FR3036618A1 - VEGETABLE EXTRACTS FOR COSMETICS, SOLVENTS AND METHODS FOR OBTAINING SAME - Google Patents

Abstract

The invention relates to NaDES, processes involving these NaDES, plant extracts obtained by the use of the NaDES of the invention, as well as the use of these plant extracts for the preparation of cosmetic compositions, and said cosmetic compositions. The NaDES targeted by the invention are liquid at room temperature, and characterized in that they consist of a first and a second compound each selected from the group comprising the family of polyols, the family of sugars or the family of amino acids, and in that said first compound and said second compound are selected from different families, the NaDES may advantageously further comprise an aqueous phase.

Description

The invention relates to extraction processes made from plant material, as well as to the use of agrosolvents, called "green", it is possible to that is, prepared from biosourced, biodegradable and non-toxic molecules. The present invention relates more particularly to processes for preparing plant extracts, preferably intended for cosmetic compositions, comprising at least one extraction step in which said plant material is brought into contact with a liquid mixture at room temperature of specific composition. . The field of use of agrosourced extraction solvents for the production of plant extracts used as ingredients for cosmetics is becoming increasingly restricted. Today, solvents such as water, certain glycols and ethanol alone or in mixtures in water are used to obtain plant extracts for cosmetic use. Although of natural origin, they nevertheless each have disadvantages. The known aqueous solvents make it possible to obtain extracts in liquid form. However, these require the addition of a microbiological preservative to guarantee their stability. However, the scope of use of preservatives is increasingly restricted, particularly because of the toxicological data concerning these preservatives. An alternative to avoid the addition of preservative is to sterile filter the extract and package it in sterile packaging. This alternative is more expensive and induces constraints for the formulator. Another alternative is to remove water from the extract by known techniques (lyophilization, atomization, drying in a vacuum oven) and thus obtain an extract in solid form (powder). However, this solution often requires the addition of a drying aid such as maltodextrin, to guarantee the drying performance and the physical stability of the powder. On the other hand, the use of powder by the formulator has technical disadvantages.

As regards the glycols used alone or mixed with water, butylene glycol and propanediol are commonly used in the field under consideration. However, propylene glycol has proven potentially toxic, and currently tends to be avoided by manufacturers. Agrobased butylene glycol is relatively expensive, which limits its industrial use. As for propanediol agrosourced, it has the disadvantage of being derived from GMO corn. Finally, ethanol, although having a good extraction power alone or mixture in water, induces problems of transport and storage related to its volatility and flammability. On the other hand, because of its drying nature, this solvent can disrupt the hydrolipidic film of the skin and cause irritation to sensitive skin. Alternative solvents have therefore been sought, attempting to obtain solvents with the lowest adverse effects on the environment. Certain solvents made from compounds found in nature have been described, in particular NaDES (for Natural Deep Eutectic Solvent), studied in particular in Choi et al. (Plant Physiology, 156 (4): 1701-1705, 2011). NaDES have been described as liquid solvents composed of molecules found in nature, and linked together by intermolecular interactions, in particular hydrogen bonds (Dai Y., Analytica Chimica Acta, 766: 61-68, 2013). This definition incorporates 4 groups of combinations that can lead to liquid mixtures at room temperature: ionic liquids with an acid and a base, mixtures based on a sugar and a neutral compound, mixtures based on a sugar and a mixture. base and mixtures based on a sugar and an acid. NaDES can be interesting because they make it possible to extract with good yield molecules such as polyphenols (Dai Y, Anal Chem., 85 (13): 6272-8, 2013).

However, it appears that among this very large family, it is difficult to find suitable solvents for the preparation of extracts intended for cosmetic use, and used industrially.

On the one hand, most of the described NaDES include salts. However, the ionic nature of this type of solvent complicates their use in the cosmetic field. Indeed, it is well known that the formulation, gel or emulsion, of salt-based ingredients beyond a dose of 0.1% is particularly complex.

In other words, the extracts obtained from ionic solvents can not be formulated in gel or emulsion, except to add additional excipients. On the other hand, a large part of the NaDES studied includes derivatives of choline, in particular choline chloride. Or choline and its derivatives are listed in Annex II 15 of the European Cosmetic Regulation EC No. 1223/2009, which has therefore outlawed the use in cosmetics. In addition, NaDES often contain organic acids, in particular carboxylic acids. These acids, by lowering the pH of the extracts obtained, have the effect of rendering the gel or emulsion formulation difficult. In addition, cosmetic products intended for dermal application must have a suitable pH, preferably close to that of the skin (about pH 6.5), or neutral. The use of mixtures containing acids therefore requires the addition of excipients, in particular pH regulators.

In addition, not all NaDES are necessarily liquid at room temperature and physically stable, ie not forming a precipitate. However, to facilitate its industrial use in the cosmetic field, it is preferable that the solvent used is liquid at room temperature, and remains physically stable. A solvent that does not have these characteristics would be of little use.

