HK1240035B - Method for producing an extract of a matrix of vegetable origin with a non-ionic amphiphilic compound as extraction adjuvant in an aqueous medium - Google Patents

Description

Method for preparing extracts of plant-derived matrices in aqueous media using nonionic amphiphilic compounds as extraction adjuvants

Technical Field

The field of the invention relates to a process for preparing plant-based extracts in aqueous media using nonionic amphiphilic compounds as extraction aids.

Background Art

Solid-liquid extraction is the process of extracting substances present in solids, especially plants, into a liquid solvent. Maceration, infusion, and decoction are common solid-liquid extraction methods.

Solvents are liquid at working temperature and have the property of dissolving, diluting or extracting other substances without chemically modifying them and without being modified themselves. They are used in large quantities in many other industrial applications (paints, detergents, coatings, phytosanitary products, etc.) and are traditionally of petrochemical origin.

However, dwindling oil reserves and stricter regulations on chemicals have necessitated the search for more environmentally friendly alternatives.

Green extraction is based on the discovery and design of extraction process, and described extraction process reduces energy consumption, and allows the use of alternative solvent-agricultural solvent (agro-solvant), guarantees safe, high-quality extract simultaneously, and it can be used as the component (Green extraction of natural products (GNEP2013) of medicine, cosmetics, agricultural products, fine chemical industry and biofuel industry, (2014), Comptes Rendus Chimie, 17,179-180). Against this background, the improvement of existing process and the design of new process are the theme of many works that are intended to reduce the environmental impact of extraction step, cause the emergence and popularization of technology (such as by ultrasonic wave, microwave, supercritical CO ₂ and the extraction of rapid vacuum expansion). In parallel, the alternative extraction solvent that seeks non-petrochemical source constitutes another improved path.

Thus, the market for agricultural solvents derived from wood, field crops (starch or sugar production) and oily species is expanding significantly, bringing terpene derivatives, alcohols (ethanol, butanol, 1,3-propylene glycol), furfural derivatives and methyl esters (Formule Verte No. 8, December 2011, pp. 28–32).

Water is a natural solvent that is considered renewable. However, its high polarity does not allow the extraction of certain lipophilic molecules of interest.

Therefore, there is a need for new solvents for the extraction of compounds of different polarity ranges (wider and wider polarity ranges, or optimization of the extraction of lipophilic compounds).

Certain nonionic amphiphilic compounds in aqueous solution allow solubilization of lipophilic compounds at sufficient concentrations.

Nicotinamide, dimethyl isosorbide, alkyl polyglycosides and urea are examples of these nonionic amphiphilic compounds. These compounds have been explored as solubilization aids for certain lipophilic molecules in aqueous media (Sanghvi R., Evans D., Yalkowsky S. Stacking complexation by nicotinamide: a useful way of enhancing drug solubility. (2007) 336: 35-41).

However, solubility properties are not sufficient to allow the extraction of solutes from plant matrices. In fact, in the field of plant extraction, the extraction solvent must penetrate the plant matrix, destroy the membrane and release the compound into the impregnation solvent (diffusion, desorption, dissolution and other phenomena), and allow the matrix solutes to diffuse towards the liquid membrane surrounding the solid and transfer to the solvent (limiting step). Depending on the solvent used, the plant cell membrane is more or less weakened, which may or may not allow the release of the compounds contained in the cell.

Summary of the Invention

The applicants have shown that aqueous solutions of non-ionic amphiphilic compounds used in sufficient concentrations are capable of extracting solutes having a range of polarities from plant matrices.

The present invention therefore relates to a process for preparing extracts from plant matrices, which involves solid-liquid extraction using an aqueous solution containing at least one nonionic amphiphilic compound, preferably of agricultural origin, in a concentration at least equal to its minimum solubilizing concentration.

The present invention relates to the preparation of aqueous solutions of total extracts containing polar, medium-polar and lipophilic compounds or extracts enriched in lipophilic compounds of interest with the aid of nonionic amphiphilic compounds.

In the context of the present invention, the term "lipophilic compound" refers to a compound which has a positive n-octanol/water partition coefficient (also known as log P or log kow).

