WO2014077398A1

WO2014077398A1 - Method for producing polyphenol

Info

Publication number: WO2014077398A1
Application number: PCT/JP2013/081078
Authority: WO
Inventors: 幸蔵佐藤
Original assignee: 富士フイルム株式会社
Priority date: 2012-11-19
Filing date: 2013-11-18
Publication date: 2014-05-22
Also published as: JP2014114283A

Abstract

A method for producing a polyphenol, which comprises: an esterification step wherein a plant that contains at least one compound selected from the group consisting of chlorogenic acid compounds and tara tannins is given an esterification agent that is capable of esterifying a carboxyl group in each molecule of the at least one compound selected from the group consisting of chlorogenic acid compounds and tara tannins, thereby esterifying the carboxyl group in each molecule; a separation step wherein the at least one compound selected from the group consisting of chlorogenic acid compounds and tara tannins, which has been esterified in the esterification step, is given a water-immiscible organic solvent and water, thereby separating the compound into an aqueous phase and an organic phase; and a step wherein the water-immiscible organic solvent is removed from the organic phase that has been obtained in the separation step, thereby obtaining the at least one compound selected from the group consisting of chlorogenic acid compounds and tara tannins, which has been esterified.

Description

Method for producing polyphenol

The present invention relates to a method for producing polyphenols, and more particularly to a method for producing at least one polyphenol selected from the group consisting of chlorogenic acid and derivatives thereof and taratannin.

In recent years, compounds that do not originate from petroleum resources, which are said to be limited, have attracted attention, and among them, research and development that uses plant resources for chemical products, plastics, pharmaceuticals, and the like are being actively conducted.
Among them, polyphenols are particularly attracting attention from the viewpoint of health care, and various polyphenols are extracted from plants and used in various fields.
In recent years, there have been many reports that polyphenols are effective for many diseases and beauty such as cancer, diabetes, hypertension, Alzheimer's disease, HIV, melanin production suppression, etc. (Food Industry, March 30, 2005 (Vol. 48, No6) separate volume).
Chlorogenic acid, a type of polyphenol, is contained in many plants such as coffee beans, sweet potato leaves, mugwort, watermelon, sunflower, etc., but it has not been easy to separate chlorogenic acid from these plants in the past. Extraction was directly made from the raw material plant using hot water or ethanol, and the powder was obtained by distilling off the solvent from the extract.
In addition, tara tannin, a kind of polyphenol, is present in large amounts in coffins of cod growing naturally in South America, but extraction and separation from plants was difficult as with chlorogenic acid.

Recently, attempts have been made to use only components having physiological activity. For example, there is a method of obtaining a high-purity chlorogenic acid by further purifying an extract containing chlorogenic acid obtained from a plant by high performance liquid chromatography. (Biosci. Biotechnol. Biochem., 66 (11), p2336-2341 (2002)).

Also, a method of adsorbing an extract of polyphenol on a column packed with an adsorbent and then eluting with a 20% or less low-concentration ethanol aqueous solution (Japanese Patent Laid-Open No. 2006-241006), adsorbing the extract onto the adsorbent And then extracting with a dilute alkaline aqueous solution (Japanese Patent Laid-Open No. 2008-94759), and after concentrating the extract, removing non-polar solvent soluble components, adsorbing to an adsorbent, and then 35% to Techniques such as a method of elution using a 50% ethanol aqueous solution (Japanese Patent Laid-Open No. 2008-260697) and a separation method of extracting chlorogenic acid with a mixture of water and a water-miscible solvent (Japanese Patent No. 4842680) have been proposed. Yes.

However, Biosci. Biotechnol. Biochem. As described in (1), the method using chromatography has problems in terms of the cost and productivity of the resin, and it is difficult to obtain polyphenols industrially with good productivity and at low cost.
In addition, in the methods described in JP-A-2006-241006, JP-A-2008-94759, and JP-A-2008-260697, the amount of objects to be processed that can be processed at one time is limited. Currently, it is difficult to efficiently and easily obtain high-purity chlorogenic acid and its derivatives in large quantities, and in the method described in Japanese Patent No. 4842680, saccharides coexisting in plants and water-soluble proteins are present. There was a problem in terms of purity because a low-purity product in which was mixed was obtained.

The present invention has been made in view of the above-mentioned problems of the prior art, and an object of the present invention is to provide at least one compound selected from the group consisting of chlorogenic acid, one of polyphenols and derivatives thereof, and taratannin. It is an object of the present invention to provide a method for producing polyphenols, which can be obtained from plant resources containing them efficiently and in a large amount with high purity by a simple operation.
In this specification, “chlorogenic acid and its derivatives” are used to include isomers of chlorogenic acid and its derivatives, and “chlorogenic acid and its derivatives” are referred to as “chlorogenic acid compounds”. There is. That is, in the present specification, the term “chlorogenic acid compound” is used in the meaning including chlorogenic acid and its derivatives and isomers thereof.
In the present specification, “chlorogenic acid and its derivatives” and “taratannin”, which are target compounds of the production method of the present invention, are sometimes collectively referred to as “polyphenol”.

As a result of intensive studies in view of the above problems, the present inventor provides an esterifying agent to a plant containing a compound selected from the group consisting of a chlorogenic acid compound and taratannin, and consists of a chlorogenic acid compound and taratannin. An esterified polyphenol selected from the group consisting of an esterified chlorogenic acid compound and an esterified taratannin is obtained by previously esterifying a carboxyl group contained in the molecule of at least one compound selected from the group. It has been found that it can be easily obtained, and the present invention has been completed.

