CONJUGATION OF AROMATIC SUBSTANCES. 785 



ROST asserts, contrary to earlier claims, that the same occurs with gallic 

 acid (trioxybenzoic acid) and tannic acid. 1 



Although NENCKI and REKOWSKI 2 have shown that acetophenone (phen- 

 ylmethylketone), CeHs.CO.CHs, is oxidized to benzoic acid and eliminated 

 as hippuric acid, the aromatic oxyketones with hydroxyl groups, such as 

 resacetophenone, 2, 4 dioxacetophenone (HO^.CeHs.CO.CHs, pass into 

 the urine as ethereal-sulphuric acids and in part after conjugation with 

 glucuronic acid. Euxanthon, which is also an aromatic ketone, namely 



CO 

 dioxyxanthon, HO.Celis^ yCeHa.OH, passes into the urine as eux- 



X CT 

 anthic acid after conjugation with glucuronic acid. 



A conjugation of other aromatic substances with glucuronic acid, 

 which last is protected from combustion, occurs rather often. The phenols, 

 as above stated (page 725), pass in part as conjugated glucuronic acids 

 into the urine. The same is true for the homologues of the phenols, for 

 certain substituted phenols, and for many aromatic substances, also 

 hydrocarbons after previous oxidation and hydration. Thus HILDE- 

 BRANDT and FROMM and CLEMENS 3 have shown that the terpenes and cam- 

 phors, by oxidation or hydration, or in certain cases by both, are converted 

 into hydroxyl derivatives when the body in question is not previously 

 hydroxylized, and that these hydroxyl derivatives are eliminated as con- 

 jugated glucuronic acids. Conjugated glucuronic acids are detected in 

 the urine after the introduction of various substances into the organsim, 

 e.g., therapeutic agents, such as terpenes, borneol, menthol, camphor (cam- 

 phoglucuronic acid was first observed by SCHMIEDEBERG), naphthalene, 

 oil of turpentine, oxyquinolines, antipyrine, and many other bodies. 4 

 Orthonitrotoluene in dogs passes first into o-nitrobenzyl alcohol and then 



1 In regard to the behavior of gallic and tannic acids in the animal body, see C. 

 Morner, Zeitschr. f. physiol. Chem., 16, which also contains the earlier literature; also 

 Harnack, ibid., 24, and Rost, Arch. f. exp. Path. u. Pharm., 38, and Sitzungsber. d. 

 Gesellsch. zur Beford. d. ges. Naturwiss. zu Marburg, 1898. 



2 Arch. d. scienc. biol. de St. Petersbourg, 3, and Ber. d. deutsch. chem. 

 Gesellsch., 27. 



3 Hildebrandt, Arch. f. exp. Path. u. Pharm., 45, 46; Zeitschr. f. physiol. Chem., 

 36; with Fromm, ibid., 33; and with Clemens, ibid., 37; Fromm and Clemens, ibid., 

 34. Extensive investigations on the behavior of alicylic compounds with the glucuronic 

 acid conjugation in the organism have been carried out by Hamalainen, Skand. Arch, 

 f. Physiol., 27. 



4 See O. Kiihling, 1. c., which gives the literature up to 1887; also E. Kiilz, Zeitschr. 

 f. Biologic, 27; the works of Hildebrandt, Fromm and Clemens, see footnote 3; 

 Brahm, Zeitschr. f. physiol. Chem., 28; Fenyvessy, ibid., 30; Bonanni, Hofmeister's 

 Beitrage, 1; Lawrow, Ber. d. d. chem. Gesellsch., 33. 



