JP2001293302A - Method and apparatus for supercritical extraction - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an extraction method for highly separating/purifying only an aimed component from an extract containing the component to be extracted by a supercritical fluid and a compound resembling the component as a mixture with regard to a method for removing lipid components mainly from a vegetable raw material and for extracting the component by the supercritical fluid and an apparatus for the extraction method. SOLUTION: The method comprises a step of removing unnecessary substances from the raw material by the supercritical fluid, a step of separating the aimed component from the raw material with the substances removed, and a step of further purifying the separated component.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a supercritical extraction method and an apparatus therefor, and more particularly to an extraction method and an extraction apparatus for removing a lipid component from a plant material and further extracting a target component with a supercritical fluid.

[0002]

2. Description of the Related Art Since a supercritical fluid has a density close to that of a liquid and a diffusion coefficient close to that of a gas, it has an ability to penetrate various substances and to dissolve and extract a target substance. It has the property of being excellent, and in recent years, studies have been made on extracting various substances with a supercritical fluid.

For example, carbon dioxide has a critical temperature of about 31 ° C.
Since the critical pressure is about 76 atm, supercritical carbon dioxide can be extracted at a relatively low temperature as compared with a general solvent or the like without deteriorating the substance. Therefore, decaffeination of coffee beans, extraction of pop from barley, etc.
It is actually used for extraction of various substances.

[0004]

However, the ability to dissolve the substance itself is inferior to that of a liquid at room temperature such as an organic solvent, and therefore, the amount of the component to be extracted is not always large.

[0005] Further, when a target component is extracted from a mixture in which a plurality of related compounds are contained as a mixture, it is difficult to extract only the final target extract component by mere supercritical extraction. It is.

[0006] The present invention has been made in view of the above points, and is intended to highly separate only a target component from an extract containing a target component extracted by a supercritical fluid and a compound similar to the target component as a mixture. An object is to provide an extraction method and an extraction device for purification.

[0007]

SUMMARY OF THE INVENTION The present invention has been made as a supercritical extraction method and an apparatus therefor in order to solve such problems. The invention of the supercritical extraction method is characterized by a supercritical fluid. It comprises a step of removing unnecessary substances from the raw material, a step of separating a target component from the raw material from which the unnecessary substance has been removed, and a step of further purifying the separated target component.

[0008] Further, the invention of the supercritical extraction apparatus is characterized by a removing means for removing unnecessary substances from the raw material by using a supercritical fluid, a separating means for separating a target component from the raw material from which the unnecessary substances have been removed, and And purification means for purifying the target component.

These supercritical extraction methods and apparatuses remove a lipid component from a plant material, and further separate a target component together with an analogous compound from the plant material from which the lipid component has been removed,
It can be applied for supercritical extraction of plant-containing components, which further purifies only the target components from the separated mixture.

[0010] In particular, a lipid component is removed from a plant material such as a tree of the genus Taxus containing paclitaxel, and paclitaxel and its related compounds are separated from the plant material from which the lipid component has been removed. It applies to the separation and purification of paclitaxel from related compounds.

[0011]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 1 is a schematic block diagram of a supercritical extraction apparatus according to one embodiment.

As shown in FIG. 1, the supercritical extraction apparatus of the present embodiment comprises an extraction cell 1 for removing an unnecessary lipid component from a plant raw material and extracting an extract containing a target component, A separation cell 2 for separating a target component and its analogous compounds from the extract extracted in Step 1;
And a purification cell 3 for separating and purifying only the target component from the target component and its analogous compounds separated in the above.

Although not shown, the extraction cell 1 comprises a container-shaped cell body having a space in which plant materials can be held, and a lid.

The cell body and the lid are both made of stainless steel having a pressure resistance of 40 MPa or more.

A fluid inlet and an outlet are formed in one or both of the cell body and the lid.

A seal member is interposed between the cell body and the lid, and a filter is attached to the inlet and outlet of the fluid for removing unnecessary substances.

This filter is made of, for example, a sintered stainless steel.

