2,7-dihydroxy-4'-methoxyisoflavanone | 770722-02-6

• 分子结构分类: 有机化合物 - 苯丙烷和聚酮 - 异黄酮类化合物
• 英文名称: 2,7-dihydroxy-4'-methoxyisoflavanone
• 英文别名: (2R,3S)-2,7-dihydroxy-4'-methoxyisoflavanone；(2R,3S)-2,7-dihydroxy-3-(4-methoxyphenyl)-2,3-dihydrochromen-4-one
• CAS: 770722-02-6
• 化学式: C₁₆H₁₄O₅
• 分子量: 286.284
• InChiKey: PKQQPELXMZRYJY-GDBMZVCRSA-N

物化性质

• 沸点：
  549.8±50.0 °C(Predicted)
• 密度：
  1.380±0.06 g/cm3(Predicted)

计算性质

• 辛醇/水分配系数(LogP)：
  2.2
• 重原子数：
  21
• 可旋转键数：
  2
• 环数：
  3.0
• sp3杂化的碳原子比例：
  0.19
• 拓扑面积：
  76
• 氢给体数：
  2
• 氢受体数：
  5

反应信息

• 作为反应物：
  描述：

  2,7-dihydroxy-4'-methoxyisoflavanone 在 2-hydroxyisoflavanone dehydratase 作用下， 生成 刺芒柄花素
  参考文献：
  名称：

  Catalytic specificity of pea O-methyltransferases suggests gene duplication for (+)-pisatin biosynthesis

  摘要：

  S-adenosyl-L-methionine: 2-hydroxyisoflavanone 4'-O-methyltransferase (HI4'OMT) methylates 2,7, 4'-trihydroxyisoflavanone to produce formononetin, an essential intermediate in the synthesis of isoflavonoids with methoxy or methylenedioxy groups at carbon 4' (isoflavone numbering). HI4'OMT is highly similar (83% amino acid identity) to (+)-6a-hydroxymaackiain 3-O-methyltransferase (HMM), which catalyzes the last step of (+)-pisatin biosynthesis in pea. Pea contains two linked copies of HMM with 96% amino acid identity. In this report, the catalytic activities of the licorice HI4'OMT protein and of extracts of Escherichia coli containing the pea HMM1 or HMM2 protein are compared on 2,7,4'-trihydroxyisoflavanone and enantiomers of 6a-hydroxymaackiain. All these enzymes produced radiolabelled 2,7-dihydroxy-4'-methoxyisoflavanone or (+)-pisatin from 2,7,4'-trihydroxyisoflavanone or (+)-6a-hydroxymaakiain when incubated with [methyl-C-14]-S-adenosyl-L-methionine. No product was detected when (-)-6a-hydroxymaackiain was used as the substrate. HIWOMT and HMMI showed efficiencies (relative V-max/K-m) for the methylation of 2,7,4'-trihydroxyisoflavanone 20 and 4 times higher than for the methylation of (+)-6a-hydroxymaackiain, respectively. In contrast, HMM2 had a higher V-max and lower K-m on (+)-6a-hydroxymaackiain, and had a 67-fold higher efficiency for the methylation of (+)-6a-hydroxymaackiain than that for 2,7,4'-trihydroxyisoflavanone. Among the 15 sites at which HMMI and HMM2 have different amino acid residues, 11 of the residues in HMM1 are the same as found in HI4'OMTs from three plant species. Modeling of the HMM proteins identified three or four putative active site residues responsible for their different substrate preferences. It is proposed that HMM I is the pea HIWOMT and that HMM2 evolved by the duplication of a gene encoding a general biosynthetic enzyme (HIWOMT). (c) 2006 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.phytochem.2006.09.010
• 作为产物：
  描述：

  S-腺苷蛋氨酸 、 (2R,3S)-2,7,4'-trihydroxyisoflavanone 在 2,7,4'-trihydroxyisoflavanone 4'-O-methyltransferase 乙二醇甲醚 作用下， 生成 2,7-dihydroxy-4'-methoxyisoflavanone
  参考文献：
  名称：

  Catalytic specificity of pea O-methyltransferases suggests gene duplication for (+)-pisatin biosynthesis

