JP4461772B2 - Antioxidant consisting of phenolic compounds - Google Patents

Description

The present invention relates to a phenol compound that can be suitably used as an antioxidant in the fields of foods, pharmaceuticals, quasi drugs, cosmetics, and the like, and further relates to an antioxidant using the compound .

  In recent years, it has become clear that reactive oxygen species and free radicals cause various diseases. Originally, active oxygen is generated in the immune system of the living body, and has a function of attacking pathogenic bacteria that have entered from the outside. However, if the active oxygen is excessively generated and remains, it reacts with components in the living body, that is, lipids, proteins, DNA, etc., and has an adverse effect. Among them, unsaturated fatty acids that are constituents of biological membranes and the like are easily oxidized and generate lipid peroxides via free radical intermediates. This lipid peroxide is known to induce arteriosclerosis, hypertension, liver dysfunction, and the like, and is also said to be closely related to the aging phenomenon. Recently, oxidative degradation products of unsaturated fatty acids have been raised as a cause of odor (for example, see Non-Patent Document 1). In addition, foods, pharmaceuticals, cosmetics, and the like containing unsaturated fatty acids that are susceptible to oxidation also have a problem that the quality is likely to deteriorate during storage.

  In order to prevent oxidation of such unsaturated fatty acids, it is necessary to use an antioxidant. As an antioxidant, many compounds are known. Specifically, butylhydroxytoluene (BHT), butylhydroxyanisole (BHA), tocopherols, ascorbic acid and its derivatives, ubiquinone and its derivatives, flavone derivatives, Examples thereof include gallic acid derivatives and polyphenols (see, for example, Non-Patent Document 2 and Non-Patent Document 3). However, the synthetic chemicals such as BHT and BHA have a problem that they are not safe for human bodies and have application limitations, and natural antioxidants are just one step away from performance and are difficult to obtain. there were.

Prostaglandins (PGs), which are representative mediators of inflammation, are synthesized from arachidonic acid, which is an unsaturated fatty acid in vivo. That is, when arachidonic acid is released from phospholipids in the biological membrane in response to stimulation from outside the cell, it is converted into PGG2 and PGH2 by the action of cyclooxygenase (COX), which is a kind of fatty acid oxidase. Then, four kinds of physiologically important PGs (PGD2, PGE2, PGF2a, and PGI2) and thromboxane A2 are synthesized by specific synthases present in various cells.
Two types of isozymes (COX-1 and COX-2) are known as COX (see, for example, Non-Patent Document 4). COX-1 is a constitutive enzyme present in the digestive tract such as the stomach and intestine, kidneys, ovaries, seminal vesicles, and platelets, and the PG synthesized therefrom has physiological roles such as gastric juice secretion, diuresis, and platelet aggregation. Is responsible. On the other hand, COX-2 is an inductive enzyme that is newly produced by stimulation of cytokines, tumor promoters, hormones, etc., and PG synthesized therefrom is inflammatory reaction, angiogenesis, apoptosis, carcinogenesis, ovulation, labor, and bone resorption. (See, for example, Non-Patent Document 5).
As a relationship between COX and disease, there have been many reports that rheumatism and arthritis are caused by COX-2. Recent research has also revealed the relationship with human cancer cells. For example, enhanced expression of COX-2 has been reported in colorectal cancer, breast cancer, stomach cancer, esophageal cancer, lung cancer, hepatocellular carcinoma, pancreatic cancer, squamous cell carcinoma such as head and neck. Furthermore, Alzheimer's disease has been reported as a pathological condition related to COX-2 (see, for example, Non-Patent Document 6).

The COX inhibitor can be used for a therapeutic agent for these diseases, and for improvement / suppression of a disease state. Since inhibition of COX-1 also inhibits the synthesis of PG necessary for physiological functions, it is known that there is a risk of causing various side effects such as gastrointestinal disorders.
Therefore, as a means for solving the above problems, a drug that selectively inhibits only COX-2 without inhibiting COX-1 has attracted attention. That is, a selective inhibitor of COX-2 can be expected to suppress cancer growth, metastasis, inflammation and the like with few side effects. Typical examples of this are Celecoxib, Rofecoxib, JTE-522, etc., and others have been vigorously developed (see, for example, Patent Document 1, Patent Document 2, and Patent Document 3). .

  On the other hand, Non-Patent Document 7 and Non-Patent Document 8 have descriptions relating to phenol compound 1 and phenol compound 2 represented by the following chemical formulas.

・ Phenol compound 1

・ Phenol compound 2

R in the phenol compound 2 is CH (CH ₃ ) CH ₂ CH ₃ or CH ₂ CH (CH ₃ ) ₂ .

  However, Non-Patent Document 7 only describes a method for synthesizing phenol compound 1, and there is no description regarding its performance and use. Non-Patent Document 8 only discloses that the property of the phenol compound 2 has a prostaglandin production inhibitory performance.