Although not shown, the separation cell 2 comprises a container-like cell body having a space capable of holding a plant material to be separated and a lid, and a silica gel as a separation medium is provided inside thereof.

This separation cell 2 is also similar to the extraction cell 1,
The cell body and the lid are both made of stainless steel having a pressure resistance of 40 MPa or more.

As in the case of the extraction cell 1, a sealing member is interposed between the cell body and the lid, and a fluid inlet and an outlet are provided in one or both of the cell body and the lid. Are formed, and a filter is attached to the inlet and the outlet of the fluid.

Although not shown, the purification cell 3 comprises a container-like cell body having a space capable of holding raw materials to be separated and a lid, and a silica gel as a purification medium is provided in the interior thereof.

The purifying cell 3 is also made of stainless steel such that both the cell body and the lid have a pressure resistance of 40 MPa or more, like the extraction cell 1 and the separation cell 2.

Further, similarly to the extraction cell 1 and the separation cell 2,
A seal member is interposed between the cell body and the lid, and a fluid inlet and an outlet are formed in one or both of the cell body and the lid, and further, a fluid inlet and an outlet. And a filter is attached to.

The extraction cell 1, the separation cell 2, and the purification cell 3 are housed in a thermostat 4 in order to keep the supercritical fluid in a supercritical state.

The type of the thermostat 4 is not limited as long as it can maintain a constant temperature, such as a water bath or a column oven.

The supercritical extraction device of the present embodiment further comprises:
It includes a detector 5, a back pressure valve 6, a first separator 7, and a second separator 8.

The detector 5 observes the behavior of the components in the raw material in real time, and is used for judgment for switching the process during operation. In this embodiment, an ultraviolet-visible multi-wavelength detector (UV-VIS detection) is used. Container) is used.

The back pressure valve 6 is used to supply a supercritical fluid,
A valve that opens to atmospheric pressure and separates carbon dioxide and dissolved matter. A needle valve is used as the back pressure valve 6.

The back pressure valve 6 is configured to open at a pressure equal to or higher than a set condition, and has a function of keeping the pressure constant.

The first separator 7 separates the mixed fluid generated in the unnecessary matter removing step using only carbon dioxide in the first step into carbon dioxide and unnecessary matter and captures the unnecessary matter, or
The mixed fluid generated in the separation step by the separation cell 2 in the step is separated into carbon dioxide and a target component to capture the target component.

Although not shown, the first separator 7 includes a container body, a lid, a fluid introduction pipe, and a carbon dioxide discharge pipe, and contains a solvent for capturing components.

As the solvent, any solvent that dissolves the target component can be used.

The second separator 8 separates the mixed fluid generated in the purification step by the purification cell 3 in the third step into carbon dioxide and a high-concentration target component, and captures the high-concentration target component. belongs to.

Although not shown, the second separator 8 includes a container body, a lid, a fluid introduction pipe, and a carbon dioxide discharge pipe, and contains a solvent for capturing components.

As this solvent, any solvent that dissolves the target component can be used.

In addition, the supercritical extraction device of the present embodiment further includes a pressure-resistant halve (not shown), a carbon dioxide pump 9, a solvent pump 10, a piping section (shown in a diagram),
A pressure gauge (not shown) is provided.

The pressure-resistant halve is a valve for switching a flow path for changing the course of the fluid, and includes a piping portion on the near side of the extraction cell 1, a piping portion between the extraction cell 1 and the separation cell 2, and a separation cell. It is provided at a location required for switching the flow path, such as a pipe section between the second and purification cells 3.

The carbon dioxide pump 9 is a pump for introducing carbon dioxide into the system.

The solvent pump 10 is a pump for introducing a co-solvent into the system.

Further, the pressure gauge is for monitoring the pressure in the system. As the pressure gauge, an analog, digital, or any other pressure detection type can be used.

The supercritical extraction apparatus of the present embodiment has the above-described configuration. Next, using this supercritical extraction apparatus,
An embodiment of a supercritical extraction method for extracting paclitaxel, which is a target component, from a plant component consisting of bark powder of western yew, which is a raw material, will be described.