That is, the present invention is as follows.
<1> Carboxyl having at least one selected from the group consisting of chlorogenic acid, a derivative thereof, and taratannin in a molecule containing at least one selected from the group consisting of chlorogenic acid, a derivative thereof, and taratannin At least one selected from the group consisting of an esterification step for esterifying a group, an chlorogenic acid esterified by the esterification step and a derivative thereof, and taratannin, and a water-immiscible organic solvent And a separation step in which water is added to separate the aqueous phase and the organic phase, a water-immiscible organic solvent is removed from the organic phase obtained by the separation step, and esterified chlorogenic acid and its derivatives, and Obtaining at least one selected from the group consisting of taratannin, and It is a manufacturing method.
<2> The esterification step is a step of reacting a plant containing at least one selected from the group consisting of the chlorogenic acid and derivatives thereof and talatannin with an alcohol as an esterifying agent in the presence of an acid catalyst. Or it is the manufacturing method of polyphenol as described in <1> which is the process made to react with the alkylating agent which is an esterifying agent in presence of a base.

<3> A plant containing at least one of chlorogenic acid and derivatives thereof and taratannin is selected from the group consisting of coffee beans, sweet potato foliage, honeysuckle berries, mugwort foliage, sunflower seeds and cod pods <1> or <2>, which is a plant for producing a polyphenol.
<4> The ester produced by the esterification step is at least one selected from methyl ester, ethyl ester, allyl ester, butyl ester and benzyl ester, according to any one of <1> to <3> It is a manufacturing method of polyphenol.
<5> After the step of obtaining at least one selected from the group consisting of esterified chlorogenic acid and its derivative and taratannin, a deesterification step is performed, and from the group consisting of chlorogenic acid and its derivative and taratannin The method for producing a polyphenol according to any one of <1> to <4>, wherein at least one selected from the above is obtained.

The working mechanism of the present invention is not clear, but is considered as follows.
The target compounds produced by the production method of the present invention, chlorogenic acid, chlorogenic acid derivatives, isomers thereof, and taratannin all have a carboxyl group. Separation from sex protein was difficult.
In the production method of the present invention, an esterifying agent is added to a plant containing at least one selected from the group consisting of a chlorogenic acid compound that is a polyphenol having a carboxyl group and taratannin, so that the target compound is more hydrophobic. Esterified product. Therefore, by adding a water-immiscible organic solvent and water to the resulting esterified product, saccharides and water-soluble proteins that are impurities are dissolved in water and contained in the aqueous phase, and the esterified chlorogenic acid compound And an esterified product of at least one polyphenol selected from the group consisting of esterified taratannin is dissolved in a water-immiscible organic solvent and contained in the organic phase, and the organic phase is separated from the aqueous phase. Thereafter, it is considered that an esterified product of polyphenol can be obtained in high yield by removing the water-immiscible organic solvent from the organic phase.
The esterified polyphenol can be efficiently regenerated from the chlorogenic acid compound or taratannin by deesterifying and returning to the carboxyl group as necessary.
In a preferred embodiment of the present invention, esterification of polyphenol is carried out by reacting an alcohol or alkylating agent as an esterifying agent with polyphenol in the presence of an acid or a base.

According to the present invention, at least one selected from the group consisting of chlorogenic acid which is a kind of polyphenol and derivatives thereof, and taratannin is efficiently obtained in a large amount and high purity from a plant containing them by a simple operation. A process for producing polyphenols is provided.

2 is an NMR spectrum of methyl esterified chlorogenic acid obtained in Example 1. 2 is an NMR spectrum of chlorogenic acid benzyl ester obtained in Example 5. 2 is an NMR spectrum of taratannin methyl ester obtained in Example 6.

Hereinafter, embodiments of the present invention will be described in detail. However, the description of the constituent elements described below is an example (representative example) of the embodiments of the present invention, and the embodiments of the present invention are based on these contents. There is no limitation. The present invention can be implemented with various modifications within the scope of the gist.

In the present specification, a numerical range indicated by using “to” indicates a range including the numerical values described before and after “to” as the minimum value and the maximum value, respectively. In addition, the expression “substituent” is used in a sense including an unsubstituted one and a substituent further having a substituent unless otherwise specified. For example, the expression “alkyl group” is used to include both an unsubstituted alkyl group and an alkyl group further having a substituent. The same applies to other substituents.
In this specification, the term “process” is not limited to an independent process, and is included in the term if the intended effect of the process is achieved even when it cannot be clearly distinguished from other processes.
In this specification, “room temperature” means “25 ° C.” unless otherwise specified.

The production method of the present invention is a method for efficiently producing at least one selected from the group consisting of a chlorogenic acid compound, which is a kind of polyphenol, and taratannin, from plants with high purity.
The process of the manufacturing method of this invention and its effect | action are demonstrated. First, an esterifying agent is imparted to a plant containing a polyphenol having a carboxyl group in the molecule. Preferably, a plant containing a polyphenol such as a chlorogenic acid compound is reacted with an esterifying agent selected from the group consisting of an alcohol and an alkylating agent in the presence of an acid or a base to esterify the carboxyl group of the polyphenol in the molecule. As a result, the polyphenol becomes a water-insoluble or slightly water-soluble esterified product. Thereafter, a water-immiscible organic solvent and water are added to the reaction solution containing polyphenols in which the carboxyl group is esterified to partition the organic phase and the aqueous phase. In this step, an organic phase containing an esterified polyphenol is obtained. After separating the organic phase, the water-immiscible organic solvent is removed from the organic phase to separate the esterified polyphenol.
Known polyphenols having a carboxyl group in the molecule include chlorogenic acid compound and taratannin according to the present invention, rosmarinic acid contained in a large amount of shibori leaves, and cinalin contained in artichokes. The production method of the present invention is useful in the production of any of the polyphenols described above, but among these, for the production of a compound selected from the group consisting of a chlorogenic acid compound and taratannin that are difficult to separate from plant materials. The effect is remarkable when applied.
Hereinafter, the production method of the present invention will be described in detail in the order of steps.

