JP5301982B2 - Process for producing concentrated phorbol ester - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for producing a concentrated phorbol ester by which the phorbol ester concentrated to a high concentration can be produced from a vegetable oil and fat containing the phorbol ester. <P>SOLUTION: The method for producing the concentrated phorbol ester includes: an esterification step (A) of esterifying a fatty acid in the vegetable oil and fat containing the phorbol ester with a lower alkyl alcohol using at least a cation exchange resin, and affording a reaction mixture containing an ester mixed oil having &le;2 mg-KOH/g acid value; a step (B) of separating the layer of the lower alkyl alcohol from the ester mixed oil; and a step (C) of concentrating the resultant layer of the lower alcohol. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a method for producing a concentrated phorbol ester that produces a concentrated phorbol ester from a phorbol ester-containing vegetable oil.

Vegetable fats and oils can be used as raw material fats and oils of fatty acid lower alkyl esters for light oil alternative fuels that are attracting attention as biomass fuels. As a method for producing fatty acid lower alkyl esters from vegetable fats and oils, the applicant has disclosed Patent Document 1 Has been proposed.
The method described in Patent Document 1 uses a cation exchange resin to esterify a fatty acid in a raw material with a lower alkyl alcohol to obtain a reaction mixture containing an ester mixed oil having an acid value of 2 mg-KOH / g or less. A process and a transesterification step of transesterifying the fat and oil in the ester mixed oil with a lower alkyl alcohol while adjusting the amount of the alkali catalyst according to the acid value. It describes that fatty acid lower alkyl ester is produced using a mixed oil derived therefrom.

However, in the method described in Patent Document 1, it has not been disclosed to separate and concentrate phorbol ester from a deoxidized mixed oil derived from vegetable oil.
Phorbol ester has a property as a carcinogenic promoter, so it needs to be removed or reduced. When producing fatty acid lower alkyl esters from vegetable oil containing phorbol ester, phorbol ester is separated and concentrated. To do is an important issue.

By the way, phorbol ester is known to be dissolved in methanol, and can be extracted from vegetable oils.
For example, Patent Document 2 discloses (a) a step of removing polar components from crude vegetable oil and fat using lower alkyl alcohol or any lower alkyl alcohol-water mixture, (b) from step (a) by distillation. Removing alcohol, (c) adding bleaching earth to the product obtained in step (b) at the usual bleaching temperature and filtering, and (d) obtaining in step (c) at a lower temperature. A method for refining vegetable fats and oils by the process of deodorizing the resulting product is described. By using this method, a small amount of components can be recovered without destroying the components present in crude vegetable oils and fats. And fat can be purified.

In addition, for the purpose of analyzing toxic substances in vegetable oils and fats, establishing quantification methods for phorbol esters, simplifying phorbol ester quantification methods, and identifying phorbol ester structures in vegetable oils and fats, A method for extracting ball ester is known (see Non-Patent Documents 1 to 3).
For example, Non-Patent Document 1 describes that phorbol ester is extracted from vegetable oils and fats using dichloromethane as a solvent and then the solvent is removed, and the obtained phorbol ester is dissolved in tetrahydrofuran (THF). Later, a method for quantifying phorbol esters by high performance liquid chromatography (HPLC) is described.
Non-patent document 2 describes a method of extracting methanol four times using methanol as a solvent. By quantifying phorbol ester from a mess-up phorbol ester solution by HPLC, quantification of phorbol ester is described. A simple method for performing is described.
Non-Patent Document 3 describes a method of dissolving in petroleum ether, extracting as a solid phase, and purifying this by a chromatography method using a dichloromethane-acetonitrile solvent. A method for identifying the structure of phorbol esters has been described.

However, in the methods in Patent Document 2 and Non-Patent Documents 1 to 3, there is no description about obtaining a high concentration of phorbol ester at the time of concentration, and because vegetable oils and fats that have not been deoxidized are used. The concentrate obtained by concentrating the extract of vegetable oils and fats contains a large amount of impurities such as fatty acids, and has a problem that a phorbol ester concentration cannot be obtained at a high concentration.
Therefore, when producing these fatty acid lower alkyl esters from vegetable oils and fats containing phorbol esters, there is a problem that the amount of treatment increases when the phorbol ester concentrate is discarded. is there.
Therefore, in order to reduce such a processing amount, it has been desired to provide a method for producing a phorbol ester capable of separating and concentrating a highly concentrated phorbol ester.