It follows from these various disadvantages that plant extracts prepared with known solvents, including known NaDES, require additional treatments for use in cosmetic preparations. For example, it may be necessary to use additional excipients or to remove the solvent contained in the extract. A solvent may be removed for example by heating the extract or using another solvent. These additional steps can alter the molecules of interest contained in the plant extract, and in addition decrease the profitability of the processes.

Thus, it remains essential to improve the processes for the preparation of existing plant extracts so as to make them compatible with the requirements specific to the cosmetic field, in particular the safety of the products, while maintaining high quality plant extracts, rich in molecules of interest.

The object of the invention is therefore to provide plant extracts that are compatible with the technical and regulatory requirements specific to the cosmetic field, cosmetic compositions comprising them, as well as solvents and processes making it possible to obtain them.

To do this, the inventors have developed particular NaDES solvents, which meet in all respects the requirements already stated. In particular, the NaDES of the invention are free of organic acid, inorganic compounds and salts, and specifically elaborated for their great capacity to solubilize and extract molecules of interest in biological products, and in particular plants. As a result, their chemical composition does not interfere with the gel or emulsion formulation. In addition, the NaDES of the invention meet the regulatory requirements for cosmetics, because they are free of choline or its derivatives, in particular they do not include choline chloride.

In addition, the NaDES of the invention are not cytotoxic, and their presence in plant extracts or cosmetic compositions is well tolerated by cutaneous cells (see experimental part).

These solvents may further be used in conventional extraction processes without industrialization difficulties. Indeed, the NaDES of the invention are liquid at room temperature and have a viscosity compatible with plant extraction operations.

The plant extracts obtained with the NaDES of the invention are therefore themselves capable of being formulated into gel or emulsion without the disadvantages already mentioned. The inventors have furthermore discovered that the plant extracts of the invention possess an excellent sensory profile, which is particularly advantageous in the cosmetic field. The plant extracts of the invention can therefore be used for the preparation of cosmetic compositions directly, without it being necessary to eliminate the solvent which they contain, or to use a specific excipient.

In addition, the inventors have determined that, surprisingly and unexpectedly, the plant extracts of the invention are bacteriostatic. Thus, once filtered, the plant extracts of the invention, although free from chemical preservatives, remain biologically stable. The resulting plant extracts can therefore be stored without the addition of preservatives, and without the need to keep them sterile. This additional advantage makes it possible to reduce the amount of preservative included in the cosmetic compositions formulated with these extracts.

The invention therefore relates to NaDES, processes using these NaDES, plant extracts obtained by the use of the NaDES of the invention, as well as the use of these plant extracts for the preparation of cosmetic compositions, and said cosmetic compositions.

The invention is aimed primarily at liquid NaDES at room temperature, characterized in that said NaDES consist of a first and a second compound each selected from the group comprising the family of polyols, the family of sugars or the family of amino acids and in that said first compound and said second compound 30366186 are selected from different families, the NaDES may advantageously further comprise an aqueous phase. As already stated, NaDES have been described in the literature, in particular in Choi et al. (Plant Physiology, 156 (4): 1701-1705, 2011). By "NaDES" is meant within the meaning of the invention a mixture of compounds of natural origin that can be used as a solvent and having a superstructure based on hydrogen interactions. Briefly, it is possible to determine that a given mixture indeed has the superstructure of a NaDES by two-dimensional NMR spectroscopy, in particular by NOESY sequence (for Nuclear Overhauser Effect SpectroscopY). The presence of correlation spots (off-diagonal peaks) reflects a certain spatial proximity between the spins considered, and makes it possible to detect the superstructure of the NaDES. This superstructure and methods for detecting it are well known to those skilled in the art, and have been specifically described in Dai Y. et al. (Analytica Chimica Acta, 766: 61-68, 2013), to which those skilled in the art can refer. It has been observed in the prior art that for a given combination of compounds it is possible to obtain several NaDES by varying the relative proportions of the compounds under consideration. In other words, a given combination of compounds can give rise to several chemical compositions as defined by NaDES, which are distinguished by their molar ratios. This is for example the case of the glycerol / choline chloride mixture which is capable of forming NaDES, especially in the molar ratios 3: 1 (Jhong et al., 2009) and 2: 1 (Abbott et al., 2011), or still for the glycerol / choline acetate mixture, which is capable of forming NaDES especially in the molar ratios 1: 1, 1.5: 1 and 2: 3 (Zhao et al., 2011). Those skilled in the art will therefore have no difficulty, for a given mixture of the invention, by varying the proportions of the compounds, to obtain one or more NaDES.

In the context of the invention, the term "ambient temperature" denotes a temperature of 15 and 27 ° C, preferably 20 ° C. For the purposes of the invention, the term "liquid at room temperature" means that the NaDES have a viscosity of less than 3000 mPa.s at 20 ° C. Preferably, the NaDES of the invention are liquid at a temperature of between 2 and 40 ° C. By "polyols" is meant in the sense of the invention organic compounds having at least two alcohol groups, such as diols, triols and sugar alcohols. It is understood that the polyols within the meaning of the invention do not have a carbonyl group (aldehyde or ketone), which distinguishes them from the sugars defined below. By "sugar" is meant in the sense of the invention carbohydrates, namely organic compounds containing a carbonyl group (aldehyde or ketone) and at least two hydroxyl groups (-OH).