According to the invention, the term “non-ionic amphiphilic compound” means a compound that is soluble in water in all proportions and that does not have surfactant properties so as to avoid the formation of micelles.

This extraction method is an alternative to polluting petrochemical organic solvents such as ethyl acetate, hexane, acetone, etc., since the preferred non-ionic amphiphilic compounds can be of agricultural origin, ie, derived essentially from plant biomass.

The method according to the invention carries out the extraction of the plant matrix with the aid of an aqueous solution containing a minimum sufficient concentration, ie a minimum solubilizing concentration, of a nonionic amphiphilic compound, preferably of agricultural origin.

The term "minimum hydrotropy concentration" refers to the concentration above which these nonionic amphiphilic compounds begin to form aggregates, i.e., new microenvironments with physical properties that differ from those observed when the compound is diluted and from micellar behavior. This minimum hydrotropy concentration is specific for each nonionic amphiphilic compound and is generally of the order of molar concentration. It can be determined by several physicochemical methods, such as by measuring surface tension, electrical conductivity or dynamic and static light scattering (Self-association of nicotinamide in aqueous solution: Light-scattering and vapor pressure osmometry studies (1996) 85(8):848-853), or simply by establishing a solubility curve for the lipophilic compound (a function of the dissolved solute content relative to the concentration of the nonionic amphiphilic compound). Sudan red (a lipophilic dye that is easily measured by spectrophotometry) can be used as a reference. The value of this concentration depends on the properties of the nonionic amphiphilic compound and not on the properties of the solute. It corresponds to the minimum concentration above which the solute's dissolution curve takes on an exponential form.

According to another characteristic of the invention, the aqueous solution containing said non-ionic amphiphilic compound, preferably of agricultural origin, constitutes the only extraction solvent used.

According to an advantageous characteristic of the invention, the solid-liquid extraction is carried out by immersing the plant matrix in said aqueous solution containing a minimum concentration of at least one nonionic amphiphilic compound at least equal to the minimum solubilizing concentration, and the solid-liquid extraction is maintained under stirring.

According to the present invention, the expression "an aqueous solution containing at least one nonionic amphiphilic compound in a concentration at least equal to the minimum solubilizing concentration" means an aqueous solution containing at least one nonionic amphiphilic compound in a concentration greater than or equal to the minimum solubilizing concentration (CMH) mentioned above. It is also necessary to take into account the water content that may be present in the plant matrix and to adjust the concentration of the nonionic amphiphilic compound accordingly so that it can be satisfactorily used in the method according to the invention.

According to another feature of the present invention, the concentration of the nonionic amphiphilic compound in the aqueous solution is 1 to 10 times, preferably 1 to 6 times, more preferably 1 to 2 times, even more preferably 1.4 to 1.8 times the minimum solubilizing concentration. Advantageously, in practice, the nonionic amphiphilic compound can be used in an aqueous solution at a concentration equal to 1.5 mol/L.

According to another advantageous feature of the invention, the nonionic amphiphilic compound is present in the aqueous extraction solution at a concentration of less than 60% by weight relative to the weight of the solution, preferably less than 50% by weight relative to the weight of the solution, more preferably less than 40% by weight relative to the weight of the solution, and even more preferably less than 30% by weight relative to the weight of the solution. It will be observed in particular that this concentration threshold implicitly excludes the use of ethanol as an extraction solvent for lipophilic compounds, which is usually used in much higher proportions, in the range of about 80%.

According to another characteristic of the invention, the aqueous solution is heated to a temperature ranging from 20° C. to reflux, for a period ranging from a few minutes to several hours, depending on the extraction technique used.

According to another characteristic of the invention, the ratio between plant substrate (expressed in kilograms) and said aqueous solution (expressed in litres) is between 1:5 and 1:50.

According to another feature of the present invention, the solid-liquid extraction is performed by any other extraction system known to those skilled in the art (such as extraction by microwaves or ultrasound, or countercurrent extraction, etc.).

According to an advantageous characteristic of the invention, the extraction is followed by solid-liquid separation by filtration or centrifugation.