JP 2007-176773 A JP 2002-194381 A J. Agric. Food Chem. 1997,45,3152-3157 Industrial Crops and Products 12 (2000) 111-118 J. Nat. Prod. 2002, 65, 1434-1440

  An object of the present invention is to solve the above-described conventional problems and achieve the following object. That is, an object of the present invention is to provide a method for producing a concentrated phorbol ester capable of producing a highly concentrated phorbol ester from a phorbol ester-containing vegetable oil.

Means for solving the above problems are as follows. That is,
<1> Esterification of a fatty acid in a phorbol ester-containing vegetable oil using at least a cation exchange resin to obtain a reaction mixture containing an ester mixed oil having an acid value of 2 mg-KOH / g or less. A concentrated phorbol ester comprising: a step (A); a step (B) for separating a lower alkyl alcohol layer from the ester mixed oil; and a step (C) for concentrating the obtained lower alcohol layer. It is a manufacturing method.
<2> The method for producing a concentrated phorbol ester according to <1>, wherein the phorbol ester-containing vegetable oil is Jatropha oil.

  According to the present invention, there is provided a concentrated phorbol ester that can solve the conventional problems and achieve the above-mentioned object, and can produce a highly concentrated phorbol ester from a phorbol ester-containing vegetable oil. A manufacturing method can be provided.

(Method for producing concentrated phorbol ester)
The method for producing a concentrated phorbol ester of the present invention comprises at least an esterification step (A), a separation step (B), and a concentration step (C), and if necessary, other steps. Become.

<Esterification step (A)>
In the esterification step (A), a cation exchange resin is used to esterify a fatty acid in a phorbol ester-containing vegetable oil with a lower alkyl alcohol, and the reaction mixture contains an ester mixed oil having an acid value of 2 mg-KOH / g or less. It consists of the process of obtaining.
Here, the reaction mixture is an untreated mixture obtained in the esterification step (A), and the ester produced in the esterification step (A), the fat and oil as the main component of the raw material, In addition to the ester mixed oil composed of other components originally contained in the raw material, it refers to one containing unreacted lower alkyl alcohol and by-product water. That is, an ester mixed oil is obtained by removing lower alkyl alcohol and moisture from the reaction mixture which is an untreated mixture obtained in the esterification step (A).

-Phorbol ester-containing vegetable oils-
The phorbol ester-containing vegetable oil is derived from plants and contains oil and fat (fatty acid triglyceride) as a main component. Examples of the plant include plants of Euphorbiaceae.
The plant of Euphorbiaceae is not particularly limited as long as it contains phorbol ester and can be appropriately selected according to the purpose. For example, jatropha oil is preferable.
In addition, the phorbol ester-containing vegetable oils and fats are unrefined products that contain gums mainly composed of phospholipids, free fatty acids (hereinafter sometimes referred to as free fatty acids), odor components and the like. Unrefined fats and oils may be sufficient and the refined fats and oils from which at least one part of these was removed by the refinement | purification process may be sufficient.
Hereinafter, the main component refers to a component occupying at least 50%.

  Moreover, the said phorbol ester containing vegetable oil may be used individually by 1 type, or may mix and use 2 or more types. Furthermore, you may use for the said phorbol ester containing vegetable fat and oil, for example, mixing the fatty acid collect | recovered in manufacturing processes, such as another substance. When there are too many such fatty acids, adverse effects may be exerted on each step. Therefore, the amount is preferably 10 parts by mass or less and more preferably 5 parts by mass or less with respect to 100 parts by mass of the phorbol ester-containing vegetable oil.

-Cation exchange resin-
In the esterification step (A), esterification is performed using a cation exchange resin.
This is an esterification reaction between a free fatty acid contained in fats and oils and a lower alkyl alcohol using a cation exchange resin as an acid catalyst. The cation exchange resin is a solid catalyst and can be recovered. As a stationary phase, it can be used for continuous reaction, and it does not mix in subsequent processes.