For the purposes of the invention, the term "amino acid" means organic compounds having two functional groups: at the same time a carboxyl group -COOH or a carboxylate group and an amine -NH 2 group, the amine group optionally being capable of being methylated, and that is, -NR2 or N + R3, or at least one R = CH3.

Preferably, the NaDES of the invention comprise the above-defined mixtures, with the exception of mixtures selected from the group consisting of: trimethylglycine and glucose, in a molar ratio of 5: 2, trimethylglycine and sucrose, in a 4: 1 molar ratio, trimethylglycine and sucrose, in a 1: 1 molar ratio, trimethylglycine and sucrose, in a molar ratio of 2: 1, trimethylglycine and trehalose, in a molar ratio of 4: 1 , trimethylglycine and sorbitol, in a 3: 1 molar ratio, trimethylglycine and mannose, in a 5: 2 molar ratio, trimethylglycine, inositol, and raffinose, in a molar ratio of 9: 1: 1 , trimethylglycine, sucrose, and proline in a 1: 1: 1 molar ratio, trimethylglycine, sucrose, and proline in a 5: 5: 2 molar ratio, trimethylglycine, glucose, and proline in a molar ratio 1: 1: 1, proline and sucrose, in a molar ratio 2: 1, proline and sucrose, in a 3: 1 molar ratio, proline and sucrose, in a molar ratio of 4: 1, proline and sucrose, in a 1: 1 molar ratio, proline and sorbitol, in a 1: 1 molar ratio, proline and glucose, in a 1: 1 molar ratio, proline and glucose, in a molar ratio of 5: 3, serine and glucose, in a molar ratio 5: 4. Preferably, the polyols, sugars and amino acids used in the invention are chosen for their low cost.

Advantageously, the polyol is chosen from the group comprising glycerol, sorbitol, xylitol, mannitol, inositol, butylene glycol and propanediol and isosorbide. More preferably, the polyol is selected from the group consisting of glycerol, sorbitol, xylitol, and butylene glycol. In a very advantageous manner, the polyol is glycerol or sorbitol. In a particularly advantageous manner, the polyol is glycerol.

Advantageously, the sugar is selected from the group consisting of fructose, glucose, lactose, sucrose, xylose, galactose and trehalose. More preferably, the sugar is selected from the group consisting of fructose and glucose. Particularly advantageously, the sugar is fructose.

Advantageously, the amino acid is selected from the group consisting of glycine, trimethylglycine (betaine), arginine, glutamine and proline. More advantageously, the amino acid is trimethylglycine (betaine).

Thus, advantageously, the NaDES of the invention consist of a first and a second compound each selected from the group comprising the family of polyols, the family of sugars or the family of amino acids, the NaDES may advantageously furthermore comprise an aqueous phase, and wherein: said first compound is a sugar selected from the group consisting of fructose and glucose; and said second compound is a polyol selected from the group consisting of glycerol, sorbitol, xylitol, and butylene glycol.

More advantageously, the NaDES of the invention consist of a first and a second compound each selected from the group comprising the family of polyols, the family of sugars or the family of amino acids, the NaDES may advantageously also comprise a aqueous phase, and wherein: said first compound is fructose; and said second compound is a polyol selected from the group consisting of glycerol, sorbitol, xylitol, and butylene glycol. On the other hand, advantageously, the NaDES of the invention consist of a first and a second compound each chosen from the group comprising the family of polyols, the family of sugars or the family of amino acids, the NaDES being advantageously able to comprise in addition to an aqueous phase, and wherein: said first compound is trimethylglycine (betaine); and said second compound is a polyol selected from the group consisting of glycerol, sorbitol, xylitol, and butylene glycol.

Finally, advantageously, the NaDES of the invention consist of a first and a second compound each selected from the group comprising the family of polyols, the family of sugars or the family of amino acids, the NaDES may advantageously also comprise a phase wherein said first compound is trimethylglycine (betaine); and said second compound is a sugar selected from the group consisting of fructose and glucose.

Preferably, the NaDES of the invention consist of a combination of a first and a second compound selected from the group consisting of: Fructose and glycerol, Butylene glycol and trimethylglycine, Fructose and butylene glycol, fructose and trimethylglycine, glucose and trimethylglycine, fructose and sorbitol, fructose and xylitol, sorbitol, trimethylglycine, and xylitol and trimethylglycine. It is well known to those skilled in the art that the viscosity of a solvent determines its more or less good penetration of the matrix to be extracted, and therefore plays a role in the extraction yield. As indicated above, the NaDES of the invention have, in particular, the characteristic of being liquid at ambient temperature, that is to say of having a viscosity of less than 3000 mPa.s at 20.degree. solvents of choice for the preparation of plant extracts.

