Abstract: A novel non-fluorescent rhodamine dye forms a twisted intramolecular charge transfer state. A substituent that causes steric hindrance is introduced at an ortho position of a dimethylamino group on the xanthene ring of tetramethylrhodamine, which is a general rhodamine that exhibits strong fluorescence, and a certain amount of twist is imparted in a ground state. As a result, the formation of the twisted intramolecular charge transfer state is promoted in the excited state and non-fluorescence is exhibited.

Abstract: A novel non-fluorescent rhodamine dye forms a twisted intramolecular charge transfer state. A substituent that causes steric hindrance is introduced at an ortho position of a dimethylamino group on the xanthene ring of tetramethylrhodamine, which is a general rhodamine that exhibits strong fluorescence, and a certain amount of twist is imparted in a ground state. As a result, the formation of the twisted intramolecular charge transfer state is promoted in the excited state and non-fluorescence is exhibited.

Abstract: Fluorescent probes and their salts have high fluorescence quantum yield and high resistance to photobleaching suitable for visualizing various pH environments within cells such as weakly basic, neutral, and weakly acidic environments.

Abstract: A near-infrared fluorescent probe has fluorescence in the near-infrared region. Like CaSiR-1, the probe has rhodamines as the fluorescent mother nucleus and accumulates in the cytoplasm. The probe makes it possible to visualize concentration fluctuations in metal ions, such as calcium ions, within the body.

Abstract: [Problem] To provide a novel near-infrared quencher. [Solution] A compound represented by general formula (I) or a salt thereof.

Abstract: Fluorescent probes and their salts have high fluorescence quantum yield and high resistance to photobleaching suitable for visualizing various pH environments within cells such as weakly basic, neutral, and weakly acidic environments.

Abstract: Fluorescent probes and their salts show sufficient solubility in water and detect sulfane sulfur in vivo.

Abstract: [Problem] To provide: a compound resulting from substituting with a silicon atom the oxygen atom at position 10 of a xanthene ring site of a rhodamine of which amino groups at position 3 and position 6 have an asymmetrical structure; a method for producing the compound; and a fluorescent probe that uses the compound. [Solution] The compound represented by general formula (I) or a salt thereof.

Abstract: A compound represented by the formula (I) (R1 represents hydrogen atom or a monovalent substituent; R2 and R3 represent hydrogen atom, an alkyl group, or a halogen atom; R4 and R5 represent an alkyl group or an aryl group; R6 and R7 represent hydrogen atom, an alkyl group, or a halogen atom; R8 represent hydroxy group or a dialkoxyboranetriyl group; and X represents silicon atom, germanium atom, or tin atom), which is a novel fluorophore usable as a mother nucleus of an off/on type fluorescent probe not utilizing the intramolecular photoinduced electron transfer.

Abstract: A compound represented by the formula (I) (R1 represents hydrogen atom or a monovalent substituent; R2 and R3 represent hydrogen atom, an alkyl group, or a halogen atom; R4 and R5 represent an alkyl group or an aryl group; R6 and R7 represent hydrogen atom, an alkyl group, or a halogen atom; R8 represent hydroxy group or a dialkoxyboranetriyl group; and X represents silicon atom, germanium atom, or tin atom), which is a novel fluorophore usable as a mother nucleus of an off/on type fluorescent probe not utilizing the intramolecular photoinduced electron transfer.

Abstract: [Problem] The present invention addresses the problem of providing a compound that is useful for preventing or treating diseases associated with malfunctioning of PGI2 receptors, in particular, pulmonary hypertension. [Solution] A positive allosteric regulator of a PGI2 receptor which comprises a compound represented by formula (1) or a pharmaceutically acceptable salt, hydrate or solvate thereof. (1) (In the formula, R1 is a branched chain or cyclic alkyl or alkenyl having 3 to 10 carbon atoms which may be substituted, R2 is a hydrogen atom or an alkyl having 1 to 6 carbon atoms which may be substituted, R3 is 1 to 4 substituents which are the same or different independently selected from the group consisting of a hydrogen atom, a halogen atom, an alkyl having 1 to 6 carbon atoms which may be substituted, and an alkoxy having 1 to 6 carbon atoms which may be substituted, and A is an aryl which may be substituted or a heteroaryl which may be substituted.

Abstract: [Problem] To provide a novel near-infrared quencher. [Solution] A compound represented by general formula (I) or a salt thereof.

Abstract: A compound represented by the formula (I) (R1 represents a substituent on the benzene ring; R2 represents a monovalent substituent; R3 and R4 represent hydrogen atom, or an alkyl group; R5 and R6 represent an alkyl group, or an aryl group; R7 and R8 represent hydrogen atom, or an alkyl group; R9 and R10 represent hydrogen atom, or a monovalent substituent; and X represents silicon atom, germanium atom, or tin atom), or a salt thereof.

Abstract: [Problem] To provide a novel fluorescent probe for detecting the activity of calpain. [Solution] A compound represented by general formula (I) or a salt thereof.

Abstract: [Problem] To provide a fluorescent probe having a novel fluorophore. [Solution] A compound represented by general formula (I), or a salt thereof.

Abstract: A compound represented by the formula (I) [R1 represents hydrogen atom or a substituent; R2, R3, R6, and R7 represent hydrogen atom, an alkyl group, a halogen atom, or a hydrophilic substituent; R4 and R5 represent an alkyl group or an aryl group; R8 and R9 represent a group cleaved by contact with an object substance for measurement; and X represents silicon atom, germanium atom, or tin atom] or a salt thereof, which is useful as a fluorescent probe that emits red fluorescence by contact with an object substance for measurement.

Abstract: A compound represented by the formula (I) (R1 represents hydrogen atom or a monovalent substituent; R2 and R3 represent hydrogen atom, an alkyl group, or a halogen atom; R4 and R5 represent an alkyl group or an aryl group; R6 and R7 represent hydrogen atom, an alkyl group, or a halogen atom; R8 represent hydroxy group or a dialkoxyboranetriyl group; and X represents silicon atom, germanium atom, or tin atom), which is a novel fluorophore usable as a mother nucleus of an off/on type fluorescent probe not utilizing the intramolecular photoinduced electron transfer.

Abstract: [Problem] To provide: a compound resulting from substituting with a silicon atom the oxygen atom at position 10 of a xanthene ring site of a rhodamine of which amino groups at position 3 and position 6 have an asymmetrical structure; a method for producing the compound; and a fluorescent probe that uses the compound. [Solution] The compound represented by general formula (I) or a salt thereof.

Abstract: A compound represented by the formula (I) (R1 represents hydrogen atom or a monovalent substituent; R2 and R3 represent hydrogen atom, an alkyl group, or a halogen atom; R4 and R5 represent an alkyl group or an aryl group; R6 and R7 represent hydrogen atom, an alkyl group, or a halogen atom; R8 represent hydroxy group or a dialkoxyboranetriyl group; and X represents silicon atom, germanium atom, or tin atom), which is a novel fluorophore usable as a mother nucleus of an off/on type fluorescent probe not utilizing the intramolecular photoinduced electron transfer.

Abstract: A compound represented by the formula (I) (one of substituents represented by R1 is a trapping group for an object substance for measurement; R2 and R3 represent hydrogen, alkyl, or halogen; R4 and R5 represent alkyl or aryl; R6 and R7 represent hydrogen, alkyl, or halogen; R8 represents hydrogen, alkylcarbonyl, or alkylcarbonyloxymethyl, and X represents silicon, germanium, or tin, which can be used as a fluorescent probe that enables red color bioimaging using intramolecular photoinduced electron transfer.