[Esterification process]
In the production method of the present invention, an esterification step is first performed.
In the esterification step, a plant containing at least one selected from the group consisting of a chlorogenic acid compound and taratannin is esterified with a carboxyl group having at least one selected from the group consisting of a chlorogenic acid compound and taratannin in the molecule. It is the process of providing the esterifying agent to be converted. Preferably, a plant containing at least one member selected from the group consisting of a chlorogenic acid compound and taratannin is reacted with an alcohol in the presence of an acid catalyst, or reacted with an alkylating agent in the presence of a base to produce chlorogen. In this step, at least one selected from the group consisting of an acid compound and taratannin is esterified in the molecule.

(plant)
The plant used as a raw material may be any plant as long as it contains at least one selected from the group consisting of a chlorogenic acid compound and taratannin.
The plant containing chlorogenic acid and its derivatives and at least one of taratannin is selected from the group consisting of coffee beans, sweet potato stover, honeysuckle seed, mugwort stover, sunflower seed and cod seed. Plant.
Among these, from the viewpoint of producing a large amount of high-purity polyphenol, a plant containing a large amount of at least one selected from the group consisting of chlorogenic acid compounds and taratannin is preferable.
From such a viewpoint, preferred examples of the plant containing a chlorogenic acid compound include green coffee beans, sweet potato stems and leaves, honeysuckle berries, mugwort stems and leaves, sunflower seeds, sugar beet, burdock, udon, and apples. Moreover, a chlorogenic acid compound can also be extracted from propolis containing a resin collected by bees as a plant-derived raw material.
As a plant containing cod tannin, cod seeds are preferable.
These plants may use only 1 type as a raw material, and may use 2 or more types together, but from the viewpoint of obtaining a large amount of polyphenols having similar characteristics, one plant is used as a raw material. It is preferable.
In the present invention, those used as a raw material for polyphenol in the present invention, such as leaves, stems and berries of a plant containing polyphenol, are sometimes referred to as plant raw materials.

(Polyphenol according to the present invention)
1. Chlorogenic acid and its derivative A chlorogenic acid compound is a general term for a compound group represented by the following general formula (1). Chlorogenic acid refers to one to three of the four hydroxyl groups of quinic acid in which R ¹ , R ² , R ³ , and R ⁴ in the compound represented by formula (1-1) are all hydrogen atoms, A compound having an ester bond with a caffeic acid partial structure represented by the formula (1-2), and the quinic acid represented by the formula (1-1) has a carboxyl group.
Examples of chlorogenic acid derivatives include compounds in which R ^{5 in the} structure represented by the following general formula (1) is other than a hydrogen atom, for example, an alkyl group such as a methyl group. In addition, various isomers exist in chlorogenic acid and its derivatives, and these chlorogenic acid derivatives or isomers can also be obtained by the production method of the present invention.
In the present invention, by carrying out an esterification step, a chlorogenic acid compound represented by the following general formula (1) is esterified as shown by the following general formula (2), and then carboxylated in the molecule. To the separation step. The esterification step will be described in detail below.

In the general formula (1), R ¹ , R ² , R ³ , and R ⁴ each independently represent a hydrogen atom or a partial structure represented by the formula (1-2), and R ¹ to R ⁴ One to three is a partial structure represented by the formula (1-2). R ⁵ represents a hydrogen atom or a methyl group.

In the general formula (2), R represents a hydrocarbon group. R ¹ , R ² , R ³ , and R ⁴ each independently represent a hydrogen atom or a partial structure represented by formula (2-2), and 1 to 3 of R ¹ to R ⁴ are represented by formula (2 -2).
As the hydrocarbon group represented by R, an alkyl group having 1 to 8 carbon atoms, an alkenyl group having 2 to 8 carbon atoms, an aralkyl group having 7 to 8 carbon atoms and the like are preferable. More specifically, a methyl group, Ethyl group, propyl group, allyl group, n-butyl group, benzyl group and the like are preferable.
R ⁵ represents a hydrogen atom or a methyl group. In general formula (2), the compound in which R ⁵ is a hydrogen atom is a chlorogenic acid ester.

2. Taratannin Taratannin is a general term for a compound group represented by the following general formula (3), and R ¹ , R ² , R ³ , and R ⁴ in the compound represented by the formula (3-1) are all hydrogen. A compound in which one to four of the four hydroxyl groups of the quinic acid atom is an ester bond with a gallic acid partial structure represented by the formula (3-2). Like the chlorogenic acid compound, the compound (3- The quinic acid part represented by 1) has a carboxyl group.
In the present invention, by carrying out an esterification step, esterification is performed as shown by the following general formula (4), so that the carboxyl group contained in the molecule of the taratannin represented by the following general formula (3) is separated. It attaches to a process.

