What is "phenylglyoxal"

n. (context organic compound English) An organic compound with formula C₆H₅C(O)C(O)H, used as a reagent to modify the amino acid arginine.

Phenylglyoxal is the organic compound with the formula CHC(O)C(O)H. It contains both an aldehyde and a ketone functional group. It is yellow liquid when anhydrous but readily forms a colorless crystalline hydrate. It has been used as a reagent to modify the amino acid, arginine.