D-Pyroglutamic acid (PCA) is a cyclic derivative of glutamic acid physiologically present in mammalian tissues. It has been shown that PCA releases GABA from the cerebral cortex and displays anti-anxiety effects in a simple approach-avoidance conflict situation in the rat.

2-Furoyl-LIGRLO-amide is a potent and selective protease-activated receptor 2 (PAR2) agonist.

33-Dimethylglutaric acid is a compound found in human urine.