308 VII. ACIDS, AMIDES, ALDEHYDES AND HYDROCARBONS 



(6) Succinic Acid. Employing a method for the isolation of succinic 

 acid worked out by Thomas and Weitzel,^^ WeitzeP^ reported that man ex- 

 cretes, by way of the kidney, 2 to 12 mg. of succinic acid daily. 



A number of factors result in an increase in the excretion of succinic acid. 

 For example, the elimination of this dicarboxylic acid in man was aug- 

 mented by the ingestion of 250 mg. of glucose. ^^ The higher dicarboxylic 

 acids may likewise serve as sources of urinary succinate. Thus, Flaschen- 

 trager and Bernhardt" demonstrated the presence of small amounts of 

 succinic acid anilide and succinic aniline after the feeding of adipic acid 

 or the half anilide of sebacic acid to the dog. WeitzeP^ also reported the 

 greatest increase in succinate after adipic acid (Ce) and pimelic acid (C?) 

 had been given; the author is of the opinion that suberic (Cs) and azelaic 

 (Cg) acids also exhibit some activity. Glutaric (Cs) acid was found to be 

 entirely inactive insofar as succinate formation is concerned. 



The fatty acids having an odd number of carbon atoms or having 

 branched chains are very important sources of succinate. Thomas and 

 Weitzel*^ observed that the ingestion of synthetic fats, produced from 

 petroleum in Germany during the war, increased succinic acid excretion; 

 these fats were characterized by a high proportion (50%) of fatty acids 

 having an odd number of carbon atoms. After the administration of one 

 such fat to nine subjects, the succinic acid output was markedly increased; 

 in a second series following the administration of another synthetic fat, no 

 alteration in the normal excretion of succinic acid could be noted. These 

 authors suggest that the increased succinic acid output results from a 

 disturbance in enzymic decomposition brought about by branched mono- 

 carboxylic acids, or by normal and abnormal branched dicarboxylic acids. 

 Similar results have been reported by Hanson. ^^'^^ 



The effect of alkylated succinic acid derivatives on the urine succinic 

 acid varies with the chain length of the substituent. Thus, Emmrich, 

 Neumann, and Emmrich-Glaser^^ found that considerable amounts of suc- 

 cinic acid were present in the urine of the dog after methyl-, ethyl-, n-pro- 

 pyl-, or n-butyl-succinic acid had been fed ; the utilization of n-hexyl-suc- 

 cinic acid was somewhat greater than that of its homologues. In a later 



68 K. Thomas and G. Weitzel, Z. physiol. Chem., 282, 170-174 (1947). 

 " G. Weitzel, Z. physiol. Chem., 282, 174-180 (1947). 



60 B. Flaschentrager and K. Bernhard, Z. physiol. Chem., 256, 71-74 (1938). 

 «i G. Weitzel, Z. physiol. Chem., 282, 185-191 (1947). 

 «2 K. Thomas and G. Weitzel, Z. physiol. Chem., 282, 180-185 (1947). 

 " H. Hanson, Erndhrung, 6, 273-277 (1941); Chem. Zentr., 113, JI, 2153 (1942). 

 " H. Hanson, Z. gis. exptl. Med., 113, 226-244 (1943). 



66 R. Emmrich, P. Neumann, and I. Emmrich-Glaser, Z. physiol. Chem., 267, 228-241 

 (1941). 



