Abstract: A compound represented by the following formula (I): 1

Abstract: A compound represented by general formula (IA) or a salt thereof useful as a fluorescent probe for zinc: wherein R1 and R2 represent a hydrogen atom or a group represented by formula (A), wherein X1, X2, X3, and X4 represent a hydrogen atom, an alkyl group, a 2-pyridylmethyl group, or a protective group for an amino group, and m and n represent 0 or 1 provided that R1 and R2 do not simultaneously represent hydrogen atoms; R3 and R4 represent a hydrogen atom or a halogen atom; and R5 and R6 represent a hydrogen atom, an alkylcarbonyl group, or an alkylcarbonyloxymethyl group, and R7 represents a hydrogen atom or an alkyl group.

Abstract: A method for measurement of a target substance in a sample by means of fluorescence, which comprises the step of carrying out the measurement in the presence of (1) a specific fluorescent probe which specifically reacts with the target substance to generate fluorescence, and (2) a donor which, per se, has long-lived fluorescence and is capable of inducing fluorescence resonance energy transfer to the specific fluorescent probe that acts as an acceptor, provided that the donor forms no binding to the specific fluorescent probe by means of a chemical bond; and the step of converting fluorescence, wherein said fluorescence is resulted from a reaction between the acceptor and the target substance, into long-lived excitation fluorescence by the fluorescence resonance energy transfer which is induced on the acceptor.

Abstract: A compound represented by general formula (I) or (II) or a salt thereof and an agent for measurement of a reactive oxygen comprising said compound or a salt thereof: 1

Abstract: A compound represented by the following formula: wherein R1 and R2 represent amino groups that substitute at adjacent positions on the phenyl ring, provided that either of R1 and R2 represents a mono(C1-6 alkyl)-substituted amino group and the other represents an unsubstituted amino group, and wherein R3 represents hydrogen atom or an alkyl group and R4 represents hydrogen atom or an acyl group, and an agent for measurement of nitrogen monoxide which comprises said compound.

Abstract: Compounds represented by the following general formula (I): wherein R1, R2, R3, R4, R5, and R6 independently represent a hydrogen atom, a halogen atom, a C1-6 alkyl group, or a C1-6 alkoxyl group, R7 and R8 independently represent a C1-6 alkyl group or an aryl group which may be substituted, R9 and R10 independently represent a hydrogen atom, a C1-6 alkyl group, or a C1-6 alkoxyl group, and R11 represents a hydrogen atom or a C1-6 alkanoyl group, or salts thereof. The aforementioned compounds are substantially non-fluorescent and react with singlet oxygen under a physiological condition to give a fluorescent substance, and therefore they are useful as agents for measurement of singlet oxygen.

Abstract: A compound represented by the following general formula: wherein R1 and R2 represent amino groups present at adjacent positions each other on the phenyl ring; R3, R4, R5 and R6 independently represent a C1-6 alkyl group; R7, R8, R9 and R10 independently represent a hydrogen atom, a C1-6 alkyl group, an allyl group, or a halogen atom; R11 represents a hydrogen atom or a C1-18 alkyl group; and X− represents an anion, and an agent for nitric oxide measurement comprising said compound. The compound efficiently reacts with nitric oxide to give a fluorescent compound that emits strong fluorescence by irradiation with excitation light of a long wavelength. This fluorescent compound is characterized in that said compound is detectable in a fluorescence wavelength range hardly influenced by autofluorescence of cells, and its fluorescence intensity is not attenuated under an acidic condition.

Abstract: A compound represented by the following formula (I): 1

Abstract: A compound represented by the following formula (I): wherein R1 and R2 represent amino group that substitute at adjacent positions on the phenyl ring, provided that either of R1 and R2 represents a mono(C1-6 alkyl)-substituted amino group and the other represents an unsubstituted amino group; and R3 and R4 independently represent hydrogen atom or an acyl group, and an agent for measurement of nitrogen monoxide which comprises said compound.

Abstract: A compound represented by the following general formula: 1

Abstract: A compound represented by the following general formula: wherein R1 and R2 represent amino groups present at adjacent positions each other on the phenyl ring; R3, R4, R5 and R6 independently represent a C1-6 alkyl group; R7, R8, R9 and R10 independently represent a hydrogen atom, a C1-6 alkyl group, an allyl group, or a halogen atom; R11 represents a hydrogen atom or a C1-18 alkyl group; and X− represents an anion, and an agent for nitric oxide measurement comprising said compound. The compound efficiently reacts with nitric oxide to give a fluorescent compound that emits strong fluorescence by irradiation with excitation light of a long wavelength. This fluorescent compound is characterized in that said compound is detectable in a fluorescence wavelength range hardly influenced by autofluorescence of cells, and its fluorescence intensity is not attenuated under an acidic condition.

Abstract: A compound useful for the measurement of nitrogen monoxide under a substantially neutral condition which is represented by the following formula (I): ##STR1## wherein R.sup.1 and R.sup.2 represent amino groups that substitute at adjacent positions on the phenyl ring; R.sup.3 and R.sup.4 independently represent a hydrogen atom or an acyl group; R.sup.5, R.sup.6, R.sup.7, and R.sup.8 independently represent a hydrogen atom, a C.sub.1-6 alkyl group, allyl group, or a halogen atom.

Abstract: An NO radical measuring method comprising the steps of mixing a test sample solution containing NO radicals with hydrogen peroxide or an analogous substance thereto and luminol or an analogous substance thereto, and measuring the intensity of chemiluminescence. The method enables a trace amount of NO radical to be measured with accuracy and in real time. An apparatus used for this method is also disclosed.