The present invention relates to novel C-glycoside compounds having a hydroxylated aromatic group, to the compositions, especially cosmetic compositions, comprising same, and also to the use thereof as an antioxidant.

Antioxidants are used in cosmetics for combating the free radicals (0 ^" ₂ , HO°, etc.) that result in chain reactions that may damage DNA, inter alia, and more generally that induce cell ageing.

The role of antioxidants is thus to capture the free radicals and convert them to substances that are harmless to the keratin materials of human beings. Indeed, antioxidants neutralize the reactive oxygen species which are continually generated by the metabolism. These reactive oxygen species (ROSs) disrupt biological mechanisms (especially at the protein, DNA or lipid level) and induce an oxidizing stress. This in turn contributes to the development and acceleration of cell degeneration. Indeed, free radicals are one of the causes of tissue ageing, via in particular the appearance of wrinkles. Among the exogenous factors capable of promoting the formation of reactive oxygen species, mention may be made of solar rays.

Antioxidants may therefore be used in various cosmetic areas such as anti-ageing, protection against oxidative stresses and especially exogenous stresses due to sun exposition, or else anti-pigmentation (the synthesis of melanin being an oxidative process).

Oxidative stress and in particular UV radiation also play a part in melanogenesis and pigmentation of the skin, directly (effect of UV rays on the activation of tyrosinase) or indirectly (effect of UV rays on the production of free radicals, which are capable of non-enzymatically oxidizing DOPA (dihydroxyphenylalanine) derivatives) or else by promoting inflammation known for accentuating skin pigmentation.

The production of reactive oxygen species therefore causes damage to DNA, proteins or lipids, contributing in particular to accelerating cell ageing of the skin and/or integu- merits.

In particular, the effects of oxidative stress adversely affect cell respiration and especially result in an accelerated ageing of the skin, with in particular a dull and/or grey complexion, an uneven complexion, a loss of radiance and/or transparency of the skin, the premature formation of wrinkles or fine lines, a loss of softness, suppleness and elasticity of the skin, the appearance of pigment spots, in particular of actinic lentigo. The effects of oxidative stress are also manifested by a reduction in the vigour of the hair and/or a deterioration in the appearance thereof, in particular a dull appearance.

Many antioxidants exist already, such as tocopherol (vitamin E) or derivatives thereof, vitamin C or derivatives thereof, carotenoids, ubiquinone, green tea, etc.

However, there is a need for alternative antioxidants, that make it possible in particular to protect the keratin materials of human beings (the skin and/or its integuments) from the harmful or unattractive effects of oxidative stress. The Applicant has surprisingly demonstrated that certain C-glycoside compounds having a hydroxylated aromatic group have antioxidant properties, and especially free- radical scavenging properties.

One subject of the present invention is therefore the cosmetic use of a C-glycoside compound of formula (I) as defined below as an antioxidant.

Another subject of the invention is novel compounds of formula (Γ) as defined below.

Compounds (I) and (Γ) make it possible to treat keratin materials (the skin and in- teguments) for the effects of oxidative stress, in particular for the effects of UV radiation.

The invention also relates to a method for the cosmetic treatment of keratin materials, comprising the application to said keratin materials of a cosmetic composition as de- fined above. This method finds an advantageous application in the treatment of the skin. The term 'skin', is understood to mean the skin of the face and/or of the body, the scalp and the semi-mucosa (lips).

The term "integuments" is understood to mean head hair, body hair, eyelashes, nails and preferably head hair.

In particular, oxidative stress may result from sun exposition.

According to another particular embodiment of the invention, the composition is in- tended for topical administration to keratin materials (the skin and/or its integuments), preferably to the skin.

Compounds (I) and (Γ) make it possible to prevent and/or treat the signs of skin ageing.

Among the signs of skin ageing induced by an oxidative stress, mention is especially made of a loss of firmness and/or elasticity and/or tone and/or suppleness of the skin, the formation of wrinkles and fine lines, expression lines, in particular on the forehead and in the space between the eyebrows, perioral wrinkles and fine lines, and/or slack- ening in the area around the lips, in particular in the top lip area (area between the top lip and the nose), a dull appearance of the complexion, and the papery appearance of the skin.

