Patent Application
20100310615
The invention relates to compositions of stilbene polyphenol derivatives for preventing and controlling the majority of pathologies and the aging of living organisms and tissues. It also relates to a process for preparing these compositions, and to their applications, especially in the fields of cosmetology, dietetics, and therapeutics.
More than fifty years ago, a theory developed whereby the aging of the human body is a result of the accumulation of multiple damage caused to the tissues by free-radical species or oxidizing chemical reactivities.
In the middle of the 1950s, after numerous studies on rubber, the chemist Harman observed that preventing the formation of free radicals was the most certain way to prevent its degradation and cracking. By analogy, he then suggested that the aging of human tissues (appearance of wrinkles in the skin, for example) might be caused by the “abnormal” formation, within cells, of highly reactive chemical species, and especially free radicals, and by the reaction sequences that they triggered.
Reactive oxygen species (ROS) are formed at the mitochondrial level by uncontrolled “transfer” of one or more electrons to oxygen (ROS: superoxide anion, peroxides, peroxynitrites, free radicals, etc.).
These ROS subsequently propagate to the other cellular compartments or to the cytoplasm, depending on their water/fat solubility, where they produce considerable damage.
In this kind of context, the search for active substances for controlling aging has been conducted, over the recent decades, on the basis of their capacity to break the chain oxidation reactions, in other words to prevent the oxidative stress. In effect, any substance capable of interacting with the ROS will lessen the deleterious effects and, over the longer term, will have a positive impact on health, and, for the same reasons, will slow down aging and the development of the main pathologies. Such substances are free radical scavengers (capable of delivering a single electron at a time) and/or antioxidants (transfer of two electrons at the same time) such as vitamins (E and C) and polyphenols.
However, the damage caused by the aging of the body or accompanying the major pathologies is unlikely to be solely the consequence of poor control of the flow of electrons owing to “leaks” of the mitochondrial metabolism and of intracellular ROS, but is also likely to involve other sources of potential deleterious effects, involving the Maillard reaction and carbonyl stress.
In carbonyl stress, the carbonyl (aldehyde) function of glucose exerts its electrophilic properties with regard to the nucleophilic residues of proteins (amines, thiols, etc.): this is the starting point for carbonyl stress, which is amplified by formation of propagators.
The chemical species produced, or glycation products, are considered to be end products: these are AGES, for Advanced Glycated End-Products, in which glucose or its fragments are joined irreversibly to the amino acid residues.
The Maillard reactions which take place increase, at the same time, the reducing capacity of the sugars and of their derivatives. The dicarbonyl compounds which form acquire an oxidizability which is much greater even then their precursors, and readily transfer their electrons to oxygen, for example. Starting from the superoxide anion formed initially, the same sequence of ROS as in the case of intracellular stress is produced. Accordingly, the carbonyl stress is coupled with a second type of an oxidative stress.
In contradistinction to the mechanisms set out above for the ROS of mitochondrial origin, this new oxidative stress occurs outside the cells, within the extracellular matrix. It therefore affects the amino acids or protein residues of this matrix, and especially the fibers of collagen and of elastin. This oxidative stress, which is particularly significant in view of the fact that the enzymatic protection systems are not as effective as those situated within the cell, results in an increase in the alkylation phenomena which add to the glycation and glycoxidation products resulting from carbonyl stress.
Accordingly, carbonyl stress, coupled with an extracellular oxidative stress, is at least as significant as the intracellular oxidative stress in the development of aging and the establishment of the tissue alternations that accompany the major pathologies.
The study by the inventors of the phenomena leading to tissue aging has therefore led them to a more extended appreciation of the biochemical mechanisms responsible for such aging and to develop new concepts permitting the definition of new biological targets of complementary action for their more effective control.
Their research has therefore resulted in modification to the structure of polyphenols having antioxidant and free-radical-scavenger properties, such as those which make up plant extracts, in order to provide them with greater abilities to likewise scavenge carbonyl stressors.
