L-Pyroglutamic acid β-naphthylamide

L-Pyroglutamic acid β-naphthylamide (PYR) is a synthetic glutamic acid derivative. It serves as a chromogenic substrate for the detection of pyrrolidonyl peptidase activity, commonly used in microbiological research for bacterial identification (e.g., Enterococcus and Streptococcus) in both in vitro assays and clinical laboratory settings.