Submitted to: Lipids
Publication Type: Peer reviewed journal
Publication Acceptance Date: 3/25/2003
Publication Date: 5/20/2003
Citation: PIAZZA, G.J., NUNEZ, A., FOGLIA, T.A. ISOLATION OF UNSATURATED DIOLS AFTER OXIDATION OF CONJUGATED LINOLEIC ACID WITH PEROXYGENASE. LIPIDS. 2003. VOL. 38, no. 3. p. 255-261. Interpretive Summary: Conjugated linoleic acid (CLA) is made from chemical or enzymatic treatment of linoleic acid, a common component of vegetable oils. Dietary CLA supplementation is beneficial because some structural forms of CLA suppress cancer development, are antiatherogenic, and have both growth-promoting and body fat-reducing properties. The biological mode of action of CLA is not well understood. The products obtained from the action of a peroxygenase enzyme and an oxidant on CLA were investigated. One of the products was a novel derivative whose structure has not been previously reported. This research will aid in our understanding of the biological effects of CLA in the diet. More generally, the findings expand our understanding of how value-added products from fats and oils may be obtained by mild bioprocessing techniques instead of classical chemical ones.
Technical Abstract: Oat seeds are a rich source of peroxygenase, an iron heme enzyme that participates in oxylipin metabolism in plants. An isomer of conjugated linoleic acid, 9(Z),11(E)-octadecadienoic acid, believed to have anticarcinogenic activity, was used as a substrate for peroxygenase using t-butyl hydroperoxide as the oxidant. After conversion to methyl esters, the major oxidation products were characterized using high performance liquid chromatography with detection by electron impact mass spectrometry (HPLC-EI-MS) and atmospheric pressure chemical ionization mass spectrometry (HPLC-APCI-MS). The structures of the products were confirmed with proton and carbon nuclear magnetic resonance spectroscopy (NMR). Although the expected monoepoxide was formed on the cis double bond [9,10-epoxy- 11(E)octadecenoic acid], an additional more polar product was detected, which accounted for approximately 50% of the total oxidized product. The more polar product was determined to be 9,12-epoxy-10(Z)octadecenoic acid, a 2,5-dihydrofuranoid fatty acid.