It is therefore an object of the invention to provide new compositions of polyphenol derivatives that constitute overactivated polyphenols which both are capable of acting very efficiently on a larger number of biological targets (oxidative and carbonyl stress) and are stabilized.
Another object of the invention is to provide a process for obtaining such polyphenol derivatives from plant extract polyphenols.
In accordance with yet a further aspect, the invention aims to exploit properties of these polyphenol compositions of phloroglucinol type in cosmetology, dietetics, and therapeutics.
The polyphenol derivative compositions of the invention are characterized in that said polyphenols comprise monomers, oligomers or polymers of units conforming to the formula (I):
These units are characterized by the simultaneous presence of a resorcinol nucleus (nucleus A) and of a para-phenol nucleus (nucleus B), which are joined to one another by a carbon linkage such as C. In the simplest case, the two nuclei A and B are merged and the segment C is absent, corresponding to the case of phloroglucinol of formula (II):
The nuclei A and B of these units are most often separate, and the segment C is composed of 2 carbons, which in one alternative are sp2 hybridized and form a vinyl: this is the case for resveratrol of formula (III):
Segment C may also be composed of sp3 hybridized carbons and may serve, in particular, as a point of attachment between the monomers, for forming polymers.
Said derivatives are overactivated, with regard to their nucleophilic power, by alkylation of at least one phenolic function of each unit, and are stabilized by esterification, with mixtures of predominantly unsaturated fatty acids (UFA), of all of the others which have remained free.
Generally speaking, the specific substitutions of the derivatives in the compositions of the invention lead to a modulation of their activity and enable them, at the same time and specifically, to inhibit the principal mechanisms involved in the primary pathologies and the aging as set out above.
Advantageously, the number of —O-alkyl groups per molecule is not equal to the number of hydroxyls present on average per molecule, and preferably is 1 or 2.
The alkyl group or groups are more particularly groups having an electron donor effect: methyls, isopropyls or tert-butyls, for maximum boosting of the nucleophilicity of the aromatic nuclei and, consequently, of their capacity to scavenge carbonyl stressors.
Effective stabilization is obtained by formation of UFA esters between the phenolic functions that have remained free and the fatty acids from vegetable oils containing predominantly unsaturated fatty acids (UFA). The oils are selected for their favorable effect on health. Advantageously, the active substances obtained then contain proportions of unsaturated fatty acids that are identical with those of the oils from which they originate.
Said esters preferably comprise the mixtures of acyl radicals R from the fatty acids of olive oil (Olea europea) or grapeseed oil (Vitis vinifera).
The radicals in question are more especially radicals R of saturated fatty acids (SFA=stearic acid; 7-8%), of monounsaturated fatty acids (MUFA=oleic acid; 55-75%), and of essential polyunsaturated fatty acids (PUFA; 15-18%): diunsaturated (linoleic acids) and triunsaturated (linolenic acids) of the ω-6 and ω-3 series, which are present in the derivatives of the invention in proportions identical to those of the oils which produce a maximum benefit for health, according to the data obtained from epidemiology.
This stabilization makes it possible, furthermore, to protect the overactivated stilbene polyphenols from certain premature destruction (oxidation in the air or in the light), while giving them a lipophilic character in order to enhance their chances of being absorbed.
Advantageously, however, this stabilization is temporary, and is no longer effective when the derivatives are put in place to act, so as to restore to them all of their antioxidant power. The stabilization must therefore be reversible by the simple action of the biological systems to which the stabilizing groups are then exposed, and especially enzymes such as lipases, esterases or proteases.
More specifically, the invention relates to compositions characterized in that said derivatives conform to the formula (IV):
in which
and the diastereoisomers and regioisomers of these moieties.
As an example, it is possible to give the dimer (epsilon-viniferin) and trimer (miyabenol C), of formulae (V) and (VI):
According to one preferred embodiment of the invention, the derivatives defined above correspond to plant extract derivatives which have been alkylated and then stabilized. They therefore have the structures of the polyphenols present as a mixture in these plant extracts.