The term "oxidative stress" as used in the present application covers all of the dam- age caused by an increase in oxygen free radicals in a subject.

The extent of the damage generated by this oxidative stress depends on the rapidity with which the free radicals are created and subsequently deactivated by antioxidants. The compounds used according to the invention therefore correspond to the formula (I) below:

in which:

- S denotes a monosaccharide; the S-CH ₂ D bond represents a bond of anomeric C nature;

- D-X denotes a -CH(OH)- or -CO- group;

- -A-B- denotes -CH ₂ -CH ₂ - or -CH=CH-; - Y denotes a hydrogen atom or an -OR group, R denoting a hydrogen atom or a C-| - C4 alkyl radical; and also solvates thereof, and optical iosmers thereof. S may be a monosaccharide chosen from glucose, galactose, mannose, xylose, lyxose, fucose, arabinose, rhamnose, glucuronic acid, galacturonic acid, iduronic acid, N-acetylglucosamine and N-acetylgalactosamine.

In particular, S may be a monosaccharide chosen from D-glucose, D-galactose, D- mannose, D-xylose, D-lyxose, L-fucose, L-arabinose, L-rhamnose, D-glucuronic acid, D-galacturonic acid, D-iduronic acid, N-acetyl-D-glucosamine and N-acetyl-D- galactosamine.

Advantageously, S denotes a monosaccharide chosen from glucose, xylose and rhamnose. In particular, S denotes a monosaccharide chosen from D-glucose, D- xylose and L-rhamnose.

Preferably, S denotes a monosaccharide chosen from glucose and xylose. More particularly, S denotes a monosaccharide chosen from D-glucose and L-xylose.

Preferably, S denotes glucose. In particular, S denotes D-glucose.

As C-1 -C4 alkyl group, mention may especially be made of methyl, ethyl, isopropyl, n- propyl, n-butyl, i-butyl, isobutyl and sec-butyl groups.

R is preferably a methyl group.

Preferably, -A-B- denotes -CH2-CH2-. Preferably, -D-X- denotes a -CH(OH)- group.

Preferably, Y denotes H or -OMe. As examples of compounds of formula (I), mention may in particular be made of the following compounds:

The acceptable solvates of the compounds used in the present invention comprise conventional solvates such as those formed during the last step of the preparation of said compounds due to the presence of solvents. By way of example, mention may be made of the solvates due to the presence of water or of linear or branched alcohols such as ethanol or isopropanol. Compounds of formula (I) may be prepared according to schemes I and II below:

Scheme I by reaction of a sugar of formula (II) (corresponding to the monosaccharide corresponding to the S group) with a compound of formula (III) in which A, B and Y have the same meaning as that described previously for the compounds of formula (I), especially at a temperature between 45 and 95°C (preferably at 90°C), in water, or a water/ethanol mixture or a water/dioxane mixture, in the presence of a base such as sodium hydrogen carbonate, sodium hydroxide or lithium hydroxide, in particular over 1 to 20 hours.

The ketone compound (la) is thus obtained, which corresponds to a compound of formula (I) in which D-X represents C=0.

The hydroxylated compound (lb) (compound (I) for which D-X = CH-OH) may be ob- tained according to scheme II:

(la) (lb)

Scheme II in which the compound la is reduced, in particular in the presence of sodium boro- hydride in water, or a water/ethanol mixture or a water/dioxane mixture, at ambient temperature (25°C), in particular over 1 to 20 hours.

The crude product obtained may be purified, for example over silica gel or by recrys- tallization, so as to obtain the desired product.

The compounds (I) have a good solubility in water at ambient temperature.

Another subject of the invention is the novel compounds of formula (Γ):

corresponding to the compounds of formula (I) described previously for which X is a monosaccharide with the exception of xylose.

For the compounds of formula (Γ):

Preferably, S denotes a monosaccharide chosen from glucose and rhamnose. In particular, S denotes a monosaccharide chosen from D-glucose and L-rhamnose.

Preferably, S denotes glucose. In particular, S denotes D-glucose.

R is preferably a methyl group. Preferably, -A-B- denotes -CH2-CH2-.

