Soybean lecithin

Other Reactions of Phospholipids. The unsaturated fatty acid groups in soybean lecithin can be halogenated. Acetic anhydride combined with the amino group of phosphatidylethanolamine forms acetylated compounds. PhosphoHpids form addition compounds with salts of heavy metals. Phosphatidylethanolamine and phosphatidjhnositol have affinities for calcium and magnesium ions that are related to interaction with their polar groups. 

The total commercial lecithin potential if all vegetable oils were degummed worldwide would be 552,000 t (Table 7). Although soybean, sunflower, and rape lecithins are available in the market, the principal commercial interest is only in soybean lecithin. The aimual worldwide production is 130,000 t (Table 8). 

Choline occurs widely in nature and, prepared synthetically, it is available as an article of commerce. Soybean lecithin and egg-yolk lecithin have been used as natural sources of choline for supplementing the diet. Other important natural-food sources include Hver and certain legumes (18—22). 

Vitamins and lipids are often required for animal cells to grow in serum-free medium. Phosphoethanolamine and ethanolamine are key additives that facilitate the growth of the mammary tumor cell line 64024 (Kano-Sueoka and Errick, 1981). In addition, ethanolamine promotes the growth of human lymphocytes and mouse hybridoma cells. Short-term cultures of human diploid lung and foreskin fibroblasts grow in medium that includes among its supplements soybean lecithin, cholesterol, sphingomyelin, and vitamin E. 

Emulsifiers. Natural lecithin is one of the most widely used emulsifiers because it is metabolized in the body. However, type I allergic reaction to soybean lecithin emulsified in lipid solutions has been observed [195], Among the synthetic emulsifying agents, block copolymers of polyoxyethylene-polyoxypropylene (poloxamer) have attracted increasing interest for parenteral emulsions. Other examples of emulsifiers commonly found in parenteral formulations are given in Table 9 [190]. 

Figure 4. (a) Planar bilayer membrane system for single-channel currents measurement. Soybean lecithin in n-decane was applied to a hole separating two aqueous chambers. Chambers were filled with metal chloride salt at pH 7.2. The voltage was applied to the outer cell with respect to the inner. The currents across the bilayer were recorded on a PCM recorder through a patch-clamp amplifier and a lowpass filter, (b) Typical records of current observed at -t-50.0 mV (symmetrical 0.5 M solution). Currents increase upward from the zero level shown by the dotted line in each panel. 

A premixture of 8 and soybean lecithin gave stable single channel currents with well-defined transitions between open and closed states with the 0.1-Is time scale. The conductance level detected was 6.1 0.5 pS at 0.5 M KCl solution. At various transmembrane voltages with different molar ratios of 8-to-lipid in the range 1/200 - 1/3000, an identical conductance level was always observed. This observation is therefore compatible with the original idea that monomeric 8 itself defines a pore mouth with a specified diameter in the single lipid layer. It gave a cation/anion... 

Vitamins—fat soluble Whole amounts of Sorbita was mixed with PN-Twin no. 2 (2.2 L) Sodium citrate, sodium pyrosulfite, sodium thioglycollate, HCO-60, benzyl alcohol, polysorbate 80 Aminoethylsulfonic acid, sesame oil, soybean lecithin, D-sorbitol, concentrated glycerin 1,157.1 5.1... 

Table 8 Phospholipids of Soybean Lecithin Distribution (By % Weight) of Fatty Acids...

The unsaturated phospholipid from soybean lecithin also shows a similar effect, while the unsaturated phospholipids from red blood cell membranes, although showing a slight effect of cholesterol interaction, still show a prominent polymethylene peak in the high resolution spectrum. 

As an example of an asymmetric membrane integrated protein, the ATP synthetase complex (ATPase from Rhodospirillum Rubrum) was incorporated in liposomes of the polymerizable sulfolipid (22)24). The protein consists of a hydrophobic membrane integrated part (F0) and a water soluble moiety (Ft) carrying the catalytic site of the enzyme. The isolated ATP synthetase complex is almost completely inactive. Activity is substantially increased in the presence of a variety of amphiphiles, such as natural phospholipids and detergents. The presence of a bilayer structure is not a necessary condition for enhanced activity. Using soybean lecithin or diacetylenic sulfolipid (22) the maximal enzymatic activity is obtained at 500 lipid molecules/enzyme molecule. With soybean lecithin, the ATPase activity is increased 8-fold compared to a 5-fold increase in the presence of (22). There is a remarkable difference in ATPase activity depending on the liposome preparation technique (Fig. 41). If ATPase is incorporated in-... 

