title: Microbial synthesis of trans isomer of eicosapentaenoic acid (EPA) from the chemically synthesized trans isomer of linolenic acid by a delta12 desaturase-defective mutant of Mortierella alpina 1S-4.
abstract: The mono trans geometrical isomer of eicosapentaenoic acid, 5c,8c,11c,14c,17t-eicosapentaenoic acid (20:5delta5c,8c,11c,14c,17t), was synthesized by fatty acid microbial conversion using a delta12-desaturase defective mutant of an arachidonic acid (AA)-producing fungus, Mortierella alpina 1S-4. The substrate for the bioconversion, a geometrical isomer of linolenic acid, was prepared by isomerization of linseed oil methyl ester by the nitrous acid method, followed by purification on a AgNO3-silica gel column. The structure and double bond geometry were identified after hydrazine reduction followed by permanganate oxidation to 20:5delta5c,8c,11c,14c,17t. The biosynthetic route from 18:3delta6c,9c,12t to 20:5delta5c,8c,11c,14c,17t was presumed to mimic the route from linoleic acid to arachidonic acid.
authors.affiliation: Department of Food and Nutrition, Faculty of Agriculture, Kinki University, Nakamachi, Nara, Nara 631-8505, Japan. sirasaka@nara.kindai.ac.jp
authors.forename: Norifumi
authors.initials: N
authors.lastname: Shirasaka
authors.forename: Shigenori
authors.initials: S
authors.lastname: Miyamoto
authors.forename: Tetsuo
authors.initials: T
authors.lastname: Murakami
authors.forename: Hajime
authors.initials: H
authors.lastname: Yoshizumi
authors.forename: Sakayu
authors.initials: S
authors.lastname: Shimizu
mesh_terms: D016718:Arachidonic Acid / Q000378:metabolism; D002849:Chromatography, Gas; D002851:Chromatography, High Pressure Liquid; D015118:Eicosapentaenoic Acid / Q000096:biosynthesis*; D044943:Fatty Acid Desaturases / Q000235:genetics* / Q000378:metabolism*; D006834:Hydrazines / Q000737:chemistry; D007202:Indicators and Reagents; D008043:Linseed Oil / Q000737:chemistry; D013058:Mass Spectrometry; D020094:Mortierella / Q000201:enzymology* / Q000235:genetics*; D009154:Mutation / Q000235:genetics / Q000502:physiology; D010084:Oxidation-Reduction; D012835:Silver Nitrate / Q000737:chemistry; D013237:Stereoisomerism; D017962:alpha-Linolenic Acid / Q000138:chemical synthesis / Q000378:metabolism*
chemical_list: D006834:Hydrazines; D007202:Indicators and Reagents; D017962:alpha-Linolenic Acid; D016718:Arachidonic Acid; D008043:Linseed Oil; D012835:Silver Nitrate; D015118:Eicosapentaenoic Acid; D044943:Fatty Acid Desaturases; C040448:delta-12 fatty acid desaturase