Provided is a compound which is bioapplicable and amyloid-selective, and is useful as an amyloid oxygenation catalyst applicable not only to Aβ 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 X1 and X2 are identical or different, and each represent a halogenoalkyl group or a halogen atom; X3 represents a bromine atom, an iodine atom, or a selenium atom; R1 and R2 are identical or different, and each represent a hydrogen atom or an optionally substituted alkyl group; R3 and R4 are identical or different, and each represent a hydrogen atom, a halogen atom, an alkoxy group, or an optionally substituted alkyl group, or R1 and R3 or R2 and R4 are optionally taken together to form an optionally substituted alkylene group or alkenylene group; R5 and R6 are identical or different, and each represent a hydrogen atom or an optionally substituted alkyl group; R7 and R8 are identical or different, and each represent a hydrogen atom, a halogen atom, an alkoxy group, or an optionally substituted alkyl group, or R5 and R7 or R6 and R8 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.