Preferably, -D-X- denotes a -CH(OH)- group. Preferably, Y denotes H or -OMe.

As compounds of formula (Γ), use may be made of the compounds 1 to 4 and 9 to 12 described previously.

The present invention also relates to a composition comprising, in a physiologically acceptable medium, a compound of formula (Γ) as described above. The composition is in particular a cosmetic composition.

The compound of formula (Γ) or (I) may be present in the composition in an amount which may be between 0.01 and 10% by weight, preferably between 0.1 and 5% by weight, especially between 0.5 and 3% by weight, relative to the total weight of the composition. Another subject of the invention is a method for the cosmetic treatment of keratin materials, comprising the application to said keratin materials of a composition comprising a compound of formula (Γ) as defined previously. In particular, the treatment method aims to protect the keratin materials from oxidative stress, in particular from the effects of UV radiation.

In particular, the treatment method aims to prevent the signs of skin ageing. It also aims to prevent skin pigmentation induced by an oxidative stress, in particular by UV radiation.

It also aims to prevent and/or improve the dull appearance of the hair, and/or to improve the vigour and/or appearance of the hair.

The invention also relates to a method for the cosmetic treatment of keratin materials, for protecting the keratin materials from the effects of oxidative stress, in particular from the effects of UV radiation, comprising the application to said keratin materials of a composition comprising a C-glycoside compound of formula (Γ) as defined previ- ously.

It also relates to a method for the cosmetic treatment of the skin intended to prevent and/or treat the skin ageing induced by an oxidative stress comprising at least one step that consists in applying to skin exhibiting signs of skin ageing induced by an oxidative stress at least one composition comprising a C-glycoside compound of formula (Γ) as defined previously.

In particular, the method according to the invention aims to prevent and/or reduce the pigment spots of the skin, in particular actinic lentigo; to lighten the skin; to prevent the dull complexion and/or grey complexion, and/or to improve the brightness and/or the evenness of the complexion; to improve the radiance and/or transparency of the skin; to improve the softness, suppleness and/or elasticity of the skin; and/or to prevent and/or reduce wrinkles and/or fine lines.

The composition also comprises a physiologically acceptable medium, which is preferably a cosmetically or pharmaceutically acceptable medium, especially a derma- tologically acceptable medium, i.e. a medium that has no unpleasant odour, colour or appearance, and that does not cause the user any unacceptable stinging, tautness or redness. In particular, the composition is suitable for topical application to keratin materials, in particular to the skin.

The term "physiologically acceptable medium" means a medium that is compatible with human keratin materials such as the skin of the body or of the face, the lips, mu- cous membranes, the eyelashes, the nails, the scalp and/or the hair.

The composition according to the invention may then comprise any adjuvant commonly used in the envisaged application field.

Mention may be made especially of water; organic solvents, especially C1 -C6 alcohols and C2-C10 carboxylic acid esters; carbon-based and/or silicone oils, of mineral, animal and/or plant origin; waxes, pigments, fillers, colorants, surfactants, emulsifiers, coemulsifiers; cosmetic or dermatological active agents, UV-screening agents, polymers, hydrophilic or lipophilic gelling agents, thickeners, preservatives, fragrances, bactericides, odour absorbers and antioxidants.

These optional adjuvants may be present in the composition in a proportion of from 0.001 % to 80% by weight and especially from 0.1 % to 40% by weight relative to the total weight of the composition.

Depending on their nature, these adjuvants may be introduced into the fatty phase or into the aqueous phase of the composition and/or into lipid vesicles. In any case, these adjuvants, and the proportions thereof, will be chosen by a person skilled in the art such that the advantageous properties of the compounds according to the invention are not, or are not substantially, adversely affected by the envisaged addition.

As oils that can be used in the invention, mention may be made of mineral oils (liquid petroleum jelly), oils of plant origin (avocado oil, soybean oil), oils of animal origin (lanolin), synthetic oils (perhydrosqualene), silicone-based oils (cyclomethicone) and fluorinated oils (perfluoropolyethers). As fatty substances, use may also be made of fatty alcohols (cetyl alcohol), fatty acids, waxes (carnauba wax, ozokerite). As emulsifiers and coemulsifiers that can be used in the invention, mention may for example be made of fatty acid esters of polyethylene glycol such as PEG-100 stearate, and fatty acid esters of glycerol such as glyceryl stearate.

