(2E,4R,5R)-2,4-dimethyl-5-hydroxy-2-heptenoic acid | 145937-02-6

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 脂肪酰基
• 英文名称: (2E,4R,5R)-2,4-dimethyl-5-hydroxy-2-heptenoic acid
• 英文别名: (4R,5R)-(E)-2,4-dimethyl-5-hydroxy-2-heptenoic acid；(E,4R,5R)-5-hydroxy-2,4-dimethylhept-2-enoic acid
• CAS: 145937-02-6
• 化学式: C₉H₁₆O₃
• 分子量: 172.224
• InChiKey: BQBLEYAKFUJYCO-BNJXCVJPSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  1.5
• 重原子数：
  12
• 可旋转键数：
  4
• 环数：
  0.0
• sp3杂化的碳原子比例：
  0.67
• 拓扑面积：
  57.5
• 氢给体数：
  2
• 氢受体数：
  3

反应信息

• 作为反应物：
  描述：

  (2E,4R,5R)-2,4-dimethyl-5-hydroxy-2-heptenoic acid 、 三甲基硅烷化重氮甲烷 以 甲醇 、 正己烷 为溶剂， 反应 0.08h， 生成 (2E,4R,5R)-2,4-dimethyl-5-hydroxy-2-heptenoic acid methyl ester
  参考文献：
  名称：

  Stereospecificity of the Dehydratase Domain of the Erythromycin Polyketide Synthase

  摘要：

  The dehydratase (DH) domain of module 4 of the 6-deoxyerythronolide B synthase (DEBS) has been shown to catalyze an exclusive syn elimination/syn addition of water. Incubation of recombinant DH4 with chemoenzymatically prepared anti-(2R,3R)-2-methyl-3-hydroxypentanoyl-ACP (2a-ACP) gave the dehydration product 3-ACP. Similarly, incubation of DH4 with synthetic 3-ACP resulted in the reverse enzyme-catalyzed hydration reaction, giving an similar to 3:1 equilbrium mixture of 2a-ACP and 3-ACP. Incubation of a mixture of propionyl-SNAC (4), methylmalonyl-CoA, and NADPH with the DEBS beta-ketoacyl synthase-acyl transferase [KS6][AT6] dido-main, DEBS ACP6, and the ketoreductase domain from tylactone synthase module 1 (TYLS KR1) generated in situ anti-2a-ACP that underwent DH4-catalyzed syn dehydration to give 3-ACP. DH4 did not dehydrate syn-(2S,3R)-2b-ACP, syn-(2R,3S)-2c-ACP, or anti-(2S,3S)-2d-ACP generated in situ by DEBS KR1, DEBS KR6, or the rifamycin synthase KR7 (RIFS KR7), respectively. Similarly, incubation of a mixture of (2S,3R)-2-methyl-3-hydroxypentanoyl-N-acetylcysteaminethioester (2b-SNAC), methylmalonyl-CoA, and NADPH with DEBS [KS6][AT6], DEBS ACP6, and TYLS KR1 gave anti-(2R,3R)6-ACP that underwent syn dehydration catalyzed by DEBS DH4 to give (4R,5R)-(E)-2,4-dimethyl-5-hydroxy-hept-2-enoyl-ACP (7-ACP). The structure and stereochemistry of 7 were established by GC-MS and LC-MS comparison of the derived methyl ester 7-Me to a synthetic sample of 7-Me.

  DOI：

  10.1021/ja107344h
• 作为产物：
  描述：

  (4S,2'S,3'R)-3-(2'-methyl-3'-hydroxypentanoyl)-4-benzyl-2-oxazolidinone 在 potassium tert-butylate 、 potassium carbonate 、 红铝 作用下， 以 四氢呋喃 、 甲醇 、 甲苯 为溶剂， 反应 4.33h， 生成 (2E,4R,5R)-2,4-dimethyl-5-hydroxy-2-heptenoic acid
  参考文献：
  名称：

  Cane, David E.; Tan, Weitian; Ott, Walter R., Journal of the American Chemical Society, 1993, vol. 115, # 2, p. 527 - 535

  摘要：

  DOI：

文献信息

• Mechanism and Stereospecificity of a Fully Saturating Polyketide Synthase Module: Nanchangmycin Synthase Module 2 and Its Dehydratase Domain
  作者：Xun Guo、Tiangang Liu、Chiara R. Valenzano、Zixin Deng、David E. Cane