JP 2003-176264 A (Claims, p9) JP2003-160554A (Claims, p15) JP 2002-080453 A (Claims, p2) Satoru Iida, 7 others, “Analysis and coping with body odor generation mechanism”, Abstracts of the 51st SCCJ Research Discussion Meeting, 2002, p. 64-67 Kenji Fukuzawa, “Pharmacology of Free Radical Defense and Prospects for Drug Development”, Nippon Clinic, October 1988, 46, 10, p. 2269-2276 Sies, H., two others, “Antioxidant Functions of Vitamins”, Annals New York Academy of Sciences, 1992, 669, p. 7-20 Hirata Yukio, Morita Ikuo, “COX-1 and COX-2”, Medical Review, 1996, p105-118 Hideo Nakamura, Journal of Japanese Pharmacology, 2001, 118, p219-230 Murota Seigo and Yamamoto Shozo, “Modern Chemistry Special Issue 38 New Developments in Prostaglandin Research”, Tokyo Chemical Doujin, 2001 Choi, Y. H., 4 others, Tetrahedron Lett., 1995, 36, 1871-1874 Xin-Sheng, 3 others, Tetrahedron Lett., 1983, 24, 3247-3250

An object of the present invention is to provide an excellent antioxidant comprising a phenol compound useful in the fields of foods, pharmaceuticals, quasi-drugs, cosmetics and the like in view of the above situation.

As a result of intensive studies to solve the above problems, the present inventors have found that a specific phenol compound can be easily synthesized, and further, that the compound has an excellent free radical scavenging effect. The headline and the present invention were completed.

That is, the present invention is an antioxidant comprising a specific phenol compound 6 and / or compound 10 among the compounds represented by the following general formula (1).

R ¹ in Formula (1) represents an alkyl group that may have 1 to 18 carbon atoms, and R ² represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a protecting group for a phenolic hydroxyl group. Show.

The antioxidant comprising the phenolic compound of the present invention has an excellent antioxidant effect and can be used in the fields of foods, pharmaceuticals, quasi drugs and cosmetics.

O About phenol compound R ¹ of the compound represented by the formula (1) is an alkyl group having 1 to 18 carbon atoms, and the alkyl group may be either branched or unbranched. Specific examples of such alkyl groups include methyl, ethyl, propyl, butyl, isobutyl, pentyl, hexyl, heptyl, octyl, 2-ethylhexyl, nonyl, decyl, lauryl. Group, stearyl group and the like. More preferred alkyl groups are linear alkyl groups, and specific examples include methyl, ethyl, propyl, butyl, pentyl, hexyl, heptyl, octyl, nonyl, and decyl groups. It is done.
In the general formula (1), R ² is a hydrogen atom, an alkyl group having 1 to 4 carbon atoms, or a protecting group for a phenolic hydroxyl group. Examples of the alkyl group having 1 to 4 carbon atoms of R ² include a methyl group, an ethyl group, and a propyl group. Examples of the protecting group for the phenolic hydroxyl group of R ² include ether-based protecting groups such as methoxymethyl group, tetrahydropyranyl group, benzyl group and 4-methoxybenzyl group, trimethylsilyl group and t-butyldimethylsilyl group. Examples include silyl-type protective groups, and ester-type protective groups such as acetyl group, propionyl group, butyroyl group, isobutyroyl group, pivaloyl group, benzoyl group and trioyl group, and ester-type protective groups are preferable. R ^{2 in the} general formula (1) is preferably a methyl group or an ethyl group, and more preferably a methyl group.
The phenol in the general formula (1) may be bonded with a protecting group for a phenolic hydroxyl group. Examples of the protecting group for the phenolic hydroxyl group include those described above.
Among the compounds represented by the formula (1), the specific phenol compound 6 and / or the compound 10 is hereinafter referred to as a phenol compound of the present invention.

-Synthesis of phenolic compounds of the present invention
The phenol compound of the present invention can be prepared, for example, by reacting a compound represented by the following formula (2) (hereinafter referred to as a compound of the formula (2)) in the presence of a basic compound.

R ¹ in the formula (2) represents an alkyl group which may have 1 to 18 carbon atoms, and R ² represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a protecting group for a phenolic hydroxyl group. R ³ represents a hydrogen atom or a protecting group for a phenolic hydroxyl group. X represents a benzenesulfonyl group or a toluenesulfonyl group.

When synthesizing the compound of formula (1), the compound of formula (2) reacts with the basic compound to produce the compound of formula (3) in which the double bond is isomerized. And from this compound of Formula (3), elimination of the HX group occurs, and it is presumed that a furan ring is formed (see the following scheme). When R ² and R ^{3 in} the formula (2) are phenolic hydroxyl protecting groups that can be removed under basic conditions, deprotection of the protecting groups also occurs.

