5-oxopyrrolidine-2-carboxylic acid; 5-oxo-Proline; 5-oxo-DL-Proline; (±)-2-Pyrrolidone-5-carboxylic Acid; (±)-Pyroglutamic Acid; 5-Oxo-DL-proline; 5-Oxopyrrolidine-2-carboxylic Acid; DL-2-Pyrrolidinone-5-carboxylic Acid; DL-2-Pyrrolidone-5-carboxylic Acid; DL-Pyroglutamate; DL-Pyroglutamic Acid; DL-Pyrrolidonecarboxylic Acid; NSC 40887