In the general formula (3), R ¹ , R ² , R ³ , and R ⁴ each independently represent a hydrogen atom or a partial structure represented by the formula (3-2), and ¹ of R ¹ to R ⁴ 4 to 4 are partial structures represented by the formula (3-2).
Further, in the present invention, the taratannin is a gallic acid residue in which some of the three hydroxyl groups in the gallic acid residue represented by the formula (3-2), which is the partial structure of the compound represented by the general formula (3), are further removed. It may be a compound ester-bonded to a group. That is, taratannin is an extract from a plant raw material, and various derivatives are present as a mixture in the obtained talatannin extract. Taratannin in the present specification refers to the general formula (3). It is used in the meaning including the tala tannin represented and its various derivatives and isomers.

In the general formula (4), R represents a hydrocarbon group. R ¹ , R ² , R ³ , and R ⁴ each independently represent a hydrogen atom or a partial structure represented by the formula (4-2), and ¹ to ⁴ of R ¹ to R ⁴ are represented by the formula (4 -2).
In addition, the esterified product of taratannin in the present invention is a part of the three hydroxyl groups in the gallic acid residue that is a partial structure represented by the formula (4-2) bonded to the compound represented by the general formula (4). May be a compound further esterified with a gallic acid residue.
R is preferably a methyl group, ethyl group, propyl group, allyl group, n-butyl group, benzyl group or the like.

(Applying esterifying agent)
1. Pretreatment When esterifying a polyphenol selected from the group consisting of chlorogenic acid and taratannin, after drying the plant raw material containing polyphenol, an esterifying agent is added to the material refined using a mill or a crusher. The plant raw material containing polyphenol may be extracted directly using a solvent selected from the group consisting of water, a lower alcohol having 1 to 4 carbon atoms, and a mixture of water and a lower alcohol. Then, after extracting the component soluble in the solvent (dissolvable component), the extract of the plant containing polyphenol obtained by distilling off the solvent may be esterified by adding an esterifying agent.
In the extraction with a water-immiscible solvent after the esterification step, from the viewpoint of avoiding the deterioration of the liquid separation due to the presence of the solvent-insoluble component, in the esterification step, the soluble component is extracted in advance, It is preferable to take a method in which an esterifying agent is added to the product from which water is removed.

When polyphenol is extracted from a plant raw material in advance, the extraction solvent is preferably a solvent selected from water, methanol, ethanol, or a mixture containing two or more of water, methanol, and ethanol.
The amount of the solvent used for the extraction is preferably 3 to 50 times, more preferably 5 to 20 times in terms of mass ratio with respect to the total amount of plant raw materials.
The extraction temperature can be selected in the range of room temperature (25 ° C.) to 100 ° C., and the extraction time may be in the range of 30 minutes to 5 hours. Preferable extraction conditions include conditions where the extraction temperature is from room temperature to 80 ° C. and the extraction time is from 1 hour to 5 hours.

2. Esterification treatment The esterification of the carboxyl group of polyphenol in the molecule can be carried out either acidic or alkaline.
2-1. Esterification treatment under acidic conditions Esterification treatment under acidic conditions is esterification of a carboxyl group with an alcohol performed in the presence of a so-called acid catalyst, and is usually performed in the presence of an excess alcohol serving as a reaction solvent. Is called. In the case of this embodiment, alcohol functions as an esterifying agent.

In the production method of the present invention, many inorganic acids, organic acids, solid acids, and Lewis acids can be used as the acid catalyst used when the esterification treatment is performed under acidic conditions. As the acid catalyst, sulfuric acid, sulfonic acid compound, hydrogen chloride, phosphoric acid, polyphosphoric acid, zeolite, amberlyst, trifluoroacetic acid and the like are preferable in view of catalytic activity and economy. Of these, sulfuric acid, methanesulfonic acid are preferred. P-Toluenesulfonic acid and phosphoric acid are particularly preferred.

The amount of the acid catalyst to be used is not particularly limited, but is preferably in the range of 0.2 to 50 times, more preferably 1 to 10 times the mass ratio of the polyphenol to be extracted. It is. Note that the content of polyphenols extracted can be predicted in advance in the literature depending on the type of plant raw material, and the amount of acid catalyst used may be determined based on the value, or may be roughly estimated by preliminary extraction. The amount of the acid catalyst used may be determined based on the obtained content. The content of polyphenol in the plant material can be easily quantified by analyzing the extracted components by liquid chromatography or the like, or by measuring the NMR spectrum.
For example, cod pods are known to contain 50% to 56% by mass of tara tannin in the mass of cocoons, and similarly, green coffee beans It is known to contain 3% to 10% by mass of a chlorogenic acid compound.

As the alcohol used as the esterifying agent, usually an alcohol having 1 to 10 carbon atoms is used, more preferably, a lower alcohol having 1 to 4 carbon atoms, benzyl alcohol, or the like. Most preferred alcohols include methanol, Examples include ethanol and benzyl alcohol.

The larger the amount of alcohol used, the better. However, in consideration of economy and productivity, the mass ratio is in the range of 5 to 100 times, more preferably in the range of 5 to 20 times the total amount of plant raw materials. It is.

Preferred reaction conditions for esterification under acidic conditions are a reaction temperature of room temperature (25 ° C.) to 100 ° C., a reaction time of 1 hour to 12 hours, and a more preferred condition is a reaction temperature of room temperature to 80 ° C. The reaction time is 2 to 8 hours. If the reaction temperature is too high or the reaction time is too long, the ester bond between the hydroxyl group of quinic acid and caffeic acid or gallic acid is cleaved by the transesterification reaction, which is not preferable.

