A compound represented by the following formula (I) ** Formula ** wherein R1, R2, R3 and R4 may be the same or different and are each independently a hydrogen atom, a nitro group, a halogen group, a cyano group, a hydroxyl group, a thiol group, an amino group, a guanidino group, a formyl group, a lower alkyl group, a lower alkenyl group, a lower alkynyl group, a lower acyl group, a carboxyl group, a group sulfo, a phosphono group, a lower alkoxy group, a lower alkylthio group, a lower alkylamino group, a lower acyloxy group, a lower acylamino group, a lower alkoxycarbonyl group, a carbamoyl group, a lower alkylcarbamoyl group, a lower alkylsulfonylamino group or a sulfamoyl group, HetAr is a 5 to 10 membered aromatic ring containing 1-3 heteroatoms selected from a nitrogen atom, an oxygen atom and a sulfur atom, and optionally having a su stituuent or substituents, X is a lower alkylene group that optionally has a substituent or substituents, a lower alkenylene group that optionally has a substituent or substituents, a lower alkynylene group that optionally has a substituent or substituents, or a thiophenylene group, Y is a carbonyl group, a thiocarbonyl group or a sulfonyl group, and A is -OR5 (R5 is a hydrogen atom or a lower alkyl group), a group of the following formula (II): ** Formula ** wherein R6 and R7 they may be the same or different and are each independently a hydrogen atom, a hydroxyl group, a lower alkyl group that optionally has a substituent or substituents, a lower alkenyl group that optionally has a substituent or substituents, a lower alkynyl group which optionally has a substituent or substituents or a lower alkoxy group which optionally has a substituent or substituents, or R6 and R7 may be tar joined to form a cyclic amino group that optionally has a substituent or substituents, a group of the following formula (II-2): -U-CH (R6 ') R7' (II-2) wherein U is O or S , and R6 'and R7' may be the same or different and are each independently a hydrog