Accordingly, said plant extracts are essentially composed of derivatives of resveratrol, the latter conforming to the formula (III):
In a first group of this class, the extracts are more particularly vine extracts.
The invention relates especially to derivatives of extracts of vine shoots and/or stems (Vitis vinifera).
The invention relates accordingly to compositions of polyphenol derivatives from vine shoot extracts, these extracts comprising large amounts of polyphenol derivatives which constitute, as indicated earlier on above, vinylogous equivalents of phloroglucinol. These are, especially, polyphenols of formulae III, VII, VIII, IX, and X below, corresponding, respectively, to resveratrol, piceatannol, epsilon-viniferin, pallidol, miyabenol C.
In a second group of said first class, the derivatives are derivatives of Polygonum extracts (Polygonum cuspidatum).
In a third group, the derivatives are derivatives of fruit extracts, such as of mulberry plants (Morus sp).
The compositions of polyphenol derivatives of the invention are advantageously obtained by a process comprising the reaction of the plant extract polyphenol compositions defined above
The alkylation reaction employs reactants which are available commercially, such as halides (iodides, bromides, etc.) or sulfuric esters, in a proportion of one-and-a-half chemical equivalents. They are added slowly to a solution of the polyphenol extract in an aprotic solvent (anhydrous acetone, for example), and in the presence of an inorganic base (potassium carbonate, etc.), which is heated at reflux, with stirring and under an inert atmosphere (nitrogen, argon, ideally).
The alkylation reaction is halted, after cooling, by addition of a dilute acid (hydrochloric acid, for example) until an acid pH is obtained. Stirring is continued for 45 additional minutes, approximately. The reaction mixture is concentrated under vacuum (evaporation of the solvent). The aqueous phase is extracted with an equal volume of immiscible solvent (ethyl acetate, dichloromethane, etc.), which is itself washed with two equivalent volumes of distilled water (until neutrality). This organic phase is dried over anhydrous sodium sulfate and then filtered and evaporated under reduced pressure to leave the residue of the alkylated polyphenols.
The acylating agent is prepared from a vegetable oil by a process comprising:
The saponification reaction is performed in aqueous phase in the presence of an alkaline agent such as potassium hydroxide in an at least stoichiometric amount, preferably at the reflux temperature. The solution is then brought to acid pH by addition of inorganic acid, then extracted with an organic solvent so as to isolate the mixture of the free acids formed during the reaction.
The dehydration reaction takes place at reflux, in the presence of a solvent capable of producing an azeotrope with water, so as to allow it to be removed in line with its formation. Toluene, for example, is used, and the water is trapped by a Dean Stark system.
The chloridation reaction is conducted in the presence of a solvent capable of dissolving the free fatty acids. It is catalyzed by Lewis base and carried out by slow addition of the chloridating agent, at a controlled temperature, close to 0° C. When the addition is ended, stirring is continued at the ambient temperature and the reaction mixture is then concentrated by evaporation under vacuum, and the chlorides are purified by distillation.
Advantageously:
The acylation reaction is usually carried out in the presence of a solvent which allows solubilization, even partial solubilization, of the alkylated polyphenol compounds resulting from the alkylation reaction described above.
Appropriate solvents are selected from halogen derivatives such as dichloromethane, chloroform or 1,2-dichloroethane, or nitrogen derivatives such as pyridine, or even hexane, depending on the alkylated compounds to be dissolved.
The alkylated polyphenol derivatives, in solution in the selected reaction solvent, and advantageously admixed with a basic catalysis agent (for example, triethylamine or pyridine), are placed under stirring and in an inert atmosphere (argon, nitrogen).
Two equivalents of FA anhydrides or chlorides, as prepared above, are used as acylating agents. They are added dropwise, in solution in the solvent for the reaction, unless that solvent is pyridine alone. Where pyridine is both the solvent and the basic catalyst, an “inverse” addition is operated. This involves the solution of the polyphenol derivatives being added dropwise to the acylpyridinium compounds formed beforehand.
