The compounds of the following formula: ##STR00001## wherein Ar, R and R.sup.1 have the meanings given in the specification. This series of sulfonamido derivatives with a conserved uronamide group at the 5' position provide superior A3 receptor affinity as well as selectivity. These new adenosine agonists are sulfonamido derivatives N-substituted with aliphatic groups (cyclic or linear) or aromatic radicals.