R ¹ in the above formula (3) represents an alkyl group which may have 1 to 18 carbon atoms, and R ² represents a hydrogen atom, an alkyl group having 1 to 4 carbon atoms or a protecting group for a phenolic hydroxyl group. X represents a benzenesulfonyl group or a toluenesulfonyl group.

When R ² and R ^{3 in} formula (2) are phenolic hydroxyl protecting groups, preferred are protecting groups that can be easily removed when they are no longer needed. For example, they can be removed by treatment with a basic compound. Examples include silyl-type protecting groups and acyl-type protecting groups.
Specifically, a trimethylsilyl group, a t-butyldimethylsilyl group, an acetyl group, a propionyl group, a butyroyl group, an isobutyroyl group, a pivaloyl group, a benzoyl group, and a toluoyl group can be preferably used, and more preferably an acetyl group or a propionyl group. , Butyroyl group, isobutyroyl group, pivaloyl group, benzoyl group or toluoyl group.

The basic compound used in the reaction from the compound of formula (2) to the phenol compound of the present invention includes sodium hydride, potassium hydride, sodium hydroxide, potassium hydroxide, alkoxide (for example, sodium methoxide, sodium ethoxide, potassium t-butoxide, etc.), n-butyllithium, s-butyllithium, t-butyllithium and the like, preferably sodium hydride.
The amount of the basic compound used in the reaction with the compound of the formula (2) varies depending on the structure of R ² and R ³ in the formula (2) and the kind of the basic substance, but 2 to 10 chemical equivalents are appropriate. Preferably it is 3-5 chemical equivalent.

  In this reaction, a solvent may be used. Methanol, isopropyl alcohol, n-butyl alcohol, s-butyl alcohol, t-butyl alcohol, tetrahydrofuran, 1,4-dioxane, diethyl ether, 1,2-dimethoxyethane, N, N-dimethylformamide, hexamethylphosphoric triamide, N, N-dimethylpropylene urea, a mixed solvent thereof and the like can be preferably used.

The reaction temperature is 0 ° C to 100 ° C, preferably 25 ° C to 80 ° C. When the reaction temperature is too low, the reaction proceeds slowly, and when the reaction temperature is too high, side reactions may proceed. Although this reaction time varies depending on conditions, it is usually several tens of minutes to several hours. After completion of the reaction, the phenol compound of the present invention can be obtained by known methods such as solvent extraction and column chromatography.

○ Synthesis of the compound of formula (2) The compound of formula (2) is produced, for example, by oxidizing a compound represented by the following formula (4) (hereinafter referred to as the compound of formula (4)) with an oxidizing agent such as hydrogen peroxide. it can. Further, the compound of the formula (4) is obtained by reacting an electrophile such as phenylselenyl chloride with a compound represented by the following general formula (5) (hereinafter referred to as the compound of the formula (5)). It can be synthesized by forming a 5-membered ether with the terminal hydroxyl group of the chain.

R ¹ , R ² , R ³ and X in the formula (4) are the same as those in the formula (2), and R ⁴ represents an alkyl group having 1 to ⁴ carbon atoms or a substituted or unsubstituted aryl group, preferably Is a methyl group or a phenyl group, and Y represents a sulfur atom or a selenium atom.

  The oxidizing agent for synthesizing the compound of the formula (2) from the compound of the formula (4) is not particularly limited, but hydrogen peroxide, peracetic acid, trifluoroperacetic acid, perbenzoic acid, m-chloroperoxide. Peracids and peroxides such as benzoic acid and t-butyl hydroperoxide can be suitably used. The amount of peracid or peroxide used in this reaction is 1 to 10 chemical equivalents, preferably 1.1 to 2 chemical equivalents.

  This oxidation reaction may use a solvent, such as dichloromethane, chloroform, 1,2-dichloroethane, tetrahydrofuran, 1,4-dioxane, diethyl ether, 1,2-dimethoxyethane, acetonitrile, toluene, water, and mixed solvents thereof. Can be preferably used.

  The temperature of this oxidation reaction is −20 ° C. to 100 ° C., preferably 0 ° C. to 80 ° C. If this reaction temperature is too low, the reaction proceeds slowly, and if the reaction temperature is too high, side reactions may proceed. This reaction time varies depending on the conditions, but is usually from several tens of minutes to several hours. After completion of this reaction, the compound of formula (2) can be obtained by a known method such as solvent extraction or column chromatography.

-About the synthesis | combination of a formula (4) compound As above-mentioned, a formula (4) compound is compoundable by cyclizing the following formula (5), for example.

R ¹ , R ² , R ³ and X in the formula (5) are the same as those in the formula (2).

  In the reaction for obtaining the compound of formula (4) from the compound of formula (5), phenylselenyl chloride and dimethyl (methylthio) sulfonium tetrafluoroborate can be used as the reaction partner of the compound of formula (5). The usage-amount of this compound is 1-5 chemical equivalent, Preferably it is 1.1-1.5 chemical equivalent. In the cyclization reaction, an appropriate amount of an amine such as diisopropylethylamine or a weakly basic compound such as molecular sieves can be used in addition to the above compound.