One alternative which may be employed involves adding, with vigorous stirring, a basic aqueous phase (Na3PO4, K3PO4) to the organic solution (CHCl3, CH2Cl2) of the alkylated polyphenol derivatives and of the acylating agents, thus producing Schotten-Baumann conditions.
Whatever procedure is adopted, the reaction is carried out preferably at ambient temperature, for a time of approximately 7 to 8 hours.
The esterified derivatives thus formed are purified by addition of acidulated water (HCl, qs acid pH), then by a number of washes of the organic phase with distilled water. After drying over sodium sulfate, the solution is filtered and then evaporated to dryness to yield the stabilized and alkylated active flavonoid substances.
The dual-effect active substances of the invention, capable of trapping not only the ROS, irrespective of their intracellular or extracellular origin, but of also trapping the dicarbonyl compounds (antiglycation and anti-AGEs), are of great interest as the most comprehensive and most effective means to date for combating skin aging.
The compositions of the invention are therefore particularly appropriate for the production of cosmetic preparations.
In these preparations, the compositions are combined with vehicles which are appropriate for external use. Advantageously, their fat-soluble nature favors their incorporation into the product forms that are commonly used in cosmetology.
The invention is therefore directed to cosmetic compositions characterized in that they comprise an amount effective for controlling skin aging of one or more compositions of stilbene polyphenol derivatives as defined above in combination with inert vehicles which are appropriate for external use.
These compositions take a form appropriate for topical administration, such as cream, ointment, emulsion, gel, liposomes, lotion.
They contain from 0.5% to 5% of active product, preferably from 2% to 3%.
The invention also relates to a method of preventing skin aging, characterized by the application to the skin, or the ingestion, of one or more cosmetic compositions as defined above.
According to another aspect of great interest, the compositions of the invention can be used in dietetics. By virtue especially of their anti-free-radical and carbonyl-compound-scavenging properties, they ensure better preservation of foods. Moreover, they generally constitute a provider of vitamin factor. They are therefore added with advantage to drinks, as for example to fruit juices, tonic drinks, to dairy products and derivatives such as butter. They can also be used as they are in liquid form, or else as granules or the like, gels or in paste form, incorporated, for example, into confectionery such as fruit gums, candies, chewing gums.
The properties of the compositions of the invention are also advantageously exploited for use as medicaments.
The invention thus also relates to pharmaceutical compositions characterized in that they comprise a therapeutically effective amount of at least one composition as defined above, in combination with a pharmaceutically acceptable vehicle.
These compositions advantageously take a form appropriate for—in particular—oral, topical or parenteral administration.
Accordingly, for oral administration, the compositions take the form more particularly of tablets, gel capsules, solutions or syrups.
For topical administration, the compositions take the form of cream, ointments, gels, patches or lotions.
For parenteral administration, the compositions take the form of a sterile or sterilizable injectable solution.
Other characteristics and advantages of the invention are given, by way of illustration, in the examples which follow, in which reference is made to
1.560 g of phloroglucinol (12.3 mmol) are dissolved in 20 ml of anhydrous acetone in a double-necked flask with a top-mounted condenser. With stirring under an argon atmosphere, in the presence of 1.685 g (12.3 mmol, 2 chemical eq) of potassium carbonate (K2CO3), 766 microliters of methyl iodide are added (=1.746 g; d=2.28 g/ml at 25° C.), i.e., 12.3 mmol=1 molar equivalent relative to the resveratrol. The reaction is heated at reflux for 3 hours.
The reaction mixture is filtered on a No. 4 frit to remove the K2CO3, and the acetone is evaporated under vacuum. The residue is taken up in 15 ml of ethyl acetate. The organic phase is washed with 2 times 15 ml of distilled water, dried over sodium sulfate, filtered and evaporated to dryness to leave a residue of 1357 mg, which is identified as 5-methoxyresorcinol (crude yield=89%; mw=124) on the basis of its spectral constants: 1H NMR, acetone-d6, 500 MHz, δ ppm: 5.95 (1H, d); 5.90 (2H, d); 3.65 (3H, s, CH3). 13C NMR, acetone-d6, 125 MHz, δ ppm: 167.2 (s); 164.22 (2 s); 100.61 (d); 98.26 (2 d); 59.6 (quad.).
