FR2695931A1 - Process for obtaining sesquiterpene lactone parthenolide, and therapeutic preparation containing such a product for the treatment of migraine. - Google Patents

Abstract

Method for obtaining sesquiterpene lactone, particularly parthenolide (formula I), avoiding deterioration of the compound during extraction and characterized in that plants containing the desired compound are selected and contacted with an extraction fluid, with dissolution of the desired compound, said extraction fluid consisting of a supercritical fluid or a liquid under pressure. The extraction fluid is removed after a suitable contact period, and the temperature and/or pressure conditions are modified to lower the solvent power of the extraction fluid now in a gaseous state and discharged, said desired compound being collected in the form of a solid paste-like or liquid extract.

Description

The present invention relates to a process for obtaining sesquiterpene lactone and in particular parthenolide.

More particularly, the invention relates to the extraction of a fraction rich in parthenolide from the aerial part of plants naturally containing this compound and more especially from feverfew.

Parthenolide corresponds to the formula developed below

parthenolide
Parthenolide is a sesquiterpene lactone having pharmacological properties and known to reduce in particular the frequency and intensity of headaches and migraines.

Feverfew or Tanacetum parthenium (L.) Schulz
Beep; Synonyms: Chrysanthemum parthenium (L.) Bernh, Leucanthemum parthenium Smith, Anthemis colala L. may contain up to 0.6% parthenolide. This Asteraceae, native to the Caucasus is currently widespread in Europe and part of the American continent. For a long time it has been used in the United Kingdom in folk medicine to treat fever (hence its name Fever few), arthritis and all head pain. Several recent clinical studies seem to confirm the interest of this compound according to its traditional use by directly involving sesquiterpene lactones, including parthenolide, the main active ingredient of this plant.

Due to the extreme fragility of sesquiterpenic lactones, the manufacture and marketing of parthenolide-rich extracts is very delicate. In addition, given the regulatory constraints on acceptable residual solvents in drugs, it is desirable to use a gentle extraction technique without organic solvents.

The invention aims to implement a process for obtaining sesquiterpene lactones and in particular parthenolide from an extraction medium consisting of supercritical fluids or liquids under pressure.

 It has been found that the use of this technique is particularly suitable for the extraction of sensitive compounds and whose integrity must be respected in order to ensure the preservation of their pharmacological properties.

For this purpose, the invention relates to a process for obtaining sesquiterpene lactone and in particular parthenolide, a process which avoids the degradation of the compound being extracted, and the process is characterized by selecting the plants containing the desired compound and contact with an extraction fluid by dissolving the desired compound and said extraction fluid consists of a supercritical fluid or a liquid under pressure, the extraction fluid is removed after a suitable contact time and the temperature and / or pressure conditions so as to lower the solvent power of the extraction fluid then brought to the gaseous state and discharged, the desired compound being collected in the form of solid, pasty or liquid extract.

According to an advantageous embodiment of the invention, the plant products from which the extraction is carried out consist of the aerial part of the plant called feverfew.

More particularly, in the context of the implementation of the invention, in the context of supercritical fluids or of their mixture, the conditions of pressure and temperature are such that the pressure is greater than the critical pressure and the temperature is higher. at the critical temperature.

In the case of pressurized liquids, the pressure and temperature conditions are such that the pressure is below or above the critical pressure and the temperature is below the critical temperature.

The invention uses the properties of supercritical fluids or pressurized liquids having, under appropriate and sufficient temperature and pressure conditions, an increased dissolution power with respect to constituents while limiting the risk of degradation of sensitive compounds. to the action of organic solvents or heat-sensitive or also sensitive to oxidation.

According to an advantageous form of implementation of the invention, the extraction fluid comprises a percentage of between 0 and 20% of co-solvent.

And in particular the co-solvent consists of water or an organic solvent including ethanol.

An advantageous embodiment of the invention uses carbon dioxide in the state of supercritical fluid or liquid under pressure.

It is known that this product has the peculiarities of being inexpensive and abundant while being free of toxic effects; in addition, its critical pressure and temperature are low and correspond respectively to 73 bar and 31.30 C.

In the context of carrying out the process, the substance containing the desired constituents is introduced into an extractor and the starting substance is brought into contact with the extraction fluid brought to the desired temperature and pressure conditions, after a contact time. the extraction fluid loaded with the desired compounds is recovered and subjected to a modification of the physical pressure and / or temperature conditions which lead to lowering its solvent power, thus making it possible to collect the extracted compound, the extraction fluid in the form of gas being evacuated.

