Metabolism of p-hydroxybenzoic acid and p-hydroxyphenylacetic acid in the monkey

p-hydroxy benzoic acid was fed to a monkey in one, two and three gram doses, the urine was collected for 36 hours following each dose, evaporated and extracted. The urine was found in every case to contain only the uncombined acid. This agrees with the findings of other investigators who have fed this acid to several of the lower animals. In each case from 50-60 per cent. of the acid was recovered from the urine.

After feeding p-hydroxyphenylacetic acid in one or two gram doses, approximately 60 per cent. of this acid was recovered from the urine of the monkey. Some of this acid existed in the free state, while a portion of it was excreted in the urine in combination with glycocoll as p-hydroxyphenaceturic acid. p-hydroxyphenaceturic acid up to this time was found only on one instance and the amount was insufficient for analysis. The melting point of 154.5-155 is two degrees higher than the melting point cited in the literature. The acid is relatively soluble in alcohol, ethylacetate and warm water but insoluble in ether, benzol and cold water. On boiling with conc. HCl, the acid split up into its two components p-hydroxyphenylacetic acid and glycocoll. The analysis of the compound agrees with the theoretical values for carbon, hydrogen and nitrogen.

The process of metabolism in the organisms of the monkey in regard to P-hydroxybenzoic acid and @-hydroxyphenylacetic acid is comparable to that found in lower animals and unlike that found in man. In man, the p-hydroxybenzoic acid is combined with gloycocoll and excreted as P-hydroxyhippuric acid, while in the lower animals, the acid after ingestion is excreted uncombined in the urine.

p-hydroxyphenylacetic acid on the contrary is found free in the urine of man after ingestion and combined with gylcocoll in the urine of animals.