An N-acylglycine that is the 4-amino derivative of hippuric acid; used as a diagnostic agent in the measurement of renal plasma flow. ChEBI: P-aminohippuric acid is an N-acylglycine that is the 4-amino derivative of hippuric acid; used as a diagnostic agent in the measurement of renal plasma flow. It has a role as a Daphnia magna metabolite. It is a conjugate acid of a p-aminohippurate.