Those skilled in the art can however easily prepare less viscous NaDES if necessary. Indeed, the addition of water to the combination of compounds described above reduces the viscosity of NaDES while retaining its properties, including preserving the described superstructure. Advantageously, the NaDES according to the invention further comprise an aqueous phase, consisting of water.

Also, preferably, the NaDES of the invention consist of a mixture selected from the group consisting of: fructose, glycerol, and water, butylene glycol, trimethylglycine, and water, fructose, butylene glycol, and water, fructose, trimethylglycine, and water, glucose, trimethylglycine, and water, 3036618 11 fructose, sorbitol, and water, fructose, xylitol, and water, sorbitol, trimethylglycine, and water; and xylitol, trimethylglycine, and water. It should be noted that not all NaDES obtained from a given combination of compounds have exactly the same properties. For example, their respective melting temperatures may be different (Zhao et al., 2011), or they may be unstable, rapidly forming a precipitate. However, it is preferable, in the context of extraction processes used industrially, to have solvents which are stable over time, both to guarantee the quality of the processes used and the extracts obtained, and to store these extracts at room temperature. In a particularly interesting way, the NaDES of the invention are advantageously physically stable. Preferably, the NaDES of the invention are physically stable at a temperature between 4 and 40 ° C above 2 ° C, for 1 year.

By "physically stable" is meant within the meaning of the invention that the NaDES does not precipitate and remains clear. In particular, NaDES does not form a precipitate after being stored at room temperature for 1 year. The inventors have selected, in the NaDES of the invention, those among the most physically stable and which can be stored for a long time. These NaDES do not form a precipitate and remain clear for at least one year storage between 4 and 40 ° C. These specific NaDES are therefore particularly interesting.

Preferably, the NaDES of the invention consist of a mixture selected from the group consisting of: Fructose, glycerol, and water, in a molar ratio of 1/1/3, fructose, glycerol, and water, in a molar ratio 1/1/5, butylene glycol, trimethylglycine, and water, in a 1/1/5 molar ratio, fructose, butylene glycol, and water, in a 1/1/3 molar ratio, fructose, trimethylglycine, and water, in a molar ratio 1/1/5, glucose, trimethylglycine, and water, in a molar ratio 1 / 1/5, 10 fructose, sorbitol, and water, in a molar ratio 1/1/5, fructose, xylitol, and water, in a molar ratio 1/1/5, sorbitol, trimethylglycine, and water, in a 1/1/5 molar ratio; and xylitol, trimethylglycine, and water, in a 1/1/5 molar ratio.

The NaDES of the invention can be prepared without difficulty according to usual methods from the indicated compounds, which those skilled in the art can obtain commercially or according to well-known preparation methods. For example, the NaDES of the invention can be prepared by mixing all the compounds at a temperature of between 2 and 95 ° C, preferably 70 ° C. This mixture may for example be carried out in a stirred reactor equipped with a double jacket in which circulates a coolant. Depending on the NaDES considered, the skilled person may choose to vary the duration of the mixing step from a few minutes to a few hours, in view of his technical knowledge.

Typically, this time is about one hour. The NaDES of the invention have the advantage of being excellent extraction solvents, and in particular to allow the production of compounds whose extraction is however deemed difficult. It has thus been shown that the NaDES of the invention are extraction solvents capable of extracting chlorogenic acid from flowers of Calendula officinalis (experimental part and FIG. 1).

In addition, as already indicated, the NaDEs of the invention are well tolerated by cutaneous cells (experimental part and FIG. 2), and do not hinder the formulation in gel or emulsion.

The invention therefore also relates to the uses of at least one NaDES of the invention as a solvent for the production of plant extracts, advantageously for the production of plant extracts for cosmetic compositions. In addition, the invention relates to extraction processes using at least one NaDES 10 of the invention as extraction solvent. Thus, the invention is directed to processes for extracting plant matter comprising at least one step in which said plant material is brought into contact with a liquid NaDES at room temperature, characterized in that said NaDES consists of a first and a second compounds each selected from the group comprising the family of polyols, the family of sugars or the family of amino acids, wherein said first compound and said second compound are selected from different families, NaDES may advantageously further comprise an aqueous phase.

