title: Cyclization of natural allene oxide in aprotic solvent: formation of the novel oxylipin methyl cis-12-oxo-10-phytoenoate.
abstract: Allene oxide, (9Z,11E)-12,13-epoxy-9,11-octadecadienoic acid (12,13-EOD), was prepared by incubation of linoleic acid (13S)-hydroperoxide with flaxseed allene oxide synthase (AOS) and purified (as methyl ester) by low temperature HPLC. Identification of pure 12,13-EOD was substantiated by its UV and (1)H NMR spectra and by GC-MS data for its methanol trapping product. The methyl ester of 12,13-EOD (but not the free carboxylic acid) is slowly cyclized in hexane solution, affording a novel cyclopentenone cis-12-oxo-10-phytoenoic acid. Free carboxylic form of 12,13-EOD does not cyclize due to the exceeding formation of macrolactone (9Z)-12-oxo-9-octadecen-11-olide. The spontaneous cyclization of pure natural allene oxide (12,13-EOD) into cis-cyclopentenone have been observed first time.
authors.affiliation: Kazan Institute of Biochemistry and Biophysics, Russian Academy of Sciences, PO Box 30, 420111 Kazan, Russia.
authors.forename: Natalia V
authors.initials: NV
authors.lastname: Medvedeva
authors.forename: Lucia S
authors.initials: LS
authors.lastname: Mukhtarova
authors.forename: Faina K
authors.initials: FK
authors.lastname: Mukhitova
authors.forename: Alsu A
authors.initials: AA
authors.lastname: Balandina
authors.forename: Shamil K
authors.initials: SK
authors.lastname: Latypov
authors.forename: Alexander N
authors.initials: AN
authors.lastname: Grechkin
mesh_terms: D002851:Chromatography, High Pressure Liquid; D003500:Cyclization; D003517:Cyclopentanes / Q000737:chemistry; D019597:Flax / Q000201:enzymology; D057927:Hydrophobic and Hydrophilic Interactions; D019746:Intramolecular Oxidoreductases / Q000378:metabolism*; D007783:Lactones / Q000737:chemistry; D008041:Linoleic Acids / Q000138:chemical synthesis* / Q000737:chemistry*; D008054:Lipid Peroxides / Q000737:chemistry*; D018942:Macrolides / Q000737:chemistry; D008956:Models, Chemical; D012997:Solvents / Q000737:chemistry*; D013057:Spectrum Analysis; D013237:Stereoisomerism; D013696:Temperature
chemical_list: D003517:Cyclopentanes; D007783:Lactones; D008041:Linoleic Acids; D008054:Lipid Peroxides; D018942:Macrolides; D012997:Solvents; C055944:12,13-epoxy-9(2),11-octadecadienoic acid; C008285:linoleic acid hydroperoxide; D019746:Intramolecular Oxidoreductases; C021377:hydroperoxide isomerase; C013905:cyclopentenone