Diacylglycerols analysis

Indirect analysis of the enantiomeric ratio of an alcohol can be accomplished via separation and quantitation of the diastereomers of eq 1 by high-performance liquid chromatography (HPLC), gas-liquid chromatography (GLC), or supercritical fluid chromatography (SFC). For example, diastereomeric diacylglycerol l-(l-naphthyl)ethyl carbamates are separated by HPLC on a silica gel column, as are the diastereomeric derivatives of the tertiary monoterpene alcohol linalool, diastereomers of (unsym-... 

S. Kimura, Studies on Energy Metabolism of Diacylglycerol Using Expiration Analysis, The Japanese Society of Nutrition and Food Science, 2002. 

Fig. 4. Fractional crystallization of anhydrous milk-fat (AMF) (A), MF-TAC (B), and milk-fat MF-TAC with 0.1% milk-fat diacylglycerol (MF-DAC) (Q determined by pNMR measurements of solid fat content, turbidity measurements, and polarized light microscopy coupled to image analysis at 22.5°C. Symbols in (A) and (B) represent the average and standard errors of three replicates. See Figures 2 and 3 for other abbreviations.

Yu, K., R. Li, T. Hatanaka, and D. Hildebrand. 2008. Cloning and functional analysis of two type 1 diacylglycerol acyltransferases from Vemonia galamensis. Phytochemistry 69 1119-1127. 

Walsh, J.P. Bell, R.M. sn-l,2-Diacylglycerol kinase of Escherichia coli. Structural and kinetic analysis of the lipid cofactor dependence. J. Biol. Chem., 261, 15062-15069 (1986)... 

Preparation of TBDMS derivatives of fatty acids and diacylglycerols Dissolve fatty acids or diacylglycerols (microgram quantities) in N,N-dimethylformamide (500 yUl) and add the silylation mixture (500 fll prepared by dissolving 1 mM TBDMCS and 2.5 mM imidazole in 1 ml of DMF). The reaction mixture is heated in a capped vial at 80 °C for 90 min. After cooling, the reaction mixture is diluted with 5 ml of water and extracted three times with petroleum ether. The extracts are combined and evaporated to dryness, and the residue is dissolved in hexane for GC-MS analysis. 

Figure 7. GC analysis of a synthetic mixture of diacylglycerols as their TBDMS ethers on a 25 m x 0.25 mm i.d. capillary column, coated with RSL-300 (methyl 50% phenylsiloxane) polarizable stationary phase. Tentative peak identification as given in the figure. Temperature programming was from 40-290 °C, ballistic 290 °C, isothermal for 0.5 min 290-330 C, I0°C/min 330-360 °C, 1 C/min. Dioleoyl-glycerol retained 21.23 min. Carrier gas, hydrogen at 1 bar head pressure. Manual on-column injection with fused-silica needle at 40 °C. (Reproduced from Ref. 188 with permission).

Prior to the analysis a triacylglycerol internal standard, 1,3-diheptadecanoyl-2,6(Z)-octadecenoyl-glycerol (17 0, 18 1, 17 0), is added to the sample. The sample is then separated into its triacylglycerol components by silver nitrate TLC. The band for /8-SOS (symmetrically disaturated 2-oleoyl-l,3-diacylglycerols) is isolated and the total jS-SOS acylglycerols are converted to methyl esters which are then analysed by GLC. 

Monoacylglycerols and diacylglycerols. The early GC/MS methods of analysis of MGs and DGs utilized TMS ethers, which were unstable and could... 

Lehner, R., Kuksis, A. and Itabashi, Y. (1993) Chiral phase HPLC analysis of the stereospecificity of mono- and diacylglycerol acyltransferases from rat intestine. Lipids, 28, 29-34. 

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