The NaDES used in the process of the invention corresponds in all respects to the NaDES of the invention described above. In particular, it is preferably not a mixture selected from the group consisting of: trimethylglycine and glucose, in a 5: 2 molar ratio, trimethylglycine and sucrose, in a molar ratio of 4: 1, trimethylglycine and sucrose in a molar ratio 1: 1, trimethylglycine and sucrose, in a molar ratio of 2: 1, trimethylglycine and trehalose, in a molar ratio of 4: 1, trimethylglycine and sorbitol, in a molar ratio of 3: 1 , Trimethylglycine and mannose, in a 5: 2 molar ratio, trimethylglycine, inositol, and raffinose, in a molar ratio of 9: 1: 1, trimethylglycine, sucrose, and proline in a 1: 1: 1 molar ratio, trimethylglycine, sucrose, and proline in a molar ratio of 5: 5: 2, trimethylglycine, glucose, and proline in a molar ratio of 1: 1: 1, proline, and sucrose, in a molar ratio 2: 1, 5 proline and sucrose, in a molar ratio of 3: 1, the pro and sucrose, in a 4: 1 molar ratio, proline and sucrose, in a 1: 1 molar ratio, proline and sorbitol, in a 1: 1 molar ratio, proline and glucose, in one ratio. 1: 1 molar, proline and glucose, in a molar ratio of 5: 3, serine and glucose, in a molar ratio of 5: 4. The processes of the invention can employ the usual extraction techniques, such as, for example, solid / liquid extraction, microwave assisted extraction, ultrasonic assisted extraction and liquid extraction. pressure. The processes of the invention can be carried out at usual temperatures. Advantageously, the processes of the invention are carried out at room temperature. It should be noted that the processes of the invention can be carried out with any type of plant material, that is to say any known plant or plant family. The invention is further directed to the plant extracts obtained by carrying out the methods of the invention. Like the methods of the invention, plant extracts are not limited to those obtained with a particular plant or family of plants. They may furthermore be obtained from all or part of a plant or several plants, that is to say for example the seeds, leaves, fruits, flowers and / or bulbs of one or more plants. The plant extracts of the invention include natural molecules extracted from the plant. Advantageously, the plant extracts of the invention comprise phenolic compounds, polyphenolic compounds, phenolic acids, organic acids, terpenoids (such as monoterpenes, sesquiterpenes, diterpenes, triterpenes, tetraterpenes, carotenoids, xanthophylls, sterols, triterpenic saponins and steroids, lactones), alkaloids, sugars, amino acids, peptides, and / or proteins. In a particularly interesting way, the plant extracts of the invention are bacteriostatic. By "bacteriostatic" or "microbiologically stable" is meant within the meaning of the invention that their microbiological load, that is to say their content in bacteria, yeasts and molds, does not increase over time. It is generally considered that a bacteriostatic medium, even if it does not allow the destruction of the microorganisms it contains, prevents their growth after the inoculation of the germs.

The bacteriostatic character of the extract of the invention is readily demonstrated by routine microbiology tests. As already indicated, the plant extracts of the invention are easily formulated and stable in cosmetic compositions of gel and emulsion type. By "easily formable" is meant within the meaning of the invention that the plant extract does not cause physical instability in the formulation at the time of manufacture, nor does it require the addition of stabilizing compounds in the formulation. For the purposes of the invention, the plant extracts are "stable in cosmetic compositions" in that the cosmetic composition is physically stable for 1 month at 20 ° C. and 40 ° C.

In addition, the invention relates to the uses of a plant extract for the preparation of a cosmetic composition, characterized in that said plant extract is obtained by contacting a plant material with a NaDES (Natural Deep Eutectic) Solvent) at room temperature, and characterized in that said NaDES consists of a first and a second compound each selected from the group consisting of the family of polyols, the family of sugars or the family of amino acids, wherein said first compound and said second compound are chosen from different families, NaDES may advantageously comprise an aqueous phase.

Finally, the invention is directed to cosmetic compositions comprising at least one plant extract according to the invention, namely obtained by contacting a plant material with a NaDES of the invention.

In other words, the invention relates to cosmetic compositions comprising at least one plant extract obtained by contacting a plant material with a NaDES (Natural Deep Eutectic Solvent) liquid at room temperature, characterized in that said NaDES consists of in a first and a second compound each selected from the group consisting of the family of polyols, the family of sugars or the family of amino acids, wherein said first compound and said second compound are selected from different families, NaDES may advantageously comprise an aqueous phase. Advantageously, the cosmetic compositions of the invention are gels or emulsions, such as, for example, water-in-oil (W / O) or oil-in-water (HIE) emulsions. When the compositions are emulsions, they may include the emulsifiers and co-emulsifiers generally used in the cosmetics field. By way of example, mention may be made in particular of glycerol stearate or laurate, sorbitol stearates or oleates, alkyl dimethiconecopolyol and their mixtures for an W / O emulsion. It is also possible to use polyethylene glycol monostearate, isostearate or monolaurate, polyoxyethylenated sorbitol stearate or oleate, dimethiconecopolyols and mixtures thereof for an HIE emulsion.

When the compositions are gels, they may advantageously comprise hydrophilic gelling agents such as, for example, carboxyvinyl polymers (carbomer), acrylic copolymers (such as copolymers of acrylates / alkyl acrylates), polyacrylamides, polysaccharides (such as hydroxyethyl or hydroxypropylcelluloses), natural gums and clays, or lipophilic gelling agents, such as for example modified clays such as bentones, metal salts of fatty acids such as aluminum stearates, hydrophobically treated silica, ethyl cellulose.

Preferably, the compositions of the invention are intended for the care of the skin, the care of the hair, makeup or sun protection.

