WO1997024145A1

WO1997024145A1 - Diagnostic drugs

Info

Publication number: WO1997024145A1
Application number: PCT/JP1996/003828
Authority: WO
Inventors: Hideo Utsumi; Hiroaki Sano
Original assignee: Daiichi Radioisotope Laboratories, Ltd.
Priority date: 1995-12-28
Filing date: 1996-12-26
Publication date: 1997-07-10
Also published as: AU1208697A

Abstract

Diagnostic drugs containing as the active ingredient 5-membered cyclic N-oxyl compounds represented by general formula (I) or (II), wherein R represents C1-4 alkyl; and R?1 and R2¿ represent each hydrogen or C¿1-4? alkyl. By administering such a drug to a living body, information on active oxygen and free radicals present in the tissues of the living body can be obtained in the form of biological images such as ESR, NMR, magnetoencephalogram, etc. Thus it is useful as a diagnostic drug for diseases and symptoms in which active oxygen and free radicals seemingly participate, for example, cerebral ischemia, cardiac diseases, digestive diseases, cancer, aging, inflammation and cataract. By administering the drug to normal or sick test animals, active oxygen and free radicals formed in the tissues or organs in a normal or sick state can be externally detected and imaged. Based on these results, it is usable as a detection reagent for examining in which diseases active oxygen and free radicals participate, thus providing useful medical information. Further, the presence of active oxygen or free radicals in a living tissue can be examined and the quantities thereof can be measured by homogenizing a sample taken up from a living body, adding an appropriate buffer and the drug thereto, reacting the mixture for an appropriate period of time and then measuring the signal strength by ESR. Thus these drugs are useful as reagents for detecting active oxygen in samples taken up from living bodies.

Description

Technical field for detailed diagnostics

The present invention relates to a drug for detecting active oxygen and free radicals present in a living tissue, and more specifically, by obtaining information on active oxygen and free radicals in the brain, heart or other tissues as magnetic information. The present invention relates to an agent for diagnosing a disease associated with active oxygen or free radicals, such as a tumor or an ischemic disease, and a method for detecting the disease using the same. Background technology

Reactive oxygen can be defined as oxygen species that are short-lived but highly reactive and participate in various in vivo oxidation reactions. The range varies depending on the definition, but in a narrow sense, the hydroxyl radical (· Ο Η), superoxide (〇 ₂ —), singlet oxygen ('0 ₂ ), hydrogen peroxide (H in refers broad meaning to ₂ O, pel O alkoxy radicals derived from the reaction between the active species and the biological component (such as unsaturated fatty acids L) (LOO ') and alkoxy radicals. (LO -) and Eta ₂ Omicron Hypochlorite ion (C 1 Ο), which is formed by the reaction of ₂ , ₂ with C 1— with myelin peroxidase, etc., is also active oxygen, etc. Hydroxyl radical and superoxide are radicals, but what is a radical? Is defined as an atom or molecule with one or more unpaired electrons, while singlet oxygen and hydrogen peroxide are not radicals per se, but can result from some radical reactions or other radicals. Triggered a reaction It is something.

Active oxygen and radicals are generally unstable, and their lifetimes are Benzyl radical 1 0 ⁵ to 1 0 ⁴ seconds, simple Mechiruraji local atmospheric gas phase, such as human mud nitroxyl radical is 1 0 ² to 1 0 ² sec.

In recent years, active oxygen and free radicals exhibiting various physiological activities in living organisms have attracted attention in the fields of biology, medicine, and pharmacy, and have been studied. Causes of the generation of this active oxygen and free radicals in the living body include ultraviolet rays, radiation, air pollution, oxygen, lipid peroxidation, metal ions, ischemia, and reperfusion.

Reactive oxygen and free radicals in the living body generated by these factors cause various in vivo reactions such as peroxidation of lunar substances, denaturation of proteins, and decomposition of nucleic acids. Known diseases associated with such phenomena include cerebral ischemia, heart disease, gastrointestinal diseases, cancer, aging, and inflammation. As described above, active oxygen and free radicals in the living body are related to various diseases, so if they can be detected non-invasively from outside the body, the causes of various diseases can be investigated and useful medical information can be obtained. sell.