In plant materials, a large amount of lipid exists in addition to the target component.

When supercritical carbon dioxide is used, the target component in the raw material hardly dissolves in a supercritical fluid containing only carbon dioxide, but the lipid in the raw material dissolves well in the supercritical carbon dioxide. Can remove lipids.

If the lipid is not removed in advance, when the separation cell 2 is connected in a later step, the silica gel as the separation medium is contaminated at an early stage, and an effective separation operation cannot be performed.

Therefore, in the first step, unnecessary lipids are removed from the plant raw material with carbon dioxide.

The flow of the first step is shown by a thick line in FIG.

After accommodating the plant material in the extraction cell 1, supercritical carbon dioxide is supplied from the carbon dioxide pump 9 to the extraction cell 1.

The target component such as paclitaxel in the plant material is hardly soluble in supercritical carbon dioxide, but the lipid in the material is well soluble in supercritical carbon dioxide. Therefore, supercritical carbon dioxide dissolves only lipid. Transport.

When the back pressure valve 6 is opened, the flow path (pipe) of the supercritical carbon dioxide communicates with the outside and is released to the atmosphere, so that the carbon dioxide in the supercritical state becomes gas. .

As a result, the gasified carbon dioxide and the dissolved lipid are separated by the first separator 7.

At this time, undesired substances such as lipids remain in the first separator 7, and if left undisturbed, the undesired substances are inadvertently added to the supercritical fluid or co-solvent in the second and third steps described later. There is a risk of contamination.

Therefore, after the end of the first step, the first separator 7
It is necessary to remove unnecessary substances from the wastewater, which can be removed by extruding with a co-solvent or supercritical carbon dioxide.

That is, when the coexisting solvent and supercritical carbon dioxide are passed through the first separator 7, unnecessary substances are pushed out from the first separator 7 and removed, and the unnecessary substances are discharged from the unnecessary substance discharge line to the outside of the system. It will be done.

The first separator 7 is newly filled with a coexisting solvent.

In the first step as described above, only unnecessary lipids are removed from the plant raw materials, and components other than the lipids remain in the extraction cell 1.

In the first step, the extraction cell 1
A pressure-resistant valve (not shown) between the gas and the separation cell 2 is closed so that supercritical carbon dioxide does not flow toward the separation cell 2.

Next, in the second step, the pressure-resistant valve between the extraction cell 1 and the separation cell 2 is opened, and supercritical carbon dioxide is supplied as in the first step.
From 10, ethanol as a coexisting solvent is supplied to the extraction cell 1.

The flow of the second step is shown by a thick line in FIG.

The extracted components other than paclitaxel, its analogous compounds, and other lipids in the raw material do not dissolve in supercritical carbon dioxide, but dissolve in ethanol, which is a co-existing solvent. Therefore, these mixed components such as paclitaxel, It is transported in a state of being dissolved in a mixed fluid of supercritical carbon dioxide and a co-solvent, and is supplied to the separation cell 2 side.

Here, the mixed components such as paclitaxel supplied to the separation cell 2 are adsorbed on the filler (silica gel) in the separation cell 2 when passing through the separation cell 2, , A difference occurs in the time of passing through the separation cell 2.

Since the time required to pass through the separation cell 2 filled with a predetermined filler is measured by a basic test using paclitaxel sold as a standard reagent, paclitaxel as the target component is separated from the separation cell. If paclitaxel and its related compounds can be separated by capturing substances (solutes) that pass within a predetermined time close to the time of passing through No. 2.

Accordingly, the target component, paclitaxel and its related compounds, are transported in a state of being dissolved in a mixed fluid of supercritical carbon dioxide and a co-solvent, and supplied to the first separator 7.

When the back pressure valve 6 is opened in the same manner as in the first step, carbon dioxide turns into a gas, and the gaseous carbon dioxide and a solution in which paclitaxel and its analogous compounds are dissolved (in the above coexisting solvent). Is dissolved).