As hydrophilic thickeners or gelling agents, mention may be made of carboxyvinyl polymers (carbomer), acrylic copolymers such as acrylate/alkyl acrylate copolymers, polyacrylamides, polysaccharides, natural gums and clays, and, as lipophilic thickeners or gelling agents, mention may be made of modified clays such as bentones, metal salts of fatty acids and hydrophobic silica.

As active agents, it will be advantageous to introduce into the composition used according to the invention at least one compound chosen from: desquamating agents; moisturizers; depigmenting or propigmenting agents; anti-glycation agents; NO- synthase inhibitors; agents for stimulating the synthesis of dermal or epidermal macromolecules and/or for preventing their degradation; agents for stimulating fibroblast and/or keratinocyte proliferation or for stimulating keratinocyte differentiation; muscle relaxants and/or dermo-decontracting agents; tensioning agents; anti-pollution agents and/or free-radical scavengers; agents acting on the capillary circulation; agents acting on the energy metabolism of cells; and mixtures thereof.

Examples of such additional compounds are: retinol and derivatives thereof such as retinyl palmitate; ascorbic acid and derivatives thereof such as magnesium ascorbyl phosphate and ascorbyl glucoside; tocopherol and derivatives thereof such as tocopheryl acetate; nicotinic acid and precursors thereof such as nicotinamide; ubiquinone; glutathione and precursors thereof such as L-2-oxothiazolidine-4- carboxylic acid; plant extracts and especially plant proteins and hydrolysates thereof, and also plant hormones; marine extracts such as algal extracts; bacterial extracts; ceramides; hydroxy acids such as salicylic acid and 5-n-octanoylsalicylic acid; resveratrol; oligopeptides and pseudodipeptides and acyl derivatives thereof; manganese and magnesium salts, in particular the gluconates; and mixtures thereof. As indicated previously, the composition according to the invention may also contain UV screening agents or photoprotective agents that are active in UVA and/or UVB light, in the form of organic or inorganic compounds, the latter optionally being coated in order to render them hydrophobic.

The organic photoprotective agents may especially be chosen from dibenzoylmethane derivatives; anthranilates; cinnamic derivatives; salicylic derivatives; camphor derivatives; benzophenone derivatives; β,β-diphenylacrylate derivatives; triazine derivatives other than those of formula (I); benzalmalonate derivatives, especially those mentioned in patent US 5 624 663; benzimidazole derivatives; imidazolines; p- aminobenzoic acid (PABA) derivatives; benzotriazole derivatives; methylenebis- (hydroxyphenylbenzotriazole) derivatives as described in patent applications US 5 237 071 , US 5 166 355, GB 2 303 549, DE 197 26 184 and EP 893 1 19; ben- zoxazole derivatives as described in patent applications EP 0 832 642, EP 1 027 883, EP 1 300 137 and DE 101 62 844; screening polymers and screening silicones such as those described especially in patent application WO 93/04665; oc-alkylstyrene- based dimers, such as those described in patent application DE 198 55 649; 4,4- diarylbutadienes such as those described in patent applications EP 0 967 200, DE 197 46 654, DE 197 55 649, EP-A-1 008 586, EP 1 133 980 and EP 133 981 ; merocyanine derivatives such as those described in patent applications WO 04/006 878, WO 05/058 269 and WO 06/032 741 ; the indanylidene screening agents of pat- ents EP-A-0 823 418 and EP-A-1 341 752. As examples of organic UV-screening agents, mention may be made of those denoted hereinbelow under their INCI name:

Dibenzoylmethane derivatives:

Butylmethoxydibenzoylmethane, sold under the trade name Parsol 1789 by the company DSM Nutritional Products. para-Aminobenzoic acid derivatives:

PABA,

Ethyl PABA,

Ethyl Di hydroxy propyl PABA,

Ethylhexyl dimethyl PABA sold in particular under the name Escalol 507 by ISP, Glyceryl PABA,

PEG-25 PABA sold under the name Uvinul P25 by BASF,

Salicylic derivatives:

Homosalate sold under the name Eusolex HMS by Rona/EM Industries,

Ethylhexyl salicylate sold under the name Neo Heliopan OS by Symrise,

Dipropylene glycol salicylate sold under the name Dipsal by Scher,

TEA salicylate sold under the name Neo Heliopan TS by Symrise.

