p-Cymene metabolism in rats and guinea-pigs

Abstract
1. The metabolism of p-cymene was studied in rats and guinea-pigs. 2. Following intragastric or inhalation dosage (100mg/kg) urinary metabolite excretion was nearly complete within 48h, amounting to 60–80% dose. The inhalation experiments gave the lowest values. 3. 18 urinary metabolites were detected and identified. Of these, rats did not excrete two and guinea-pigs did not excrete a third. 4. No ring-hydroxylation of p-cymene was detected in rats, but guinea-pigs formed small amounts of carvacrol and hydroxycarvacrol. 5. Oxidation of both the methyl and isopropyl groups of p-cymene occurred extensively in both species. The following types of metabolites were formed: monohydric alcohols, diols, mono- and di-carboxylic acids and hydroxyacids. Conjugation with glycine of the cumic acid formed was extensive in guinea-pigs.