The sn-1 and sn-3 protons were reported at 4.142 to 4.161 ppm and 4.298 to4.326 ppm. The sn-2 (H B) protons for the triacylglycerols of saturated fatty acids were reported at 5.241-5.283 ppm in CDCl 3, with values around 5.27 ppm common for mid-to long-chain fatty acid moieties. These assignments have been described in the literature (Lie Ken Jie and Lam, 1995), where also the dependence of these signals on the fatty acid chain attached to the glycerol moiety is discussed. Figures 1 to 3 depict 1H-NMR spectra of various glycerol esters of stearic acid.īesides the tripling of the integration values of the protons in the fatty acid chain, the NMR spectrum of tristearin, the triacylglycerol ester of stearic acid, shows the peaks for the sn-2 proton at about 5.3 ppm (triplet of triplets) and two distinct absorptions (4.17 and 4.33 ppm both are doublets of doublets) of the sn-1 and sn-3 protons (H A1 and H A2 see structure inscribed in part a of Fig. glycerol esterified with more than one fatty acid. In nature, triacylglycerols rarely exist in the form of a glycerol triester of only one fatty acid, but rather they are mixed species, i.e. Triacylglycerol esters are the most common esters in which fatty acids occur naturally.
Department of Agriculture, Peoria, IL, USA. National Center for Agricultural Utilization Research, Agricultural Research Service, U.S.
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