Conventionally known methods for detecting free radicals include an indirect method in which a reaction reagent is placed in a reaction system, and the resulting change in absorbance or light emission in the reaction system is detected.Indirect methods detect unpaired electrons in free radicals directly. Electron spin resonance 1 ectoron Spin Resonance (ESR) method. The ESR method can measure both solution and solid samples, and it can be used to measure opaque or heterogeneous samples.Therefore, detection of active oxygen in collected biological samples and living organisms is extremely important. It is advantageous.

However, ESR devices that have been generally used so far use X-band (approximately 9.5 GHz) microwaves. Was impossible. Recently, an ESR device using a low-frequency microwave called an L-band (390 to 155 Ο Μ 開発_Z ) (hereinafter referred to as “Shi-band £ 31¾ device”) has been developed. It is becoming possible to measure free radicals in large volume samples, especially biological samples, in vivo.

The principle of the ESR method is that a stable radical administered to a living body is usually acted on by an oxidoreductase in the living body or reacts with a reducing agent such as active radical oxygen ascorbic acid such as various radicals. Because of the loss of magnetism, this signal change is measured and analyzed to non-invasively image in vivo reactive oxygen and free radical reactions.

Therefore, in order to carry out the ESR method, it was essential to provide a diagnostic agent containing a stable radical compound, which can be called an ESR contrast agent.

On the other hand, the principle of the nuclear magnetic resonance (NMR) method was discovered in 1945, and it was applied to medical imaging equipment (Magnetic Resonance Imaging; MR I). Also, auterbur was first in 1973. Subsequent advances in this diagnostic method have been remarkable and have now become one of the most widely used diagnostic methods.

MRI was first introduced as a diagnostic method that does not require a contrast agent.However, to enhance the ability to detect lesions that are difficult to shade, the usefulness of the use of contrast agents is now recognized and generalized. ing. Accordingly, the emergence of a contrast agent with higher detectability has been desired.

At present, there are several types of contrast agents for MRI, including the nitroxide radical. One of the nitroxide radicals, PCA (2,2,5,5-tetramethylpyrrolidine-11-oxy-13-carboxylic acid; 3-carboxyproxil), has been studied as a contrast agent for tumors and myocardial infarction. Its imaging effect has been proven [see, for example, Magn. Reson. Imaging 3: 89-97; 1985, Investigative Radiology 20: 591-595; 1985].

However, there are organs such as the brain that cannot be imaged with current MRI contrast agents, and the emergence of new MRI contrast agents is awaited. In addition, there are many nerve cells in the brain, and the change in electromotive force associated with their activity is widely used as electroencephalogram (EEG). On the other hand, the current flowing through the nerve accompanying the electromotive force creates a magnetic field around it, and the recording of the magnetic field created by this is called a magnetoencephalogram (MEG). Because the strength and direction of the magnetic field are determined by the position, strength, and direction of the current, measuring a brain magnetic field is basically equivalent to measuring an electroencephalogram. It is difficult to accurately estimate the active site of the electroencephalogram because the electrical conductivity of the living body is not constant and varies greatly in tissues and bones, and only the strength information of the potential is obtained.

On the other hand, magnetoencephalography, which measures changes in the magnetic field caused by biomagnetism, can accurately estimate the active site because the permeability of the magnetic field in living tissue is almost the same as in air and the magnetic field is not distorted. It is. However, the magnetic field from the brain was extremely weak, one hundred millionth of the earth's magnetism, and its measurement required a highly sensitive magnetic sensor, which was difficult. However, about 20 years ago, a magnetic fluxmeter using a superconducting quantum interference device (SQUID) was developed, and for the first time stable biomagnetic recording of the brain and other parts became possible. At present, medical devices have been developed that can externally non-invasively image active sites of nerve cells in the brain using this magnetometer.

This diagnostic method is used to find the focus of epileptic seizures, and is becoming a useful test method for determining the application of surgical treatment for epilepsy. In the future, it is expected to be applied to the diagnosis of early symptoms of Alzheimer's disease.However, as mentioned above, the magnetic field from the brain is extremely weak. ing.

