Imidazole-containing peptides having immunomodulatory activity

Abstract

Imidazole-containing peptide of the formula: ##STR1## wherein R.sup.1 is a branched alkyl group, a branched alkyloxy group or an aryl-substituted lower alkyloxy group, R.sup.2 and R.sup.4 are the same or different and each is hydrogen atom or a lower alkyl group, R.sup.3 and R.sup.5 are a phenyl-substituted lower alkyl group, R.sup.6 is hydrogen atom or a lower alkoxycarbonyl group, R.sup.7 is hydrogen atom or a nitrogen-containing heterocyclic group-substituted lower alkylthio group, X.sup.1 and X.sup.2 are the same or different and each is ##STR2## A is a lower alkylene group which may be substituted with a substituent selected from the group consisting of a lower alkoxy group, hydroxymethyl group and a group of the formula: ##STR3## and R.sup.8 and R.sup.9 are the same or different and each is hydrogen atom or a lower group, or a pharmaceutically acceptable salt thereof, which is useful as an immunomodulator and as an agent for the treatment and/or prophylaxis of autoimmune diseases such as rheumatoid arthritis, multiple sclerosis, systemic lupus erthematodes, glomerulonephris, rhumatic fever or type I diabetes and atopic allergy, a processes for the preparation thereof, and a pharmaceutical composition containing said compound as an active ingredient.