450 mg of resveratrol (1.97 mmol) are dissolved in 10 ml of anhydrous acetone in a double-necked flask with a top-mounted condenser. With stirring under an argon atmosphere, in the presence of 270 mg (1.97 mmol, 2 chemical eq) of potassium carbonate (K2CO3), 123 microliters of methyl iodide are added (=280 mg; d=2.28 g/ml at 25° C.), i.e., 1.97 mmol=1 molar equivalent relative to the resveratrol. The reaction is heated at reflux for 3 hours.
The reaction mixture is filtered on a No. 4 frit to remove the K2CO3, and the acetone is evaporated under vacuum. The residue is taken up in 15 ml of ethyl acetate. The organic phase is washed with 2 times 15 ml of distilled water, dried over sodium sulfate, filtered and evaporated to dryness to leave a residue of 548 mg (crude yield=91.6%, on the basis of monomethylated resveratrols; mw=304).
FT-IR spectroscopic study of this extract of O-methylated resveratrols establishes the characteristics which are common to all of these methylated derivatives, including the most complex of the plant stilbenoid polyphenol extracts, labeled with arrows in the spectrum (
This mixture of monomethylated resveratrols is characterized in NMR by the correlations, which are indicative of alkylation, between aromatic oxygen-bearing carbons in the resveratrol (δ=160 ppm) and the protons of methyl ethers (δ=3.8 ppm). The HMBC 2D NMR spectrum (
Operation takes place on 10.08 g (44 mmol) of stilbenoid polyphenol extract as obtained by the process of patent FR 2 766176, which are dissolved in 50 ml of acetone. 12.25 g of activated K2CO3 (88 mmol=4 chemical eq) and then 3.15 ml (33 mmol, 1.5 chemical eq) of the alkylating agent, in this case dimethyl sulfate (DMS), are added with stirring under an argon atmosphere.
The calculation of the chemical equivalents is made on the basis of an “average” of 3 hydroxyl residues per unit of resveratrol. Thus it is considered that each portion of 228 g of extract corresponds to “1 mol of resveratrol”, and possesses three phenolic functions, of which only one is to be converted to alkyl ether. The chemical equivalent of the alkylating reactant is therefore equal to a third of the number of moles of resveratrol extract employed, on the basis that the molecular weight is 228.
The clear solution obtained is heated at reflux for 7 hours, and the reaction is cooled. Following addition of a dilute hydrochloric acid solution, until an acid pH is obtained (220 ml), stirring is continued for 45 minutes more. The reaction mixture is concentrated under vacuum (evaporation of the acetone). The residual aqueous phase is extracted with an equal volume of ethyl acetate, which is washed with two times 200 ml of distilled water (until the washing water is neutral). This organic phase is then dried over anhydrous sodium sulfate, filtered, and evaporated under reduced pressure, to leave the residue of the alkylated stilbenoid polyphenols (9.923 g; crude yield=93.2%, average mw=242).
In the preferred case where each molecule of the initial extract undergoes a single methylation per stilbenoid unit (“resveratrol”), a mixture of the various possible regioisomers and stereoisomers is obtained, such as the monomers and dimers featured below.
Generally speaking, however, the different phenolic functions of each of the molecules react with different kinetics. For resveratrol, for example, the proportions between the various position isomers are as follows:
The result of this is a great diversification of the overactivated active stilbenoid substances which are composed of monomethylated derivatives of the above figure, but they are nevertheless accompanied, to a minority degree, by possible di- and tri-methylated isomers.