The cation exchange resin is not particularly limited and may be appropriately selected according to the purpose. Examples include an acid solid cation exchange resin and an acid gel cation exchange resin, but an acid gel cation exchange resin is used. Then, since the esterification reaction rate increases more, it is preferable.
The reason for this is not clear, but can be inferred as follows. That is, the acid-type solid cation exchange resin has a reduced catalytic ability due to adhesion or adsorption of water generated by the esterification reaction. However, an acidic gel cation exchange resin can take water as hydration water. This is considered to be due to the fact that the catalytic ability is not lowered by water.
The degree of cross-linking of the acidic gel cation exchange resin is preferably in the range of 3% to 10%. If it is 3% or more, it is preferable from the viewpoint of resin strength, and if it is 10% or less, it is preferable from the viewpoint of the removal efficiency of fatty acids. The degree of crosslinking is more preferably 4% to 8%. Of these, those having a degree of crosslinking of 4% are particularly preferred because the esterification reaction rate of fatty acids is the highest and the mechanical strength of the resin is sufficient.

  The acidic gel type cation exchange resin is not particularly limited, and for example, a sulfonated product of styrene-divinylbenzene copolymer is preferable. For example, Diaion SK104 (trade name, cross-linking degree 4%) manufactured by Mitsubishi Chemical Corporation, SK106 (trade name, cross-linking degree 6%), SK1B (trade name, cross-linking degree 6%) and SK110 (trade name, cross-linking degree 10%), Dow Chemical Co., Ltd. (trade name, cross-linking degree 4%) ), Amberlite (trade name, degree of cross-linking 4%) manufactured by Rohm & Haas.

-Lower alkyl alcohol-
The lower alkyl alcohol is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include alcohols having 4 or less carbon atoms. Specific examples include methanol, ethanol, propanol and butanol. It is done. Of these, methanol is preferable. These may be used alone or in combination of two or more.
The amount of the lower alkyl alcohol added is not particularly limited and may be appropriately selected depending on the fatty acid distribution in the raw material, but is preferably 5 parts by mass to 50 parts by mass with respect to 100 parts by mass of the raw material. 10 mass parts-30 mass parts are more preferable, and 15 mass parts-25 mass parts are especially preferable. Within such a range, a sufficient esterification reaction rate can be obtained, and an excessive increase in the recovery cost and equipment capacity of the lower alkyl alcohol can be suppressed.
The lower the amount of water in the lower alkyl alcohol, the better. However, in practice, it is preferably 1,500 ppm or less, more preferably 1,000 ppm or less, and particularly preferably 600 ppm or less.

-Acid value-
In this esterification step (A), the acid value of the ester mixed oil is 2 mg-KOH / g or less, preferably 1 mg-KOH / g or less, more preferably 0.1 mg-KOH / g to 0.5 mg-KOH. Esterification is performed so as to be / g. The lower the acid value of the ester mixed oil reached in the esterification step (A), the better, but the practical lower limit is about 0.1 mg-KOH / g. In order to set the acid value to 2 mg-KOH / g or less, conditions such as column type, column temperature, column residence time, and the amount of lower alkyl alcohol used may be adjusted.
When such an esterification step (A) is performed before the separation step (B) and the concentration step (C), fatty acids as impurities contained in the extract to be separated can be reduced. The phorbol ester-containing concentration can be improved.

  That is, when the fatty acid whose acid value exceeds 2 mg-KOH / g is contained in the ester mixed oil, the free fatty acid becomes an impurity in the concentration step, so the concentration rate (concentration) of the phorbol ester is not improved. .

The acid value is the concentration of the acidic substance expressed by the mass (mg) of potassium hydroxide required for neutralization per 1 g of the sample, and in the case of fats and oils, it means the concentration of fatty acids. An acid value of 1 mg-KOH / g corresponds to a fatty acid concentration of 0.46% by mass (in terms of palmitic acid). The acid value is sometimes referred to as AV (Acid Value).
In actual measurement, the reaction mixture was sucked with an evaporator to remove unreacted lower alkyl alcohol and water to obtain an ester mixed oil, which was further pretreated by passing it through a filter paper containing anhydrous sodium sulfate. Thereafter, a neutralization titration method is preferred.