If information on active oxygen-free radicals in living tissue can be obtained as a living body image by magnetic resonance, which is a noninvasive measurement method, cerebral ischemia and heart disease Research on conditions that are thought to involve free radicals such as active oxygen and free radicals such as disease, gastrointestinal diseases, cancer, aging, inflammation, and cataracts (hereinafter referred to as “reactive oxygen-related diseases”) Useful for diagnosing symptoms. Therefore, there is a need to provide a diagnostic agent capable of imaging various biological tissues, particularly brain tissues. Disclosure of the invention

The present inventors have searched for a stable radial compound that can be used to obtain information on active oxygen and free radicals in a living body as a biological image by magnetic resonance spectroscopy and magnetoencephalography. Ring N-oxyl compounds can easily detect active oxygen and free radicals, and can also image brain tissue that had been difficult to image conventionally. The present inventors have found that the present invention is useful for obtaining a biological image by a magnetic resonance method or a magnetoencephalogram, and completed the present invention.

That is, the present invention provides the following formula (I) or (I I)

(I) (I I)

(Wherein, R represents an alkyl group having 1 to 4 carbon atoms, and R 1 to R ₅ each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). It provides a diagnostic agent comprising a compound as an active ingredient. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a drawing showing a mouse brain band 1 ′: SR-CT image by 3-carboxy-proxil.

FIG. 2 is a drawing showing an L-band ESR-CT image of mouse brain by 3-carboxy-1-proxyl methyl ester.

FIG. 3 is a drawing showing an L-band ESR-CT image of mouse brain by 3-carboxy-proxylethyl ester.

FIG. 4 is a drawing showing an L-band ESR-CT image of mouse brain with 2-ethyl-2,5,5-trimethyloxazolidinoxyl. BEST MODE FOR CARRYING OUT THE INVENTION

The 5-membered ring N-oxyl compound that can be used in the present invention is a compound represented by the above formula (I) and a compound represented by the above formula (II). Among them, the compound (I) is an ester of a pyrrolidineoxyl derivative having a carboxyl group and an alcohol, and is a known compound or a compound which can be easily produced according to a method for producing a known compound. Examples of preferred compounds (I) include 3-carboxy-proxyl methyl ester and 3-carboxy proxy / reethyl ester.

On the other hand, the compound (Π) can be produced, for example, by condensing an amino alcohol and a ketone. Preferred examples of the compound include 2-ethyl-2,5,5-trimethyloxazolidinoxyl and the like. Are mentioned.

In order to prepare the diagnostic agent of the present invention using the above 5-membered ring N-oxyl compound, the compound is prepared by using a suitable pharmaceutically acceptable solvent such as physiological saline and isotonic phosphate. It may be dissolved in a buffer or the like, and if necessary, an optional component such as propylene glycol or benzyl alcohol may be added to form a formulation. Preferred dosage forms of the diagnostic agent of the present invention include injections, infusions, coatings, eye drops and the like.

The diagnostic agent of the present invention obtained as described above can be used as a diagnostic agent for related diseases such as active oxygen which detects the presence of active oxygen / free radicals by intravascular administration. It can be used for MRI imaging of diseases such as the heart, magnetoencephalography or ESR imaging.

The agent of the present invention can be administered to a normal experimental animal or a disease model experimental animal to detect and image an active oxygen-free radical generated from a tissue or an organ in a normal or diseased state from the outside. These results can be used as detection reagents for examining which diseases active oxygen and free radicals are involved in, and medically useful information can be obtained.

Furthermore, the collected biological sample is homogenized, an appropriate buffer solution and the agent of the present invention are added, and after reacting for an appropriate time, the ESR is measured to determine the amount of active oxygen and free radicals in the biological tissue. It can be used as a detection reagent whose presence or absence and amount can be measured.

The amount of the diagnostic agent of the present invention to be used varies depending on the purpose, the target organ, and the disease. In general, it may be administered in an amount of about 0.1 to 50 Omg Zkg. Example

Hereinafter, the present invention will be described more specifically with reference to Synthesis Examples and Examples, but the present invention is not limited to these Examples. Synthesis example 1

Synthesis of 3-carboxy-1-proxyl methyl ester:

1 g of carboxy-proxil (5.37 mmo 1) Dissolved in 10 ml of tan. After adding 0.65 ml of methanol (16.1 mmoj) at room temperature and then 525 mg of dimethylaminopyridine (4.30 mmo), the reaction mixture was cooled to 0 ° C and dicyclohexylcarbodiimide was added. 1.22 g (5.91 mmo i) was added, and the mixture was stirred at 0 "C for 1 hour. The reaction mixture was diluted with 10 ml of dichloromethane, washed with water, and dried.