2-2. Esterification treatment under alkaline conditions Esterification under alkaline conditions is a reaction between a carboxylic acid anion and an alkylating agent, and a polyphenol containing a carboxyl group is reacted with an alkylating agent in the presence of a base in a suitable reaction solvent. Is. In the case of this embodiment, the alkylating agent functions as an esterifying agent.

As the reaction solvent, alcohol, ketone, ester, ether, amide and the like are preferably used. More specifically, acetone, methyl ethyl ketone, methyl acetate, ethyl acetate, dimethyl carbonate, tetrahydrofuran, acetonitrile, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, and the like are preferable, acetone, methyl ethyl ketone, dimethylformamide, dimethylacetamide, and N More preferred is at least one selected from the group consisting of -methylpyrrolidone.

Only 1 type may be used for the reaction solvent and it may use 2 or more types together according to the objective.
The amount of the reaction solvent is preferably in the range of 2 to 20 times by mass ratio, more preferably in the range of 3 to 10 times the total amount of plant raw materials.

As the base, it is necessary to use a compound having the ability to dissociate the carboxyl group that polyphenol has in the molecule. Usually, a compound having a pKa of conjugate acid of 6 or more is used.
Examples of inorganic bases having a conjugate acid having a pKa of 6 or more include alkali metal hydroxides, alkali metal carbonates, alkali metal hydrogencarbonates, alkali metal phosphates, alkali metal alkoxides, and the like. Examples of the organic base include triethylamine, 1,8-diazabicyclo [5,4,0] -7-undecene (DBU), 1,5-diazabicyclo (4,3,0) nonene-5 (DBN), 4 -Dimethylaminopyridine (DMAP), tetraalkylammonium hydroxide and the like.
If the basicity of the base used is too strong, the phenolic hydroxyl group of the caffeic acid part or gallic acid part of the polyphenol will also be alkylated, and there is a concern that the yield of polyphenol will decrease. When using a base, care must be taken that the basicity of the base used is in an appropriate range. From such a point of view, anhydrous alkali hydrogen carbonate and anhydrous dibasic alkali phosphate are more preferably used as the base having appropriate basicity.

The amount of the base to be used is preferably equimolar to 3-fold mol, more preferably 1.1-fold mol to 2-fold mol, relative to the number of moles of polyphenol to be esterified. In addition, the number of moles of polyphenols contained in raw materials such as plant raw materials and extracts obtained by extracting plant raw materials with a solvent can be calculated from the polyphenol content and polyphenol molecular weight measured in advance by the method described above. It is.

As the esterifying agent used in the presence of a base, any alkylating agent usually used in organic synthesis can be used.
As the alkylating agent, for example, alkyl halide, alkyl sulfate, alkyl sulfonate, alkyl carbonate, alkyl phosphate, etc. are preferably used, and more specifically, methyl iodide, butyl bromide, allyl bromide, benzyl chloride. Benzyl bromide, dimethyl sulfate, diethyl sulfate, methyl methanesulfonate, methyl benzenesulfonate, methyl p-toluenesulfonate, ethyl p-toluenesulfonate, dimethyl carbonate and the like are preferable.

It is desirable that the amount of esterifying agent used is the same as the above-mentioned amount of base used or slightly more than the amount of base used. That is, the amount of the esterifying agent to be used is preferably 1.1 times to 3.5 times mole, more preferably 1.2 times to 2.5 times mole, relative to the number of moles of polyphenol to be alkylated. .

Preferred reaction conditions for esterification under alkaline conditions are a reaction temperature of room temperature to 100 ° C. and a reaction time of 30 minutes to 12 hours, and more preferred conditions are a reaction temperature of room temperature to 80 ° C. under a nitrogen stream. The time is 1 to 8 hours. If the reaction temperature is too high or the reaction time is too long, the phenolic hydroxyl group possessed by caffeic acid or gallic acid is also alkylated, so that the yield may be lowered. For this reason, it is preferable to set it as the said reaction conditions.

When the chlorogenic acid compound or talatannin is esterified under the above acidic condition or alkaline condition, the compound represented by the general formula (2) or the general formula (4) is generated.
The obtained ester is preferably at least one selected from the group consisting of methyl ester, ethyl ester, allyl ester, butyl ester and benzyl ester from the viewpoint of ease of esterification and deesterification, and among these, , Methyl esters, allyl esters and benzyl esters are particularly preferred.

[Separation process]
In the separation step, a water-immiscible organic solvent and water are added to at least one selected from the group consisting of an esterified chlorogenic acid compound and taratannin obtained in the esterification step, and an aqueous phase and an organic phase It is the process of separating.
Since the compound represented by the general formula (2) or the general formula (4) has an esterified carboxyl group, the polarity of the molecule is higher than that of the compound represented by the general formula (1) or the general formula (3). Is significantly reduced and is soluble in water-immiscible organic solvents.
Therefore, when the reaction solution is poured into water after completion of the esterification step, and then an appropriate water-immiscible organic solvent is added and distributed, the desired esterified polyphenol is distributed into the organic phase. Here, most of the polyphenol can be transferred to the organic phase by separating the aqueous phase from the organic phase and further extracting the aqueous phase repeatedly with a water-immiscible organic solvent.

