3β-hydroxy-9β-pimara-7,15-dien-19,6β-olide | 62994-56-3

• 分子结构分类: 有机化合物 - 脂质和类脂质分子 - 异戊烯醇脂质
• 英文名称: 3β-hydroxy-9β-pimara-7,15-dien-19,6β-olide
• 英文别名: 3β-hydroxy-5α,9β-pimara-7,15-dien-6β,19β-olide；3β-Hydroxy-9β-pimara-7,15-dien-19,6β-olid；3beta-Hydroxy-9beta-pimara-7,15-dien-19,6beta-olide；(1R,2R,5R,9R,12R,13S,16R)-5-ethenyl-13-hydroxy-1,5,12-trimethyl-10-oxatetracyclo[7.6.1.02,7.012,16]hexadec-7-en-11-one
• CAS: 62994-56-3
• 化学式: C₂₀H₂₈O₃
• 分子量: 316.441
• InChiKey: SPZLJXUKZRAIQP-KSYFULEYSA-N

计算性质

• 辛醇/水分配系数(LogP)：
  3.6
• 重原子数：
  23
• 可旋转键数：
  1
• 环数：
  4.0
• sp3杂化的碳原子比例：
  0.75
• 拓扑面积：
  46.5
• 氢给体数：
  1
• 氢受体数：
  3

反应信息

• 作为反应物：
  描述：

  3β-hydroxy-9β-pimara-7,15-dien-19,6β-olide 在 dehydrogenase from leaves of Oryza sativa 、 三羟甲基氨基甲烷盐酸盐 、 nicotinamide adenine dinucleotide 作用下， 以 水 为溶剂， 反应 0.67h， 生成 稻壳酮A
  参考文献：
  名称：

  Biosynthesis of Rice Phytoalexin: Enzymatic Conversion of 3β-Hydroxy-9β-pimara-7,15-dien-19,6β-olide to Momilactone A

  摘要：

  Momilactone A是一种重要的水稻二萜类植物抗毒素，可通过水稻叶片中3β-羟基-9β-吡喃-7,15-二烯-19,6β-内酯3位脱氢合成。通过比较天然和合成化合物在GC/MS分析后的质谱和保留时间，证实了紫外线照射水稻叶片中存在3β-羟基-9β-吡喃-7,15-二烯-19,6β-内酯。紫外线照射水稻叶片中的可溶性蛋白部分显示出将3β-羟基-9β-吡喃-7,15-二烯-19,6β-内酯转化为momilactone A的脱氢酶活性。该酶需要NAD+或NADP+作为氢受体。反应的最佳pH值为8。当NAD+作为辅因子以1mM的浓度提供时，3β-羟基-9β-吡喃-7,15-二烯-19,6β-内酯的Km值为36μM。紫外线照射可诱导3β-羟基-9β-吡喃-7,15-二烯-19,6β-内酯及其脱氢酶活性随时间变化。

  DOI：

  10.1271/bbb.66.566

文献信息

• Kato, Tadahiro; Aizawa, Hiroyasu; Tsunakawa, Mitsuaki, Journal of the Chemical Society. Perkin transactions I, 1977, # 3, p. 250 - 254
  作者：Kato, Tadahiro、Aizawa, Hiroyasu、Tsunakawa, Mitsuaki、Sasaki, Nobuki、Kitahara, Yoshio、Takahashi, Norindo

  DOI：——

  日期：——
• Identification of a Biosynthetic Gene Cluster in Rice for Momilactones
  作者：Kazuhiro Shimura、Atsushi Okada、Kazunori Okada、Yusuke Jikumaru、Kwang-Wook Ko、Tomonobu Toyomasu、Takeshi Sassa、Morifumi Hasegawa、Osamu Kodama、Naoto Shibuya、Jinichiro Koga、Hideaki Nojiri、Hisakazu Yamane

  DOI：10.1074/jbc.m703344200

  日期：2007.11

  Rice diterpenoid phytoalexins such as momilactones and phytocassanes are produced in suspension-cultured rice cells treated with a chitin oligosaccharide elicitor and in rice leaves irradiated with UV light. The common substrate geranylgeranyl diphosphate is converted into diterpene hydrocarbon precursors via a two-step sequential cyclization and then into the bioactive phytoalexins via several oxidation steps. It has been suggested that microsomal cytochrome P-450 monooxygenases (P-450s) are involved in the downstream oxidation of the diterpene hydrocarbons leading to the phytoalexins and that a dehydrogenase is involved in momilactone biosynthesis. However, none of the enzymes involved in the downstream oxidation of the diterpene hydrocarbons have been identified. In this study, we found that a putative dehydrogenase gene (AK103462) and two functionally unknown P-450 genes (CYP99A2 and CYP99A3) form a chitin oligosaccharide elicitor- and UV-inducible gene cluster, together with OsKS4 and OsCyc1, the diterpene cyclase genes involved in momilactone biosynthesis. Functional analysis by heterologous expression in Escherichia coli followed by enzyme assays demonstrated that the AK103462 protein catalyzes the conversion of 3 beta-hydroxy- 9 beta H-pimara-7,15-dien-19,6 beta-olide into momilactone A. The double knockdown of CYP99A2 and CYP99A3 specifically suppressed the elicitor-inducible production of momilactones, strongly suggesting that CYP99A2, CYP99A3, or both are involved in momilactone biosynthesis. These results provide strong evidence for the presence on chromosome 4 of a gene cluster involved in momilactone biosynthesis.