Abstract: Disclosed is a compound represented by formula (1) or a salt thereof, formula (1): wherein X is a residue of a compound having activity of binding to at least one member selected from the group consisting of amyloid ? proteins, tau proteins, ?-synuclein, and TDP-43; m is an integer of 0 to 6; n is an integer of 1 to 5; and J is a group selected from the group consisting of wherein R1 and R2 are each independently a hydrogen atom, a fluorine atom, methyl, or trifluoromethyl; R3 is trifluoromethyl or trifluoromethoxy; and p is an integer of 1 to 4, provided that m+n?5 when J is J-1, and m+n?7 when J is J-2 or J-3.

Abstract: Disclosed are a curcumin derivative or a salt thereof, which contains a fluorine atom, represented by formula (I): (wherein R1a and R1b are each independently a hydrogen atom, alkyl, acetyl, or methoxycarbonyl; R2s are each independently a fluorine atom, CHF2—, CF3—, CHF2O—, or CF3O—; R3s are each independently a hydrogen atom or a fluorine atom; A is alkyl, cyano, carboxyl, alkoxycarbonyl, or R4—(CH2)m—; R4 is hydroxy, carboxy, cyano, acetyloxy, alkoxycarbonyl, alkoxyalkoxy, hydroxyalkoxy, or CONR5R6; R5 and R6 are each independently a hydrogen atom or alkyl; and m is an integer from 1 to 5), and a diagnostic imaging agent for diagnosing a disease in which an amyloid ? peptide aggregate accumulates, the diagnostic imaging agent containing a compound having a 1,3-dicarbonyl structure, wherein the compound exists in a keto form and an enol form, and the keto form and the enol form have different affinities, respectively, to the amyloid ? peptide aggregate.

Abstract: Disclosed are a curcumin derivative or a salt thereof, which contains a fluorine atom, represented by formula (I): (wherein R1a and R1b are each independently a hydrogen atom, alkyl, acetyl, or methoxycarbonyl; R2s are each independently a fluorine atom, CHF2—, CF3—, CHF2O—, or CF3O—; R3s are each independently a hydrogen atom or a fluorine atom; A is alkyl, cyano, carboxyl, alkoxycarbonyl, or R4—(CH2)m—; R4 is hydroxy, carboxy, cyano, acetyloxy, alkoxycarbonyl, alkoxyalkoxy, hydroxyalkoxy, or CONR5R6; R5 and R6 are each independently a hydrogen atom or alkyl; and m is an integer from 1 to 5), and a diagnostic imaging agent for diagnosing a disease in which an amyloid ? peptide aggregate accumulates, the diagnostic imaging agent containing a compound having a 1,3-dicarbonyl structure, wherein the compound exists in a keto form and an enol form, and the keto form and the enol form have different affinities, respectively, to the amyloid ? peptide aggregate.