According to an advantageous feature of the invention, the nonionic amphiphilic compound, preferably of agricultural origin, is an alkyl polyglycoside of the general formula Alk-O-Zp, in which:

Alk represents a saturated or unsaturated, linear or branched hydrophobic aliphatic hydrocarbon fragment having 3 to 7 carbon atoms, and

Z represents a hydrophilic glycoside group, such as glucose, xylose, arabinose, and

1<p<5

According to a particular embodiment of the invention, Z represents a glucose group.

According to another particular embodiment of the invention, Z represents a xylose group.

According to yet another particular embodiment of the invention, Z represents an arabinose group.

According to a particular embodiment of the present invention, Alk represents a saturated or unsaturated, linear or branched hydrophobic aliphatic hydrocarbon fragment having 7 carbon atoms.

According to another particular embodiment of the present invention, Alk represents a saturated or unsaturated, linear or branched hydrophobic aliphatic hydrocarbon fragment having 6 carbon atoms.

According to yet another particular embodiment of the present invention, Alk represents a saturated or unsaturated, linear or branched hydrophobic aliphatic hydrocarbon fragment having 5 carbon atoms.

According to yet another particular embodiment of the present invention, Alk represents a saturated or unsaturated, linear or branched hydrophobic aliphatic hydrocarbon fragment having 4 carbon atoms.

According to another characteristic of the invention, the nonionic amphiphilic compound of agricultural origin is a combination of a C7 fatty alcohol derived from ricin and wheat glucose (sans OGM).

According to an advantageous characteristic of the invention, the compound is a pentylglucoside, the hydrophobic pentyl fragment of which corresponds to a C5 alcohol obtained by fermentation of sugar beet or potato flour, and the glycosidic fragment of which originates from cereals.

According to an advantageous characteristic of the invention, the compound is a combination of a C4 fatty alcohol and a xyloside.

In the context of the present application, the abbreviation APG stands for alkyl polyglucoside and the abbreviation APX stands for alkyl polyxylgoside, both abbreviations optionally being followed by the symbol Cx, x denoting the number of carbon atoms of the alkyl moiety.

In another particular embodiment of the present invention, the nonionic amphiphilic compound, preferably of agricultural origin, is a diol selected from isopentyl glycol (3-methyl-1,3-butanediol) and/or methylpropanediol, preferably isopentyl glycol.

The nonionic amphiphilic compound useful in the context of the present invention may advantageously be one of the commercial products Isopentyldiol from Kuraray or Dub Diol from Stearinerie Dubois.

The present invention also relates to the use of an aqueous solution containing at least one nonionic amphiphilic compound, preferably of agricultural origin, in a concentration at least equal to the minimum solubilizing concentration, as a solvent, preferably as the sole extraction solvent, for solid-liquid extraction of plants, fungi, lichens, algae, microalgae cultures or dedifferentiated plant cell cultures. This use relates to all solvents and plant matrices mentioned in connection with the process according to the invention.

According to the invention, the term "plant matrix" refers to all or part of a plant, fungus, lichen, algae, microalgae culture or dedifferentiated plant cell culture.

The plants, fungi, lichens or algae are dried or fresh, frozen or thawed, and are whole (neither crushed nor ground), crushed or ground. The microalgae culture or dedifferentiated plant cell culture is whole, ground, and preferably fresh, but can be dried, filtered to recover biomass, and optionally pretreated, for example by ultrasonication, to release intracellular contents.

The term "plant parts" especially relates to above-ground parts, such as stems, branches, leaves, fruits, seeds and/or flowers; and/or below-ground parts, such as rhizomes, roots and/or bulbs.

The expression "part of a lichen, fungus or algae" refers to any organ of these organisms, such as thalles, fruiting bodies, macrofruiting bodies, mycelium and/or filaments.

In a particular embodiment of the invention, all or parts of the whole plant (neither crushed nor ground) will be used.