Advantageously, the extraction fluid after modification of the thermal and / or pressure conditions intended to ensure the separation of the extracted compound, is recycled after having undergone a modification of the temperature and / or pressure conditions so as to reduce it to the state of supercritical fluid or fluid under pressure to ensure a new phase of extraction.

Thus, according to a first embodiment, the gas phase extraction fluid is compressed to be brought to the desired pressure and then cooled to the desired temperature for recycling.

Alternatively, the gaseous phase extraction fluid is cooled to be condensed and then pumped and heated to bring it to pressure and temperature conditions for recycling into the extractor.

According to another more particular characteristic, the plant containing parthenolide, in particular feverfew, is introduced into at least one extractor in which the vegetable load is brought into contact with the extraction fluid consisting of carbon dioxide and whose temperature is brought to a level between 10 and 600C and the pressure between 60 and 500 bar.

According to another characteristic, the separation phase of the extract of the extraction fluid is carried out in one or more separators arranged in series, in particular of the cyclone type.

According to one variant, the separation between the extraction fluid and the extracted compound is obtained by simple reduction of pressure without changing the temperature, the pressure being lowered to a level between 0 and 100 bar.

According to a development of the invention, the recovery of the extracts consisting of the desired compound is carried out by simple collection of separate extracts.

Alternatively, this recovery can be carried out by trapping the extract in the separators on a liquid or solid support, during the extraction phase and during the modification or modifications of the physical conditions of the extraction fluid to reduce its solvent power to allow separation as dry extract of the desired compound.

Advantageously, the extraction fluid consists of carbon dioxide comprising between 0 and 20% of a co-solvent consisting of alcohol or water.

And more particularly, the extraction is carried out and at a temperature between 30 and 600 and at a pressure between 150 and 300 bar.

The invention also relates to the compounds, especially parthenolide extracted according to the above operating phases and having improved pharmacological properties due to the purity of the product and the absence of degradation related to non-aggressive extraction methods.

The invention also relates to therapeutic preparations comprising as active ingredient at least the parthenolide extract according to the above method.

Other features and advantages of the invention will emerge from the description which follows and which is given in connection with some examples presented for explanatory purposes without limitation.

The invention uses the properties of supercritical fluids or pressurized liquids under conditions of temperature and pressure which give this extraction fluid an increased dissolution power with respect to the desired compounds and to extract within the material first constituted here of festering fever (flowers, leaves, stems).

Three examples of implementation of the invention using, as extraction fluid, carbon dioxide comprising from 0 to 20% of cosolvent, in particular ethanol or water, are described below.

Example 1
Load: aerial parts of Chrysanthemum parthenium dried, milled, moisture content: 9.5%, containing 0.86% parthenolide calculated relative to the dry matter.

The parthenolide assay is performed by HPLC.

The charge is extracted - at 280 bar and 60 C with addition of 25ml of water every 60 minutes; for a total solvent content of 130 kg of CO2 per kg of filler, an extract yield of 1.78% with respect to the dry matter is obtained, the extract containing 28% of parthenolide.

The mass balance of the operation is given in the table below.

<tb> Echantillo <SEP> Time <SEP> Mass <SEP> Rendemen <SEP> Mass <SEP> of <SEP> Parthenolide <SEP> Yield <SEP> in <SEP> Yield <SEP> cumulative
<tb><SEP> extracted <SEP> cumulative <SEP> Parthenolide <SEP> ds <SEP> extracted <SEP> parthenolide <SEP> (%) <SEP><SEP> in <SEP> padded <SEP> (%)
<tb><SEP> (min) <SEP> (g) <SEP> (%) <SEP> (mg) <SEP> (%) <SEP> (MH) <SEP> (MS) <SEP> (MH) ) <SEP> (MS)
<tb><SEP> E3 <SEP> 1 <SEP> 60 <SEP> 4.10 <SEP> 1.64 <SEP> 1237 <SEP> 30.2 <SEW> 0.49 <SEP> 0.55 <SEP> 0.49 <SEP> 0.55
<tb><SEP> E3.2 <SEP> 120 <SEP> 1.70 <SEP> 2.32 <SEP> 416 <SEP> 24.5 <SEP> 0.17 <SEP> 0.18 <SEP> 0.66 <SEP> 0.73
<tb> E3.3 <SEP> 180 <SEP> 0.46 <SEP> 2.50 <SEP> 100 <SEP> 21.7 <SEP> 0.040 <SEP> 0.044 <SEP> 0.70 <SEP> 0 78
<tb> Total <SEP> 6.26g <SEP> 2.50 <SEP>% <SEP> 1753 <SEP> mg <SEP> 28.0 <SEP>% <SEP> 0.70 <SEP>% <SEP > 0.78 <SEP>%
<Tb>
The parthenolide concentration in the final residue is <
Example 2
The same feedstock treated at 280 bar and 350 ° C. has an extract yield of 2.22% relative to the dry matter, for a solvent content of 220 kg of CO 2 per kg of filler; the richness of the parthenolide extract is then 24.9%.

