Described are xanthin derivatives of the general formula (I), in which substituents have the meaning described in claims, tautomers, stereoisomers, mixtures, precursors and salts thereof having inhibiting dipeptidyl peptidase-IV activity. Described is also a method for the preparation thereof, a pharmaceutical composition containing thereof and their use in the preparation of a medicament for treating type I and type II diabetes mellitus, arthritis, allograft transplantation and osteoporosis caused by calcitonin.Described are xanthin derivatives of the general formula (I), in which substituents have the meaning described in claims, tautomers, stereoisomers, mixtures, precursors and salts thereof having inhibiting dipeptidyl peptidase-IV activity. Described is also a method for the preparation thereof, a pharmaceutical composition containing thereof and their use in the preparation of a medicament for treating type I and type II diabetes mellitus, arthritis, allograft transplantation and osteoporosis caused by calcitonin.