As a specific method of the esterification step (A), there is a method in which a column filled with a cation exchange resin is prepared, and a mixture of a lower alkyl alcohol and a raw material is supplied to the column and allowed to pass through.
Regarding the conditions for passing through the column, the column temperature is preferably 40 ° C to 70 ° C, more preferably 50 ° C to 65 ° C, and particularly preferably 60 ° C to 65 ° C. The column residence time is particularly preferably 60 minutes to 480 minutes, 90 minutes to 360 minutes, and 90 minutes to 240 minutes.
With such column temperature and column residence time, the fluidity of the mixture is good, the reaction rate is sufficient, and the column does not need to be excessively large or pressure-resistant, which is efficient.

Before supplying the mixture of the lower alkyl alcohol and the raw material to the column, it is preferable to wash the cation exchange resin with alcohol as a pretreatment. As the alcohol for washing, it is preferable to use the same lower alkyl alcohol as that used for the esterification reaction.
Such washing is preferably performed until the moisture in the alcohol before and after passing through the column does not change. By washing in this way, the water in the cation exchange resin is replaced with alcohol, and the esterification efficiency of the fatty acid can be further increased. Specifically, it is preferable to wash with 2 to 5 times the volume of alcohol of the cation exchange resin.

<Separation step (B)>
The separation step (B) is a step of separating the oil layer and the lower alcohol layer contained in the ester mixed oil using a gravity difference or the like.

The method for separating the oil layer and the lower alcohol layer contained in the ester mixed oil is not particularly limited and may be appropriately selected depending on the purpose. For example, stationary separation, centrifugation, filter separation, etc. Can be mentioned.
In the stationary separation method, the oil layer and the lower alcohol layer are separated by standing at a temperature (20 ° C. to 90 ° C.) for a time (0.5 hour to 10 hours) in a stationary separation tank such as a vessel. Is the method.
The centrifugation method is a method of separating an oil layer and a lower alcohol layer at a temperature (20 ° C. to 90 ° C.) and a centrifugal effect (500 G to 3000 G) using a centrifuge, a decanter, or the like.
The filter separation method is carried out by a liquid-liquid separation filter composed of a nonwoven fabric (material: polyethylene, polypropylene, polyester, etc., filtration accuracy: 2 μm to 20 μm), and the fine oil layer is agglomerated and coarsened while standing and separated. This is a method for separating the alcohol layer.

<Concentration step (C)>
The concentration step (C) is a step of concentrating the lower alkyl alcohol layer obtained from the separation layer.
In the esterification step (A), the ester mixed oil is separated into an oil layer containing a fatty acid alkyl ester and a lower alkyl alcohol layer in which the phorbol ester is dissolved. When the lower alkyl alcohol layer is concentrated, the phorbol ester is increased. A concentrate concentrated to a concentration is obtained.

The concentration method is not particularly limited and may be appropriately selected depending on the intended purpose. Examples thereof include a method of evaporating lower alcohol (evaporation method) and a membrane separation method.
Examples of the evaporation method include evaporator evaporation and topping evaporation at a laboratory level, and topping evaporation in an actual apparatus, flash evaporation, liquid film lowering evaporation, forced stirring thin film evaporation, and the like.
Evaporation by the evaporator includes a method in which a low boiling point component is distilled off by reducing the pressure at a temperature (10 ° C. to 90 ° C.) while rotating the flask.
Examples of the topping evaporation include a method in which a low boiling point component is distilled off at a temperature (10 ° C. to 90 ° C.) and a pressure (0.1 kPa to 100 kPa) while stirring in a normal vessel vessel.
As the flash evaporation, a low-boiling component is continuously supplied by a flash evaporator while continuously supplying the liquid at a temperature temperature (10 ° C. to 90 ° C.) in a reduced pressure atmosphere of pressure (0.1 kPa to 100 kPa). And a method of concentrating the high-boiling components.
As the liquid film descending evaporation and the forced stirring thin film evaporation, the liquid is continuously cooled to a temperature (10 ° C. to 90 ° C.) in the same manner as the flash evaporation in the liquid film descending evaporation apparatus and the forced stirring thin film evaporation apparatus. And a method of separating the high-boiling component and the low-boiling component by distilling off the low-boiling component while continuously supplying the reduced-pressure atmosphere at a reduced pressure of 0.1 kPa to 100 kPa.