In the present invention, the water-immiscible organic solvent means that an organic solvent is mixed with an equal amount of 10% by mass saline solution at 25 ° C., stirred well, allowed to stand at room temperature (25 ° C.) for 5 minutes, then 2 An organic solvent that can be visually confirmed to be phase-separated into phases.
Examples of the water-immiscible organic solvent used in the separation step include, for example, acetate, carbonate, ether and the like, and more specifically, ethyl acetate, isopropyl acetate, butyl acetate, dimethyl carbonate, carbonate, and the like. Particularly preferred are diethyl, methylcyclopentyl ether and the like.

In addition to polyphenols, oligosaccharides, oligosaccharides, polysaccharides, proteins, amino acids, and the like coexist in plant raw materials. However, they remain highly polar even after the esterification step according to the present invention described above, and remain in the aqueous phase at the time of distribution.
Therefore, according to the production method of the present invention, only the target polyphenol can be efficiently separated from the plant raw material by a very simple operation.
In addition, since caffeine contained in a large amount in coffee beans is basic, when the reaction solution after completion of esterification is poured into water, the solution is strongly acidic, for example, hydrochloric acid or the like is added to bring the pH to 2 or less. By doing so, it remains in the aqueous phase and is not extracted into the organic phase. For this reason, when using the plant raw material containing a chlorogenic acid compound and caffeine, adjusting the pH of the liquid mixture of water and a water-immiscible organic solvent to 2 or less in a separation process is obtained chlorogen. This is preferable from the viewpoint of increasing the purity of the acid compound.

By performing the separation step of the present embodiment, the esterified product of high-purity polyphenol can be easily separated from water-soluble impurities.

[Step of removing solvent from organic phase]
By removing the water-immiscible organic solvent from the organic phase separated in the separation step, at least one selected from the group consisting of an esterified chlorogenic acid compound and taratannin is obtained. The removal of the organic solvent can be carried out by removing water by adding a desiccant such as anhydrous sodium sulfate or anhydrous magnesium sulfate, if necessary, and then distilling off under normal pressure or reduced pressure.
In addition, “removal of the solvent” in this step does not necessarily mean that the solvent is completely removed and brought to an absolutely dry state, but at least a part of the solvent is removed to a solid state that can be handled. Used in the meaning including the embodiment.
The solid content obtained after removing the solvent may be further subjected to post-treatment such as recrystallization, purification by column chromatography or the like according to the purpose.

The esterification treatment step in the production method of the present invention can be carried out on a large scale using a general-purpose reaction kettle generally used. Therefore, a large amount of esterified polyphenol can be obtained at a time by the subsequent separation step.

[Deesterification process]
The polyphenol obtained here can be used for various purposes as it is, but the ester group can be returned to the original carboxyl group as necessary.
For example, the esterified polyphenol represented by the general formula (2) or the general formula (4) is a non-polyphenol such as acetonitrile, dimethylformamide, dimethylacetamide, N-methylpyrrolidone, dimethylimidazolidinone, picoline, collidine and the like. It can be easily deesterified and regenerated by treatment with trimethylsilyl iodide, trimethylsilyl chloride / sodium iodide, lithium iodide, sodium iodide, sodium hexadecylthiolate, etc. in a protic polar solvent. .
The compound in which the carboxyl group is regenerated becomes a polyphenol represented by the general formula (1) or the general formula (3), and can be used for various applications.

Examples of the present invention will be described below, but the present invention is not limited to these examples. Hereinafter, “%” represents “mass%” unless otherwise specified.
[Example 1]
(Preprocessing)
Indonesian green coffee beans (Robusta seed) were dried and pulverized with a grinder.
To 500 g of finely ground coffee beans, 2.5 L of water and 2.5 L of methanol were added and heated under reflux for 3 hours with stirring. The chlorogenic acid compound contained in the green coffee beans was extracted with a mixed solvent of water and methanol. . The obtained extract was cooled, insoluble matter was filtered off, and the residue was thoroughly washed with methanol. The liquid separated by filtration and the methanol liquid from which the insoluble matter was washed were mixed.
The solvent was distilled off under reduced pressure by a rotary evaporator from a mixed solution of the filtrate obtained by extracting green coffee beans with a mixed solvent of water and methanol and the methanol solution from which the insoluble matter was washed, to obtain a solid content (coffee 280 g of a mixed bean extract of water and methanol).
(Esterification process)
To 100 g of the obtained solid content, 2 L of methanol and 50 g of sulfuric acid were added and stirred at 50 ° C. for 5 hours. After cooling, methanol was distilled off under reduced pressure to obtain a residue (solid content).

(Separation process and evaporation of solvent)
To the residue obtained in the esterification step described above, 1.5 L of water and 1.5 L of ethyl acetate were added and stirred at room temperature (25 ° C.) for 15 minutes.
The stirred mixture separated into an organic phase and an aqueous phase upon standing. The separated organic phase was separated. 1 L of ethyl acetate was added to the aqueous phase and partitioned again, and the organic phase was separated. The obtained organic phases were combined, washed with 10% by mass brine, and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure to obtain 14.2 g of crude methyl esterified chlorogenic acid.
The obtained crude methyl esterified chlorogen was mainly composed of methyl 5-caffeoylquinate, in addition to methyl 3-caffeoylquinate, methyl 4-caffeoylquinate, from NMR spectrum and liquid chromatography analysis. It was confirmed to contain methyl 3,5-dicaffeoylquinate, methyl 3,4-dicaffeoylquinate, methyl 4,5-dicaffeoylquinate and methyl caffeate.
The purity of the total chlorogenic acid methyl ester combined with these chlorogenic acid methyl ester compounds was 78%, and it was found that highly pure methyl esterified chlorogenic acid could be obtained by a simple operation.
(Post-processing: Purification)
The obtained crude methyl esterified chlorogenic acid was purified by silica gel chromatography (eluent: ethyl acetate / n-hexane = 3/1) to give a single methyl esterified chlorogenic acid [5-monocaffeoylquinic acid. 5.1 g of methyl (the following structure)] was obtained.
The NMR spectrum of the obtained purified product is shown in FIG.

