Phenylacetylglutamine is a product formed by the conjugation of phenylacetate and glutamine. It is a common metabolite that occurs naturally in human urine. The highly-nitrogenous compound is most commonly encountered in human subjects with urea cycle disorders,. These conditions, such as uremia or hyperammonemia, tend to cause high levels of nitrogen in the form of ammonia in the blood. Uremic conditions are a result of defects in enzymes that convert ammonia to urea, the primary nitrogenous waste metabolite in the urea cycle. Phenylacetylglutamine is a product formed from the conjugation of phenylacetate and glutamine. Technically, it is the amino acid acetylation product of phenylacetate (or phenylbutyrate after beta-oxidation). Phenylacetylglutamine is a normal constituent of human urine, but other mammals such as the dog, cat, rat, monkey, sheep, and horse do not excrete this compound. Phenylacetyl-CoA and L-glutamine react to form phenylacetylglutamine and coenzyme A. The enzyme (glutamine N-acetyl transferase) that catalyzes this reaction has been purified from human liver mitochondria and shown to be a polypeptide species distinct from glycine-N-acyltransferase. Phenylacetylglutamine is a major nitrogenous metabolite that accumulates in uremia. It has been shown that over 50% of urine phenylacetylglutamine may be derived from kidney conjugation of free plasma phenylacetic acid and/or from the kidney's preferential filtration of conjugated phenylacetic acid. Phenylacetylglutamine is a microbial metabolite found in Christensenellaceae, Lachnospiraceae and Ruminococcaceae.

Metabolism and Physiological Effects of Phenylacetylglutamine References