Phosphatides table

Six two-component models were tested under sink conditions (models 5.1-10.1 in Table 7.3), employing three negatively charged lipids (dodecylcarboxylic acid, phosphatidic acid, and phosphatidylglycerol). These models were also tested in the absence of the sink condition (models 5.0-10.0 in Table 7.3). 

Table 12.5). Phosphoglycerides are derivatives of glycerophosphoric acid (l,2-diacyl-sn-3-phosphate) which is also called phosphatidic acid. 

The simplest of the glycerophospholipids is phosphatidic acid, in which phosphate is linked to the third hydroxyl function, forming a phosphate ester. More complex glycerophospholipids are derivatives of phosphatidic acid in which one of several groups is attached commonly choline, ethanolamine, serine, or myo-inositol. Structures are collected in table 19.1. 

PE), usually present in the ratio of approximately 3 1 and making up about 90% of the total weight of the lecithin phospholipids (Table 9.1). It is known that the two main phospholipids account for most of the stabilization and emulsification activity of the lecithin, but it is thought that minor components such as sphingomyelin and phosphatidic acid also play some as yet undefined role in the process. It might be emphasized here that the natural mixture of components is more effective at stabilizing emulsions than any of the major components in either purified or synthetic form, alone or in artificial admixtures. 

Selected examples of analytical methods used for the determination of global profiling of lipids are listed in Table 5. Extraction is usually based on simple liquid extraction, using modified Folch or Blight and Dyer extraction (4,5). For more acidic lipids, such as PSs and phosphatidic acids, adjustment of the pH in the aqueous phase is required. The analysis is most typically performed with LC-MS in RPLC mode, with the UHPLC methods gradually replacing the conventional HPLC methods. HRMS systems, such... 

In the case of phosphatides, we have made the assumption that one phosphatidyl-choline is equivalent to 2 hydroxyl groups. The following Table XX gives the results of... 

In the enzymatic degumming process, part of the hydratable phosphatides is enzymatically modified by removing the fatty acid on the C-2 position of the glycerol, using a phospholipase A2 enzyme as biocatalyst. These modified phosphatides facilitate the removal of the remaining NHP. Table 4.10 shows the results of an enzymatic degumming... 

In the soft-degumming process, a chelating agent (EDTA) is added to the oil to remove the cations from the nonhydratable phosphatides, thereby making them hydratable again (Table 4.11) [4]. 

The primary phosphatides of soybean oil are phosphatidylcholine, phosphatidyl-ethanolamine, and phosphotidylinositol, which generally make up 55.3%, 26.3%, and 18.4% of the total phosphatides, respectively (50). The stereospecific distribution of the acyl groups in these phospholipids for a typical soybean lipid is shown in Table 5. In all the phospholipids, the saturated acyl groups are concentrated in the... 

TABLE 17. Content of Total Phosphatides (TP) and Nonhydratable Phosphatides (NHP) of Crude Sunflower Oil [Based on (67)]. 

Soybean oil contains 1.5-3.0% phospholipids (71). Crude soybean lecithin has an oil content of about 30%. PC is present at a level of about 16%., PE about 14%, and inositol phospholipids about 12% (7). As can be seen in Table 18 (8), the fatty acid compositions of soybean phospholipids are rich in polyunsaturated fatty acids. Miscellaneous low-level constituents include water, phosphatidic acid, pigments, galactosyl glycerides, various glycolipids, phosphatidylserine, carbohydrates, sterols, and tocopherols. Phosphorus content of crude soybean oil extracted from flours can vary depending on extraction temperature and flour moisture (72). 

The lipid composition of the brain varies slightly depending on the particular section of the brain studied (Table 1). The white matter of the brain consists primarily of myelinated neurons and myelin is predominantly sphingolipid (e.g., sphingomyelin) and cholesterol (Fig. 1). The fatty acid composition of myelin is mostly saturated and contains relatively little DHA. The gray matter of the brain, on the other hand, has very little myelin and the phosphatides PS, PE, and PI of the active neuronal membranes make up the bulk of the lipid (Salem, et al., 1986). These lipids are very unsaturated and DHA and AA are the predominant building blocks thereof. 

Fig. 23. Use of neutron contrast variation to examine lateral phase separations in liposomes composed of a 3 7 mixture of deuterated DMPC (Table 6) and protonated DMPA (dimyristoyl phosphatidic acid) at 30°C. The chain melting transition is 23 C. Thickness Guinier plots of were...

In view of the observation that a C2o-trienoic acid of the oleic acid type, totally synthesized via oleic acid, accumulates in tissue phosphatides under certain circumstances, we investigated whether polyenoic acids of the palmitoleic acid type are formed analogously. Therefore we (IJ) analyzed the polyenoic acid fraction of livers of rats fed a fat-free diet. The acids were expected in these animals particularly, since the depot fat of the rat contains appreciable amounts of palmitoleic acid (12). The results are shown in Table III. 

In the above table the substance marked with asterisk — an alcohol insoluble fraction of the total soya bean phosphatides — has been included. 

The table contains three phosphatides, which do not belong to macromolecular but to association Colloids. For including them here see p. 262 and 265. 

On closer inspection of Table 2 on page 270, we see that the correlation between reciprocal hexol number and flocculability is not a rigorous one, so, for instance, Na agar though of lower reciprocal hexol number than the preceding Soya bean phosphatide, shows only opalescence with 6—1. 5—1 and 4—1. 

We already discussed previously (see p. 270, Table 2 p. 274 and 295) that egg lecithin, acting as a negative association colloid, has a very high equivalent weight, the soya bean phosphatide a much lower one. That means that the egg lecithin is much less mixed with acid constituents (for example phosphatidic acid) than the soya bean phosphatide and thus approximates much better to the theoretically pure phosphatide, which must consist exclusively of amphoions. 

Soybean phospholipids (Chapman, 1980) contain phosphatidic add (5%), phosphatidylinositol (20%), phosphatidylethanolamine (23%), phosphatidylcholine (39%) and unidentified components (13%). The phosphatides in crude and degummed soybean oil are given in Table 3.114 (Racicot and Handel, 1983). 

The most important phosphatides are the lecithins, cephalins, phosphatidylser-ines, and plasmalogens (a phosphatidyl derivative). Their general structures are shown in Table 23.5. 

Under suitable conditions all of the ester (and ether) linkages of a phosphatide can be hydrolyzed. What organic compounds would you expect to obtain from the complete hydrolysis of (see Table 23.5) (a) a lecithin, (b) a cephalin, and (c) a choline-based plasmalogen [Note Pay particular attention to the fate of the o ,/3-unsaturated ether in part (c).]... 

The total lipid extracts should be checked by TLC to evaluate the quality of the lipid extracted and to determine the lipid class profile. An assessment of the lipid composition of the sample may provide the analyst with a better understanding of the most appropriate methods to use. To assess the extent of lipase hydrolysis in the lipid extract use TLC and the developing solvent system 1 in Table 4.1 to test for FFA, and a two directional TLC system such as 9-1 and 2 (Table 4.1) to determine the phosphatidic acid content. The TLC method can also be used to subsequently fractionate the different lipid classes. 

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