[Example 2]
(Esterification process)
1 L of methanol and 30 g of sulfuric acid were added to 100 g of green coffee bean extract (trade name: Kaphenol P-100, manufactured by Fuji Chemical Industry), and the mixture was stirred at 50 ° C. for 4 hours to obtain an extract containing a chlorogenic acid compound. After cooling the obtained extract, methanol was distilled off under reduced pressure to obtain a solid content.
(Separation process and solvent removal)
To the obtained solid content, 1.5 L of water and 1.5 L of ethyl acetate were added and stirred at room temperature for 15 minutes, and then the organic phase was separated. 1 L of ethyl acetate was added to the aqueous phase and partitioned again, and the organic phase was separated. The obtained organic phases were combined, washed with 10% by mass brine and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure to obtain 36.0 g of crude methyl esterified chlorogenic acid.
The obtained crude methyl esterified chlorogenic acid may be purified in the same manner as in Example 1, if necessary.

Example 3
(Preprocessing)
Fresh sweet candy leaves (koganesengan) were dried by ventilation and then powdered by a pulverizer.
1 L of water and 1 L of methanol were added to 100 g of the obtained powder, and the mixture was stirred at room temperature for 10 hours.
Insoluble matters were filtered off from the obtained extract to obtain an extract containing a chlorogenic acid compound. The residue was washed thoroughly with methanol. The liquid separated by filtration and the methanol liquid from which the insoluble matter was washed were mixed. The solvent was distilled off under reduced pressure from the mixture of the filtrate and the methanol solution obtained by washing the insoluble matter to obtain 16.5 g of a solid content.
(Esterification process)
To the obtained solid content, 500 ml of methanol and 30 g of methanesulfonic acid were added and stirred at 50 ° C. for 6 hours. After cooling, methanol was distilled off under reduced pressure to obtain a residue (solid content).
(Separation process and solvent removal)
The obtained residue was partitioned by adding 500 ml of water and 500 ml of ethyl acetate. The organic phase was separated and the aqueous phase was extracted again with 500 ml of ethyl acetate. The obtained organic phases were combined, washed with 10% by mass brine, and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure to obtain 5.1 g of crude methyl esterified chlorogenic acid.
The obtained crude methyl esterified chlorogenic acid may be purified in the same manner as in Example 1, if necessary.

Example 4
(Esterification process)
To 100 g of green coffee bean extract (trade name: Kaphenol P-100, manufactured by Fuji Chemical Industry), 1.5 L of benzyl alcohol and 40 g of sulfuric acid were added and stirred at 60 ° C. for 6 hours. After cooling, benzyl alcohol was distilled off under reduced pressure using a vacuum pump to obtain a residue (solid content).
(Separation process and solvent removal)
1 L of water and 1 L of ethyl acetate were added to the residue (solid content) and stirred at room temperature for 15 minutes, and then the organic phase was separated. The organic phase was washed with 10% by mass brine and dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure to obtain 34.5 g of a crude benzyl esterified chlorogenic acid.
The obtained crude benzyl esterified chlorogenic acid may be purified in the same manner as in Example 1, if necessary.

Example 5
(Esterification process)
A mixture of 100 g of green coffee bean extract (Fuji Kagaku Kogyo, trade name: Kaphenol P-100), 25.3 g of benzyl chloride, 16.8 g of sodium hydrogen carbonate and 500 ml of dimethylacetamide at 65 ° C. for 5 hours under a nitrogen stream. Stir with heating.
(Separation process and solvent removal)
After cooling, the reaction solution was poured into a mixture of 2 L of 6N hydrochloric acid and 1 L of ethyl acetate, the pH of the mixture was adjusted to 1, and after stirring for 30 minutes, insoluble materials were filtered off and the organic phase was separated. The organic phase was washed with 10% by mass brine, dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure. Further, the residue was washed with n-hexane to obtain 35.2 g of a crude benzyl esterified chlorogenic acid.
10 g of the crude product was purified by silica gel chromatography (eluent: ethyl acetate / n-hexane = 4/1) to obtain 5.1 g of benzyl esterified chlorogenic acid (mixture with benzyl monocaffeoylquinate). The NMR spectrum of the obtained purified product is shown in FIG.