Next, in the third step, the pressure-resistant valve existing in the flow path to the extraction cell 1 and the separation cell 2 is closed, and the mixed fluid of supercritical carbon dioxide and the coexisting solvent is
It is supplied directly to the first separator 7.

The flow of the third step is shown by a thick line in FIG.

Since the solution in which paclitaxel and its analogous compounds are dissolved is captured in the first separator 7 as described above, the solution is dissolved in the mixed fluid and supplied to the purification cell 3.

When the mixed component of paclitaxel and its analog compound supplied to the purification cell 3 passes through the purification cell 3, there is a difference in the time of passing through the cell similarly to the case of the separation cell 2. Thus, paclitaxel and its related compounds are separated.

Therefore, the target paclitaxel is:
It is transported in a state of being dissolved in a mixed fluid of supercritical carbon dioxide and a co-solvent, and is supplied to the second separator 8.

When the back pressure valve 6 is opened, the carbon dioxide turns into a gas, and the gaseous carbon dioxide is separated from the solution in which paclitaxel is dissolved.

As described above, the first step of separating only lipids by the extraction cell 1, the second step of separating paclitaxel and its analogous compounds from components other than lipids by the separation cell 2, and the paclitaxel and its analogous compounds by the purification cell 3 By the three steps of the third step of separating and purifying only paclitaxel from pulp, it became possible to purify only the target component paclitaxel from the plant raw material with high purity.

Also, by using the single supercritical fluid apparatus as described above, simply performing an operation such as switching a pressure-resistant valve provided at a predetermined position in each pipe section, the above-described three steps can be taken. Since the operation can be performed, these three steps can be continuously performed by operating the apparatus continuously.

In the above embodiment, the case where paclitaxel is extracted as the target component has been described. However, the present invention can be applied to the case where a plant component other than paclitaxel is extracted. It is also possible to apply the present invention to the extraction of.

The type of supercritical fluid used for extraction is
Not only the carbon dioxide of the above embodiment, but also any type of supercritical fluid can be used according to the type of the extraction component.

However, when the target component is a plant extract component, it is preferable to use supercritical carbon dioxide from the viewpoint of removing lipids.

Further, in the above embodiment, the extraction cell 1,
As the separation cell 2 and the purification cell 3, those made of stainless steel were used. These extraction cell 1, separation cell 2, and purification cell 3 were used.
Is not limited to this.

However, from the viewpoint of maintaining the corrosion resistance,
Stainless steel is preferred.

Further, these extraction cell 1, separation cell 2,
The structure of the purification cell 3 is also not limited to the structure including the cell body and the lid as in the above-described embodiment and having a filter, and the structure can be arbitrarily changed in design.

The point is that the structure should have a fluid inlet / outlet, a space capable of holding the raw material, and a structure that prevents solids in the raw material from flowing out of the cell.

The materials of the cell body, lid and filter are not limited, but are preferably made of stainless steel from the viewpoint of corrosion resistance.

Further, in the above embodiment, a filler made of silica gel is filled as a separation medium (filler) in the separation cell 2, but the type of the filler is not limited to this. Octadecyl silica resin (O
(DS resin), activated carbon, zeolite, and the like.

Similarly, octadecyl silica resin (ODS resin), activated carbon, zeolite and the like can be used as the filler in the purification cell 3.

These fillers can be used as a mixture of two or more kinds.

Further, in the above embodiment, the detector 5 is provided in the flow path of the supercritical fluid, but the detector 5 may be an infrared spectrometer, a Raman spectrometer, or the like in addition to the UV-VIS detector of the above embodiment. It is possible to use a vessel or the like.

Further, in the above embodiment, the supercritical carbon dioxide is gasified by the back pressure valve 6 and the first separator 7 and the second
Supercritical carbon dioxide and unnecessary substances (lipids) by the separator 8
Alternatively, the target component (such as paclitaxel) is separated, but the means for separating the supercritical fluid and the target component is not limited to this, and can be arbitrarily changed depending on the type of the supercritical fluid.

[0086]

Embodiments of the present invention will be described below.