  DOI：10.1021/ja1073432

  日期：2010.10.27

  Recombinant nanchangmycin synthase module 2 (NANS module 2), with the thioesterase domain from the 6-deoxyerythronolide B synthase (DEBS TE) appended to the C-terminus, was cloned and expressed in Escherichia coli. Incubation of NANS module 2+TE with (+/-)-2-methyl-3-keto-butyryl-N-acetylcysteamine thioester (1), the SNAC analog of the natural ACP-bound substrate, with methylmalonyl-CoA (MM-CoA) in the absence of NADPH gave 3,5,6-trimethy1-4-hydroxypyrone (2), identified by direct comparison with synthetic 2 by radio-TLC-phosphorimaging and LC-ESI(+)-MS-MS. The reaction showed K(cat) 0.5 +/- 0.1 min(-1) and K(m)(1) 19 +/- 5 mM at 0.5 mM MM-CoA and k(cat)(app) 0.26 +/- 0.02 min(-1) and K(m)(MM-CoA) 0.11 +/- 0.02 mM at 8 mM 1. Incubation in the presence of NADPH generated the fully saturated triketide chain elongation product as a 5:3 mixture of (2S,4R)-2,4-dimethy1-5-ketohexanoic acid (3a) and the diastereomeric (2S, 4S)-3b. The structure and stereochemistry of each product was established by comparison with synthetic 3a and 3b by a combination of radio-TLC-phosphorimaging and LC-ESI(-)-MS-MS, as well as chiral capillary GC-MS analysis of the corresponding methyl esters 3a-Me and 3b-Me. The recombinant dehydratase domain from NANS module 2, NANS DH2, was shown to catalyze the formation of an (E)-double bond by syndehydration of the ACP-bound substrate anti-(2R,3R,4S,5R)-2,4-dimethyl-3,5-dihydroxyheptanoyl-ACP6 (4), generated in situ by incubation of (2S,3R)-2-methyl-3-hydroxypentanoyl-SNAC (5), methylmalonyl-CoA, and NADPH with the recombinant [KS6][AT6] didomain and ACP6 from DEBS module 6 along with the ketoreductase from the tylactone synthase module 1 (TYLS KR1). These results also indirectly establish the stereochemistry of the reactions catalyzed by the KR and enoylreductase (ER) domains of NANS module 2.
• Cane, David E.; Tan, Weitian; Ott, Walter R., Journal of the American Chemical Society, 1993, vol. 115, # 2, p. 527 - 535
  作者：Cane, David E.、Tan, Weitian、Ott, Walter R.

  DOI：——

  日期：——
• Stereospecificity of the Dehydratase Domain of the Erythromycin Polyketide Synthase
  作者：Chiara R. Valenzano、Young-Ok You、Ashish Garg、Adrian Keatinge-Clay、Chaitan Khosla、David E. Cane

  DOI：10.1021/ja107344h

  日期：2010.10.27

  The dehydratase (DH) domain of module 4 of the 6-deoxyerythronolide B synthase (DEBS) has been shown to catalyze an exclusive syn elimination/syn addition of water. Incubation of recombinant DH4 with chemoenzymatically prepared anti-(2R,3R)-2-methyl-3-hydroxypentanoyl-ACP (2a-ACP) gave the dehydration product 3-ACP. Similarly, incubation of DH4 with synthetic 3-ACP resulted in the reverse enzyme-catalyzed hydration reaction, giving an similar to 3:1 equilbrium mixture of 2a-ACP and 3-ACP. Incubation of a mixture of propionyl-SNAC (4), methylmalonyl-CoA, and NADPH with the DEBS beta-ketoacyl synthase-acyl transferase [KS6][AT6] dido-main, DEBS ACP6, and the ketoreductase domain from tylactone synthase module 1 (TYLS KR1) generated in situ anti-2a-ACP that underwent DH4-catalyzed syn dehydration to give 3-ACP. DH4 did not dehydrate syn-(2S,3R)-2b-ACP, syn-(2R,3S)-2c-ACP, or anti-(2S,3S)-2d-ACP generated in situ by DEBS KR1, DEBS KR6, or the rifamycin synthase KR7 (RIFS KR7), respectively. Similarly, incubation of a mixture of (2S,3R)-2-methyl-3-hydroxypentanoyl-N-acetylcysteaminethioester (2b-SNAC), methylmalonyl-CoA, and NADPH with DEBS [KS6][AT6], DEBS ACP6, and TYLS KR1 gave anti-(2R,3R)6-ACP that underwent syn dehydration catalyzed by DEBS DH4 to give (4R,5R)-(E)-2,4-dimethyl-5-hydroxy-hept-2-enoyl-ACP (7-ACP). The structure and stereochemistry of 7 were established by GC-MS and LC-MS comparison of the derived methyl ester 7-Me to a synthetic sample of 7-Me.