Example 6
(Esterification process)
Dried cod powder (dried cod seeds, finely pulverized (from Peru). Importer, Kawamura Tsusho) 100 g of methanol and 50 g of sulfuric acid were added and stirred at 40 ° C. for 6 hours. An extract containing was obtained. The obtained extract was cooled, insoluble matters were filtered off, and the residue was washed with methanol. The liquid separated by filtration and the methanol liquid from which the insoluble matter was washed were mixed. The solvent was distilled off under reduced pressure from a mixture of the filtrate and methanol from which insolubles had been washed to obtain a residue (solid content).
(Separation process and solvent removal)
To the obtained residue were added 1.5 L of water and 2 L of ethyl acetate, and the mixture was stirred at room temperature for 15 minutes, and then the organic phase was separated. 1 L of ethyl acetate was added to the aqueous phase for partitioning again, and the resulting organic phase was separated. The organic phases were combined, washed with 10% by mass brine, dried over anhydrous magnesium sulfate, and the solvent was distilled off under reduced pressure to obtain 51.4 g of crude methyl esterified taratannin (including a small amount of methyl gallate). ).
(Post-processing: Purification)
10 g of the obtained crude product was purified by silica gel chromatography (eluent: ethyl acetate / n-hexane = 5/1) to obtain 8.1 g of methyl esterified taratannin free of methyl gallate. The NMR spectrum of the obtained purified product is shown in FIG.

Example 7
(Deesterification process)
A mixture of 2.0 g of the purified methyl esterified chlorogenic acid obtained in Example 1, 3.3 g of trimethylsilyl chloride, 4.5 g of sodium iodide and 40 ml of acetonitrile was stirred at 40 ° C. for 5 hours. Acetonitrile was distilled off from the reaction solution under reduced pressure, 30 ml of water and 30 ml of ethyl acetate were added, and the organic phase was separated. Water was distilled off from the aqueous phase under reduced pressure, ethanol was added to the residue, and inorganic substances were filtered off. Ethanol was distilled off from the filtrate, and the residue was recrystallized from a small amount of water to obtain chlorogenic acid (5-monocaffeoylquinic acid). Yield 1.2g.

[Comparative Example 1]
The solid content obtained by the pretreatment in Example 1 (mixed solvent extract of water and methanol of green coffee beans, hereinafter sometimes referred to as green coffee bean extract) was analyzed by liquid chromatography. The purity of the chlorogenic acid compounds (monocaffeoylquinic acid and dicaffeoylquinic acid) was 15.0%. As a result of analysis, this extract contained a large amount of saccharide and about 10% protein in addition to the chlorogenic acid compound.
For the solid content (raw coffee bean extract) obtained in the pretreatment of Example 1, using water, water / ethanol, water / methanol, methanol, ethanol, etc. as a solvent, chlorogenic acid compound, sugar, water-soluble Attempts were made to separate proteins, but the solubility of chlorogenic acid compounds and saccharides in various solvents was very similar, making separation difficult.
Further, the green coffee bean extract was heated and dissolved in 100 times amount (mass ratio) of acetone, and acetone was removed from the soluble matter to obtain a chlorogenic acid compound having a purity of 65%. It was less than 2%.
From the comparison between Example 1 and Comparative Example 1, the yield of chlorogenic acid is extremely low when the esterification step performed in advance is not performed. According to the production method of the present invention, high purity can be achieved by a simple process. It can be seen that chlorogenic acid can be obtained in high yield.

According to the production method of the present invention, the polyphenol is efficiently obtained at a time by a simple operation from a plant raw material containing at least one compound selected from the group consisting of a chlorogenic acid compound that is a kind of polyphenol and taratannin. It can be isolated in large quantities and with high purity.
Polyphenols have been reported to have antitumor activity, antidiabetic activity, antihypertensive activity, antiviral activity, etc., and polyphenols obtained by the production method of the present invention can be used for many drugs, functional foods, cosmetics, etc. Use is expected. These polyphenols are also useful as raw materials for quinic acid, caffeic acid and gallic acid, which are useful as chemical products.
The disclosure of Japanese Patent Application 2012-253646 filed on November 19, 2012 and the disclosure of Japanese Patent Application 2013-236198 filed on November 14, 2013 are hereby incorporated by reference in their entirety. Incorporated into the description.

Claims

A plant containing at least one selected from the group consisting of chlorogenic acid and its derivatives and taratannin is esterified with a carboxyl group having at least one selected from the group consisting of chlorogenic acid and its derivatives and taratannin in the molecule An esterification step for providing an esterifying agent to be converted;
Separation in which a water-immiscible organic solvent and water are added to at least one selected from the group consisting of chlorogenic acid and derivatives thereof and taratannin esterified in the esterification step to separate an aqueous phase and an organic phase. Process,
Removing the water-immiscible organic solvent from the organic phase obtained by the separation step to obtain at least one selected from the group consisting of esterified chlorogenic acid and derivatives thereof, and taratannin;
The manufacturing method of the polyphenol containing this.
The esterification step is a step of reacting a plant containing at least one selected from the group consisting of the chlorogenic acid and derivatives thereof and taratannin with an alcohol in the presence of an acid catalyst, or in the presence of a base. The method for producing a polyphenol according to claim 1, which is a step of reacting with an alkylating agent.
A plant comprising at least one selected from the group consisting of chlorogenic acid and derivatives thereof and taratannin is a group consisting of coffee beans, sweet potato stems, honeysuckle berries, mugwort stalks, sunflower seeds and cod pods The method for producing a polyphenol according to claim 1 or 2, wherein the plant is selected from plants.
The ester produced by the esterification step is at least one selected from the group consisting of a methyl ester, an ethyl ester, an allyl ester, a butyl ester, and a benzyl ester. Process for producing polyphenols.
After the step of obtaining at least one selected from the group consisting of the esterified chlorogenic acid and derivatives thereof and taratannin, a deesterification step is performed to select from the group consisting of chlorogenic acid and derivatives thereof and taratannin The method for producing a polyphenol according to any one of claims 1 to 4, wherein at least one kind is obtained.