  This cyclization reaction may use a solvent, and is preferably performed in an aprotic polar solvent, such as tetrahydrofuran, 1,4-dioxane, diethyl ether, 1,2-dimethoxyethane, hexamethylphosphoric triamide, N, N-dimethylpropylene urea, acetonitrile, N, N-dimethylformamide, dimethyl sulfoxide, a mixed solvent thereof and the like can be preferably used.

  The temperature of this cyclization reaction is 0 ° C to 100 ° C, preferably 25 ° C to 80 ° C. If this reaction temperature is too low, the reaction proceeds slowly, and if the reaction temperature is too high, side reactions may proceed. This reaction time varies depending on the conditions, but is usually from several tens of minutes to several hours. After completion of this reaction, the compound of formula (4) can be obtained by a known method such as solvent extraction or column chromatography.

○ Synthesis of compound of formula (5) The compound of formula (5) is obtained by reacting a compound represented by the following formula (6) (hereinafter referred to as compound of formula (6)) with a strongly basic compound, and the substituent X is bonded. It can be synthesized by reacting an anion obtained by extracting a hydrogen atom from the carbon in question with a carbon atom of a carbonyl group in a compound represented by the following formula (7) (hereinafter referred to as formula (7) aldehyde).

R ¹ , R ² , R ³ and X in the formula (6) are the same as those in the formula (2).

R ¹ —CHO (7)
R ¹ in formula (7) is the same as in formula (5).

  As the strongly basic compound that acts on the compound of formula (6) to generate an anion, an alkyl metal compound and an alkali metal can be used. Specifically, alkyl lithium compounds such as n-butyllithium, s-butyllithium, t-butyllithium and phenyllithium, and n-butylmagnesium chloride, s-butylmagnesium chloride, t-butylmagnesium chloride, n-butylmagnesium. Examples thereof include Grignard compounds such as bromide, s-butylmagnesium bromide and t-butylmagnesium bromide. Specific examples of the alkali metal include metal lithium and metal sodium. Preferred compounds of this strongly basic compound include n-butyllithium, n-butylmagnesium chloride or n-butylmagnesium bromide. The amount of the strongly basic compound used is preferably 0.7 to 1.3 chemical equivalents, more preferably 0.9 to 1.1 chemical equivalents, relative to the compound of formula (6).

  The reaction of the compound of formula (6) with a strongly basic compound is preferably carried out in an aprotic solvent, such as tetrahydrofuran, 1,4-dioxane, diethyl ether, 1,2-dimethoxyethane, hexamethylphosphoric tri Amides, N, N-dimethylpropylene urea, mixed solvents thereof and the like can be preferably used. The reaction temperature is preferably -100 ° C to 25 ° C, more preferably -80 ° C to 0 ° C. This reaction time varies depending on conditions, but is usually from several minutes to several tens of minutes.

  An aldehyde of formula (7) is added to a reaction vessel containing an anion generated by the reaction of the compound of formula (6) and a strongly basic compound. The reaction temperature at that time is preferably −100 ° C. to 25 ° C., and preferably −80 ° C. to 0 ° C. This reaction time varies depending on conditions, but is usually from several minutes to several tens of minutes. After completion of this reaction, the compound of formula (5) can be isolated and purified by a known method such as solvent extraction or column chromatography.

  The compound of formula (6) can be synthesized, for example, by substituting the hydroxyl group of the compound represented by the following formula (8) with a toluenesulfonyl group or a benzenesulfonyl group by a known method.

R ² and R ^{3 in} Formula (8) are the same as those in Formula (2).

The phenolic compound of the present invention has free radical scavenging activity. Therefore, it can mix | blend and use for prescriptions, such as a foodstuff, a pharmaceutical, a quasi-drug, and cosmetics, as an antioxidant.

<Example>
EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these Examples. Ts represents a p-toluenesulfonyl group.

<Synthesis Example 1>
Synthesis of Compound 2 First, Compound 2 was synthesized using the following Compound 1 as a starting material.

