Convenient method for the determination of mono-, di-, and triacylglycerine distribution including regioisomers by C-13 nuclear magnetic resonance spectroscopy [Japanese]

摘要

By using carbon-13 (C-13) nuclear magnetic resonance (NMR) spectrometer, we have developed a easy quantitative method for determining the molar ratio of partial acylglycerines <1,2diacylglycerine (DG), 1,3-DG, 1-monoacylglycerine (MG), and 2-MG > to triacylglycerine (TG) and/or glycerin. For refinement of some measurement conditions, we set the five kinds of palmitoyl acylglycerines (TG, 1,2-DG, 1,3-DG, I-MG, and 2-MG) and glycerine as model compounds. After examining the solubility of these model compounds, we decided that pyridine-d(G) was suitable as an NMR measuring solvent. We also set the delay time of the pulse repeating at 15s, which is five times longer than the longest spin-lattice relaxation times (Ti) of proton (H-1) NMR signals of the glycerine moieties protons and C-13 NMR signals of the glycerine moieties carbons. Good agreement was observed between the result of the C-13 NMR and that of the reverse-phase high performance liquid chromatography (HPLC) by the model compounds, When the characteristic peaks are quantitatively measured in C-13 NMR of the commercial diacylglycerins product, each molar ratio of the derivatives, such as TG, 1,2-DG and 1,3-DG, can easily be determined.