(Na ₂ SO, the solvent was distilled off. The residue was purified by column chromatography (silica gel, hexane: ethyl acetate = 4: 1) to obtain 765 mg (7%) of a yellow oil. This product was stored in a cool place.

Synthesis of 3-carboxy-1-proxylethyl ester:

Except for replacing methanol with ethanol, the same procedure as in Synthesis Example 1 was carried out to obtain 4 g of 3-force ruboxoxyproxylethyl ester 2. () 4 g (yield: 59.1%). This was also stored in a cool place. Synthesis example 3

Synthesis of 2-ethyl-1,2,5,5-trimethyloxazolidinoxyl:

The synthesis was performed as follows with reference to the method of Keana et al. [J. Am. Chem. Soc., 89, 3055-3056 (1967)].

(1) Synthesis of 2-ethyl-2,5,5-trimethyloxazolidine

2-amino-2-methyl-1-propanol 40 g (449 mmo1), 2-butanone 40 g (554 mmo1), and p-toluenesulfonic acid 300 mg (1.6 mmo1) ]) Was dissolved in 300 ml of benzene and heated under reflux for 7 days. During reflux, a mixture of 50 ml of benzene and 40 g of 2-butanone was added every 24 hours (dehydration reaction occurred due to reflux). This forms an oxazolidine ring). After completion of the reaction, the reaction solution was cooled, washed three times with 50 ml of a saturated sodium bicarbonate solution and once with 50 ml of a saturated sodium chloride solution, dried over anhydrous sodium sulfate, and the solvent was distilled off.

(2) Synthesis of 2-ethyl-2,5,5-trimethyloxazolidinoxyl

To 2.0 g of 2-ethyl-1,2,5,5-trimethyloxazolidine obtained in (1) above, 3 mL of anhydrous ether was added, mixed, and then mixed in an ice bath. A solution of 2.8 g of perbenzoic acid in 10 OmI of anhydrous ether was added slowly with stirring. After confirming that the solution was oxidized by 3-benzoic perbenzoic acid and turned yellow, stirring was stopped and the mixture was released overnight at room temperature.

After standing, the mixture was washed three times with 5 O ml of a saturated sodium hydrogen carbonate solution and once with 50 ml of a saturated sodium chloride solution, dried over anhydrous sodium sulfate, and then the solvent was distilled off. Then, use a silica gel column (diameter 3 cm mx length 57 cm, Cogel C-200, 150 g) and hexane ether (99: 1 to 25: 1 (vZv )) Was purified using eluent as the elution solvent, _e fractionated fractions were analyzed by ESR and TLC, and the solvent of the fraction containing the target compound was distilled off to obtain 2-ethyl-2,5,5- Trimethyloxazolidine oxyl (3 20 mg, yield: 14.2%) was obtained. This was kept in a cool place. Example 1

Living body distribution:

As test samples, use 3-carboxy-proxyl, 3-carboxyl mouth xinolemethylesterol, 3-carboxy-proxy / reethyl ester and 2-ethyl-2,5,5-trimethyloxazolidinoxyl A biodistribution test by ESR was performed.

As experimental animals, use 36 mice (dd Y female) as 3 animals per group Was. In the experiment, a test sample was administered into the tail vein of a mouse under anesthesia under 7.5 μmo] and left for 3, 10 and 30 minutes. Then, blood was quickly removed and the brain was removed. Subsequently, 9 times as much phosphate buffer as the extracted brain and blood was added and homogenized. A portion of this homogenized sample is added, a potassium ferricyanide solution is added thereto to a final concentration of 5 mM, and the test sample, which has been converted to a hydroxylamine form with active oxygen in the living body, is reconverted into a double-mouthed oxide radical. (One-electron oxidation) A sample for ESR was obtained. The concentration of the test sample after one-electron oxidation was measured by X-band ESR, and it was taken as the concentration in the biological sample.

On the other hand, a test sample solution was prepared in the same amount as that administered to the mouse, treated under the same conditions as after adding a 9-fold amount of phosphate buffer, and the concentration of the test sample was measured by X-band ESR. The total dose was used.

For each sample, 15 mm was taken in a 1001 cavity (length: 16.5 mm), placed in a quartz cell, and the ESR spectrum was measured under the following conditions.

