylpyran-2-one 、 、 5-十九烷基间苯二酚
  参考文献：
  名称：

  Alkylresorcylic acid synthesis by type III polyketide synthases from rice Oryza sativa

  摘要：

  Alkylresorcinols, produced by various plants, bacteria, and fungi, are bioactive compounds possessing beneficial activities for human health, such as anti-cancer activity. In rice, they accumulate in seedlings, contributing to protection against fungi. Alkylresorcylic acids, which are carboxylated forms of alkylresorcinols, are unstable compounds and decarboxylate readily to yield alkylresorcinols. Genome mining of the rice Oryza sativa identified two type III polyketide synthases, named ARAS1 (alkylresorcylic acid synthase) and ARAS2, that catalyze the formation of alkylresorcylic acids. Both enzymes condensed fatty acyl-CoAs with three C-2 units from malonyl-CoA and cyclized the resulting tetraketide intermediates via intramolecular C-2 to C-7 aldol condensation. The alkylresorcylic acids thus produced were released from the enzyme and decarboxylated non-enzymatically to yield alkylresorcinols. This is the first report on a plant type III polyketide synthase that produces tetraketide alkylresorcylic acids as major products. (C)2010 Published by Elsevier Ltd.

  DOI：

  10.1016/j.phytochem.2010.02.012

文献信息

• A New Family of Type III Polyketide Synthases in Mycobacterium tuberculosis
  作者：Priti Saxena、Gitanjali Yadav、Debasisa Mohanty、Rajesh S. Gokhale

  DOI：10.1074/jbc.m306714200

  日期：2003.11

  The Mycobacterium tuberculosis genome has revealed a remarkable array of polyketide synthases (PKSs); however, no polyketide product has been isolated thus far. Most of the PKS genes have been implicated in the biosynthesis of complex lipids. We report here the characterization of two novel type III PKSs from M. tuberculosis that are involved in the biosynthesis of long-chain alpha-pyrones. Measurement of steady-state kinetic parameters demonstrated that the catalytic efficiency of PKS18 protein was severalfold higher for long-chain acyl-coenzyme A substrates as compared with the small-chain precursors. The specificity of PKS18 and PKS11 proteins toward long-chain aliphatic acyl-coenzyme A (C-12 to C-20) substrates is unprecedented in the chalcone synthase (CHS) family of condensing enzymes. Based on comparative modeling studies, we propose that these proteins might have evolved by fusing the catalytic machinery of CHS and beta-ketoacyl synthases, the two evolutionarily related members with conserved thiolase fold. The mechanistic and structural importance of several active site residues, as predicted by our structural model, was investigated by performing site-directed mutagenesis. The functional identification of diverse catalytic activity in mycobacterial type III PKSs provide a fascinating example of metabolite divergence in CHS-like proteins.