Provided are a compound which is useful as an in vivo applicable, amyloid-oxygenating catalyst selective for amyloid and applicable not only to an A² peptide, but also to other amyloids and a drug containing the compound for preventing and/or treating amyloid-related diseases. Disclosed is a boron-dipyrrin complex represented by the following formula (1) wherein X 1 and X 2 are the same or different and each represent a halogenoalkyl group or a halogen atom； R 1 represents a hydrogen atom, an alkyl group, or a group represented by formula (b): R 2 and R 6 are the same or different and each represent a hydrogen atom or a halogen atom； R 3 , R 4 , R 5 , and R 7 are the same or different and each represent a hydrogen atom, a halogen atom, or an alkyl group； R 8 represents a hydrogen atom or -(CH 2 ) l -(Y) m -(CH 2 ) n -Z wherein Y represents -CO-, -CONH-, or a triazole ring, Z represents a carboxyl group, a sulfonic acid group, or a -CO-peptide residue, 1 and n each represent an integer of 1 to 6, and m represents 0 or 1； R 9 and R 10 are the same or different and each represent a hydrogen atom, an alkyl group, an alkoxy group, a halogen atom, an amino group, a nitro group, or a cyano group； and R 8 and R 10 together optionally form an alkylene group.
