|Kuo, Tsung Min|
Submitted to: Bioresource Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 20, 2007
Publication Date: February 8, 2008
Citation: Levinson, W.E., Kuo, T., Knothe, G.H. 2008. Characterization of fatty amides produced by lipase-catalyzed amidation of multihydroxylated fatty acids. Bioresource Technology. 99:2706-2709. Interpretive Summary: Surplus vegetable oils represent attractive renewable resources for the production of useful chemicals. Previously, we investigated the reaction parameters for directly adding ammonia to the reactive terminal of common fatty acids and their derivatives by an enzymatic method to form a group of new compounds called fatty amides with enhanced ability to undergo chemical reactions. In this study, we further determined the chemical structure of two new compounds by use of modern analytical instruments including gas chromatography, mass spectrometry and nuclear magnetic resonance spectroscopy that led to confirmation of the structural organization of these new fatty amides. The impact of this study provides new information for scientists to develop new products from low cost vegetable oils and search for their potential new uses.
Technical Abstract: Novel multi-hydroxylated primary fatty amides produced by direct amidation of 7,10-dihydroxy-8(E)-octadecenoic acid (DOD) and 7,10,12-trihydroxy-8(E)-octadecenoic acid (TOD) were characterized by GC-MS and NMR. The amidation reactions were catalyzed by immobilized Pseudozyma (Candida) antarctica lipase B (Novozym 435) in organic solvent with ammonium carbamate. The mass spectra of the products exhibited characteristic primary amide peaks at m/z 59 and m/z 72 that differed in peak intensities. The mass spectrum of the amidation product of DOD exhibited a base peak at m/z 72 and the m/z 59 peak, while present, was less prominent. In the spectrum of the TOD product, prominent m/z 59 and m/z 72 peaks were present, but the base peak was at m/z 75. Other peaks present in both spectra were consistent with cleavage next to the hydroxyl groups. The mass spectrum, together with proton and 13C NMR data, suggest that the products of lipase-catalyzed direct amidation of 7,10-dihydroxy-8(E)-octadecenoic acid and 7,10,12-trihydroxy-8(E)-octadecenoic acid are, 7,10-dihydroxy-8(E)-octadecenamide and 7,10,12-trihydroxy-8(E)-octadecamide acid, respectively. Amidation of multihydroxylated fatty acids has increased the melting point, but reduced the surface active property of the resulting primary amides.