Cinnamic derivatives:

Ethylhexyl methoxycinnamate sold especially under the trade name Parsol MCX by DSM Nutritional Products,

Isopropyl methoxycinnamate,

Isoamyl methoxycinnamate sold under the trade name Neo Heliopan E 1000 by Symrise,

Cinoxate,

DEA Methoxycinnamate,

Diisopropyl methylcinnamate,

Glyceryl ethylhexanoate dimethoxycinnamate

Merocyanine derivatives:

Octyl 5-N,N-diethylamino-2-phenylsulfonyl-2,4-pentadienoate. β, β-Diphenylacrylate derivatives:

Octocrylene sold especially under the trade name Uvinul N539 by BASF,

Etocrylene sold especially under the trade name Uvinul N35 by BASF, Benzophenone derivatives:

Benzophenone-1 sold under the trade name Uvinul 400 by BASF,

Benzophenone-2 sold under the trade name Uvinul D50 by BASF, Benzophenone-3 or Oxybenzone sold under the trade name Uvinul M40 by BASF, Benzophenone-4 sold under the trade name Uvinul MS40 by BASF,

Benzophenone-5,

Benzophenone-6 sold under the trade name Helisorb 1 1 by Norquay,

Benzophenone-8 sold under the trade name Spectra-Sorb UV-24 by American Cy- anamid,

Benzophenone-9 sold under the trade name Uvinul DS-49 by BASF,

Benzophenone-12,

n-hexyl 2-(4-diethylamino-2-hydroxybenzoyl)benzoate sold under the trade name Uvinul A+ or in the form of a mixture with octyl methoxycinnamate under the trade name Uvinul A + B by BASF,

Benzylidenecamphor derivatives:

3-Benzylidenecamphor manufactured under the name Mexoryl SD by Chimex, 4-Methylbenzylidenecamphor sold under the name Eusolex 6300 by Merck,

Benzylidenecamphorsulfonic acid manufactured under the name Mexoryl SL by Chimex,

Camphor benzalkonium methosulfate manufactured under the name Mexoryl SO by Chimex,

Terephthalylidenedicamphorsulfonic acid manufactured under the name Mexoryl SX by Chimex,

Polyacrylamidomethylbenzylidenecamphor manufactured under the name Mexoryl SW by Chimex, Phenylbenzimidazole derivatives:

Phenylbenzimidazolesulfonic acid sold in particular under the trade name Eusolex 232 by Merck,

Disodium phenyl dibenzimidazole tetrasulfonate sold under the trade name Neo Heliopan AP by Symrise.

Benzotriazole derivatives:

Drometrizole trisiloxane sold under the name Silatrizole by Rhodia Chimie, Methyle- nebis(benzotriazolyl)tetramethylbutylphenol sold in solid form under the trade name MIXXIM BB/100 by Fairmount Chemical, or in micronized form as an aqueous disper- sion under the trade name Tinosorb M by Ciba Specialty Chemicals.

Triazine derivatives:

Bis(ethylhexyloxyphenol)methoxyphenyltriazine sold under the trade name Tinosorb S by Ciba Geigy,

Ethylhexyltriazone sold in particular under the trade name Uvinul T150 by BASF,

Diethylhexylbutamidotriazone sold under the trade name Uvasorb HEB by Sigma 3V, 2,4-bis(n-butyl 4'-aminobenzalmalonate)-6-[(3-{1 ,3,3,3-tetramethyl-1 -[(trimethylsilyl)- oxy]disiloxanyl}propyl)amino]-s-triazine,