The membrane separation method includes a pervaporation method.
The pervaporation method is a membrane process in which a supply liquid is evaporated through a membrane, and at that time, only a specific component is separated and recovered by a membrane separation function. The membrane to be used is a polymer membrane without pores or an inorganic membrane (zeolite membrane or the like) having fine pores at the molecular level. The mixed solution is flowed to the supply side of the membrane, and the supply liquid is partially evaporated through the membrane by keeping the permeate side in vacuum, and concentrated.

There is no restriction | limiting in particular as a method of measuring content of the phorbol ester in the said concentrate, For example, the method as described in Industrial Crops and Products 12 (2000) 111-118) is mentioned.
Specifically, the following methods are mentioned.
First, a standard solution in which TPA (12-O-tetradecanoyl phosphor-13-acetate) is dissolved in methanol is prepared, and a calibration curve is prepared. Next, a solution obtained by dissolving a concentrate containing phorbol ester in a methanol solvent is stirred and then centrifuged, and the supernatant is used as an analysis sample. The phorbol ester in the analysis sample can be detected by high performance liquid chromatography, and the content of the phorbol ester in the concentrate can be measured using the calibration curve.

<Other processes>
There is no restriction | limiting in particular as said other process, According to the objective, it can select suitably, For example, the degumming process (P) etc. in the case of using unrefined fat as said phorbol ester containing vegetable fat. Can be mentioned.
That is, when using unrefined fats and oils, first, after performing the degumming step (P), the esterification step (A) of the fatty acid in the raw material is performed, and then the separation step (B) and the concentration step (C) are performed. It is preferable to implement.
In addition, when using refined fats and oils, an esterification process (A) can be performed without performing a degumming process (P).

-Degumming step (P)-
The degumming step (P) is for removing insoluble substances such as colloidal impurities and gums mainly composed of phospholipids contained in unrefined fats and oils when unrefined fats and oils are used as raw materials. It is a process, and after implementing this process, an esterification process (A) is performed.
The specific method of the degumming step (P) is not particularly limited, and may be a method in which an adsorbent is mixed with unrefined oil and fat together with warm water, and the resulting mixture is then filtered to remove insoluble matters. However, a method of adding phosphoric acid as a modifier to an unrefined oil and fat and adding an adsorbent and filtering is preferable. When phosphoric acid is used, the degumming rate is increased, and by-products are easily separated in each subsequent step, so that the separation efficiency is improved. As a result, a high-purity fatty acid lower alkyl ester can be obtained in a high yield. As the adsorbent, pearlite, diatomaceous earth, activated clay and the like can be used, but diatomaceous earth and pearlite are preferable, and pearlite is more preferable because it has higher adsorption ability. Note that pearlite is a foam formed by heat treating obsidian at a high temperature.

  Specifically, the unrefined fat / oil is preferably heated to 50 ° C. to 70 ° C., more preferably 60 ° C. to 70 ° C., and phosphoric acid and pearlite are added thereto, preferably 1 minute to 60 minutes, more preferably Is mixed and stirred for 10 to 40 minutes. After mixing and stirring, the mixture is filtered with a filter equipped with a filter such as a cloth filter to remove insoluble matters, and a degummed product is obtained as a filtrate. When the treatment temperature is 50 ° C. to 70 ° C., useful components in the unrefined fats and oils are not altered or deteriorated and can be effectively degummed.

  Here, the addition amount of phosphoric acid is preferably 0.01 parts by mass to 0.1 parts by mass with respect to 100 parts by mass of the unrefined fats and oils. When the amount is 0.01 parts by mass or more, degumming effectively proceeds, and when the amount is 0.1 parts by mass or less, phosphoric acid that has not contributed to degumming tends to remain. Moreover, it is more preferable to adjust suitably the addition amount of phosphoric acid according to the gum content of unrefined fats and oils. The gum content is A. O. C. It can be measured by S test method Ca 9f-57.