Among the plants useful in the context of the present invention, mention may in particular be made of the fruits of Physalis peruviana, the fruits of Embelia ribes, the leaves of Myrtus communis, the underground parts and leaves of Piper species, the leaves of Eucalyptus globulus, the rind of Garcinia mangostana, the female inflorescences of Humulus lupulus, the bark of Cinchona species, the aerial parts of Urtica dioica, the aerial parts of Helichrysum species, the fruits of Vanilla species, the rhizomes of Curcuma species, the rhizomes of Zingiber officinale, the fruits and leaves of Olive (Olea europaea).

Algae useful in the context of the present invention include in particular cyanobacteria or blue algae, as well as eukaryotic organisms including the euglena, cryptophytes, adhesiophytes, glaucophytes, red algae or red algae, the Stramenopiles including in particular diatoms and brown algae or brown algae, and finally the green algae including in particular the Ulvae.

Among the lichens useful in the context of the present invention, mention may in particular be made of the thalluses of Cetraria islandica, the thalluses of Usnea spp., the thalluses of Cladonia spp. and the thalluses of Lobaria spp.

Among the fungi useful in the context of the present invention, mention may in particular be made of: Coriolus versicolor, Cordyceps spp.

Among the plant cell cultures useful in the present invention, mention may be made in particular of Mimosapudica cell cultures and Tripterygium wilfordii cell cultures.

At a certain concentration, nonionic amphiphilic compounds will surprisingly be able to extract lipophilic compounds from water. This minimum solubilizing concentration is specific for each nonionic amphiphilic compound and can be easily determined, for example, by spectrophotometric determination of the solubility of Sudan Red. This minimum solubilizing concentration is generally on the order of molar concentration.

Preferably, the nonionic amphiphilic compound is an alkyl glycoside or an alkyl polyglycoside.

The nonionic amphiphilic compound useful in the context of the present invention may advantageously be one of the commercially available raw materials SEPICLEAR (Société SEPPIC) and WHEATOLEO (Société WHEATOLEO). It may also be a xylose monomer fragment having an anomeric hydroxyl function substituted by a C4 alkoxy group.

The extraction conditions (duration, concentration of non-ionic amphiphilic compound, pH, temperature, etc.) can be varied depending on the plant/non-ionic amphiphilic compound pair to optimize the extraction yield and/or selectivity. Such specific variations are within the domain of those skilled in the art using their general knowledge in the field of solid-liquid extraction.

Generally, the method involves the maceration of dry or fresh plant matrix grounds in an aqueous solution containing a concentration of a nonionic amphiphilic compound at least equal to the minimum solubilizing concentration, under stirring, at a temperature between 20°C and reflux, to allow extraction of the lipophilic compound.

According to a preferred embodiment, no other solvents are used in the extraction step itself besides the aqueous solution of the non-ionic amphiphilic compound.The aqueous solution of the non-ionic amphiphilic compound used in the specific concentration is the only solvent used in the extraction process.

In a particular embodiment of the present invention, the ratio of plant (kg) to solvent (L) is 1:5 to 1:50. Of course, the residue can be re-extracted one or more times to completely extract the plant.

The extraction can be performed in a conventional reactor or assisted by any other extraction system known to those skilled in the art (microwave, ultrasound, countercurrent extraction, etc.).

Depending on the extraction technique used, the duration of the extraction can vary from a few minutes to a few hours.

The extraction can be applied to fresh plant matrices homogenized with non-ionic amphiphilic compounds, taking into account the moisture content of the plant matrix.

The extraction is followed by solid-liquid separation by centrifugation and/or filtration.

The term "centrifugation" refers to the act of separating the components of a mixture according to their differences in density by subjecting them to centrifugal forces, using a decanter centrifuge or any type of centrifuge, in order to obtain a completely clear solution.

The term "filtration" refers to frontal or tangential filtration, in which the presence of filtration aids (such as perlite or diatoms, etc.) may be considered. This filtration captures the last solid residues with the goal of obtaining a completely clear solution. It can be followed by membrane filtration with a cutoff defined according to the size of the molecules in question. It can also be replaced by or followed by filtration on resins or silica to enrich the compounds of interest, for example by using adsorption resins.

In a particular embodiment, the solution obtained after solid-liquid separation is stored as is or lyophilized, said solution comprising the molecule of interest and a non-ionic amphiphilic compound allowing a better solubility of the extract in the final product.

