abstract |
The present invention relates to substituted xanthines of general formula n n n n n n n n n n wherein R 1 to R 4 are as defined herein, 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). |