Moreover, it is preferable that phosphoric acid is added with the form of aqueous solution, In that case, 70 mass% or more of the phosphoric acid concentration of phosphoric acid aqueous solution is preferable, and 75 mass%-90 mass% are more preferable. Such a concentration is preferable because water as a solvent is less likely to adversely affect the subsequent process than the degumming process (P) and the filterability of the gum is deteriorated.
The amount of pearlite added is preferably 0.03 to 0.15 parts by mass, more preferably 0.03 to 0.1 parts by mass, and still more preferably 100 parts by mass of unrefined fats and oils. It is 0.03 mass part-0.05 mass part. When it is 0.03 parts by mass or more, degumming effectively proceeds, while when it is 0.15 parts by mass or less, loss of unrefined fats and oils can be suppressed and the amount of pearlite to be discarded can be reduced.

  In the degumming step (P), unrefined fats and oils containing a large amount of adsorbent may be circulated and supplied to the filter to form a precoat phase on the surface of the filter so that the filtration can be performed more smoothly. In this case, the amount of pearlite added is preferably 0.2 parts by mass to 1.0 part by mass, more preferably 0.2 parts by mass to 0.7 parts by mass with respect to 100 parts by mass of the unrefined fat. 2 parts by mass to 0.4 parts by mass are particularly preferable. Even in this case, when the added amount of pearlite is within such a range, it is possible to effectively degumming while suppressing the loss of unrefined oil and fat and reducing the amount of pearlite to be discarded.

  In addition, before and after the degumming step (P) and during the degumming step (P), it is preferable to remove impurities from the unrefined fat as necessary. Contaminants may be removed by the same method and the same apparatus as the gum removal, or may be removed by a method such as stationary separation in an unrefined oil storage tank, a filtration device, or centrifugation. Contaminants include soil, gravel, and garbage, and in some cases, metal may be included. Moreover, it is preferable that the moisture content of the degummed product is 2,000 ppm or less, and when exceeding this, it is preferable to remove moisture here appropriately.

  EXAMPLES Hereinafter, although this invention is demonstrated more concretely based on an Example and a comparative example, this invention is not limited to the following Example.

Example 1
100 parts by mass of Indonesian Jatropha oil and 20 parts by mass of methanol were added to a 300 mL beaker to prepare a mixed solution thereof.

-Esterification process (A)-
This mixed solution was passed through a column (column) packed with 800 mL of a cation exchange resin (Diaion SK104H (crosslinking degree: 4%), manufactured by Mitsubishi Chemical Corporation) heated to 60 ° C. over 15 minutes, Methyl esterification was performed to obtain an ester mixed oil.
The acid value of this ester mixed oil was measured by the method of Standard Oil Analysis Test Method 2.3.1-1996 (acid value). The measured acid value was 0.8 mg-KOH / g.

-Separation process (B)-
The obtained ester mixed oil was transferred to a separatory funnel and subjected to a liquid separation operation, allowed to stand for 30 minutes, and then separated into a methanol layer and an oil layer.
-Concentration step (C)-
Methanol was distilled off from the separated methanol layer solution by using an evaporator (RE-46, manufactured by Yamato Kagaku Co., Ltd.) under a reduced pressure of 1 kPa under a temperature condition of 40 ° C. to perform concentration.