Thus, a total extract containing compounds of a broad polarity range (polar, mid-polar, non-polar) was obtained.

The extract thus obtained can also be diluted in a volume of water, optionally supplemented with one or more adjuvants chosen from salts, acids or bases, so that the final concentration of the non-ionic amphiphilic compound is lower than the sufficient concentration defined above. Thus, the lipophilic compound can be recovered by precipitation and solid-liquid separation (such as filtration or centrifugation).

Thus, an extract rich in lipophilic compounds is obtained. The lipophilic compounds of interest may be flavonoids, phenolic acids, terpenes (mono-terpenes, di-terpenes, triterpenes) and sterol compounds, diarylheptane derivatives, lignans, coumarins, quinones, anthraquinones, xanthones, phloroglucinols, iridoids, sesquiterpene lactones, alkaloids, sucrose esters, polar lipids, and the like.

They may in particular be kavalactones, myrtucommulones, anthracene, quinine and its derivatives, vanillin and its derivatives, α-mangostin, xanthohumol, monogalactosyldiacylglycerol and digalactosyldiacylglycerol, maslinic acid, ursolic acid, rosmarinic acid, carnosol, galangin, brevifoliain, cardamom, curcuminoids, gingerol, shogaol.

The total extract or extracts enriched in lipophilic compounds may be diluted, concentrated, dried or preserved as is by adding suitable approved preservatives such as glycols, or sorbic acid, benzoic acid, citric acid and its salts, etc., or alcohol (minimum 15°) to the desired final product.

Vacuum drying, freeze drying or nebulization techniques can be considered to prepare dry extracts. The extract obtained can be dried with or without a matrix and/or dissolved in a liquid matrix.

The liquid, paste or dry extract obtained as defined above can be used as such in cosmetic, pharmaceutical or food compositions intended for topical or oral administration.

The advantages are:

If the filtrate is stored as is or lyophilized, a total extract is prepared containing molecules of a wide polarity range, as well as non-ionic amphiphilic compounds, which allow a better solubility of the extract in the final product.

If the lipophilic compounds are purified by precipitation, an extract rich in lipophilic compounds is prepared, obtained by means of aqueous extraction and substances of agricultural origin replacing toxic and petrochemical-based solvents such as hexane, ethyl acetate or acetone.

DETAILED DESCRIPTION

The following examples are offered for informational purposes only and are not limiting.

Example

Example 1: Enriched Perennial Herb Extract

100 g of dried and ground Peru juncea fruit was stirred with 700 mL of a 1.5 M aqueous solution of heptyl glucoside (SEPICLEAR Société SEPPIC) at 40°C for 2 hours. After filtration, the filtrate was acidified to pH 2 and then diluted with 15 volumes of water. After centrifugation, the precipitate was removed and dried. This yielded an enriched extract of 2.1% by weight.

Example 2: Enriched Perennial Herb Extract

20 g of dried and ground Peru juncea fruit was stirred with 140 mL of a 0.75 M aqueous heptyl glucoside solution at 40°C for 2 hours. After filtration, the filtrate was diluted with 6.6 volumes of water. After centrifugation, the precipitate was removed and dried. This yielded an enriched extract of 0.64% by weight.

Example 3: Enriched Perennial Herb Extract

20 g of dried and ground Peru juncea fruit was stirred with 140 mL of a 3 M aqueous heptyl glucoside solution at 40°C for 2 hours. After filtration, the filtrate was diluted with 22 volumes of water. After centrifugation, the precipitate was removed and dried. This yielded an enriched extract of 0.98% by weight.

Results obtained with different enriched P. peruviana extracts:

extract Yield Sucrose ester content According to Example 1 2.11% 19.5% According to Example 2 0.64% 16.4% According to Example 3 0.98% 16.2% Ethyl acetate (1 h, reflux) 2.04% 12.9% Heptane (1h, reflux) 1.04% 3.0%

In Examples 1 to 3, extracts rich in sucrose esters were produced by extracting Peru sempervirens fruit with an aqueous solution of heptyl glucoside, followed by precipitation of the extract by dilution. The fruit sugars were extracted but remained in solution during dilution and did not precipitate. The resulting extracts were superior in quality to those obtained using petrochemically derived solvents (ethyl acetate, heptane).

