A series of glycoconjugates, in which [Met5]enkephalin or [D-Ala2,Met5]enkephalin have been linked through an ester bond to the HO-6 of various D-glycopyranose moieties, were synthesized by classical solution methods. The biological activities of these compounds were determined on selective pharmacological preparations: guinea pig ileum and mouse vas deferens for opioid activity, and two mouse cell lines, fibroblasts L929 and melanoma B16BL6, to study the influence on growth processes. The results reported in this study demonstrate the differential effect of the carbohydrate part in enkephalin-related glycoconjugates on receptor recognition. In addition, synthesized neo-glycopeptides stimulate growth of the examined mouse cell lines, whereas parent peptide demonstrated some growth inhibitory properties. Full growth curves showed a dose-dependent effect at concentrations of 10(-7) to 10(-10) M.