As for the preceding example, the alkylated (methylated) structures of these stilbenoid compounds are deduced from the analysis of their various spectra:
Step 1: Saponification of Olive Oil:
50.46 g of “virgin” olive oil (57 mmol, =“171 eq”), placed in a round-bottom flask equipped with a condenser, are admixed with 16.08 g of potassium hydroxide (285 mmol, 1.67 eq) in solution in 2.5 ml of ethanol and 50 ml of water. The reaction is taken to reflux for 5 hours. It is stirred for a further 14 h, at ambient temperature.
After the resulting solution has been extended with 300 ml of water, tenth-concentration (3.7%; w/v) hydrochloric acid is added until an acid pH is obtained in the aqueous phase (approximately 250 ml). The contents of the round-bottom flask, which comprises a pasty “insoluble” product at the surface, are then transferred to a separating flask and extracted with 700 ml of hexane. The organic phase is separated off and then washed with 2 times 300 ml of distilled water (to give a neutral pH of this aqueous phase).
The organic phase is dried over sodium sulfate, filtered on a No. 4 frit, and then evaporated to yield a residue of 42.9 g (crude yield=88.8%).
The infrared spectrum recorded in ATR mode with Fourier transform (
Step 2: Activation of Fatty Acids Obtained from the Saponification of Olive Oil by Formation of Chlorides:
The solution of 41.5 g of free fatty acids (147.1 mmol) obtained from step 1 in 232 ml of chloroform (stabilized on amylene) is stirred under an argon atmosphere in a round-bottom flask which is cooled by an ice bath. Using a dropping funnel, 13.8 ml of oxalyl chloride (162 mM=1.1 eq) are introduced dropwise over a period of 30 minutes. 1 ml of dimethylformamide (DMF) is introduced, and stirring is continued over the ice bath for 5 minutes. Concentration of the reaction mixture under reduced pressure (chloroform and oxalyl chloride in excess) then gives 44.3 g of an oily residue with a slight yellow coloration (crude yield=100%).
By distillation in a ball oven (kugelrohr) under a high vacuum (2 mmHg), this residue is decolorized (colorless liquid), by collecting the fractions which distill at from 178 to 195° C.
In order to analyze the composition of the mixture of fatty acid chlorides obtained, a few microliters of distillate are exposed to methanol. The total mixture is then injected into a gas chromatograph equipped with a “FAME” (fatty acid methyl ester) column and an online mass detector (DSQ-II). In the chromatogram shown in
The FT-IR (
8.4 g (35 mmol) of O-alkylated resveratrol oligomers according to example 3 are suspended in 106 ml of hexane admixed with 9.3 ml of triethylamine (70 mmol), and are stirred under an argon atmosphere. 10.65 g of the chlorides prepared in example 4, diluted in 45 ml of hexane (35.1 mmol, 1 eq) are added dropwise.
The reaction is left for a further 6 hours with stirring at ambient temperature, before being placed in a separating funnel and washed with 100 ml of tenth-concentration hydrochloric acid, then 90 ml of a 10% (w/v) NaHCO3 solution in water, and finally with distilled water until neutrality (two times 90 ml). The organic phase is dried over sodium sulfate, filtered, then evaporated to dryness, under reduced pressure. It leaves a residue of 19.21 g of stabilized and alkylated vine shoot active stilbenoid substances (=24.64 mmol; crude yield=70.6%, average mw=774).
With the aim of obtaining means of identifying these active substances, the whole product is then subjected to spectral measurements:
In the preferred case in which each molecule of the initial extract has undergone only one methylation per stilbenoid unit (“resveratrol”), and in which the residual phenolic functions are all acylated by the olive oil FA mixture, a mixture is obtained of the various possible regioisomers and stereoisomers of monomers and dimers that are featured below:
Butyrospermum parkii butter
Butyrospermum parkii butter
| Number | Date | Country | Kind |
|---|---|---|---|
| 07/08020 | Nov 2007 | FR | national |
| Filing Document | Filing Date | Country | Kind | 371c Date |
|---|---|---|---|---|
| PCT/IB2008/054818 | 11/17/2008 | WO | 00 | 5/14/2010 |
