L-Cycloserine

L-Cycloserine (CAS No.: 339-72-0) is a bioactive small molecule widely used in neuropharmacology and anti-infective research, characterized as a dual inhibitor of gamma-aminobutyric acid (GABA) transaminase and branched-chain aminotransferases in Mycobacterium tuberculosis. By inhibiting GABA transaminase, it modulates intracellular GABA levels and influences inhibitory neurotransmission, while its activity against mycobacterial aminotransferases disrupts branched-chain amino acid metabolism and contributes to antimycobacterial effects. In addition, L-Cycloserine acts as a potent inhibitor of serine palmitoyl transferase, a key enzyme in the sphingolipid biosynthesis pathway, thereby affecting the production of sphingolipid species in neural tissues. These combined mechanisms underlie its observed anticonvulsant properties in vivo and its capacity to alter neurochemical signaling, including the suppression of neuropeptide synthesis in brain tissue. In vitro and in vivo studies indicate that L-Cycloserine exhibits inhibitory activity in the low micromolar range against relevant enzymatic targets and demonstrates antimicrobial potency against M. tuberculosis at low microgram per milliliter levels. This compound is commonly employed in cell-based assays and animal models to investigate GABAergic signaling, sphingolipid metabolism, and host–pathogen interactions, with experimental concentrations or dosing regimens varying according to specific study designs and therapeutic hypotheses.