FATTY ALDEHYDES 317 



that a considerable diaciduria developed, even in cases in which the fatty 

 acids themselves were not diacidogenic. Table 1 records the quantitative 

 results. 



The following excretion compounds were found to result after the ad- 

 ministration to dogs of comparatively large amounts of lauric acid mono- 

 amide : 



CHa-(CH2),o-CONH2 * (HOOC-(CH2),o-CONH2) > 



Lauramide Dodecanedioic acid 



monoamide 



HOOC-(CH2)8CONH2 > HOOC(CH2)6CONH2 > 



Sebacic acid Suberic acid 



monoamide monoamide 



HOOC(CH2)4-CONH2 > HOOC-(CH2)2CONH2 



Adipic acid Succinic acid 



monoamide monoamide 



The several products were identified by paper chromatography. '°^ Simi- 

 larly, after 2-methylnonanoic acid amide (CHs- (CH2)6-CH(CH3) -CO- 

 NHo) was fed, 2-meth5dazelaic acid amide, 2-methylpimelic acid amide, 

 and 2-methylglutaric acid amide were demonstrated. In fact, the cor- 

 responding malonic acid derivative, H00C-CH(CH3) -00X112, probably 

 accounted for the C4 fraction recovered, which was absent from norm;il 

 urine. ^"^ 



It would thus appear that the presence of the amide group renders fatty 

 acids readily susceptible to diacidogenesis. Even those acids which do 

 not normally undergo this change may be induced to follow this method 

 of oxidation if the acid is bound up with an amide. The introduction of a 

 methyl side chain markedly increases the susceptibility of these acid amides 

 to an oxidation pattern of this nature. There is considerable e\ddence 

 that, after the formation of the diacid, the resulting compound can undergo 

 sufficient /8-oxidations so that short-chain dicarboxylic acids are the final 

 product of oxidation. 



5. Fatty Aldehydes 



The importance of the aldehydes of fatty acids in the tissues was first 

 emphasized by Feulgen and his collaborators, ^"^"^^^ and by Behrens 

 alone.''- It was shown that these aldehydes have a wide-spread distribu- 



'«8 R. Feulgen and K. Voit, Arch. ges. Physiol. {Pfluger's), 206, 389-410 (1924). 



'"^ R. Feulgen, K. Imhauser, and M. Behrens, Z. physiol. Chem., ISO, 161-179 (1929). 



i'" R. Feulgen and M. Behrens, Z. physiol. Chem., 256, 15-20 (1938). 



'" R. Feulgen and T. Bersin, Z. physiol. Chem., 260, 217-245 (1939). 



11= M. Behrens, Z. physiol. Chem., 191, 183-186 (1930). 