2,4,6-Tris(diisobutyl 4'-aminobenzalmalonate)-s-triazine,

2,4,6-Tris(dineopentyl 4'-aminobenzalmalonate)-s-triazine,

2,4-Bis(dineopentyl 4'-aminobenzalmalonate)-6-(n-butyl 4'-aminobenzoate)-s-triazine, the symmetrical triazine screening agents described in patent US 6 225 467, patent application WO 2004/085 412 (see compounds 6 and 9) or the document Symmetrical Triazine Derivatives IP.COM Journal, IP.COM INC West Henrietta, NY, US (20 September 2004), especially 2,4,6-tris(biphenyl)-1 ,3,5-triazines (in particular 2,4,6- tris(biphenyl-4-yl-1 ,3,5-triazine) and 2,4,6-tris(terphenyl)-1 ,3,5-triazine which is also mentioned in Beiersdorf patent applications WO 06/035 000, WO 06/034 982, WO 06/034 991 , WO 06/035 007, WO 2006/034 992 and WO 2006/034 985.

Anthranilic derivatives:

Menthyl anthranilate sold under the trade name Neo Heliopan MA by Symrise,

Imidazoline derivatives:

Ethylhexyldimethoxybenzylidenedioxoimidazoline propionate, Benzalmalonate derivatives:

Dineopentyl 4'-methoxybenzalmalonate,

Polyorganosiloxane containing benzalmalonate functions, for instance Polysilicone- 15, sold under the trade name Parsol SLX by DSM Nutritional Products. 4,4-Diarylbutadiene derivatives:

1 ,1 -Dicarboxy(2,2'-dimethylpropyl)-4,4-diphenylbutadiene,

Benzoxazole derivatives:

2,4-bis[5-1 (dimethylpropyl)benzoxazol-2-yl-(4-phenyl)imino]-6-(2-ethylh exyl)imino- 1 ,3,5-triazine, sold under the name of Uvasorb K2A by Sigma 3V,

and mixtures thereof.

The preferential additional organic screening agents are chosen from:

Ethylhexyl methoxycinnamate,

Homosalate,

Ethylhexyl salicylate,

Octocrylene,

Butylmethoxydibenzoylmethane

Terephthalylidenedicamphorsulfonic acid,

Disodium phenyldibenzimidazoletetrasulfonate,

Phenylbenzimidazolesulfonic acid, Benzophenone-3,

n-Hexyl 2-(4-diethylamino-2-hydroxybenzoyl)benzoate,

4-Methylbenzylidenecamphor,

Ethylhexyl triazone,

Bis(ethylhexyloxyphenol)methoxyphenyltriazine,

Diethylhexylbutamidotriazone,

2,4-bis(n-butyl 4'-aminobenzalmalonate)-6-[(3-{1 ,3,3,3-tetramethyl-1 -[(trimethylsilyl)- oxy]disiloxanyl}propyl)amino]-s-triazine,

2,4,6-Tris(biphenyl-4-yl)-1 ,3,5-triazine _!

2,4,6-Tris(dineopentyl 4'-aminobenzalmalonate)-s-triazine,

2,4,6-Tris(diisobutyl 4'-aminobenzalmalonate)-s-triazine,

2,4-Bis(dineopentyl 4'-aminobenzalmalonate)-6-(n-butyl 4'-aminobenzoate)-s-triazine,

Methylenebis(benzotriazolyl)tetramethylbutylphenol,

Drometrizole trisiloxane,

Polysilicone-15,

Dineopentyl 4'-methoxybenzalmalonate,

1 ,1 -Dicarboxy(2,2'-dimethylpropyl)-4,4-diphenylbutadiene,

2,4-Bis[5-1 (dimethylpropyl)benzoxazol-2-yl-(4-phenyl)imino]-6-(2-ethylh exyl)imin

1 ,3,5-triazine,

and mixtures thereof.

The mineral screening agents are chosen from coated or uncoated metal oxide pigments in which the mean size of the primary particles is preferentially between 5 nm and 100 nm (preferably between 10 nm and 50 nm), for instance titanium oxide (amorphous or crystallized in rutile and/or anatase form), iron oxide, zinc oxide, zirconium oxide or cerium oxide pigments, which are all UV-photoprotective agents that are well known per se.

The pigments may be coated or uncoated.

