L-Kynurenine (L-Kyn) is a precursor of kynurenic acid which is the only recognized endogenous excitatory amino acid receptor antagonist in the central nervous system. L-Kyn is known to be a pigment generating component in animals. In mammals, it modulates the transmission of glutamate neurotransmitter. It is also considered to be a sex-attracting pheromone in vertebrates.', 'L-Kynurenine is a key intermediate in the breakdown of L-tryptophan and the formation of nicotinamide adenine dinucleotide (NAD+) via the kynurenine pathway. L-kynurenine is involved in a variety of neurological processes and diseases. L-kynurenine is a substrate for kynureninase/kynurenine hydrolase; kynurenine 3-monooxygenase and kynurenine-oxoglutarate transaminase.', 'Key intermediate in the breakdown pathway of tryptophan.