・ Compound 1

・ Compound 2

In 350 mL of tetrahydrofuran, 14.4 g (79.9 mmol) of Compound 1, 22.3 mL (160 mmol) of triethylamine and 976 mg (7.99 mmol) of N, N-dimethylaminopyridy were dissolved, and pivaloyl chloride 19. 7 mL (160 mmol) was added dropwise. The mixture was stirred at room temperature for 16 hours and then washed twice with 100 mL of saturated saline. The organic layer was dried over anhydrous magnesium sulfate and concentrated.
Next, the obtained residue was dissolved in 270 mL of tetrahydrofuran and 90 mL of methanol, and 15.7 g (87.9 mmol) of sodium p-toluenesulfinate and 923 mg (0.799 mmol) of tetrakistriphenylphosphine palladium (0) were added for 4 hours. Refluxed. After the reaction, 90 mL of distilled water was added and stirred and left at 4 ° C. The produced crystals were collected by filtration. The filtrate was concentrated and extracted with 200 mL of ethyl acetate, and the organic layer was washed with 100 mL of distilled water. The organic layer was dried over anhydrous magnesium sulfate, concentrated, and recrystallized from a mixed solvent of ethyl acetate-hexane. The obtained crystals were combined with the aforementioned crystals to obtain 20.3 g (yield 63%) of a yellow crystalline compound.
The chemical shift value of ¹ H-NMR spectrum measured in deuterochloroform of this product is 1.36 (9H, s), 2.44 (3H, s), 3.80 (3H, s), 3.93. (2H, d), 6.06 (1H, dt), 6.33 (1H, d), 6.83-6.94 (3H, m), 7.33 (2H, d), 7.75 ( 2H, d).
The wave numbers (cm ⁻¹ ) absorbed in the infrared absorption spectrum (KBr pellet method) were 2980, 1747, 1600, 1508, 1480, 1465, 1420, 1399, 1343, 1314, 1304, 1289, 1269. It was.
The results of CHN elemental analysis were as follows: carbon 65.65% and hydrogen 6.51%.
Based on the above analysis, it was confirmed that the obtained compound was the compound 2.

Synthesis of Compound 3 Subsequently, Compound 3 was synthesized by reacting Compound 2 with propionaldehyde.

・ Compound 3

4.45 g (7.45 mmol) of Compound 2 was dissolved in a mixed solvent of 50 mL of tetrahydrofuran and 10 mL of 1,3-dimethyl-2-imidazolinone, and cooled to −78 ° C. with dry ice / acetone. To this solution, 7.4 mL (11.8 mmol) of 1.6 M t-butyllithium / pentane solution was added dropwise. Further, after stirring at the same temperature for 5 minutes, 0.87 mL (12.1 mmol) of propionaldehyde was added dropwise. After dropping, the mixture was stirred at the same temperature for 10 minutes and then gradually heated. When the temperature of the reaction solution reached −30 ° C., a 2 mL methanol solution containing 1 g of citric acid was added to stop the reaction. To this reaction mixture, 60 mL of saturated brine, 20 mL of distilled water and 20 mL of acetic acid ethyl ester were added and stirred, and then the organic layer was separated. The aqueous layer was extracted with 20 mL of ethyl acetate, and the combined organic layer was dried over anhydrous magnesium sulfate. The solvent was distilled off from the organic layer, and purification by silica gel column chromatography was performed to obtain 3.72 g (yield 73%) of a pale yellow high-viscosity liquid compound.
The chemical shift values of ¹ H-NMR spectrum measured in deuterated chloroform of this product are 0.97-1.01 (3H, m), 1.24-1.44 (11H, m), 2.43 ( 3H, s), 3.71 (1H, t), 3.80 (3H, s), 4.30-4.32 (1H, m), 5.72 (1H, dd), 6.16 (1H , D), 6.78-6.80 (2H, m), 6.93 (1H, d), 7.31 (2H, d), 7.71 (2H, d).
The wave numbers (cm ⁻¹ ) absorbed in the infrared absorption spectrum (KBr pellet method) were 3511, 2972, 1753, 1598, 1509, 1268, 1124.
The results of CHN elemental analysis were 65.19% carbon and 7.00% hydrogen.
Based on the above analysis, it was confirmed that the obtained compound was the compound 3.

Synthesis of Compound 4 Subsequently, Compound 3 was reacted with phenylselenyl chloride and cyclized to synthesize Compound 4.

Compound 4

9.03 g (19.6 mmol) of Compound 3 was dissolved in 50 mL of acetonitrile, and 2 g of molecular sieves 3A and 4.36 g (22.8 mmol) of phenylselenyl chloride were added thereto, followed by stirring at room temperature for 2 hours. This reaction mixture was washed twice with 100 mL of saturated brine, and the obtained organic layer was dried over anhydrous magnesium sulfate. The solvent was distilled off from the organic layer, and the residue was purified by silica gel column chromatography to obtain 10.9 g (yield 90%) of a pale yellow highly viscous liquid compound.
Chemical shift values of ¹ H-NMR spectrum measured in deuterated chloroform of this product are 1.07-1.11 (3H, m), 1.24-1.38 (11H, m), 2.37 ( 3H, s), 3.50 (1H, dd), 3.73 (1H, dd), 3.79-3.89 (4H, m), 4.68 (1H, d), 6.87-7 .55 (12H, m).
The wave numbers (cm ⁻¹ ) absorbed in the infrared absorption spectrum (KBr pellet method) were 2971, 1754, 1598, 1509, 1478, 1463, 1274, 1118. Furthermore, the result of mass spectrometry was M ⁺ = 617.
Based on the above analysis, it was confirmed that the obtained compound was the compound 4.