The coated pigments are pigments that have undergone one or more surface treatments of chemical, electronic, mechanochemical and/or mechanical nature with compounds as described, for example, in Cosmetics & Toiletries, February 1990, Vol. 105, pp. 53-64, such as amino acids, beeswax, fatty acids, fatty alcohols, anionic surfac- tants, lecithins, sodium, potassium, zinc, iron or aluminium salts of fatty acids, metal alkoxides (titanium or aluminium alkoxides), polyethylene, silicones, proteins (collagen, elastin), alkanolamines, silicon oxides, metal oxides or sodium hexametaphos- phate. As is known, silicones are organosilicon polymers or oligomers of linear or cyclic, branched or crosslinked structure, of variable molecular weight, obtained by polymeri- zation and/or polycondensation of suitably functionalized silanes, and consist essentially of a repetition of main units in which the silicon atoms are linked together via oxygen atoms (siloxane bond), optionally substituted hydrocarbon-based radicals being directly attached via a carbon atom to the said silicon atoms.

The term "silicones" also includes the silanes required for their preparation, in particular alkylsilanes.

The silicones used for the coating of the pigments suitable for the present invention are preferably chosen from the group consisting of alkylsilanes, polydialkylsiloxanes and polyalkylhydrosiloxanes. More preferably still, the silicones are chosen from the group containing octyltrimethylsilane, polydimethylsiloxanes and polymethylhydrosi- loxanes. Needless to say, before being treated with silicones, the metal oxide pigments may have been treated with other surface agents, in particular with cerium oxide, alumina, silica, aluminium compounds or silicon compounds, or mixtures thereof.

The coated pigments are more particularly titanium oxides that have been coated: - with silica, such as the product Sunveil from the company Ikeda and the product Eusolex T-AVO from the company Merck,

- with silica and iron oxide, such as the product Sunveil F from the company Ikeda,

- with silica and alumina, such as the products Microtitanium Dioxide MT 500 SA and Microtitanium Dioxide MT 100 SA from the company Tayca, Tioveil from the company Tioxide and Mirasun TiW 60 from the company Rhodia,

- with alumina, such as the products Tipaque TTO-55 (B) and Tipaque TTO-55 (A) from the company Ishihara and UVT 14/4 from the company Kemira,

- with alumina and aluminium stearate, such as the product Microtitanium Dioxide MT 100 TV, MT 100 TX, MT 100 Z and MT-01 from the company Tayca, and the products Solaveil CT-10 W, Solaveil CT 100 and Solaveil CT 200 from the company Uniqema,

- with silica, alumina and alginic acid, such as the product MT-100 AQ from the company Tayca,

- with alumina and aluminium laurate, such as the product Microtitanium Dioxide MT 100 S from the company Tayca,

- with iron oxide and iron stearate, such as the product Microtitanium Dioxide MT 100 F from the company Tayca,

- with zinc oxide and zinc stearate, such as the product BR351 from the company Tayca,

- with silica and alumina and treated with a silicone, such as the products Microtita- nium Dioxide MT 600 SAS, Microtitanium Dioxide MT 500 SAS or Microtitanium Dioxide MT 100 SAS from the company Tayca, - with silica, alumina and aluminium stearate and treated with a silicone, such as the product STT-30-DS from the company Titan Kogyo,

- with silica and treated with a silicone, such as the product UV-Titan X 195 from the company Kemira, or the product SMT-100 WRS from the company Tayca,

- with alumina and treated with a silicone, such as the products Tipaque TTO-55 (S) from the company Ishihara or UV Titan M 262 from the company Kemira,

- with triethanolamine, such as the product STT-65-S from the company Titan Kogyo,

- with stearic acid, such as the product Tipaque TTO-55 (C) from the company Ishihara,

- with sodium hexametaphosphate, such as the product Microtitanium Dioxide MT 150 W from the company Tayca.