-Measurement of phorbol ester content-
The content of phorbol ester in the obtained concentrate was measured as follows.
First, TPA was dissolved in methanol, a standard solution was prepared so as to have a predetermined concentration, and a calibration curve was created. Next, a solution in which 1 g of a phorbol ester-containing concentrate was dissolved in 25 mL of a methanol solvent was prepared, stirred for 5 minutes, and then centrifuged with a centrifuge (LC-121, manufactured by Tommy Kogyo Co., Ltd.). An analysis sample was used. The phorbol ester in this analytical sample was detected by a high performance liquid chromatography (HPLC) method under the following conditions, and the content of the phorbol ester in the concentrate was measured using the calibration curve. As a result, the phorbol ester content in the concentrate was 18.9%.
-HPLC analysis conditions Column used: Lichlorosphere 100 RP-18e
(4.0 mm ID × 125 mm × 5 μm: Merck)
Mobile phase: Acetonitrile: Water = 8/2 (V / V)
Flow rate: 1.0 mL / min
Column temperature: 25 ° C
Detection wavelength: 280 nm
Injection volume: 20 μL

(Example 2)
Add 100 parts by mass of Indonesian Jatropha oil, 50 parts by mass of methanol, and 20 mL of cation exchange resin (Diaion SK104H (crosslinking degree: 4%), manufactured by Mitsubishi Chemical Corporation) to a 300 mL beaker to prepare a mixed solution. did.
This mixed solution was stirred in a water bath at 60 ° C. for 6 hours using a magnetic stirrer apparatus to be methyl esterified to obtain an ester mixed oil (esterification step (A)).
About this ester mixed oil, it carried out similarly to Example 1, the acid value measurement, the isolation | separation process (B), and the concentration process (C) were performed, and the content of the phorbol ester in the obtained concentrate was measured. The results are shown in Table 1.

(Example 3)
In Example 2, the amount of methanol used in the mixed solution was changed from 50 parts by mass to 20 parts by mass, the amount of cation exchange resin was changed from 20 mL to 5 mL, and the stirring time in the esterification step (A) was changed from 6 hours to 15 The ester mixed oil in Example 3 was obtained in the same manner as in Example 2 except that the time was changed.
About this ester mixed oil, it carried out similarly to Example 1, the acid value measurement, the isolation | separation process (B), and the concentration process (C) were performed, and the content of the phorbol ester in the obtained concentrate was measured. The results are shown in Table 1.

Example 4
In Example 2, except that 28 parts by mass of ethanol was used in the mixed solution instead of 50 parts by mass of methanol, and the stirring time in the esterification step (A) was changed from 6 hours to 15 hours, Example 2 Similarly, the ester mixed oil in Example 4 was obtained.
About this ester mixed oil, it carried out similarly to Example 1, the acid value measurement, the isolation | separation process (B), and the concentration process (C) were performed, and the content of the phorbol ester in the obtained concentrate was measured. The results are shown in Table 1.

(Comparative Example 1)
In Example 1, instead of the esterification step (A), a mixed oil was obtained in the same manner as in Example 1 except that the mixed solution was stirred in a water bath at 60 ° C. for 0.5 hour.
About this mixed oil, it carried out similarly to Example 1, the acid value measurement, the isolation | separation process (B), and the concentration process (C) were performed, and the content of the phorbol ester in the obtained concentrate was measured. The results are shown in Table 1.

(Comparative Example 2)
In Example 3, in place of 20 mL of the cation exchange resin in the mixed solution, 0.12 parts by mass of p-toluenesulfonic acid as an esterification catalyst was used. An ester mixed oil was obtained.
About this ester mixed oil, it carried out similarly to Example 1, the acid value measurement, the isolation | separation process (B), and the concentration process (C) were performed, and the content of the phorbol ester in the obtained concentrate was measured. The results are shown in Table 1.

  Since the method for producing a concentrated phorbol ester of the present invention can remove phorbol ester from a phorbol ester-containing vegetable oil, treatment of phorbol ester in the step of producing a fatty acid alkyl ester from a phorbol ester-containing vegetable oil. As a process, it can utilize suitably.

Claims (2)

An esterification step (A) in which a fatty acid in a phorbol ester-containing vegetable oil is esterified with a lower alkyl alcohol using a cation exchange resin to obtain a reaction mixture containing an ester mixed oil having an acid value of 2 mg-KOH / g or less. )When,
A step (B) of separating the lower alkyl alcohol layer from the ester mixed oil, a step (C) of concentrating the obtained lower alcohol layer,
A process for producing a concentrated phorbol ester comprising:   The method for producing a concentrated phorbol ester according to claim 1, wherein the phorbol ester-containing vegetable oil is jatropha oil.