LIPIDES (fats and RELATED SUBSTANCES) 



73 



Table 4-1 

 Classes of lipides and their hydrolysis products 



Lipide 



I. tjimple lipides: 

 1. True fats 



(in butter, lard, oils) 



2. Waxes 



(in beeswax) 



II. Compound lipides: 



1. Phospholipides, e.g., 

 lecithins (in egg yolk, 

 brain) 



Hydrolysis Products' 



Alcohol 

 (name and formula) 



Glycerol, 

 C3H.(0H)3 



Cetyl, 



CisHcxCH^OH 



Glycerol, 



C8H5(0H)3 



Glycolipides, e.g., 

 kerasin (in brain) 



III. Derived lipides: 



1. Fatty acids ' 

 (in fats) 



2. Sterols 



(in fats, waxes) 



Galactose, 



Ga-UiaUe 



Acid and other products 

 (name and formula) 



Stearic, 



CnH^-. COOH 

 Oleic, 



C17H33 COOH 

 Cerotic, 



C^sHsi COOH 



Phosphoric, 



H.PO4 

 Oleic, 



CnH33 COOH 

 Palmitic, 



Cr.H3i COOH 

 Choline, 



(CH3)aX(0H)C.H4 0H 

 Lignoceric, 



C23H47 COOH 

 Sphingosine. 



Ci8H»(0H)2 NH. 



Oleic, 

 CitHss COOH 



Cholesterol, 



C27H450H 



* For a siven fat, e.g., butter, the typical rather than the total products of 

 hydrolysis are listed. Fatty acids, wax alcohols, and sterols may occur free or 

 combined. They are also classed as derived lipides. 



available that acts on the ester to be hydrolyzed, or by means of strong 

 acids or superheated steam. A more convenient and widely used method 

 consists in subjecting the ester to the action of a strong alkali such as 

 sodium hydroxide, whereby the alcohol and a salt of the acid are produced: 







II 

 C4H9OCCH3 + NaOH 



Butyl Sodium 



acetate hydroxide 



O 



II 

 -* C4H90H + NaOCCHs 



Butyl Sodium 



alcohol 



acetate 



This process is called saponification. If it is desired to obtain the organic 

 acid itself, the solution of the sodium salt may be treated with a strong 

 mineral acid: 