Synthesis of Compound 5 Subsequently, Compound 4 was oxidized to prepare Compound 5.

Compound 5

9.93 g (16.1 mmol) of Compound 4 was dissolved in 200 mL of dichloromethane. On the other hand, a solution prepared by dissolving 4.18 g (24.2 mmol) of m-chloroperbenzoic acid prepared in advance in 50 mL of dichloromethane was added dropwise under ice cooling. Further, after stirring at the same temperature for 30 minutes, 200 mL of 10% aqueous sodium thiosulfate solution was added to the reaction mixture to stop the reaction. The organic layer was separated from this reaction solution and dried over anhydrous magnesium sulfate. The solvent was distilled off from the organic layer, and the residue was purified by silica gel column chromatography to obtain 7.26 g (yield 98%) of a pale yellow highly viscous liquid compound.
The chemical shift values of ¹ H-NMR spectrum measured in deuterochloroform of this product are 0.91-0.95 (3H, m), 1.24-1.38 (11H, m), 2.36 ( 3H, s), 3.78 (3H, s), 4.97 (1H, m), 5.79 (1H, d), 6.67 (1H, s), 6.83 (1H, d), 6.89 (1H, d), 6.98 (1H, d), 7.37 (2H, d), and 7.80 (2H, d).
The wave numbers (cm ⁻¹ ) absorbed in the infrared absorption spectrum (KBr pellet method) were 2773, 1754, 1508, 1458, 1321, 1304, and 1283. The results of CHN elemental analysis were as follows: carbon 65.48% and hydrogen 6.59%.
Based on the above analysis, it was confirmed that the obtained compound was the compound 5.

Synthesis of Compound 6 By reacting Compound 5 obtained in Synthesis Example 1 with sodium hydride in an alcohol solvent, R ^{1 in} the general formula (1) of the present invention is an ethyl group and R Compound 6 in which ² corresponds to a methyl group was synthesized.

Compound 6

That is, 1.49 g (3.25 mmol) of Compound 5 was dissolved in 30 mL of t-butyl alcohol. On the other hand, a solution prepared by dissolving 390 mg (9.75 mmol) of sodium hydride prepared in advance in 20 mL of t-butyl alcohol was added dropwise. The reaction solution was stirred at 40 ° C. for 2 hours, and an appropriate amount of 1M / L hydrochloric acid was added to stop the reaction. After evaporating the solvent from the reaction solution, 100 mL of ethyl acetate was added for extraction, the organic layer was washed twice with 50 mL of saturated brine, and the organic layer was dried over anhydrous magnesium sulfate. The solvent was distilled off from the organic layer, and the residue was purified by silica gel column chromatography to obtain 420 mg (yield 59%) of a pale yellow highly viscous liquid compound.
The chemical shift value of ¹ H-NMR spectrum measured in deuterochloroform of this product is 1.24-1.29 (3H, m), 2.70 (2H, dd), 3.94 (3H, s). 5.62 (1H, s), 6.03 (1H, d), 6.40 (1H, d), 6.91 (1H, d), 7.13-7.16 (2H, m) there were.
The wave numbers (cm ⁻¹ ) absorbed in the infrared absorption spectrum (KBr pellet method) were 3510, 2974, 2362, 1506, 1254, and 1209. The results of CHN elemental analysis were as follows: carbon 71.54% and hydrogen 6.47%.
Based on the above analysis, it was confirmed that the obtained compound was the compound 6.

<Synthesis Example 2>
Synthesis of Compound 7 Compound 7 was synthesized by reacting Compound 2 with 1-heptanal.

Compound 7

4.45 g (11.4 mmol) of Compound 2 was dissolved in a mixed solvent of 50 mL of tetrahydrofuran and 10 mL of 1,3-dimethyl-2-imidazolinone, and cooled to −78 ° C. with dry ice / acetone. To this solution, 7.4 mL (11.8 mmol) of 1.6 M t-butyllithium / pentane solution was added dropwise. After stirring this reaction liquid at the same temperature for 5 minutes, 1.6 mL (11.5 mmol) of 1-heptanal was added dropwise. After dropping, the mixture was stirred at the same temperature for 10 minutes and then gradually heated. When the temperature of the reaction solution reached −30 ° C., a 2 mL methanol solution containing 1 g of citric acid was added to stop the reaction. To this reaction mixture, 60 mL of saturated brine, 20 mL of distilled water, and 20 mL of ethyl acetate were added and stirred, and then the organic layer was separated. The aqueous layer was extracted with 20 mL of ethyl acetate, and the combined organic layer was dried over anhydrous magnesium sulfate. The solvent was distilled off from the organic layer, and purification by silica gel column chromatography was performed to obtain 4.15 g (72%) of a pale yellow highly viscous liquid compound.
Chemical shift values of ¹ H-NMR spectrum measured in deuterated chloroform of this product are 0.84-0.87 (3H, m), 1.19-1.36 (19H, m), 2.42 ( 3H, s), 3.57 (1H, d), 3.81 (3H, s), 4.50-4.61 (1H, m), 5.72 (1H, dd), 6.18 (1H , D), 6.29 (1H, dd), 6.79 (1H, d), 6.88 (1H, s), 6.91 (1H, d), 7.31 (2H, d), 7 .71 (2H, d).
The wave numbers (cm ⁻¹ ) absorbed in the infrared absorption spectrum (KBr pellet method) were 3510, 2933, 2337, 1755, 1508, and 1268. Furthermore, the results of CHN elemental analysis were 67.41% carbon and 7.80% hydrogen.
Based on the above analysis, it was confirmed that the obtained compound was the compound 7.