( Measurement condition )

Measuring device: Electron spin resonance device [JES-RE1X (H electron

(stock) ) ]

External magnetic field: 331.5 ± 5mT

Magnetic field modulation: 100 kHz

Magnetic field modulation width: 0.1 mT

Time constant: 0.03 seconds

Microwave output: 5mW

Sweep time: 2 minutes

Measurement temperature: room temperature

From the ESR spectrum, the ratio (% dose) of the test compound (spin probe) in the brain and blood to the total dose was calculated. / od ose Divided by the weight of blood and blood (./.dose/g) of the target organ, the brain. / odose / g and blood. The ratio to / odose / g was determined. The results are shown in Tables 1 to 3, respectively.

t t

αι o

Brain blood

Test compound

J Katana ■ 1 Katana 3 min 10 min 30 min Ichiriki Noreboxy Proxy / 0.04 9 0.2 9 9 0.1 6 2 1 4 • 0 5 8 Ί ft Q 4

3 Carboxyproxil

Methinole Estenole 1.3 0 5 0.6 .7 2 0 .2 0 6 4 .6 2 2 2.6 7 6 2.1 7 7

(3) Ripoxy proxyl

0.78 9 0.7. 4 2 0.1 1 6 3. 4 5 8 2.9 1 9 3.3 7 5

2,2,5,5-trimethyloxazolidine 1.6 2 5 1.6 3 6 0. 5 2 1 4 • 5 2 4 3.69 9 0 0.

(In the table, the numbers indicate ./.dose)

to t

en o 〇 cn

Brain blood

Test compound

3 minutes 1 0 minutes 3 0 minutes 3 minutes 0 minutes 3 0

(3) Carboxyproxil 0.1 2 5 0.6. 9 4 0. 4 0 6 7.8 8 9 4. 4 26 2. 5 7 9 3

Met / Reestenoree 3.14 0 1.8 2 3 0.4 7 9 2.4 7 6 7 4 3 1.3

3 Carboxyproxil

Etizole Estenore 1.89 4.18 3 9 0. 2 8 2 2. 0 1 8 2. 1 9 9 2. 1 0 9

2-Ethyru 2,5,5-trimethyloxazolidy 3.8 1 0 4. 1 2 4】. 2 1 1 2.5 4 7 2.3 1 8 1.3 0 4

(In the table, the numbers indicate ./. Dose Zg)

t t

〇〇 cn

3 J rfilnl fi

Ayu "^ thing

3 minutes 1 o minutes 30 minutes

3-carboxyproxil 0.0 1 6 0. 1 5 7 0. 0 3 0

3—Carpoxy proxil

Mechinoresute / Re 1.2.7 0 1.0 5 2 0.1 4 3

3 Carboxyproxil

0/9 3 9 0.8 3 6 0.0 4 8

2—Echiloo 2, 5, 5—

Trimethyloxazolidi 1.49 6 1.7 7 9 1.7 2 4 Noxyl

As shown in Table 3, the ratio of brain to blood is 0.157 after 10 minutes for 3-carboxy-proxil, whereas 0.836 to 1.779 for the other test compounds. It showed a high value. This indicates that the other three test compounds can cross the cerebral vascular barrier and migrate into the brain as compared to 3-carboxy-1-proxyl, which means that they can be used as a contrast agent in the brain. Was done. Example 2

Measurement of mouse brain L-node E S R—CT image:

Four kinds of the compounds of Example 1 were administered at 15 μmo 1 to the tail vein マウス of a mouse anesthetized with Nembutal (75 mg / kg, im), and the L-band ESR-CT image of the head cross section was measured under the following conditions did.

(L band ESR—CT measurement conditions)

Measurement device: electron spin resonance device [JES-RE3L (JEOL

(stock) ) ]

External magnetic field 38.5 mT

Magnetic field gradient 0.6 mT / cm

Sweep width 1.84 mT

Sampling points: 5

Number of multiplications: 1 0

Number of projections: 1 8 (every 10 °)

Magnetic field modulation: 100 kHz

Magnetic field modulation width: 0.1 mT

Time constant: R a p i d

Microphone mouth wave output: 1 mW

Measurement temperature: Room temperature

(Result) FIG. 1 shows a mouse brain L-band ESR-CT image of 3-carboxy-proxil which is a comparison. —Ethyl 2,5,5— L-band ESR-CT images of each mouse brain of trimethyloxazolidinoxyl are shown in FIGS. 2, 3 and 4.