The mass balance is given in the table below

<tb> Sample <SEP> Time <SEP> Mass <SEP> Yield <SEP> Mass <SEP> of <SEP> Parthenolide <SEP> Yield <SEP> in <SEP> Yield <SEP> Cumulative
<tb><SEP> retrieves <SEP> cumulates. <SEP> Parthenolide <SEP> ds <SEP> extract <SEP> parthenolide <SEP> (%) <SEP> in <SEP> parthenolide <SEP> (%)
<tb><SEP> (min) <SEP> (9) <SEP> (SE) <SEP> (mg) <SEP> (t) <SEP> (MH) <SEP> (MS) <SEP> (MH) ) <SEP> (MS)
<tb><SEP> E4.1 <SEP> 90 <SEP> 3.98 <SEP> 1.59 <SEP> 979 <SEP> 24.6 <SEP> 0.39 <SEP> 0.43 <SEP> 0.39 <SEP> 0.43
<tb><SEP> E4.2 <SEP> 180 <SEP> 0.53 <SEP> 1.80 <SEP> 177 <SEP> 33.4 <SEP> 0.071 <SEP> 0.079 <SEP> 0.46 <SEP> 0.51
<tb><SEP> E4.3 <SEP> 300 <SEQ> 0.49 <SEP> 2.00 '<SEP> 87 <SEP> 17.8 <SEP> 0.035 <SEP> 0.039 <SEP> 0.50 <SEP> 0.55
<tb> Totals <SEP> 5.00g <SEP> 2.00 <SEP>% <SEP> 1243 <SEP> mg <SEP> 24.9 <SEP>% <SEP> 0.50 <SEP>% <SEP > 0.55 <SEP>%
<Tb>
The parthenolide concentration in the final residue is 0.04%
Example 3
The same batch treated at 180 bar and 350C has an extract yield of 2.49% relative to the dry matter, for a solvent content of 220 kg of CO2 per kg of filler; the richness of the parthenolide extract is then 32.5%.

The mass balance is indicated below

<tb> Sample <SEP> Time <SEP> Mass <SEP> Yield <SEP> Mass <SEP> of <SEP> Parthenolide <SEP> Yield <SEP> in <SEP> Yield <SEP> Cumulative
<tb><SEP> extracted <SEP> cumulative <SEP> Parthenolide <SEP> ds <SEP> extracted <SEP> parthenolide <SEP> (%) <SEP> in <SEP> parthenolide <SEP> (%) <SEP>
<tb><SEP> (min) <SEP> (g) <SEP> (%) <SEP> (mg) <SEP> (%) <SEP> (MH) <SEP> (MS) <SEP> (MH) ) <SEP> (MS)
<tb><SEP> E5.1 <SEP> 90 <SEP> 3.76 <SEP> 1.50 <SEP> 986 <SEP> 26.2 <SEP> 0.39 <SEP> 0.43 <SEP> 0.39 <SEP> 0.43
<tb><SEP> E5.2 <SEP> 180 <SEP> 1.36 <SEP> 2.09 <SE> 721 <SEP> 53.0 <SEP> 0.29 <SE> 0.32 <SEP> 0.68 <SEP> 0.75
<tb><SEP> E5.3 <SEP> 300 <SEQ> 0.48 <SEP> 2.24 <SEP> 118 <SEP> 24.6 <SEP> 0.047 <SEP> 0.52 <SEP> 0, 73 <SEP> 0.81
<tb> Total <SEP> 5.60g <SEP> 2.24 <SEP>% <SEP> 1825 <SEP> mg <SEP> 32.5 <SEP>% <SEP> 0.73 <SEP>% <SEP > 0.81 <SEP>%
<Tb>
The parthenolide concentration in the final residue is 0.08%.

