title: Biosynthesis of 20-hydroxyecdysone in plants: 3β-hydroxy-5β-cholestan-6-one as an intermediate immediately after cholesterol in Ajuga hairy roots.
abstract: 3β-Hydroxy-5β-cholestan-6-one was identified in the EtOAc extract of Ajuga hairy roots by micro-analysis using LC-MS/MS in the multiple reaction mode (MRM). Furthermore, administration of (2,2,4,4,7,7-(2)H6)- and (2,2,4,4,6,7,7-(2)H7)-cholesterols to the hairy roots followed by LC-MS/MS analysis of the EtOAc extract of the hairy roots indicated that cholesterol was converted to the 5β-ketone with hydrogen migration from the C-6 to the C-5 position. These findings, in conjunction with the previous observation that the ketone was efficiently converted to 20-hydroxyecdysone, strongly suggest that the 5β-ketone is an intermediate immediately formed after cholesterol during 20-hydroxyecdysone biosynthesis in Ajuga sp. In addition, the mechanism of the 5β-ketone formation from cholesterol is discussed.
authors.affiliation: Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan. Electronic address: fujimoto.y.aa@m.titech.ac.jp.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Fujimoto
authors.affiliation: Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan.
authors.forename: Izumi
authors.initials: I
authors.lastname: Maeda
authors.affiliation: Department of Chemistry and Materials Science, Tokyo Institute of Technology, Meguro, Tokyo 152-8551, Japan.
authors.forename: Kiyoshi
authors.initials: K
authors.lastname: Ohyama
authors.affiliation: Department of Integrated Bioscience, Graduate School of Frontier Science, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan.
authors.forename: Juri
authors.initials: J
authors.lastname: Hikiba
authors.affiliation: Department of Integrated Bioscience, Graduate School of Frontier Science, The University of Tokyo, Kashiwa, Chiba 277-8562, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kataoka
mesh_terms: D031328:Ajuga / Q000737:chemistry*; D002778:Cholestanones / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D002784:Cholesterol / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D002853:Chromatography, Liquid; D004441:Ecdysterone / Q000096:biosynthesis*; D007659:Ketones / Q000378:metabolism; D015394:Molecular Structure; D019906:Nuclear Magnetic Resonance, Biomolecular; D018517:Plant Roots / Q000737:chemistry / Q000378:metabolism; D053719:Tandem Mass Spectrometry
chemical_list: C000597999:3beta-hydroxy-5beta-cholestan-6-one; D002778:Cholestanones; D007659:Ketones; D004441:Ecdysterone; D002784:Cholesterol
keywords: 20-Hydroxyecdysone; Ajuga reptans var. atropurpurea; Hairy root; LC–MS/MS; Labiatae; NIH shift; Phytoecdysteroid