A test was performed using the supercritical extraction apparatus of the above embodiment.

The extraction cell is made of stainless steel
A 1 mL pressure vessel was used.

As a separation cell, a Wako Pure Chemical Industries silica gel Wacogel C-300 (particle size: 75 to 150 μm) was placed in a stainless steel empty column (7.6 mmφ × 250 mm) manufactured by GL-Science Co.
% Was used.

Further, as a purification cell, a packed column Lichrosorb DIOL-5 (4.6 mmφ × 250 m, manufactured by GL-Science) was used.
m) was used. This packed column Lichrosorb DIOL-5
(4.6 mmφ × 250 mm) is commercially available in a state filled with a filler.

As a detector, an ultraviolet-visible multi-wavelength detector was used. Each of the first separator and the second separator contained therein ethanol for extracting the extract.

As a supercritical fluid, liquefied carbon dioxide gas having a purity of 99.99% manufactured by Liquefied Carbonate Co., Ltd. was used, and as a coexisting solvent, ethanol for HPLC having a purity of 99.5% manufactured by Wako Pure Chemical Industries, Ltd. was used.

A bark powder of Western yew containing 1% of Paclitaxel (trade name: Taxol) as a plant material was used.

The chemical formula of paclitaxel is shown below.

[0095]

Embedded image

The test conditions were set at a temperature of 50 ° C. and a pressure of 30 MPa. In the test flow, first, about 50 mg of plant material was enclosed in an extraction cell together with glass beads having a diameter of 1 mm for filling.

Next, as a first step, only the supercritical carbon dioxide was passed for the first 2 hours to remove lipid components from the plant raw material.

Then, 10 mol of the supercritical carbon dioxide
% Ethanol was added as a co-solvent and separated as a second step through a separation cell. The target component was collected in the first separator for 2 hours between 40 minutes and 160 minutes after the start of the second step.

Next, in order to measure the content of paclitaxel in the substance recovered in the first separator, the solvent in the first separator was removed by distillation, and the remaining recovered material was measured as shown in FIG.
As shown in Fig. 5, the result of analysis by high performance liquid chromatography shows that the lipid contained in a large amount and other unnecessary substances were removed in comparison with Fig. 5 which is the analysis result of high performance liquid chromatography of plant raw materials. .

The content of paclitaxel was 22%.

Further, in the third step, the content of 22% paclitaxel was passed through the purification cell 3. The target substance is
After the start of the process, it was collected in the second separator for 10 minutes between 30 minutes and 40 minutes.

Finally, the paclitaxel content in the second separator was analyzed in the same way as in the first separator. The results of analysis by high performance liquid chromatography are as shown in FIG. As a result, the content of paclitaxel is
68%.

As described above, in this test example, a substance having an extremely high content of paclitaxel, which is the target plant component, can be recovered compared to the extraction method using a general supercritical fluid of 68%. Was.

[0104]

As described above, the present invention removes undesired substances from a raw material using a supercritical fluid, separates a target component from the raw material from which the unnecessary substances have been removed, and further purifies the separated target component. As a result, the content of the target component to be recovered is very high as compared with the conventional supercritical fluid extraction method, and there is an effect that a high-purity target component can be extracted.

Further, in performing separation and purification, it is not necessary to perform the operation at a high temperature unlike the extraction method using a liquid organic solvent or the like, and the operation can be performed at a relatively low temperature or a temperature close to normal temperature. This has the effect that the work can be performed easily.

Furthermore, since the target component is separated and purified after removing unnecessary substances in advance, unnecessary substances are not supplied to the separation cell or the purification cell. This has the effect that clogging does not occur and the function and accuracy of the separation cell and the purification cell are not reduced.

Further, when the present invention is applied to the extraction of a target component contained in a plant extract, lipids, which are unnecessary substances, are preferably removed with supercritical carbon dioxide, and then separated,
Since purification can be performed, there is an effect that the purity of the target component to be extracted is higher than that of a general extraction method for extracting the target component from a plant extract.

