Provided is a compound which is bioapplicable and amyloid-selective, and is useful as an amyloid oxygenation catalyst applicable not only to A?peptides but also to other amyloids, and a preventive/therapeutic drug for an amyloid-related disease using the same. A curcumin-boron complex represented by the following formula (1) : wherein X 1 and X 2 are identical or different, and each represent a halogenoalkyl group or a halogen atom; X 3 represents a bromine atom, an iodine atom, or a selenium atom; R 1 and R 2 are identical or different, and each represent a hydrogen atom or an optionally substituted alkyl group; R 3 and R 4 are identical or different, and each represent a hydrogen atom, a halogen atom, an alkoxy group, or an optionally substituted alkyl group, or R 1 and R 3 or R 2 and R 4 are optionally taken together to form an optionally substituted alkylene group or alkenylene group; R 5 and R 6 are identical or different, and each represent a hydrogen atom or an optionally substituted alkyl group; R 7 and R 8 are identical or different, and each represent a hydrogen atom, a halogen atom, an alkoxy group, or an optionally substituted alkyl group, or R 5 and R 7 or R 6 and R 8 are optionally taken together to form an optionally substituted alkylene group or alkenylene group; and m and n each represent an integer of 1 to 3, or a salt thereof.