XANTHINE DERIVATIVES, THE PREPARATION THEREOF AND THEIR USE AS PHARMACEUTICAL COMPOSITIONS

摘要

The present invention relates to substituted xanthines of general formula (see formula I) wherein R1 is, for example, H, optionally substituted alkyl, alkenyl, alkynyl, an aryl or a heterocylic group; R 2 is, for example, H, an optionally substituted alkyl or alkenyl, alkynyl cycloalkyl, an aryl or a heterocyclic group; R3 is, for example, optionally substituted alkyl, optionally substituted alkenyl, alkynyl, or aryl; and R4 is a substituted heterocyclic group; the tautomers and the stereoisomers thereof, mixtures thereof, the prodrugs and the salts thereof which have valuable pharmacological properties, particularly an inhibiting effect on the activity of the enzyme dipeptidylpeptidase-IV (DPP-IV).