Example 4: Vanilla Extract

5 kg of dried and ground vanilla pods were extracted with 50 L of a 1.5 M aqueous solution of heptyl glucoside at 50° C. for 3 h. After pressure filtration, the residue was washed with 25 L of the same solution. The filtrate was concentrated to obtain a vanilla extract in the form of a reddish-brown syrupy solution.

Results obtained with vanilla extract:

extract Yield Content of vanillin and its derivatives According to Example 4 800% 0.3%

This extract, on a heptyl glucoside basis, contains a considerable proportion of vanillin and derivatives and is simultaneously preformulated, thus facilitating its introduction into the aqueous phase of cosmetic, nutraceutical or pharmaceutical preparations.

Example 5: Enriched mangosteen extract

100 kg of dried and ground mangosteen peel was stirred with 1000 L of a 1.5 M aqueous solution of heptyl glucoside at 40°C for 2 hours. After filtration, the filtrate was acidified to pH 2 and then diluted with 11 volumes of water acidified to pH 2. After centrifugation, the precipitate was removed and dried. This yielded an extract rich in xanthone compounds (21.3% expressed as α-mangostin) with a yield of 7.3% by weight. The resulting extract was tannin-free.

In contrast, ethanol reflux extraction of dried and ground mangosteen peel yielded an extract with a lower xanthone content (19.5% expressed as α-mangostin) at the same plant mass/solvent volume ratio, but with a higher yield (27%). The resulting extract contained tannins.

In contrast, hexane reflux extraction of dried and ground mangosteen peel yielded an extract with a higher xanthone content (89.1% expressed as α-mangostin) at the same plant mass/solvent volume ratio, but with a lower yield (1.2% by weight). The resulting extract contained no tannins.

Thus, extraction with a 1.5 M aqueous solution of heptyl glucoside allows for the selective extraction of xanthones compared to ethanol extraction. It also allows for a higher extraction yield than hexane extraction.

Example 6: Enriched Kava (Piper methysticum) extract

One kilogram of dried and ground Piper methysticum (Piper methysticum) was extracted with 700 mL of a 1.5 mol/L aqueous solution of amylxylosidoside (APXC5) at 40°C under stirring for 1.5 hours. After filtration, the filtrate was diluted with four volumes of water. After centrifugation, a precipitate corresponding to an enriched Piper methysticum extract was obtained with a yield of 6.2%. The extract contained 3.0% kavalactones.

In contrast, ethyl acetate reflux extraction of dried and ground underground parts of Piper methysticum gave an 8.2% yield at the same plant mass/solvent volume ratio. The extract contained 5.3% kavalactones.

In contrast, aqueous reflux extraction of dried and ground underground parts of Piper methysticum gave a yield of 23.1% at the same plant mass/solvent volume ratio. The extract contained 0.25% kavalactones.

The three extracts have different kavalactone compositions:

The extract obtained by extraction with 1.5 mol/L aqueous amyl glucoside solution had a higher content of low-polarity kavalactones (methoxy-kavalactone, demethoxy-kavalactone, kavapol A, B and C) than the ethyl acetate extract (total kavalactones 44.8% compared to 35.3%).

- In contrast, the extract obtained by extraction with 1.5 mol/L aqueous amyl glucoside solution had a lower content of highly polar kavalactones (capsaicin, dihydrocapsaicin, somatropin and dihydrocapsaicin) than the ethyl acetate extract (total kavalactones 55.2% compared to 64.7%).

- The extract obtained by water extraction contained 1.66% kavalactones and was free of low-polarity kavalactones (methoxykavalactone, demethoxykavalactone, kavapol A, B and C).

Thus, extraction with a 1.5 mol/L aqueous solution of pentosyl glucoside allowed the selective extraction of low-polarity kavalactones with an overall yield comparable to that of ethyl acetate extraction.