The compositions according to the invention are therefore capable of comprising, in addition to at least one plant extract according to the invention, other conventional ingredients for this type of composition such as, for example, perfumes, dyes, UVA filters, UVB filters, or excipients.

The advantages of the invention are illustrated by the following examples, which do not claim to limit their scope. FIG. 1: Extractive performance of chlorogenic acid in the flowers of Calendula officinalis versus EtOH / water The compositions of the various solvents tested, including the NaDES of the invention, are indicated on the ordinate. The percentages indicated on the abscissa correspond to the percentage of chlorogenic acid extracted by the solvent relative to the quantity extracted with a control solvent, in this case the ethanol / water solvent 1: 1. FIG. 2: Quantity of total phenol acids extracted by various solvents, including a NaDES solvent of the invention. The amount of total phenol acids extracted is expressed as the amount of chlorogenic acid, per 100 grams of flower extract of Calendula officinalis. The NaDES solvent has a better performance than the other solvents, which do not have the NaDES superstructure. Figure 3: Evaluation of the viability of keratinocytes in culture treated with different solvents. Normal human keratinocytes in monolayer culture were treated with various solvents, including the NaDES of the invention. The NaDES of the invention have a cytotoxicity close on average to that of water. Figure 4: Evaluation of viability of fibroblasts in culture treated with different solvents. Normal human fibroblasts in monolayer culture were treated with various solvents, including the NaDES of the invention. The NaDES of the invention have a cytotoxicity close to the average of that of water.

FIG. 5: Two-dimensional NOESY NMR of the Fructose / Glycerine / Water Mixture in a 1: 1: 5 Molar Ratio The map obtained shows, in the upper right quadrant, a group of peaks characteristic of a NaDES superstructure. The largest peaks form a diagonal representing intramolecular hydrogen interactions, and are surrounded by adjacent lower intensity peaks. These adjacent peaks reflect the presence of intermolecular hydrogen-type interactions between the compounds of the mixture. FIG. 6: Two-dimensional NMR of NOESY sequence of the Fructose / Glycerine / water mixture in molar ratio 1: 1: 7 The figure is an enlargement of the upper right-hand corner of the NMR map (of the same type as the NMR map of FIG. 5) obtained for this fructose / glycerin / water mixture in molar ratio 1: 1: 7. A diagonal of major peaks is observed, which represents the compounds of the mixture. On the other hand, there are very few peaks adjacent to this diagonal. Although there are interactions between the compounds of this mixture, there is no NaDES superstructure. FIG. 7: Two-dimensional NMR of NOESY sequence of the Fructose / Glycerine / water mixture in molar ratio 1: 1: 10 The figure is an enlargement of the upper right-hand corner of the map obtained for this mixture. There is a diagonal of major peaks, but no peak adjacent to this diagonal. This mixture does not include NaDES superstructure. Example 1: Preparation of the mixtures of the invention. The following mixtures were prepared according to the method indicated in the description, namely: all the compounds are mixed in the proportions indicated at a temperature of 70 ° C. with stirring for 1 hour in an Erlenmeyer flask equipped with a d mechanical and closed agitation.

3036618 19 Mixture Composition of the mixture Molar composition of the mixture First Second Add First First compound water compound water compound 1 fructose glycerol yes 1 1 3 2 fructose glycerol yes 1 1 5 3 butylene trimethylglycine yes 1 1 5 glycol 4 fructose butylene glycol yes 1 1 3 5 fructose trimethylglycine yes 1 1 5 6 glucose trimethylglycine yes 1 1 5 7 fructose sorbitol yes 1 1 5 8 fructose xylitol yes 1 1 5 9 sorbitol trimethylglycine yes 1 1 5 10 xylitol trimethylglycine yes 1 1 5 Table 1: Composition of mixtures of the invention Example 2: Physico-chemical properties of the mixtures of the invention.