Claims (20)

1 - Process for obtaining sesquiterpene lactone and especially parthenolide, process avoiding degradation of the compound being extracted, and the method is characterized in that plants are selected containing the desired compound and. contacted with an extraction fluid by dissolving the desired compound and said extraction fluid consisting of a supercritical fluid or a liquid under pressure, the extraction fluid is removed after a contact time appropriate and the temperature and / or pressure conditions are modified so as to lower the solvent power of the extraction fluid then brought to the gaseous state and discharged, the desired compound being collected in the form of solid, pasty or liquid extract . 2 - Process according to claim 1, and characterized in that the plant products from which the extraction is carried out consist of the aerial part of the plant called feverfew. 3 - Process according to one of claims 1 or 2, characterized in that the conditions of pressure and temperature of the extraction fluids in the form of supercritical fluid are such that the pressure is greater than the critical pressure and the temperature is higher at the critical temperature. 4 - Process according to one of claims 1 or 2, characterized in that, in the case of pressurized liquids, the conditions of pressure and temperature are such that the pressure is less than or greater than the critical pressure and the temperature is less than the critical temperature. 5 - Process according to one of claims 1 to 4, characterized in that the extraction fluid comprises a percentage between 0 and 20% co-solvent. 6 - Process according to claim 5, characterized in that the co-solvent consists of water or an organic solvent including ethanol. 7 - Process according to one of claims 1 to 6, characterized in that the extraction fluid consists of carbon dioxide in the state of supercritical fluid or liquid under pressure. 8 - Process according to one of claims 1 to 7, characterized in that the substance containing the desired constituents is introduced into an extractor and the starting substance is brought into contact with the extraction fluid carried under the conditions of desired temperature and pressure, after a suitable contact time the extraction fluid loaded with desired compounds is recovered and subjected to a modification of its physical conditions of pressure and / or temperature which lead to lower its solvent power thus allowing to recovering the extracted compound, the extraction fluid in gaseous form being evacuated. 9 - Process according to one of claims 1 to 8, and characterized in that the extraction fluid after modification of the thermal conditions and / or pressure to ensure the separation of the extracted compound, is recycled after undergoing a modification of its temperature and / or pressure conditions so as to bring it back to the state of supercritical fluid or fluid under pressure capable of ensuring a new extraction phase. 10 - Process according to claim 9, characterized in that the gaseous phase extraction fluid is compressed to be brought to the desired pressure and then cooled to the desired temperature for recycling. 11 - Process according to claim 9, and characterized in that the gaseous phase extraction fluid is cooled, to be condensed then pumped and heated to bring it to pressure and temperature conditions for recycling in the extractor . 12 - Method according to one of claims 1 to 11, and characterized in that the plant containing parthenolide, including feverfew, is introduced into at least one extractor in which the plant load is brought into contact with the fluid of extraction consisting of carbon dioxide and whose temperature is brought to a level between 10 and 600C and the pressure between 60 and 500 bar. 13 - Method according to one of claims 1 to 12, and characterized in that the separating phase of the extract relative to its extraction fluid is performed in one or more separators arranged in series, in particular cyclone type. 14 - Method according to one of claims 1 to 12, and characterized in that the separation between the extraction fluid and the extracted compound is obtained by simple pressure decrease without temperature change, the pressure being lowered to a level understood between 0 and 100 bar. 15 - Process according to one of claims 1 to 14, and characterized in that the recovery of extracts consisting of the desired compound is carried out by simple collection of separate extracts. 16 - Method according to one of claims 13 to 15,  characterized in that the recovery of the extracts is obtained by trapping the extract in the separators on a liquid or solid support, this during the extraction phase and during the modification or modifications of the physical conditions of the extraction fluid aimed at to reduce its solvent power to allow separation as a dry extract of the desired compound. 17 - Process according to one of claims 7 to 16, characterized in that the extraction fluid consists of carbon dioxide comprising between 0 and 20% of a co-solvent consisting of alcohol or water. 18 - Process according to claim 17, characterized in that the extraction is performed and at a temperature between 30 and 600 and at a pressure between 150 and 300 bar. 19 - Compounds, in particular parthenolide extracted according to the operating phases according to one of claims 1 to 18 above and having improved pharmacological properties thanks to the purity of the product and the absence of degradation associated with processes of non-aggressive extraction. 20 - Therapeutic preparations comprising as active product at least parthenolide extract according to the process defined according to one of claims 1 to 18 above.