Patent ID: 8546291

Claim:
A compound represented by formula (1): wherein Y 1 to Y 4 each independently represent any one of the following groups: in which R α represents a hydrogen atom or a monovalent hydrocarbon group; P 1 represents a group of atoms necessary for forming a heterocyclic ring together with Y 1 and the two carbon atoms adjacent to Y 1 ; P 2 represents a group of atoms necessary for forming a heterocyclic ring together with Y 2 and the two carbon atoms adjacent to Y 2 ; P 3 represents a group of atoms necessary for forming a heterocyclic ring together with Y 3 and the two carbon atoms adjacent to Y 3 ; P 4 represents a group of atoms necessary for forming a heterocyclic ring together with Y 4 and the two carbon atoms adjacent to Y 4 ; P 5 represents a group of atoms necessary for forming a phenol ring structure together with the carbon atom to which Z 1 bonds and the two carbon atoms adjacent to the carbon atom to which Z 1 bonds; P 6 represents a group of atoms necessary for forming a phenol ring structure together with the carbon atom to which Z 2 bonds and the two carbon atoms adjacent to the carbon atom to which Z 2 bonds; P 1 and P 2 , P 2 and P 6 , P 6 and P 4 , P 4 and P 3 , P 3 and P 5 , and P 5 and P 1 optionally combine with each other to form a ring; Q 1 and Q 2 each independently represent a connecting group or a direct binding; and Z 1 and Z 2 each independently represent a hydroxyl group.