| abstract |
A compound represented by the following Formula (I) or a pharmaceutically acceptable salt thereof: <CHEM> wherein R1 represents a hydrogen atom or a carboxyl-protecting group, R2 represents a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group or a hydroxyl group, R3 represents a hydrogen atom, a halogen atom, a lower alkyl group, a lower alkoxy group, a lower alkylthio group, a nitro group, a cyano group, a hydroxyl group or an amino group; R4 represents a hydrogen atom, an amino-protecting group, an alkyl group or a cycloalkyl group, and R5 represents a hydrogen atom, a halogen atom, an alkyl group, an alkenyl group, a cycloalkyl group, an aryl group, an alkoxy group, an alkylthio group, a hydroxyl group, an imino group or an amino group. |