A compound represented by the formula (1) ** Formula ** where A is a nitrogen atom or CR4 (where R4 is a hydrogen atom, a hydroxyl group (the hydroxyl group may be substituted with a C2-6 alkenyl group or a C2-6 alkynyl group), a thiol group (the thiol group may be substituted with a C1-10 alkyl group, a C2-6 alkenyl group, a C2-6 alkynyl group or a C1-10 alkylcarbonyl group), an amino group (being the amino group substituted with one or two C2-6 alkenyl groups or one or two C2-6 alkynyl groups), a formyl group, a halogen atom, a nitro group, a cyano group, a C1-10 alkyl group, a C2 alkenyl group -6, a C2-6 alkynyl group, a C1-10 alkylcarbonyloxy group, a C1-10 alkylcarbonylamino group, a mono or di-C 1-10 alkylamino group, a C1-10 alkoxy group (the C1-10 alkyl group, the group C2-6 alkenyl, C2-6 alkynyl group, C1-10 alkylcarbonyloxy group, C1-10 alkylcarbonylamino group, mono or di-C 1-10 alkylamino group and gr or C1-10 alkoxy may be optionally substituted with one or more substituents selected from the group consisting of: a carboxyl group, a nitro group, a cyano group, a halogen atom, a C1-10 alkoxy group, a C1-10 alkylcarbonyl group , a C1-10 alkylcarbonyloxy group, a C1-10 alkoxycarbonyl group, a C1-10 alkylcarbonylamino group, an amino group, a mono or di-C 1-10 alkylamino group, a hydroxyl group, a protected hydroxyl group, a C6-14 aryl group which does not contain heteroatoms as constituent atoms of the ring, a 5- to 7-membered C2-6 heteromonocyclic group or C5-9 condensed heterocyclic group of 8 to 10 members containing 1 to 3 oxygen atoms, nitrogen atoms or sulfur atoms alone or in combination, a C6-14 -aryloxy group that does not contain heteroatoms as constituent atoms of the ring, or a 5-7 membered heteromonocyclic oxy group or C5-9 condensed 8 to 10 membered heterobicyclic oxy group containing from 1 to 3 oxygen atoms, nitrogen atoms or sulfur atoms alone or in combination, (the C-14 aryl group that does not contain heteroatoms as constituent atoms of
