title: The enzymic conversion of linoleic acid hydroperoxide by flax-seed hydroperoxide isomerase.
abstract: 1. The mode of action of flax-seed hydroperoxide isomerase was studied in vitro by using as substrates linoleic acid hydroperoxides formed by soya-bean lipoxygenase. 2. The enzyme converts only 13-hydroperoxyoctadeca-cis-9-trans-11-dienoic acid, whereas the 9-hydroperoxy isomer does not react. 3. The isomerization product was identified by chemical and spectroscopic methods as 13-hydroxy-12-oxo-octadec-cis-9-enoic acid. 4. 12,13-Epoxyoleic acid isomers do not act as intermediates in the isomerization reaction. 5. Suggestions for a functional relationship between hydroperoxide isomerase and lipoxygenase are discussed.
mesh_terms: D004988:Ethers, Cyclic / Q000378:metabolism; D007535:Isomerases / Q000378:metabolism*; D008041:Linoleic Acids / Q000096:biosynthesis / Q000378:metabolism*; D010103:Oxygen Isotopes; D010105:Oxygenases / Q000378:metabolism; D010545:Peroxides / Q000096:biosynthesis / Q000378:metabolism*; D010944:Plants / Q000201:enzymology*; D012639:Seeds / Q000201:enzymology; D013053:Spectrophotometry; D013057:Spectrum Analysis; D013237:Stereoisomerism
chemical_list: D004988:Ethers, Cyclic; D008041:Linoleic Acids; D010103:Oxygen Isotopes; D010545:Peroxides; D010105:Oxygenases; D007535:Isomerases