abstract |
The invention relates to substituted xanthins of general formula (I) wherein R1 - R4 are defined as in Claim 1, the tautomers thereof, the stereoisomers thereof, the mixtures thereof, the prodrugs and salts thereof which exhibit valuable pharmacological properties, especially an inhibitive effect on the activity of the enzyme Dipeptidylpeptidase-IV (DPP-IV). |