Synthesis of Compound 8 Subsequently, Compound 7 was reacted with phenylselenyl chloride and cyclized to synthesize Compound 8.

Compound 8

3.43 g (6.71 mmol) of Compound 7 was dissolved in 50 mL of acetonitrile, and 1 g of molecular sieves 3A and 1.35 g (7.05 mmol) of phenylselenyl chloride were added thereto, followed by stirring at room temperature for 2.5 hours. This reaction mixture was diluted with 50 mL of ethyl acetate, washed twice with 50 mL of saturated brine, and the obtained organic layer was dried over anhydrous magnesium sulfate. The solvent was distilled off from the organic layer, and the residue was purified by silica gel column chromatography to obtain 4.14 g (yield 92%) of a pale yellow highly viscous liquid compound.
Chemical shift values of ¹ H-NMR spectrum measured in deuterated chloroform of this product are 0.84-0.89 (3H, m), 1.24-1.38 (19H, m), 2.36 ( 3H, s), 3.51 (1H, dd), 3.72 (1H, dd), 3.86 (3H, s) 3.92-3.97 (1H, m), 4.67 (1H, d), 6.89-7.55 (12H, m).
The wave numbers (cm ⁻¹ ) absorbed in the infrared absorption spectrum (KBr pellet method) were 2932, 1755, 1508, 1464, and 1274. Furthermore, the result of mass spectrometry was M ⁺ = 673.
Based on the above analysis, it was confirmed that the obtained compound was the compound 8.

Synthesis of Compound 9 Subsequently, Compound 8 was oxidized to prepare Compound 9.

Compound 9

4.29 g (6.36 mmol) of Compound 8 was dissolved in 100 mL of dichloromethane. On the other hand, a solution prepared by dissolving 1.65 g (9.58 mmol) of m-chloroperbenzoic acid prepared in advance in 25 mL of dichloromethane was added dropwise under ice cooling. After stirring the reaction solution at the same temperature for 30 minutes, 100 mL of a 10% aqueous sodium thiosulfate solution was added to stop the reaction. The organic layer was separated from the reaction solution and dried over anhydrous magnesium sulfate. The solvent was distilled off from the organic layer, and the residue was purified by silica gel column chromatography to obtain 2.84 g (yield 87%) of a pale yellow highly viscous liquid compound.
Chemical shift values of ¹ H-NMR spectrum measured in deuterated chloroform of this product are 0.83-0.87 (3H, m), 1.18-1.36 (19H, m), 2.46 ( 3H, s), 3.77 (3H, s), 5.01 (1H, m), 5.79 (1H, d), 6.66 (1H, s), 6.82 (1H, d), 6.88 (1H, d), 6.98 (1H, d), 7.37 (2H, d), and 7.80 (2H, d).
The wave numbers (cm ⁻¹ ) absorbed in the infrared absorption spectrum (KBr pellet method) were 2935, 1755, 1599, 1510, 1321, and 1283. The results of CHN elemental analysis were as follows: carbon 67.68% and hydrogen 7.44%.
Based on the above analysis, it was confirmed that the obtained compound was the compound 9.

Synthesis of Compound 10 By reacting Compound 9 obtained in Synthesis Example 2 with sodium hydride in an alcohol solvent, R ^{1 in} the general formula (1) of the present invention is a hexyl group and R Compound 10 in which ² corresponds to a methyl group was synthesized.

