Melatonin is synthesized by an enzymatic pathway, in which arylalkylamine (serotonin)N-acetyltransferase cata-lyzes the rate-limiting step. Aprevious study [Khalil, ., DeAngelis, J., Ishii,M.&Cole, . (1999). Sci. USA 96, 12418–12423] reported the discovery of bromoacetyltryptamine (BAT), a new type of inhibitor of this enzyme. This compound is the precursor of a potent bifunctional inhibitor (analogue of the transition state), capable of interfering with both the substrate and the cosubstrate binding sites. .