The mixtures prepared in Example 1 were tested for their viscosity at 20 ° C and their stability at 4 ° C, 20 ° C and 40 ° C for 1 hour. The viscosity is measured with a Haake Rheostress 600 rheometer at 20 ° C., under a stress of 10 Pa. The stability is measured by visual control of the appearance of the mixture packaged in a glass and plastic bottle and placed for 1 year in enclosures. temperature stability at 4 ° C, 20 ° C and 40 ° C. The stability of the NaDES mixture is consistent when this mixture remains clear and without precipitate for 1 year of storage at 3 temperatures. Mixture Viscosity at 20 ° C (in mPa. $) Stability 1 1750 compliant 2 108 compliant 3 33 compliant 4 1155 compliant 5 290 compliant 6 484 compliant 7 1736 compliant 8 1058 compliant 9 378 compliant 10 113 compliant Table 2: Physicochemical properties Example 3: microbiological property The microbiological stability of the mixture 2 was determined by carrying out a challenge test according to the European Pharmacopoeia 8th Edition, 2014 Chapter 5.1.3, (preparations for local applications). This mixture is bacteriostatic for the 4 strains of the protocol: Pseudomonas aeruginosa AT CC 9027 Staphylococcus aureus AT CC 6538 Aspergillus brasiliensis AT CC 16404 Candida albicans AT CC 10231 Example 4: Formulation of mixtures and stability in formula This example illustrates the capacity of NaDES of the invention to be formulated at 5% gel and emulsion and to remain stable for 1 month at room temperature and 40 ° C. Protocol: The following formulations of gel (A and B) and emulsion (C and D) are prepared with 5% NaDES or 5% glycerine. The stability of the formulas is monitored in thermostatically controlled enclosures for 1 month by measuring the evolution of the viscosity, the appearance and the pH. Composition A Common name or name Corresponding name in% commercial International nomenclature of weight / weight cosmetic ingredients Demineralized water Water 93.6 Carbopol ultrez 10 Carbomer 0.3 Glidant plus liquid DMDM hydantoin, Butylcarbamate 0.5 iodopropynyl Glycerine glycerin 5 Hydroxide Sodium hydroxide 0.6 (10% w / v solution) 3036618 21 Composition B Common name or name Corresponding name in% commercial International nomenclature weight / weight cosmetic ingredients Demineralised water Water 93.6 Carbopol ultrez 10 Carbomer 0.3 Glidant plus liquid DMDM hydantoin, Butylcarbamate 0.5 iodopropynyl NaDES 5 Sodium hydroxide Sodium hydroxide 0.6 (10% w / v solution) Composition C Common name or name Corresponding name in% commercial international nomenclature weight / weight cosmetic ingredients Emulime Delta Cetyl alcohol, 6 glyceryl stearate, PEG-75 stearate, Ceteth-20, steareth-20 cetyl alcohol Cetyl alcohol 2 MOD Octyldodecyl myristate 10 Phenonip Phenoxyethanol, methylparaben, 0.7 ethylparaben, butylparaben, propylparaben Xanthan gum Xanthan gum 0.3 Demineralized water Water 66.0 Glycerine Glycerin 5 Xiameter PMX-0345 Cyclopentasiloxane, 10.0 cyclosiloxane blend cyclohexasiloxane 5 3036618 22 Composition D Common name or name Corresponding name in% commercial international nomenclature weight / weight cosmetic ingredients Emulime Delta Cetyl alcohol, 6 glyceryl stearate, PEG-75 stearate, Ceteth-20, steareth-20 Cetyl alcohol Cetyl alcohol 2 MOD Octyldodecyl myristate 10 Phenonip Phenoxyethanol, methylparaben, 0.7 ethylparaben, butylparaben, propylparaben Xanthan gum Xanthan gum 0.3 Demineralized water Water 66.0 NaDES 5 Xiameter PMX-0345 Cyclopentasiloxane, 10.0 cyclosiloxane blend cyclohexasiloxane Results show that the mixtures 1 to 10 tested are all formable in gel and emulsion and are stable in the s test conditions.

EXAMPLE 5 Determination of the Superstructure of NaDES Protocol: Each composition is analyzed by two-dimensional NOESY NMR NMR of the proton in a Bruker 5001 \ 411z DMX NMR spectrometer equipped with a cryoprobe TCI.

The Fructose / Glycerine / water mixtures in molar ratio 1: 1: 5, 1: 1: 7 and 1: 1: 10 analyzed according to the protocol gives the NMR maps presented respectively in FIGS. 5, 6 and 7. These results show that only the Fructose / Glycerine / Water mixture in 1: 1: 5 molar ratio (FIG. 5) shows between all the protons of the compounds of the positive interactions identified by signals adjacent to the main diagonal on the map (the intermolecular distance between two protons is less than 5 Angstroms).

This means that the 3 compounds of the mixture are spatially very close and all interact, and therefore this mixture is not the result of a simple solvation. The mixture has a superstructure as defined by the invention and described by Dai Y. et al. (Analytica Chimica Acta, 766: 61-68, 2013).

EXAMPLE 6 Extractive Performance The extraction performance of natural substances by the blends prepared in Example 1 was evaluated and compared to the performance of conventional solvents. For this purpose, the extraction performance of chlorogenic acid in flowers of Calendula officinalis was evaluated. Extraction protocol: the extracts are obtained by contacting 5 g of crushed dry flowers and 95 g of solvent in an Erlenmeyer flask at 70 ° C. with mechanical stirring for 3 h. The separation of the plant residue and the liquid extract is carried out by microfiltration.

The concentration of chlorogenic acid was measured by HPLC in the extracts obtained with mixtures 1 to 10 prepared in Example 1, and compared with that obtained under identical conditions for conventional solvents: ethanol (EtOH), water / ethanol at a weight ratio of 1: 1 butylene glycol / water at a weight ratio of 60:40 Propanediol / water at a weight ratio of 60:40 Water The concentration obtained with the ethanol / water solvent was used as a reference, the other concentrations being expressed as a percentage of it. The results are shown in Figure 1.