Compound 10

1.41 g (2.74 mmol) of Compound 9 was dissolved in 50 mL of t-butyl alcohol. On the other hand, a solution prepared by dissolving 548 mg (13.7 mmol) of sodium hydride prepared in advance in 30 mL of t-butyl alcohol was added dropwise. After stirring the reaction solution at 40 ° C. for 4.5 hours, an appropriate amount of 1M / L hydrochloric acid was added to stop the reaction. After evaporating the solvent from the reaction solution, 50 mL of ethyl acetate was added for extraction, the organic layer was washed twice with 25 mL of saturated brine, and the organic layer was dried over anhydrous magnesium sulfate. The solvent was distilled off from the organic layer, and the residue was purified by silica gel column chromatography to obtain 540 mg (yield 72%) of a pale yellow highly viscous liquid compound.
The chemical shift values of ¹ H-NMR spectrum measured in deuterated chloroform of this product are 0.88-0.91 (3H, m), 1.25-1.39 (8H, m), 2.66 ( 2H, t), 3.95 (3H, s), 5.59 (1H, s), 6.02 (1H, d), 6.39 (1H, d), 6.80 (1H, d), 7.13-7.16 (2H, m). The wave numbers (cm ⁻¹ ) absorbed in the infrared absorption spectrum (KBr pellet method) were 3532, 2931, 1505, 1254, and 1212. Furthermore, the results of CHN elemental analysis were as follows: carbon 74.42% and hydrogen 8.08%.
Based on the above analysis, it was confirmed that the obtained compound was the compound 10.

○ DPPH radical scavenging activity DPPH (1,1-diphenyl-2-picrylhydrazyl) using Compound 6 obtained in Example 1, Compound 10 obtained in Example 2 and dl-α-tocopherol (manufactured by Tokyo Chemical Industry Co., Ltd.) ) Radical scavenging test was conducted. The specific test procedure is as follows.
1 ml of 200 μM DPPH ethanol solution was added to 800 μl of 100 mM Tris-HCl buffer (pH = 7.4) and 200 μl of compound 6 ethanol solution (final concentration 10 μg / mL) and stirred well. This was left to stand at room temperature in a dark place for 20 minutes, and then the absorbance at 517 nm was measured (absorbance of the sample solution).
The same operation was performed for Compound 10 and dl-α-tocopherol.
As a control, 800 μl of 100 mM Tris-HCl buffer (pH = 7.4), 200 μl of ethanol, and 1 ml of 200 μM DPPH ethanol solution were used in the same manner as described above, and the absorbance was measured (absorbance of the control solution).
The same measurement was performed three times for each compound, and the average value was substituted into the following formula to calculate the DPPH radical elimination rate. The results are shown in Table 1.
DPPH radical scavenging rate (%) =
[1- (absorbance of sample solution / absorbance of control solution)] × 100

  As a result of the test, it was found that Compound 6 and Compound 10 have a free radical scavenging effect higher than that of dl-α-tocopherol.

○ Cyclooxygenase inhibitory activity The sheep seminal vesicle microsomes (manufactured by Caiman Chemical) are used as COX-1, and the sheep placenta-derived COX-2 purified product (manufactured by Caiman Chemical) is used as COX-2. The conversion rate to E2 was defined as enzyme activity. Activity measurement was performed as follows.
After adding 10 μL of each concentration of Compound 6 or Compound 10 dissolved in 10% dimethylsulfoxide aqueous solution to 70 μL of 143 mM Tris buffer (pH 7.5) containing 2.9 mM phenol and 1.4 mM hematin, 2 units 10 μL of COX-1 or COX-2 solution was added and mixed. This was preincubated at 37 ° C. for 2 minutes. Then, radiolabeled adjusted to a concentration of 25.5μM in 100mM Tris buffer [1- ¹⁴ C] arachidonic acid (Amersham Pharmacia Biotech) was added and mixed 10μL (0.14μCi). This was reacted at 37 ° C. for 2 minutes and immediately cooled on ice.
COX activity was calculated with reference to the method of Yanagi and Komatsu (Biochem. Pharmacol., 25, 937-941 (1976)). That is, 0.4 mL of a mixed solution of n-hexane / ethyl acetate (2: 1) was added to the reaction solution, stirred for 30 seconds, and then centrifuged to remove the organic layer containing unreacted arachidonic acid. After the same extraction operation was repeated twice, 50 μL of ethanol was added to the aqueous layer and stirred for 30 seconds. The mixture was centrifuged at 2000 G for 1 minute, and 0.1 mL of the aqueous layer was transferred to a liquid scintillation counter vial. To this was added 2 mL of clear sol 1 (manufactured by Nacalai Tesque) as a scintillator to prepare a prostaglandin E2 fraction cocktail. The radioactivity was measured with a liquid scintillation counter (ALSCA LSC-1000), and the ratio of radioactivity was calculated as the prostaglandin E2 conversion rate.
From the relationship between the prostaglandin E2 conversion rate and the test sample concentration, a concentration (IC ₅₀ ) that inhibits the conversion to prostaglandin E2 by 50% was calculated, and the results are shown in Table 2.

The antioxidant comprising the phenolic compound of the present invention has an excellent antioxidant effect and can be used in the fields of foods, pharmaceuticals, quasi drugs and cosmetics.

Claims (1)

An antioxidant comprising phenol compound 6 and / or compound 10 represented by the following formula.
Compound 6

Compound 10