Benzamidine derivatives

A benzamidine compound of formula (1) or a pharmaceutically acceptable salt thereof:

• wherein X represents a hydrogen atom, a carboxyl group, an alkoxycarbonyl group having 2 to 4 carbon atoms, an alkyl group having 1 to 3 carbon atoms, which may have a substituent(s), or a benzyl group which may have a substituent(s);
• the substituent(s) being a carboxyl group or alkoxycarbonyl groups having 2 to 8 carbon atoms,
• V represents a benzoyl group which may have a substituent(s) or a piperidinecarbonyl group which may have a substituent(s);
• wherein said substituent(s) on said benzoyl group or said piperidinecarbonyl group is selected from the group consisting of iminoalkylpiperidyloxy groups having 7 to 10 carbon atoms, aryl groups having 6 to 10 carbon atoms, heteroaryl groups having 4 to 5 carbon atoms, carbamoyl group, and mono- and dialkylcarbamoyl groups having 2 to 7 carbon atoms, wherein two alkyl groups in each of the dialkylcarbamoyl groups may be bonded to each other to form a ring selected from 1-pyrrolidincarbonyl group, 1-piperidinecarbonyl group, 1-piperazinecarbonyl group and 1-morpholinecarbonyl group and
• R represents a hydrogen atom, a hydroxyl group, an alkoxyl group, an amino group, a carboxyl group, an alkoxycarbonyl group, an alkylsulfonyl group, a carbamoyl group, a carbamoyl group in which one or two hydrogens are replaced with an alkyl group, a formyl group, an acyl group, or an alkylcarboxyl group.