An inhibitor of sphingolipid synthesis and aminotransferases; inhibits bacterial SPT 100 times more potently than D-cycloserine; inhibits SPT activity up to 86% in a dose-dependent manner in mouse brain microsomes following administration of doses ranging from 25-200 mg/kg; inhibits SPT in rabbit aorta and several aminotransferases in vitro and in vivo in rat; inhibits the growth of M. tuberculosis through branched chain aminotransferase inactivation, and it does so more rapidly and potently than D-cycloserine (MICs = 0.3 and 2.3 μg/ml, respectively),