ACETIC ACID AND ACETATE 263 



excreted by the frog. According to Marshall alone*" and with others,^^ 

 the dog excretes p-aminobenzenesulfonamide (sulfanilamide) iii an un- 

 changed form, whereas in rabbits it is excreted mainly as acetylamino- 

 benzcnesulfonamide. Mice excrete the unchanged form,*^ although 

 Marshall*"* found that a conjugated form was also present in the urine. 

 This conjugated form, probably acetylsulfanilamide, was excreted by the 

 fish, chicken, rat, guinea pig, cat, pig, cow, horse, and monkey, as well as 

 by the human subject and rabbit.®" As much as one-half of the sulfanila- 

 mide excreted by man may be in the form of the acetylated compound."^ 

 The acetylation reaction of sulfanilamide is given below: 



NH2 NH2 



Sulfanilamide Acetylated 



sulfanilamide 



Acetj'lation of Sulfanilamide*^ 



In the case of sulfapyridine, a species variation in metabolism has not 

 been noted. The drug may be excreted in the free form, as its acetyl 

 derivative, or it may be oxidized to a hydroxy derivative which is excreted 

 either free, acetylated, or conjugated with sulfuric or glucuronic acids. 

 The occurrence of oxidation was first demonstrated by Scudi™ in the dog, 

 with the isolation of hydroxysulf apjTidine ; apparently a similar reaction 

 obtains in the rat, since an increased glucuronic acid excretion was noted 

 in this species after the administration of sulfapyridine.'^^ ~^^ Finally, 

 Bray et al.^^ isolated an hydroxy derivative from the urine of rabbits fed 

 sulfapyridine which is believed to be simOar to the product isolated from 

 the urine of the dog after the aforementioned drug was administered. 



66 E. K. Marshall, Jr., Physiol. Revs., 19, 240-269 (1939). 



" E. K. Marshall, Jr., K. Emerson, Jr., and W. C. Cutting, /. Ajn. Med. Assoc, 108, 

 953-957(1937). 



68 A. T. Fuller, Lancet, 1937, 1, 194-198. 



6' E. S. West and W. R. Todd, Textbook of Biochemistry, IMacmillan, New York, 1955, 

 p. 512. 



™ J. V. Scudi, Science, 91, 486 (1940). 



" J. V. Scudi and H. J. Robinson, Am. J. Med. Set., 201, 711-717 (1941). 



" C. J. Weber, J. J. Lalich, and R. H. Major, Proc. Soc. Exptl. Biol. Med., 53, 190-192 

 (1943). 



" J. V. Scudi, Proc. Soc. Exptl. Biol. Med., 55, 197-199 (1944). 



