A compound is provided that has the formula NH.sub.2CH.sub.2CH.sub.2CHR.sup.1C(O)N--R (I) where R.sup.1 is p-chlorophenyl, R is a moiety capable of crossing the blood brain barrier and is as a free compound serotonin, dopamine blood brain barrier (BBB) peptide, membrane translocating protein, TAT peptides, bradykinin, beta-endorphin, bombesin, calcitonin, cholecystokinin, an enkephalin, dynorphin, insulin, gastrin, substance P, neurotensin, glucagon, secretin, somatostatin, motilin, vasopressin, oxytocin, prolactin, thyrotropin, an angiotensin, galanin, neuropeptide Y, thyrotropin-releasing hormone, gonadotropnin-releasing hormone, growth hormone-releasing hormone, luteinizing hormone, vasoactive intestinal peptide transferrin, glucosylamine, amino saccharin, lactylamine, leucine, tryptophan, glutamate and amino cholines.