Submitted to: Journal of the American Oil Chemists' Society
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 12, 2005
Publication Date: September 1, 2005
Citation: Piazza, G.J., Foglia, T.A. 2005. Preparation of fatty amide polyols via epoxidation of vegetable oil amides by oat seed peroxygenase. Journal of the American Oil Chemists' Society. 82(7):481-485. Interpretive Summary: Production of new biobased materials such as metal cutting fluids, greases, and crankcase lubricants from fats and oils is a research area receiving increased attention. One way to modify the chemical properties of fats, oils, and their derivatives is through controlled oxidation to give materials useful for aqueous formulations with low levels of volatile organics. Chemical oxidation of fats and oils produces a mixture of products, some of which are useful and others of which are wastefully not. We have found that controlled oxidation using an enzyme derived from oat seeds produces high yields of desired products that are potentially useful in aqueous formulation of such products as metal cutting fluids. We optimized the oxidation procedure and applied it to three common vegetable oils, canola oil, soybean oil, and linseed oil. We found that linseed oil gave products of the highest polarity or compatibility with water. These results will promote both the use of fats and oils and decrease the use of volatile organic solvents in commercial products.
Technical Abstract: Prior work has shown that oat (Avena sativa) seeds are a rich source of peroxygenase, an enzyme that promotes the oxidation of carbon-carbon double bonds to form epoxides. Ground and defatted oat seeds were used as a low cost source of peroxygenase. A systematic study of epoxidation of i-butyl amides from linseed oil was conducted. Hexane was used as the primary component of the reaction media to eliminate the need for extraction. It was found that the addition of a small amount of buffered water containing Tween 20 enhanced epoxidation activity using t-butyl hydroperoxide and cumene hydroperoxide as oxidants. This activity could be further enhanced by the addition of isopropyl ether. Conditions for larger scale reactions were developed and applied to amides prepared from linseed, soybean and canola oils. Due to enzymatic selectivity, epoxidation of adjacent double bonds was low, and monoepoxides predominated from the amides of oleate and linoleate; the diepoxide, N-i-butyl-9,10-15,16-diepoxy-12(Z)-octadecenamide, was obtained from amide of linolenate. The enzymatically epoxidized amides from the oils were hydrolyzed in dilute acid, and the distribution of the various classes of polyols was determined. Reflecting the high proportion of starting monoepoxides, saturated diols and diols with one double bond were the major polyols obtained from soybean and canola oils. Because linseed oil contains a high proportion of linolenate, polyols obtained from the epoxides of this oil had a major amount of the tetrol, N-i-butyl-9,10,15,16-tetrahydroxy-12(Z)-octadecenamide. In contrast the components of polyols obtained from the hydrolysis of commercial epoxide preparations of soybean and linseed methyl esters followed by amide formation were primarily saturated diols and furan derivatives resulting from the presence of adjacent epoxide groups in these preparations.