| D-Pyroglutamic acid |
| (R)-(+)-2-pyrrolidone-5-carboxylic acid |
| (R)-2-Pyrrolidone-5-carboxylic acid |
| D-5-Oxo-2-pyrrolidinecarboxylic acid |
| (R)-(+)-2-Pyrrolidinone-5-carboxylic acid |
| H-D-PYR-OH |
| (R)-5-Oxopyrrolidine-2-carboxylic Acid |
| (R)-5-Pyrrolidone-2-carboxylic Acid |
| D-Glutamic Acid Lactam |
