abstract |
Disclosed are xanthine derivatives of formula (I) wherein R1, R2, R3 and R4 are as described in the specification. Compounds of the type disclosed are useful in inhibiting dipeptidylpeptidase-IV (DPP-IV) and in the treatment of disorders such as type I and type II diabetes mellitus, arthritis, obesity, allograft transplantation and osteoporosis caused by calcitonin. |