abstract |
Compounds represented by general formula (I); prodrugs of the same; or pharmaceutically acceptable salts of both; or solvates of them. In said formula, R1, R2, R3 and R4 are each independently hydrogen, alkyl or the lik e; R5 and R6 are each independently hydrogen, alkyl or the like; X is -O-, -S- or the like; Y is a divalent group derived from a five-membered aromatic heterocycle, or the like; and Z is optionally substituted aryl or the like.< /SDOAB> |