NOVEL REDOX DERIVATIVES OF TRYPTOPHAN

The design, synthesis and study of some physicochemical properties of several potential brain targeting chemical delivery systems (CDS) of D ,L-tryptophan (Trp) are described. CDS's are based on a 1,4-dihydropyr idine <-> pyridinium salt-type redox system. The dihydropyridine moiet y was chemically attached to the amino group of Trp by either substitu ted amide or substituted carbamate linkages. While the amide bond-cont aining derivatives are known to be rather stable toward in vivo hydrol ysis, the parent Trp can be readily released from the substituted carb amate-type combinations. Lipophilicity and chemical oxidation studies performed on the new derivatives indicated that some of the new CDSs p ossess the properties required for an improved and specific brain deli very of Trp.