FATTY ACID AMIDES 315 



4. Fatty Acid Amides 



The replacement of the carbox}^! group by an acid amide group has been 

 found to influence, to an important extent, the rate of disappearance of the 

 corresponding fatty acids. Bernhard^^'"^ reported that the substitution of 

 methyl-, ethyl-, or propylamide of benzoic acid, or of hexahydrobenzoic 

 acid, did not influence the course of intermediary metabolism. In the 

 case of dicarboxyl acids which are metabolized with difficulty, it was found 

 that the transformation to the corresponding amide resulted in a more 

 readily utilized compound. Thus, Flaschentrager" found that sebacic 

 acid amide (HOOC-(CH2)8-CONH2) was better tolerated in the dog than 

 was sebacic acid, while Bernhard"*^ observed that sebacic acid-mono-A^- 

 methylamide (COOH- (CH2)8-CONH-CH3), sebacic acid-bis-A^-methyl- 

 amide (CH3-NH-OC-(CHo)8-CO-NH-CH3), and sebacic acid-mono-A^- 

 propylamide (HOOC- (CH2)8-CO-NH-CH2-CH2-CH3), as well as the 

 mono-A-propylamide of suberic acid (HOOC- (CH2)6•CONH•CH2•CH2• 

 CH3), were more slowly utilized than were the corresponding free acids. 



The amides of the normal aliphatic saturated and also straight-chain 

 unsaturated monocarboxylic acids were found, by Kuhn and Low,!"^ to be 

 readily metabolized. After the feeding of caproylamide (CH3-(CH2)6- 

 CONH2), lauramide (CH3-(CH2)io-CONH2) or palmitamide (CHg-- 

 (CH2)i4-CONH2) to rabbits, Kuhn and Low'^^ reported that no trace of 

 amide or any decomposition product could be found in the urine. The 

 same results were noted with several unsaturated acid amides, including 

 a,^-hexenoamide (CH3 • (CH2)2 • CH : CH • CONH2), ^, 7-hexenoamide (CH3 • 

 CH2-CH:CH-CH2-CONH2) and 3,5-octadienoic acid amide (CH3-CH2- 

 CH.CH-CH:CH-CH2-CONH2).'«« However, small amounts of the 

 ingested substance were excreted in the case of lauric acid anilide (CH3- 

 (CH2)io-CONHC6H5) and lauric acid methyl anihde (CH3-(CH2)ioCON- 

 HCsHg) and lauric acid methyl anilide (CH3-(CH2)ioCOX(CH3)C6H5),as 

 well as after caprinyl-D,L-alanine(CH3- (CH2)8-CONH-CH(CH3) -COOH). 



In some instances, the presence of the amide group may limit the oxida- 

 tion of the compound. Thus, /3-methyl-/?-propylacrylic acid amide (I) is 

 not completely oxidized; as much as 13% of the dose administered was 

 recovered by Kuhn and Low'"^ as the monamide of 2-methyl-butene (1,2)- 

 1,4-dicarboxylic acid (II) as indicated below: 



CH^CHoCHo-CrCHCONHo ^ HOOCCH.CHoC:CHCONH, 



I I 



CH3 CH3 



(I) (11) 



The Metabolism of /3-Methyl-/3-Propylacrylic Acid Amide (I) by co-Oxidation"'^ 



!•♦ K. Bernhard, Z. physiol. Chem., 251, 47-51 (1938). 

 W5 K. Bernhard, Z. physiol. Chem., 256, 65-70 (1938). 

 lo* R. Kuhn and I. Low, Z. physiol. Chem., 259, 182-193 (1939). 



