Glyceryl esters, hydrolysis

SNG Substitute natural gas. soaps Sodium and potassium salts of fatty acids, particularly stearic, palmitic and oleic acids. Animal and vegetable oils and fats, from which soaps are prepared, consist essentially of the glyceryl esters of these acids. In soap manufacture the oil or fat is heated with dilute NaOH (less frequently KOH) solution in large vats. When hydrolysis is complete the soap is salted out , or precipitated from solution by addition of NaCl. The soap is then treated, as required, with perfumes, etc. and made into tablets. 

Palmitic acid is present as cetyl ester in spermaceti from which, by hydrolysis, the acid may be obtained it is present in bee s wax as the mehssic ester and in most vegetable and animal oils and fats, in greater or lesser amounts, as glyceryl tripalmitate or as mixed esters, along with stearic and oleic adds, Palmitic acid is separated from stearic and oleic acids by fractional vacuum distillation and by fractional crystallization. With NaOH, palmitic add forms sodium palmitate, a soap, Most soaps are mixtures of sodium stearate, palmitate, and oleate. 

In a completely unrelated development, E. Bamann (7) showed that lanthanum hydroxide promotes the hydrolysis of glyceryl phosphate subsequently, BUTCHER and Westheimer (9) investigated the promotion of the hydrolysis of phosphate esters by lanthanum hydroxide gel, and found a more than thousandfold increase in the rate. Tliey also proposed a mechanism for the reaction which, however, involves water. 

The chemistry of complex lipids is dominated by regioselective hydrolysis reactions of (1) the glyceryl fatty acid esters and (2) phosphate diesters. Both types of reactions are routinely performed with the corresponding esterases. A large variety of lipid active transferase enzymes is also commercially available. Phospholipases Aj, A, C, and D, for example, split any of the four ester bonds of a phospholipid regioselectively. The product without a fatty acid side chain at C2 of glycerol is called a lysophospholipid. Lecithin-cholesterol-acyltransferase transfers the fatty acid at C2, often linoleic acid, to the OH group at C3 of cho-... 

Esterification of 2 nitrobenzoic chloride with glyceryl acetonide, followed by a reduction of the nitro group to the amino group. The resulted ester is condensed with 4, 7 - dichloroquinoline, followed by hydrolysis of acetonide (2). 

As an alkaline environment is encountered during interesteriflcation, the catalyst (which is nucleophilic) attacks the slightly positive carbonyl carbon at one of three fatty acid-glycerol ester bonds to form a tetrahedral intermediate. A fatty acid methyl ester is released, leaving behind a glycerylate anion. Kinetics of base-catalyzed hydrolysis of esters are second-order reactions dependent on both ester... 

Fatty oils consist mostly of glyceryl or other esters of higher fatty acids — in some cases, notable amounts of free acids themselves arc present. The amount of free acid present depends on the source from which the oil is taken. The acid content or value of fatty oils increases with time due to hydrolysis with moisture and is therefore a rough indicator of the age of the oil, i.e., it gives an idea of how old a fatty oil is. The deterioration in the flavour of the edible oils with time is due to the increase in the free acid concentration formed by hydrolysis and oxidation. 

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