7-Cl-CYNA

7-Cl-CYNA (7-chlorokynurenic acid) is a potent and selective small molecule antagonist of the glycine-binding site of the N-methyl-D-aspartate receptor (NMDAR). It is the active metabolite of AV-101 (4-chlorokynurenine), an oral prodrug developed by Vistagen. Unlike non-competitive NMDAR antagonists such as ketamine, which block the ion channel directly, 7-Cl-CYNA acts as a competitive antagonist at the glycine co-agonist site. This mechanism is intended to modulate NMDAR activity to treat various central nervous system (CNS) disorders—including major depressive disorder, neuropathic pain, and levodopa-induced dyskinesia—while potentially avoiding the dissociative and psychotomimetic side effects typically associated with channel blockers. Although AV-101 failed to meet primary endpoints in some Phase 2 depression trials, it remains under investigation for other CNS indications.

Other names

7-chlorokynurenic acid7-chloro-4-hydroxyquinoline-2-carboxylic acid