The mixtures of the invention are unquestionably more effective than any conventional solvent for the extraction of chlorogenic acid. These results illustrate the high efficiency of the mixtures of the invention in extracting biological molecules of interest, in particular in plants, with much better performances than those obtained with the usual solvents. EXAMPLE 7 Extractive Performance of NaDES as Defined in the Invention The extraction performance of NaDES according to the invention was compared with mixtures containing the same compounds but not having a superstructure as defined by the invention and described by Dai Y. et al. (Analytica Chimica Acta, 766: 61-68, 2013). For this, extracts were made according to the same protocol as Example 6 and the analysis of the total phenolic acids expressed in chlorogenic acid was carried out by HPLC (FIG. 2). In conclusion, for a combination of given compounds, the NaDES according to the invention has a better extractive performance than "non-NaDES" solvents, probably because of its superstructure.

Example 8: Tolerance by cutaneous cells measured in vitro. The cytotoxic nature of the mixtures prepared in Example 1 was tested by adding extracts in vitro in monolayer cultures of normal human fibroblasts and keratinocytes.

Protocol: Monolayer cell culture for 48h of normal human keratinocytes and normal human fibroblasts in the presence of 1% NaDES and evaluation of cell viability by MTT assay. The results are shown in Figures 3 and 4.

The NaDES of the invention have a cytotoxicity close on average to that of water. It can therefore be considered that they are devoid of cytotoxic effects and can be used in cosmetic compositions without risk to the consumer. 30

Claims (10)

REVENDICATIONS1. Use of a plant extract for the preparation of a cosmetic composition, characterized in that said plant extract is obtained by contacting a plant material with a liquid NaDES (Natural Deep Eutectic Solvent) at room temperature, characterized in that said NaDES consists of a first and a second compound each selected from the family of polyols, the family of sugars or the family of amino acids, wherein said first compound and said second compound are selected from different families, NaDES being advantageously include an aqueous phase. 2. Use according to claim 1, characterized in that the first or the second compound of said NaDES is a polyol chosen from the list consisting of glycerol, sorbitol, xylitol, mannitol, inositol, butylene glycol and propanediol and isosorbide. 3. Use according to one of claims 1 or 2, characterized in that the first or the second compound of NaDES is a sugar selected from the list consisting of fructose, glucose, lactose, sucrose, xylose, galactose and trehalose. 4. Use according to one of claims 1 to 3, characterized in that the first or the second compound of said NaDES is an amino acid selected from the list consisting of glycine, trimethylglycine, arginine, glutamine and proline . 5. Use according to one of claims 1 to 4, characterized in that said NaDES consists of a combination of a first and a second compound selected from the list consisting of: Fructose and glycerol, butylene glycol and trimethylglycine, fructose and butylene glycol, fructose and trimethylglycine, glucose and trimethylglycine, fructose and sorbitol, fructose and xylitol, sorbitol and trimethylglycine, and xylitol and trimethylglycine. 5 6. Use according to one of claims 1 to 5, characterized in that said NaDES consists of a mixture selected from the list consisting of: fructose, glycerol, and water, butylene glycol, trimethylglycine, and Fructose, butylene glycol, and water, fructose, trimethylglycine, and water, glucose, trimethylglycine, and water, fructose, sorbitol, and water, fructose, xylitol, and water; sorbitol, trimethylglycine, and water; and xylitol, trimethylglycine, and water. 7. Use according to one of claims 1 to 6, characterized in that said NaDES consists of a mixture selected from the list consisting of: Fructose, glycerol, and water, in a molar ratio 1/1 / 3, fructose, glycerol, and water, in a 1/1/5 molar ratio, butylene glycol, trimethylglycine, and water, in a molar ratio 1/1/5, fructose, butylene glycol, and water, in a 1/1/3 molar ratio, fructose, trimethylglycine, and water, in a 1/1/5 molar ratio, glucose, trimethylglycine, and water, in a 1/1/5 molar ratio, fructose, sorbitol, and water, in a 1/1/5 molar ratio, fructose, xylitol, and water, in a molar ratio 1/1 / 5, sorbitol, trimethylglycine, and water, in a 1/1/5 molar ratio; and xylitol, trimethylglycine, and water, in a 1/1/5 molar ratio. 3036618 27 8. Cosmetic composition comprising at least one plant extract obtained by contacting a plant material with a NaDES (Natural Deep Eutectic Solvent) liquid at room temperature, characterized in that said NaDES consists of a first and a second selected compounds each of the family of polyols, the family of sugars or the family of amino acids, wherein said first compound and said second compound are selected from different families, NaDES may advantageously comprise an aqueous phase. 9. Cosmetic composition according to claim 8, characterized in that said composition is an emulsion, preferably intended for the care of the skin, the care of the hair, makeup or sun protection. 10. Cosmetic composition according to claim 8 or 9, characterized in that said composition is a gel, preferably intended for the care of the skin, the care of the hair, makeup or sun protection.