| (S)-(-)-g- | butyrolactam-g-carboxylate |
| (S)-(-)-g- | butyrolactam-g-carboxylic Acid |
| L-pyro | glutamic acid |
| L- | glutamic acid g-lactam |
| L- | glutamic acid gamma-lactam |
| laevo- | glutamic acid gamma-lactam |
| | PCA |
| | pidolic acid |
| 5-L-oxo | proline |
| 5-oxo-L- | proline |
| L- | proline, 5-oxo- |
| (-)- | pyroglutamic acid |
| (S)- | pyroglutamic acid |
| (2S)-5-oxo | pyrrolidine-2-carboxylic acid |
| (S)-5-oxo | pyrrolidine-2-carboxylic acid |
| (5S)-2-oxo | pyrrolidine-5-carboxylate |
| (2S)-5-oxo | pyrrolidine-5-carboxylic acid |
| (5S)-2-oxo | pyrrolidine-5-carboxylic acid |
| 2-oxo | pyrrolidine-5(S)-carboxylate |
| 2-oxo | pyrrolidine-5(S)-carboxylic acid |
| (S)-5-oxo-2- | pyrrolidinecarboxylate |
| L-5-oxo-2- | pyrrolidinecarboxylate |
| (S)-5-oxo-2- | pyrrolidinecarboxylic acid |
| (S)-(-)-2- | pyrrolidinone-5-carboxylic Acid |
| L- | pyrrolidinonecarboxylate |
| (S)-(-)-2- | pyrrolidone-5-carboxylate |
| L-2- | pyrrolidone-5-carboxylate |
| (S)-(-)-2- | pyrrolidone-5-carboxylic acid |
| (S)-2- | pyrrolidone-5-carboxylic acid |
| 2-L- | pyrrolidone-5-carboxylic acid |
| 2-laevo- | pyrrolidone-5-carboxylic acid |
| L- | pyrrolidonecarboxylate |