Stereospecific analysis

Barbano, D. M. and Sherbon, J. W. 1975. Stereospecific analysis of high melting triglycerides of bovine milk fat and their biosynthetic origin. J. Dairy Sci. 58, 1-8. 

Breckenridge, W. C. 1978. Stereospecific analysis of triacylglycerols. In Handbook of Lipid Research, Vol. I Fatty Acids and Glycerides. A. Kuksis (Editor). Plenum Press, New York pp. 197-232. 

Ando, Y. and Takagi, T. (1993) Micromethod for stereospecific analysis of in acyl-s/z-glycerols by chiral-phase high performance liquid chromatography. J. Am. Oil Chem. Soc., 70(10), 1047-1049. 

Takagi, T. and Ando, Y. (1995) Stereospecific analysis of monounsaturated triacylglycerols in cocoa... 

Table 4.7 Triacylglycerol stereospecific analysis of evening primrose and borage oils...

Myher, J.J., Kuksis, A., Gehr, K., Park, P.W. and DiersenSchade, D.A. (1996) Stereospecific analysis of triacylglycerols rich in long-chain polyunsaturated fatty acids. Lipids, 31, 207—215. 

Stereospecific analysis of milk fat fractions containing triacylglycerols of different molecular weight have shown that, for fatty acids of chain length C4 to Ci6, the general pattern of fatty acid distribution in normal milk fat is similar to the pattern of distribution in the triacylglycerol fractions of different... 

Figure 11. Stereospecific analysis of triglycerides by the Brockerhoff method (132). The numbers 1, 2, and 3 on the glycerol symbol refer to the fatty acids at the sn-I-, sn-2-, and sn-3-positions, respectively, of the original triglyceride phenylphosphate group.

Different methods of analysis will give different and often incomplete information about such a mixture. GC analysis will separate molecular species by carbon number (sum of fatty acid chain lengths). Silver-ion HPLC will separate by number of double bonds. Stereospecific analysis measures the proportions of fatty acids at the sn-1, sn-2, and sn-3 positions, but it does not detect individual molecular species. 

Most natural triacylglycerols do not have a random distribution of fatty acids on the glycerol backbone. In plant oils, unsaturated acids predominate at the sn-2 position, with more saturated acids at sn-l and sn-3. The distribution of fatty acids at the sn-l and sn-3 positions is often similar, although not identical. However, a random distribution between these two positions is often assumed as full stereospecific analysis is a time-consuming specialist procedure. In animal fats, the type of fatty acid predominating at the sn-2 position is more variable for example, palmitate may be selectively incorporated as well as unsaturated acids (Table 5). 

In the past, pharmacokinetic and pharmacodynamic investigations of chiral drugs have neglected the influences of stereoisomerism. This is primarily a result of the lack of stereospecific analysis procedures. Nonstereospecific assays give pharmacokinetic and pharmacodynamic information which represents a complex combination of the characteristics of the separate stereoisomers. With the advent of stereospecific analysis procedures a better understanding of drug kinetics and action as possible. 

Cowan DA, Hutt AJ Stereospecific analysis and enantiomeric disposition of 3,4-methylenedioxymethamphetamine (ecstasy) in humans. Clin Chem 1999 45 1058-69. 

Applications of immunoassay to pesticide chemistry have been described which address some difficult problems in analysis by classical methods. These include stereospecific analysis of optically active compounds such as pyrethroids (38), analysis of protein toxins from Bacillus thuringiensis (5,37), and compounds difficult to analyze by existing methods, such as diflubenzuron (35) and maleic hydrazide (15 also Harrison, R.O. Brimfield, A.A. Hunter, K.W.,Jr. Nelson, J.O. J. Agric. Food Chem. submitted). An example of the excellent specificity possible is seen in assays for parathion (10) and its active form paraoxon (3). Some immunoassays can be used directly for analysis without extensive sample extraction or cleanup, dramatically reducing the work needed in typical residue analysis. An example of this is given in Figures 2 and 3, comparing the direct ELISA analysis of molinate in rice paddy water to the extraction required before GC analysis. 

Harp, T.K. E.G. Hammond. Stereospecific analysis of soybean triacylglycerols. Lipids 1998, 33, 209-216. 

Fallon, J.K. Kicman, A.T. Henry, J.A. Milligan, P.J. Cowan, D.A. Hutt, A. J. Stereospecific analysis and enantiomeric disposition of 3, 4-methylenedioxy-methamphetamine (Ecstasy) in humans. Clin. Chem. 1999,45,1058-1069. 

MiharaK, SvenssonUSH,TybringG, Hai TN, Bertilsson L,AshtonM. Stereospecific analysis of omeprazole supports artemisinin as a potent inducer of C YFCC19. Fundam Clin Pharmacol (1999) 13,671-5. 

Phillips, BE Smith, CR. Stereospecific analysis of triglycerides from Mannina emarginata seed oil. Lipids, 1972, 7, 215-217. 

Procedures for pancreatic lipase use are described by Jensen and Pitas (1976) and for lipoprotein, lingual and hepatic lipases by Paltauf et al, (1974). Stereospecific analysis of fatty acids in triacylglycerols has been fully discussed by Brecken-ridge (1978). 

Myher, J. J., Kuksis, A. and Park, P. W. (1996) Stereospecific analysis of TAG oils rich in long chain polyunsaturates, in Abstracts, 87th AOCS Annual Meeting, Indianapolis, IN, AOCS Press, Champaign, IL, p. 2. 

Kanazawa, H. Kunito, Y. Matsushima, Y. Okubo, S. Mashige, F. Stereospecific analysis of chiral drugs in plasma hy chromatography-chiroptical detector. Chromatography 1999, 20 (1), 81-87. 

Fig. 5. The stereospecific analysis of triacylglycerols. (From Gurr and James, 1980, reproduced by permission of Associated Book Publishers Ltd.)...

Fatemi, S.H. and Hammond, E.G. (1977) Glyceride structure variation in soybean varieties. I. Stereospecific analysis. Lipids 12, 1032-1036. 

Pan, W.P. and Hammond, E.G. (1983) Stereospecific analysis of triglycerides of Glycine max. Glycine soja, Avena Sativa and Avena sterilis strains. Lipids 18, 882-888. 

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