In particular, when the present invention is applied to the extraction of the target component from the plant material containing paclitaxel, not only can the lipid component be suitably removed, but also the paclitaxel and its analogous compounds can be removed from the plant material after removing the lipid component. Can be separated, and only paclitaxel can be highly separated and purified from the mixture. Therefore, the effect of extracting paclitaxel with high purity, which is generally difficult to extract with high purity, can be obtained. is there.

Further, using one supercritical fluid device,
By simply performing operations such as switching the flow path of the supercritical fluid with a valve, the three steps of removal, separation, and purification of unnecessary substances can be performed. Therefore, the apparatus is continuously operated to continuously perform these three steps. Work efficiency can be significantly improved.

[Brief description of the drawings]

FIG. 1 is a schematic block diagram of a supercritical extraction device of one embodiment.

FIG. 2 is a schematic block diagram of a step of removing unnecessary lipids.

FIG. 3 is a schematic block diagram of a separation step.

FIG. 4 is a schematic block diagram of a purification step.

FIG. 5 is an analysis chart of high-performance liquid chromatography of plant materials.

FIG. 6 is an analysis chart of high-performance liquid chromatography of components after a separation step.

FIG. 7 is an analysis chart of components after a purification step by high performance liquid chromatography.

[Explanation of symbols]

 1: Extraction cell 2: Separation cell 3: Purification cell

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Yasuhiro Uozaki 2-1 Minamijomishima-cho, Tokushima City, Tokushima Prefecture Inside of the Faculty of Engineering, Tokushima University (72) Inventor Katsushi Yano 2217-2 Hayashi-cho, Takamatsu City, Kagawa Prefecture Ryusho Sangyo Co., Ltd. Inside Research Information Center (72) Inventor Satoru Sakuriku 2217-2 Hayashi-cho, Takamatsu-shi, Kagawa Prefecture Ryusho Sangyo Co., Ltd. Inside Research Company Information Center (72) Tadahiro Takahachi 2217-2 Hayashi-cho, Takamatsu-shi, Kagawa Ryusho Sangyo Seki (72) Inventor Hirohisa Uchida 2-24-16 Nakamachi, Koganei-shi, Tokyo Faculty of Engineering, Tokyo University of Agriculture and Technology (72) Inventor Tsutomu Nakanishi 2217-43, Hayashimachi, Takamatsu-shi, Kagawa Pref. F term (reference) 4C048 TT08 UU01 UU03 XX03 4D056 AB14 AB17 AC24 BA16 CA18 CA39 CA40

Claims (6)

[Claims] 1. A process for removing unnecessary substances from a raw material using a supercritical fluid, a step for separating a target component from the raw material from which the unnecessary substances have been removed, and a step for further purifying the separated target component. Supercritical extraction method characterized. 2. A method comprising: removing a lipid component from a plant material using supercritical carbon dioxide; separating a target component from the plant material from which the lipid component has been removed; and further purifying the separated target component. A supercritical extraction method characterized in that: 3. A step of removing lipid components from a plant material containing paclitaxel with supercritical carbon dioxide;
A supercritical extraction method comprising: a step of separating paclitaxel and its analogous compound from a plant material from which a lipid component has been removed; and a step of separating and purifying paclitaxel from the separated paclitaxel and its analogous compound. 4. A removing means for removing unnecessary substances from a raw material by using a supercritical fluid, a separating means for separating a target component from the raw material from which the unnecessary substances have been removed, and a purifying means for purifying the separated target component. A supercritical extraction device characterized by the above-mentioned. 5. A removing means for removing a lipid component from a plant material using supercritical carbon dioxide, a separating means for separating a target component from a plant material from which a lipid component has been removed, and a purifying means for purifying the separated target component. A supercritical extraction device comprising: 6. A removing means for removing a lipid component from a plant material containing paclitaxel with supercritical carbon dioxide, and a separating means for separating paclitaxel and its analogous compound from a plant material containing paclitaxel from which the lipid component has been removed. And a refining means for separating and refining paclitaxel from the separated paclitaxel and its analogous compound.