Purine derivatives and adenosine A2 receptor antagonists serving as preventives/remedies for diabetes

221 5 6 2 3 4 The present invention provides a preventive or therapeutic agent of a new type for diabetes mellitus and diabetic complications on the basis of an adenosine A2 receptor antagonist action.A purine compound represented by the formula (I), its pharmacologically acceptable salt or hydrates thereof has an adenosine A2 receptor antagonistic action and is useful for prevention or therapy of diabetes mellitus and diabetic complications. In addition, adenosine A2 receptor antagonists having different structures from those of the compounds described above, for example KW6002, are also effective for prevention or therapy of diabetes mellitus and diabetic complications. In the formula, W is -CHCH-, or -CH═CH- or -C≡C-; Ris: (in the formula, X is hydrogen atom, hydroxyl group, a lower alkyl group, a lower alkoxy group, etc.; and Rand Rare the same as or different from each other and each represents hydrogen atom, a lower alkyl group, a cycloalkyl group, etc.) and the like; Ris an amino group, etc. which maybe substituted with a lower alkyl group, etc.; Ris a cycloalkyl group, an optionally substituted aryl group, etc.; and Ris a lower alkyl group etc.