Fig. 41. ATPase activity of ATP synthetase incorporated into liposomes (-O-) incubation of the enzyme with polymerized liposomes (-+-) incubation of the enzyme with monomeric liposomes of (22) followed by polymerization (- ) activity of ATP synthetase in soybean lecithin liposomes24. ATPase activity was measured in 100 mM Tris-HCl (pH 8.0) in the presence of 1 mM ATP at 37 °C by determining the liberated orthophosphate...

Unilamellar liposomes of 500-600 A diameter from soybean lecithin. 

Glycerophospholipids contain a glycerol skeleton to which two fatty acids are esterified saturated fatty acids occupy mostly sn-position 1, whereas unsaturated fatty acids are mainly present on sn-position 2. The third hydroxyl is linked to a phosphate group to which an organic base is mostly esterified (Fig. 1). The most important components of soybean lecithin are phosphatidylcholine (PC), phosphatidylethanolamine (PE), and phosphatidylinositol (PI). Phosphatidic acid (PA) may become important due to the presence of phospholipase D this enzyme slowly converts PC into PA in vegetable lecithins. Phosphatidylserine (PS), phosphatidylglycerol (PG), and lyso-phosphatidylcholine (LPC) are known as minor components lysophospholipids contain only one acyl group per molecule. Besides, ether phospholipids occur in which one or both fatty acyl... 

C Hanras, JL Perrin. Gram-scale preparative HPLC of phospholipids from soybean lecithins. J Am Oil ChemSoc 68 804-808, 1991. 

SL Melton. Analysis of soybean lecithins and beef phospholipids by HPLC with an evaporative light scattering detector. J Am Oil Chem Soc 69 784-788, 1992. 

WL Erdahl, A Stolyhwo, OS Privett. Analysis of soybean lecithin by thin layer and analytical liquid chromatography. J Am Oil Chem Soc 50 513-515, 1973. 

JD Weete. Preferential degradation of noncholine phosphatides in soybean lecithin by thermalization. J Am Oil Chem Soc 71 1195-1199, 1994. 

Imura, T., Otake, K., Hashimoto, S., Gotoh, T., Yuasa, M., Yokoyama, S., Sakai, H., Rathman, J. F., and Abe, M. (2003). Preparation and physicochemical properties of various soybean lecithin liposomes using supercritical reverse phase evaporation meOnWsfcids. Surf. B-Biointerfaces, 27, 133-140. 

These can be sprayed orally onto the buccal or the sublingual membrane to achieve a local or a systemic effect. One such spray called insulin buccal spray (IBS) was developed with soybean lecithin and propanediol [94], Soybean lecithin has high affinity for biomembranes but does not enhance the transport of drugs due to low solubility. Propanediol can improve the solubility of soybean lecithin, and act as an enhancer. IBS was administered to diabetic... 

Our previous GC analyses of the transmethylated phosphatides from this material, commercial soybean "lecithin," have shown 54% linoleic acid and 5% linolenic acid. The material designated soybean "lecithin" of course contains not only phosphatidylcholine, but also substantial amounts of phosphatidylethanolamine, phos-phatidylinositol, and phosphatidic acid. Both of the latter would confer a substantial negative charge to the microdisperse particles. 

Misato, T. Homma, Y. Ko, K. (1977) The Development of a Natural Fungicide, Soybean Lecithin. Netherlands Journal of Plant Pathology 83, Supplement 1, 395-402. 

In another, more recent study [58] 14C-tretinoin was intercalated in soybean lecithin labeled with 3H-phosphatidylcholine. The 3H/14C ratio in SC remained approximately constant, however, was lower in epidermis, and decreased steeply until a skin depth of approximately 200 pm was reached. The authors concluded that co-penetration of a drug-liposome bilayer is possible in the SC, but that based on the reduced 3H/14C ratio in deeper skin strata, drug and liposomal constituents diffuse separately in these layers. 

Feeding rats diet enriched with procyanidins complexed (1 3 w/w) with soybean lecithin (2.4%) for 3 weeks increased the TAC of their blood plasma (by 40% in young and by 30% in aged rats) (FI). Wistar rats fed a high-caloric, high-fat diet (chow supplemented with lard) and a high-caloric, normal-fat diet had decreased blood plasma TAC (by 8.8% and 9.0%, respectively) (B5). Intensive tocopherol supplementation of rats (20 g/kg diet of DL-a-tocopherol hydrogen succinate)... 

Muller, U., Weber, W., Hoffmann, A., Franke, S., Lange, R., Vieths, S. 1998. Commercial soybean lecithins A source of hidden allergens ZLebensm Unters Forsch 207 341-351. 

Alternatively, the enzyme may be used in an encapsulated form. Chen and Chang (1993) showed that hydrolysis of milk fat by lipase from Candida cyclindracea encapsulated in reverse micelles formed by soybean lecithin in isooctane, could be manipulated to favor the release of short-chain fatty acids by using a higher concentration of enzyme and a higher ratio of water to surfactant concentration at 45°C. 

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