Fluorescent compound and fluorescently labeled biological substance using the same

A fluorescent compound represented by any one of General Formulae (I) to (IV) or a salt thereof,

• in the formulae, Y represents —NR10R11 or —OR12, and Z represents a group represented by Formula (A),
• R1 to R6 represent a halogen atom, a cyano group, or a group represented by Formula (A),
• R7 to R12 represent a group represented by Formula (A), where R7 and R8 may be bonded to each other to form a 4- to 7-membered aliphatic heterocyclic ring, R10 and R11 may be bonded to each other to form a 4- to 7-membered aliphatic heterocyclic ring, and R7 to R111 each may be bonded to adjacent R2 to R5 to form a 5- to 7-membered aliphatic heterocyclic ring or aromatic heterocyclic ring,
• R21 and R22 represent a group represented by Formula (A), and R21 and R22 may be bonded to each other to form a 4- to 7-membered aliphatic heterocyclic ring, provided that at least one of R21 or R22 is an alkenyl group, an alkynyl group, an aryl group, or a heteroaryl group, and
• in a case where R21 is an aryl group and R22 is an alkyl group or an aryl group, in at least one of a combination of R7 and R8 or a combination of R10 and R11, R7 and R8, or R10 and R11 are bonded to each other to form a 4-membered aliphatic heterocyclic ring, and
• R23 represents a group represented by Formula (A),
• *-L3-R111 Formula (A)
• in the formula, L3 is a single bond or a linking group obtained by combining one or two or more kinds among an alkylene group, an alkenylene group, an alkynylene group, an arylene group, a heteroarylene group, and each group represented by any one of Formula (1-1) to Formula (1-8),
• R111 represents a hydrogen atom, an alkyl group, an alkenyl group, an alkynyl group, an aryl group, a heteroaryl group, or a monovalent aliphatic heterocyclic group,
• provided that in a case where a hydrogen atom as R111 is a dissociative hydrogen atom, the dissociative hydrogen atom may be dissociated, and
• * represents a bonding portion,
• in the formulae, R31 and R32 represent a hydrogen atom or a substituent, and
• * represents a bonding portion,
• provided that the compound represented by Formula (I) or (II) or a salt thereof satisfies the following condition α, and the compound represented by Formula (III) or (IV) or a salt thereof satisfies the following condition β,
• (Condition α)
• in a case where Z is an aryl group, the aryl group is a group represented by Formula (C),
• in the formula, R41 to R45 represent a hydrogen atom or a substituent, and
• * represents a bonding portion,
• provided that at least one of (C-1), (C-2), or (C-3) is satisfied,
• (C-1) at least one of R42, R43, or R44 is a group having any of a carboxy group or a substituent capable of being bonded to a biological substance,
• (C-2) R41 and R45 are an alkyl group or a halogen atom,
• (C-3) at least one of R41 or R45 is a fluorine atom or an alkoxy group,
• (Condition β)
• in at least one of a combination of R7 and R8 or a combination of R10 and R11, R7 and R8, or R10 and R11 are bonded to each other to form a 4-membered aliphatic heterocyclic ring.