346 VII. ACIDS, AMIDES, ALDEHYDES AND HYDROCARBONS 



Coombs and Hele^^^ reported that the following compounds do not give 

 rise to mercapturic acids in the dog: o-, m~, and p-chlorophenol, o- and p- 

 chloroanisol, m-chloroanisol, and p-chloroacetanilide. When the halogen 

 is in the side-chain, as for example in benzylchloride (CeHs -011201), mer- 

 capturic acid formation occurs, ^^^ with the elimination of the halogen and 

 the attachment of the S directly to the side-chain, as follows: 



CH2SCH2CHCOOH 



NHCOCH3 



V v" 



Benzyl chloride A'^-acetyl-S-benzylcysteine 



The ability of animals to form mercapturic acid is a general one, but is 

 not universal. Thus dogs, rabbits, and rats (Stekol,^^'"-*" du Vigneaud 

 ei al.;-^^ Stekol and Foy,262 Conway 2"), cats (Virtue^^"), and mice (StekoP^^) 

 are able to effect this synthesis, but pigs are unable to do so (Coombs and 

 Hele256). 



b. Naphthalene and Related Products, (a) Naphthalene. The metab- 

 olism of naphthalene presents many similarities to that of benzene. 

 Thus, it may be oxidized to monophenolic compounds, although in some 

 cases diphenols or quinones arise. Under such conditions, the positions 

 attacked usually differ from those which, according to Berenblum and 

 Schoental,^" are the most active in chemical substitutions in vitro. Sec- 

 ondly, naphthalene may be reduced, resulting in a partly reduced aro- 

 matic ring."" Although naphthalene is less toxic than phenol, it has 

 been shown to produce opacity of the crystalline lens in the case of the 

 rabbit; this is a condition resembling human senile cataract. 



2« H. I. Coombs and T. S. Hele, Biochem. J., 20, 606-612 (1926). 



2" J. A. Stekol, /. Biol. Chem., 128, 199-205 (1939). 



2" J. A. Stekol, J. Biol. Chem., 110, 463-469 (1935). 



«« J. A. Stekol, J. Biol. Chem., 117, 147-158 (1937). 



"6 J. A. Stekol, J. Biol. Chem., 121, 87-91 (1937). 



2" J. A. Stekol, /. Biol. Chem., 122, 333-342 (1938). 



2« J. A. Stekol, /. Biol. Chem., 12A, 129-133 (1938). 



2« J. A. Stekol, J. Biol. Chem., 1S8, 225-229 (1941). 



2M J. A. Stekol, Ann. Rev. Biochem., 2, 150-157 (1943); 10, 265-284 (1941). 



*" V. du Vigneaud, J. L. Wood, and O. J. Irish, /. Biol. Chem., 129, 171-177 (1939). 



2" J. A. Stekol and J. R. Foy, /. Biol. Chem., 118, 155-160 (1937). 



2" W. J. Conway, J. Biol. Chem., 121, 27-29 (1937). 



^* R. W. Virtue, Proc. Soc. Exptl. Biol. Med., 34, 425-427 (1936). 



2« J. H. Stekol, Proc. Soc. Exptl. Biol. Med., 33, 115-119 (1935). 



26" H. I. Coombs and T. S. Hele, Biochem. J., 21, 611-622 (1927). 



*" I. Berenblum and R. Schoental, Biochem. J., 39, Ixiv-lxv (1945). 



