Indoleamine 2,3-dioxygenase (IDO) is responsible for degradation of L-tryptophan. The metabolites from this pathway lead to certain neurological disorders like, AIDS dementia complex, etc. Thus, IDO inhibitors have significant therapeutic value and the development of potent IDO inhibitors is a major goal of my research. Potent competitive inhibitors of IDO were reported and were distinguished by replacement of the N-H function of the indole ring of the tryptophan. A series of N-Alkylated L-and D-tryptophan derivatives were synthesized using alky halides as alkylating agents. These compounds are being tested later in vivo on IDO. Tryptophanase is a pyridoxal 5-phosphate dependent tetrameric enzyme. Tryptophanase is responsible for Tryptophan degradation into Indole, Pyruvate, and Ammonia. We examined the induction of Tryptophanase in E. coli with N-alkyl derivatives of tryptophan as inducers. We have performed the inhibitory studies on pure Tryptophanase enzyme. Allyltryptophan showed maximum inhibition.