Example 7: Gelatin Capsules

Mangosteen extract according to Example 5 200 mg

Starch 45mg

Magnesium stearate 2mg

Example 8: Cream

Example 9: Exemplary Melting Profiles

Dissolution curves of Sudan Red in aqueous solutions of various nonionic amphiphilic compounds at varying concentrations were prepared. After saturating the solutions with Sudan Red and filtering, the amount of Sudan Red dissolved in each solution was measured by UV spectrophotometry at 476 nm following dilution. The dissolution curves are shown in Figure 1. The y-axis represents the DO value multiplied by the dilution, and these values are directly proportional to the concentration (according to the Beer-Lambert law).

These curves enable the determination of the minimum solubilizing concentration of the nonionic amphiphilic compounds according to the invention.

Plantacare (decyl glucoside) is unsuitable due to its pronounced surfactant behavior (high solubility at low concentrations, the compound forms micelles). Recovery of the compound of interest by dilution is not possible. In addition, the foam formation caused by the surfactant significantly hinders filtration.

According to a similar method (HPLC determination of dissolved α-mangostin), the shapes of the curves obtained with α-mangostin are comparable to those obtained with Sudan Red, indicating that the values depend on the amphiphilic compound and not on the solute.

The dissolution curves of α-mangostin in aqueous solutions of various concentrations of the nonionic amphiphilic compound are shown in FIG2 .

Therefore, it can be inferred from these curves that APXC4 has a CMH of 15-20% and amylxylosides have a CMH of 5-10%.

The CMH of isoprene glycol is 40 to 45%.

These values are necessary to implement an extraction method, for example, to extract α-mangostin from the peel of mangosteen:

Compound concentration g% Plant-derived α-mangostin g APX C4 5% 0.36 APX C4 25% 7.87 Isopentyldiol 59% 6.59 Pentylxylosides 40% 7.30 AcOEt 100% 7.49

In 25% APXC4, the content of active substances extracted from the peel of mangosteen was equal to that obtained by ethyl acetate reflux extraction, but not in 5% (the concentration was lower than that of CMH).

This active material can then be recovered by dilution when the final concentration of the amphiphilic compound is lower than that of CMH, as shown in the following table:

By diluting the amylxylosidoside solution to 15%, a small amount of α-mangostin precipitated, while the concentration was kept above CMH. In 7% amylxylosidoside, 100% of the extracted α-mangostin precipitated.

Example 10:

- Extraction of fresh olive cakes

After pressing, 10 g of ground olive pulp was weighed to recover the oil (containing 76% water); an equivalent amount of 12 g of APXC4 (dry matter) and water were added to give a final APXC4 concentration of 50% (taking into account the water content of the plant). The mixture was heated at 50°C for 3 h and filtered to recover a clear brown filtrate with a yield of 87.5%.

In parallel, the same olive pulp was freeze-dried (yield 24.5%) and extracted with ethyl acetate at reflux for 1 h. After evaporation of the solvent, a cloudy green oil was obtained with a yield of 23.4% dry matter and 5.7% fresh matter.

The extracts obtained were evaluated by CCM under the following conditions:

Stationary phase: CCM plate coated with silica gel 60

Mobile phase: ethyl acetate/cyclohexane (1:1)

Color developer: Vanillin sulfate + heated to 120℃

Comparison of the CCM spectra presented in Figure 3 shows that the extract with APXC4 (LX 1872) contains triterpenes (oleanolic acid and maslinic acid), while the AcOEt extract (LX 1874) contains triglycerides in addition to triterpenes. Thus, the molecules of interest are present without having to dry the material and extract it with toxic and volatile solvents. Furthermore, neither chlorophyll nor neutral lipids are extracted.