As is evident from these results, 3-carboxy-proxil is concentrated at a high concentration in the lower brain and hardly migrates into the brain. On the other hand, the other three compounds were also concentrated in the brain region at a high concentration, and a clear mouse brain L-band ESR-CT image was obtained. Industrial applicability

The five-membered ring N-oxyl compound, which is an active ingredient of the diagnostic agent of the present invention, has a sufficient half-life and interacts with free radicals in the living body. Reactive oxygen or other related diseases or symptoms that are useful for obtaining images and are thought to involve free radicals such as cerebral ischemia, heart disease, digestive disease, cancer, aging, inflammation, and cataract It can be used as a diagnostic agent.

That is, after administering the diagnostic agent of the present invention containing a 5-membered ring N-year-old xyl compound to a living body, a signal change in the living body of the compound is detected by ESR, NMR or the like, whereby the above-mentioned activity is obtained. Oxygen and related diseases can be detected and diagnosed.

In particular, 5-membered ring N-oxyl compounds cross the blood-brain barrier and interact with free radicals in the brain, making imaging of brain ischemia and brain tumors difficult with conventional magnetic resonance imaging. Is possible.

Therefore, the diagnostic agent of the present invention can be used for MRI and magnetoencephalography, and can be used to measure extremely large volumes of biological samples such as human head. After the development of the R device, it is expected that non-invasive diagnosis of diseases or symptoms involving active oxygen and free radicals can be obtained by obtaining images of the distribution of free radicals in the brain by the ESR method.

The 5-membered N-oxyl compound is administered to normal experimental animals and disease model experimental animals, and can detect and image active oxygen and free radicals generated from tissues and organs under normal or diseased conditions. From these results, it can be used as a reagent for detecting which disease the active oxygen-free radical is involved in, and medically useful information can be obtained.

Furthermore, after homogenizing the collected biological sample, adding an appropriate buffer solution and a 5-membered ring N-oxyl compound, and reacting for an appropriate time, the signal intensity is measured by ESR to determine the activity in the biological tissue. The presence or absence of oxygen and free radicals can be measured.

Claims

The following equation (1) or (II)

Over

(i (II)

(Wherein R represents an alkyl group having 1 to 4 carbon atoms, and R> to R ₅ represent

Each of which represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms).

2. If the N-oxyl compound is 3-carboxy-proxylmethyl ester, 3-carboxy-proxylethyl ester or 2-ethylethyl

2. The diagnostic agent according to claim 1, wherein the agent is 2,5,5-trimethyloxazolidinoxyl.

3. The diagnostic agent according to claim 1 or 2, which is a contrast agent for ESR, NMR or magnetoencephalography.

4. The diagnostic agent according to claim 1 or 2, which is an active oxygen or free radical detector.

5. In vivo, the following formula (1) or (II)

(I I)

(ι)

(Wherein, R represents an alkyl group having 1 to 4 carbon atoms, and R ₅ represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, respectively). A method for detecting a disease related to active oxygen or the like, which comprises administering, and detecting a change in a signal of the compound in a living body by ESR or NMR.

6. The detection method according to claim 4, wherein the disease associated with active oxygen and the like is a disease selected from cerebral ischemia, heart disease, digestive disease, cancer, aging, inflammation, and cataract.

7. After homogenizing the collected biological tissue, use the following formula (I) or (II)

R-

(ΐ) (II)

(Wherein, R represents an alkyl group having 1 to 4 carbon atoms, and R, or R _s represents a hydrogen atom or an alkyl group having 1 to 4 carbon atoms, respectively). After adding the compound and reacting, the signal A method for detecting active oxygen, characterized by measuring the intensity by ESR.

8. Formula (I) or (II) for the production of contrast agents for ESR, NMR or MEG

(I) (II)

(Wherein, R represents an alkyl group having 1 to 4 carbon atoms, and R and R ₅ each represent a hydrogen atom or an alkyl group having 1 to 4 carbon atoms). Use of compounds.

9. The following formula (I) or (II) for the production of active oxygen detector

(I) (II)