| abstract |
A compound represented by general formula (I), possible stereoisomer and optical isomer thereof, and pharmaceutically acceptable salts thereof, wherein R 1 , R 2 , R 3 and R 4 represent each hydrogen, etc.; R 6 and R 7 represent each optionally substituted lower alkyl; A represents a group of general formula (II) (wherein R 5 represents hydrogen, etc.); and n is an integer of from 2 to 6. These compounds can suppress the formation of active oxygen and an increase in intracellular calcium and thus are useful as a remedy for ischemic diseases. |