Metabolism of derivatives of toluene. 3. o-, m- and p-xylenes

Abstract

All 3 xylenes are mainly oxidized to the corresponding toluic acids (60, 81 and 88%, respectively). The resulting o-toluic acid is excreted mainly unconjugated and as an ester glucuronide (30% of the dose), but a small amt. (0.3% by isolation) is conjugated. The toluic acids from m- and p-xylenes are excreted chiefly as glycine conjugates, only small amts. being excreted free or conjugated with glucuronic acid. Evidence of hydroxylation was obtained in the case of all 3 isomers: 6 and 4% of doses of o- and m-xylenes, respectively, are excreted as ethereal sulfate and 10-15% of o-xylene is probably excreted as an ether glucuronide. p-Xylene may give rise to a xylenol.