  摘要：

  S-adenosyl-L-methionine: 2-hydroxyisoflavanone 4'-O-methyltransferase (HI4'OMT) methylates 2,7, 4'-trihydroxyisoflavanone to produce formononetin, an essential intermediate in the synthesis of isoflavonoids with methoxy or methylenedioxy groups at carbon 4' (isoflavone numbering). HI4'OMT is highly similar (83% amino acid identity) to (+)-6a-hydroxymaackiain 3-O-methyltransferase (HMM), which catalyzes the last step of (+)-pisatin biosynthesis in pea. Pea contains two linked copies of HMM with 96% amino acid identity. In this report, the catalytic activities of the licorice HI4'OMT protein and of extracts of Escherichia coli containing the pea HMM1 or HMM2 protein are compared on 2,7,4'-trihydroxyisoflavanone and enantiomers of 6a-hydroxymaackiain. All these enzymes produced radiolabelled 2,7-dihydroxy-4'-methoxyisoflavanone or (+)-pisatin from 2,7,4'-trihydroxyisoflavanone or (+)-6a-hydroxymaakiain when incubated with [methyl-C-14]-S-adenosyl-L-methionine. No product was detected when (-)-6a-hydroxymaackiain was used as the substrate. HIWOMT and HMMI showed efficiencies (relative V-max/K-m) for the methylation of 2,7,4'-trihydroxyisoflavanone 20 and 4 times higher than for the methylation of (+)-6a-hydroxymaackiain, respectively. In contrast, HMM2 had a higher V-max and lower K-m on (+)-6a-hydroxymaackiain, and had a 67-fold higher efficiency for the methylation of (+)-6a-hydroxymaackiain than that for 2,7,4'-trihydroxyisoflavanone. Among the 15 sites at which HMMI and HMM2 have different amino acid residues, 11 of the residues in HMM1 are the same as found in HI4'OMTs from three plant species. Modeling of the HMM proteins identified three or four putative active site residues responsible for their different substrate preferences. It is proposed that HMM I is the pea HIWOMT and that HMM2 evolved by the duplication of a gene encoding a general biosynthetic enzyme (HIWOMT). (c) 2006 Elsevier Ltd. All rights reserved.

  DOI：

  10.1016/j.phytochem.2006.09.010

文献信息

• cDNA Cloning and Biochemical Characterization of S-Adenosyl-l-Methionine: 2,7,4′-Trihydroxyisoflavanone 4′-O-Methyltransferase, a Critical Enzyme of the Legume Isoflavonoid Phytoalexin Pathway
  作者：Tomoyoshi Akashi、Yuji Sawada、Norimoto Shimada、Noriyuki Sakurai、Toshio Aoki、Shin-ichi Ayabe

  DOI：10.1093/pcp/pcg034

  日期：2003.2.15

  Formononetin (7-hydroxy-4′-methoxyisoflavone, also known as 4′-O-methyldaidzein) is an essential intermediate of ecophysiologically active leguminous isoflavonoids. The biosynthetic pathway to produce 4′-methoxyl of formononetin has been unknown because the methyl transfer from S-adenosyl-l-methionine (SAM) to 4′-hydroxyl of daidzein has never been detected in any plants. A hypothesis that SAM: daidzein 7-O-methyltransferase (D7OMT), an enzyme with a different regiospecificity, is involved in formononetin biosynthesis through its intracellular compartmentation with other enzymes recently prevails, but no direct evidence has been presented. We proposed a new scheme of formononetin biosynthesis involving 2,7,4′-trihydroxyisoflavanone as the methyl acceptor and subsequent dehydration. We now cloned a cDNA encoding SAM: 2,7,4′-trihydroxyisoflavanone 4′-O-methyltransferase (HI4′OMT) through the screening of functionally expressed Glycyrrhiza echinata (Fabaceae) cDNAs. The reaction product, 2,7-dihydroxy-4′-methoxyisoflavanone, was unambiguously identified. Recombinant G.echinata D7OMT did not show HI4′OMT activity, and G. echinata HI4′OMT protein free from D7OMT was partially purified. HI4′OMT is thus concluded to be distinct from D7OMT, and their distant phylogenetic relationship was further presented. HI4′OMT may be functionally identical to (+)-6a-hydroxymaackiain 3-OMT of pea. Homologous cDNAs were found in several legumes, and the catalytic function of the Lotus japonicus HI4′OMT was verified, indicating that HI4′OMT is the enzyme of formononetin biosynthesis in general legumes.