Claims (25)

1. A method for preparing a plant matrix extract, comprising solid-liquid extraction using an aqueous solution containing at least one nonionic amphiphilic compound, the concentration of which is at least equal to its minimum solubilizing concentration. The nonionic amphiphilic compound is characterized by being water-soluble and avoiding the formation of micelles. The nonionic amphiphilic compound is an alkyl polysaccharide of the general formula Alk-O-Zp, wherein: •Alk represents a saturated or unsaturated, straight-chain or branched hydrophobic aliphatic hydrocarbon segment having 3, 4, or 5 carbon atoms, and • Z represents a hydrophilic glycosidic group selected from glucose, xylose, and arabinose, and ·1<p<5, and The aqueous solution of the nonionic amphiphilic compound constituted the sole extraction solvent used. 2. The method according to claim 1, wherein the plant matrix extract is a plant extract. 3. The method according to claim 1, wherein the aqueous solution contains at least one nonionic amphiphilic compound of agricultural origin. 4. The method according to claim 1, characterized in that solid-liquid extraction is performed by immersing the plant in the aqueous solution containing at least one nonionic amphiphilic compound, and the solid-liquid extraction is maintained under stirring. 5. The method according to claim 1, characterized in that solid-liquid extraction is performed under microwave, ultrasonic, or countercurrent conditions. 6. The method according to claim 5, wherein the minimum solubilizing concentration of the nonionic amphiphilic compound in the aqueous solution is 1 to 10 times the minimum solubilizing concentration. 7. The method according to claim 6, wherein the minimum solubilizing concentration of the nonionic amphiphilic compound in the aqueous solution is 1 to 6 times the minimum solubilizing concentration. 8. The method according to claim 7, wherein the minimum solubilizing concentration of the nonionic amphiphilic compound in the aqueous solution is 1 to 2 times the minimum solubilizing concentration. 9. The method according to claim 8, wherein the minimum solubilizing concentration of the nonionic amphiphilic compound in the aqueous solution is 1.4 to 1.8 times the minimum solubilizing concentration. 10. The method according to claim 1, wherein the nonionic amphiphilic compound is present in the aqueous solution at a concentration of less than 60% by weight relative to the weight of the solution. 11. The method according to claim 10, wherein the nonionic amphiphilic compound is present in the aqueous solution at a concentration of less than 50% by weight relative to the weight of the solution. 12. The method according to claim 11, wherein the nonionic amphiphilic compound is present in the aqueous solution at a concentration of less than 40% by weight relative to the weight of the solution. 13. The method according to claim 12, wherein the nonionic amphiphilic compound is present in the aqueous solution at a concentration of less than 30% by weight relative to the aqueous solution. 14. The method according to claim 1, wherein the aqueous solution is heated to 20°C to the reflux temperature, depending on the extraction technique used. 15. The method according to claim 1, wherein the ratio of the plant in kilograms to the aqueous solution in liters is 1:5 to 1:50. 16. The method according to claim 1, characterized in that solid-liquid separation is performed after extraction by filtration or centrifugation. 17. The method according to claim 1, wherein the compound is an pentyl glycoside, the hydrophobic pentyl fragment of which corresponds to a _C5 alcohol obtained by fermentation of beet or potato flour, and the glycoside fragment is derived from cereals. 18. The method according to claim 1, characterized in that the plants used are selected from the following: fruits of Physalis peruviana, fruits of Embelia ribes, leaves of Myrtus communis, underground parts and leaves of Piper spp., leaves of Eucalyptus globulus, pericarps of Garcinia mangostana, female inflorescences of Humulus lupulus, bark of Cinchona sp., above-ground parts of Urtica dioica, above-ground parts of Helichrysum sp., fruits of Vanilla sp., rhizomes of Curcuma spp., rhizomes of Zingiber officinale, and fruits and leaves of Olea europaea. 19. The method according to claim 16, wherein the solution obtained after solid-liquid separation is stored as is or freeze-dried, the solution containing the molecule of interest and a nonionic amphiphilic compound that allows the extract to dissolve better in the final product. 20. The method according to claim 1, characterized in that the lipophilic compound is purified by precipitation in the obtained extract. 21. A cosmetic composition comprising a plant matrix extract obtained by performing the method as described in any one of claims 1 to 20. 22. The composition according to claim 21, wherein the composition is prepared in a form suitable for topical application. 23. A pharmaceutical composition comprising a plant matrix extract obtained by performing the method as described in any one of claims 1 to 20. 24. The composition according to claim 23, wherein the composition is prepared in a form suitable for topical application. 25. The composition according to claim 23, wherein the composition is prepared in a form suitable for oral administration.