ACETIC ACID AND ACETATE 271 



the synthesis of the pyrrole rmgs. Bloeh and Rittenberg, in unpubUshed 

 work cited by Bloeh/ noted that deuteriopropionate was not incorporated 

 into hemin; on the other hand, butyrate was about one-half as effective 

 as was acetate. The effect of this acid is presumably the result of the 

 formation of acetyl groups. 



e. Uric Acid Synthesis. Sonne et al.^"^^ reported that the earboxyl carbon 

 of acetate was hicorporated into the two ureido carbons (^ and 8) of uric acid 

 excreted by the pigeon. On the other hand, the earboxyl of glycine was 

 showai to give rise to carbon 4, while CO2 was found to be the source of 

 carbon 6 of the purine nucleus. The difference in origin of carbons 2 

 and 8 (which are derived from acetate) and that of 4- (which origmates from 

 glycine) indicates that acetate and glycine are not interconvertible in the 

 pigeon.^ 



f. Amino Acid Synthesis. Gilvorg and Bloch^^'' reported that brewery 

 yeast {Saccharomyces cerevisiae) is able to utilize acetate as a source of 

 carbon for the amino acids. Thus, when the yeast was grown on a medium 

 containing glucose and labeled acetate, it was found that the isotopic C was 

 present in most of the amino acids with the exception of phenylalanine, 

 tyrosine, and glycine, which were believed to be derived rather directly 

 from glucose. Acetic acid was found to be the major source of the carbon 

 skeleton of lysine. Arnstein and Neuberger^^^ reported that both carbons 

 of acetate appear in the glycme molecule synthesized to detoxicate adminis- 

 tered benzoic acid. It has likewise been proved that the earboxyl C of 

 acetate is converted into the dicarboxylic amino acids without first being 

 transformed to C02.^^^ 



g. Miscellaneous Syntheses Other Than via the Tricarboxylic Acid 

 Cycle. In addition to the aforementioned specific compounds which 

 originate from acetate, the synthesis of other compounds from acetate was 

 discussed earlier. This includes the ketone bodies (especially acetoacetic 

 acid, but also jS-hydroxybutyric acid), and the several polycarboxylic 

 acids of the tricarboxylic acid cycle, such as citric, isocitric, a-ketoglutaric, 

 malic, succinic, fumaric, and oxaloacetic acids. Although the partial 

 synthesis of these several acids by the incorporation of acetic acid into the 

 tricarboxylic acid cycle is generally accepted, there is some evidence 

 of syntheses of these compounds from acetate by other pathways. 



125 J. C. Sonne, J. M. Buchanan, and A. M. Delluva, /. Biol. Chem., 166, 395-396 

 (1946). 



126 C. Gilvorg and K. Bloch, ./. Biol. Chem., 193, 339-346 (1951). 



'" H. R. V. Arnstein and A. Neuberger, Biochem. J., 1^5, iii-iv (1949). 

 '28 C. B. Anfinsen, A. Beloff, and A. K. Solomon, J. Biol. Chem., 179, 1001-1013 

 (1949). 