  甲酮素（7-羟基-4′-甲氧基异黄酮，又称 4′-O-甲基麦冬苷）是具有生态生理活性的豆科异黄酮的重要中间体。由于从未在任何植物中检测到从 S-腺苷-l-蛋氨酸（SAM）到 4′-羟基麦冬皂苷的甲基转移，因此产生 4′-甲氧基麦冬皂苷的生物合成途径尚不清楚。最近有一种假说认为，SAM：daidzein 7-O-甲基转移酶（D7OMT）是一种具有不同区域特异性的酶，它通过与其他酶在细胞内的分区参与了甲萘素的生物合成，但这种假说尚未得到直接证据。我们提出了一种新的甲酮素生物合成方案，涉及以 2,7,4′-三羟基异黄酮为甲基受体，然后脱水。现在，我们通过筛选功能表达的甘草（豆科）cDNA，克隆出了编码 SAM：2,7,4′-三羟基异黄酮 4′-O-甲基转移酶（HI4′OMT）的 cDNA。反应产物 2,7-二羟基-4′-甲氧基异黄烷酮被明确鉴定。重组的棘尾草 D7OMT 不显示 HI4′OMT 活性，部分纯化了不含 D7OMT 的棘尾草 HI4′OMT 蛋白。因此认为 HI4′OMT 与 D7OMT 是不同的，并进一步介绍了它们之间遥远的系统发育关系。HI4′OMT 在功能上可能与豌豆的 (+)-6a-hydroxymaackiain 3-OMT 相同。在几种豆科植物中发现了同源的cDNA，并验证了莲花HI4′OMT的催化功能，表明HI4′OMT是一般豆科植物中甲酮素生物合成的酶。
• Catalytic specificity of pea O-methyltransferases suggests gene duplication for (+)-pisatin biosynthesis
  作者：Tomoyoshi Akashi、Hans D. VanEtten、Yuji Sawada、Catherine C. Wasmann、Hiroshi Uchiyama、Shin-ichi Ayabe

  DOI：10.1016/j.phytochem.2006.09.010

  日期：2006.12

  S-adenosyl-L-methionine: 2-hydroxyisoflavanone 4'-O-methyltransferase (HI4'OMT) methylates 2,7, 4'-trihydroxyisoflavanone to produce formononetin, an essential intermediate in the synthesis of isoflavonoids with methoxy or methylenedioxy groups at carbon 4' (isoflavone numbering). HI4'OMT is highly similar (83% amino acid identity) to (+)-6a-hydroxymaackiain 3-O-methyltransferase (HMM), which catalyzes the last step of (+)-pisatin biosynthesis in pea. Pea contains two linked copies of HMM with 96% amino acid identity. In this report, the catalytic activities of the licorice HI4'OMT protein and of extracts of Escherichia coli containing the pea HMM1 or HMM2 protein are compared on 2,7,4'-trihydroxyisoflavanone and enantiomers of 6a-hydroxymaackiain. All these enzymes produced radiolabelled 2,7-dihydroxy-4'-methoxyisoflavanone or (+)-pisatin from 2,7,4'-trihydroxyisoflavanone or (+)-6a-hydroxymaakiain when incubated with [methyl-C-14]-S-adenosyl-L-methionine. No product was detected when (-)-6a-hydroxymaackiain was used as the substrate. HIWOMT and HMMI showed efficiencies (relative V-max/K-m) for the methylation of 2,7,4'-trihydroxyisoflavanone 20 and 4 times higher than for the methylation of (+)-6a-hydroxymaackiain, respectively. In contrast, HMM2 had a higher V-max and lower K-m on (+)-6a-hydroxymaackiain, and had a 67-fold higher efficiency for the methylation of (+)-6a-hydroxymaackiain than that for 2,7,4'-trihydroxyisoflavanone. Among the 15 sites at which HMMI and HMM2 have different amino acid residues, 11 of the residues in HMM1 are the same as found in HI4'OMTs from three plant species. Modeling of the HMM proteins identified three or four putative active site residues responsible for their different substrate preferences. It is proposed that HMM I is the pea HIWOMT and that HMM2 evolved by the duplication of a gene encoding a general biosynthetic enzyme (HIWOMT). (c) 2006 Elsevier Ltd. All rights reserved.