Other titanium oxide pigments treated with a silicone are preferably Ti0 ₂ treated with octyltrimethylsilane and for which the mean size of the elementary particles is be- tween 25 and 40 nm, such as the product sold under the trade name T 805 by the company Degussa Silices, Ti0 ₂ treated with a polydimethylsiloxane and for which the mean size of the elementary particles is 21 nm, such as the product sold under the trade name 70250 Cardre UF Ti02SI3 by the company Cardre, anatase/rutile Ti0 ₂ treated with a polydimethylhydrosiloxane and for which the mean size of the elemen- tary particles is 25 nm, such as the product sold under the trade name Microtitanium Dioxide USP Grade Hydrophobic by the company Color Techniques.

The uncoated titanium oxide pigments are sold, for example, by the company Tayca under the trade names Microtitanium Dioxide MT 500 B or Microtitanium Dioxide MT 600 B, by the company Degussa under the name P 25, by the company Wacker under the name Transparent titanium oxide PW, by the company Miyoshi Kasei under the name UFTR, by the company Tomen under the name ITS and by the company Tioxide under the name Tioveil AQ. The uncoated zinc oxide pigments are, for example:

- those sold under the name Z-Cote by the company Sunsmart;

- those sold under the name Nanox by the company Elementis;

- those sold under the name Nanogard WCD 2025 by the company Nanophase Technologies.

The coated zinc oxide pigments are, for example:

- those sold under the name Z-Cote HP1 by the company Sunsmart (dimethicone- coated ZnO);

- those sold under the name Zinc Oxide CS-5 by the company Toshibi (ZnO coated with polymethylhydrosiloxane); - those sold under the name Nanogard Zinc Oxide FN by the company Nanophase Technologies (as a 40% dispersion in Finsolv TN, C12-C15 alkyl benzoate);

- those sold under the name Daitopersion ZN-30 and Daitopersion ZN-50 by the company Daito (dispersions in cyclopolymethylsiloxane/oxyethylenated polydimethyl- siloxane, containing 30% or 50% of nanozinc oxides coated with silica and poly- methylhydrosiloxane);

- those sold under the name NFD Ultrafine ZnO by the company Daikin (ZnO coated with perfluoroalkyl phosphate and copolymer based on perfluoroalkylethyl as a dispersion in cyclopentasiloxane);

- those sold under the name SPD-Z1 by the company Shin-Etsu (ZnO coated with si I icon e-g rafted acrylic polymer, dispersed in cyclodimethylsiloxane);

- those sold under the name Escalol Z100 by the company ISP (alumina-treated ZnO dispersed in an ethylhexyl methoxycinnamate/PVP-hexadecene/methicone copolymer mixture);

- those sold under the name Fuji ZnO-SMS-10 by the company Fuji Pigment (ZnO coated with silica and polymethylsilsesquioxane);

- those sold under the name Nanox Gel TN by the company Elementis (ZnO dispersed at a concentration of 55% in C12-C15 alkyl benzoate with hydroxystearic acid polycondensate).

The uncoated cerium oxide pigments are sold, for example, under the name Colloidal Cerium Oxide by the company Rhone-Poulenc.

The uncoated iron oxide pigments are sold, for example, by the company Arnaud un- der the names Nanogard WCD 2002 (FE 45B), Nanogard Iron FE 45 BL AQ, Nanogard FE 45R AQ and Nanogard WCD 2006 (FE 45R) or by the company Mitsubishi under the name TY-220,

The coated iron oxide pigments are sold, for example, by the company Arnaud under the names Nanogard WCD 2008 (FE 45B FN), Nanogard WCD 2009 (FE 45B 556), Nanogard FE 45 BL 345 and Nanogard FE 45 BL or by the company BASF under the name Transparent Iron Oxide.

Mention may also be made of mixtures of metal oxides, especially of titanium dioxide and of cerium dioxide, including the silica-coated equal-weight mixture of titanium dioxide and of cerium dioxide, sold by the company Ikeda under the name Sunveil A, and also the alumina, silica and silicone-coated mixture of titanium dioxide and of zinc dioxide, such as the product M 261 sold by the company Kemira, or the alumina, silica and glycerol-coated mixture of titanium dioxide and of zinc dioxide, such as the prod- uct M 21 1 sold by the company Kemira. The UV-screening agents are generally present in the compositions according to the invention in proportions ranging from 0.01 % to 20% by weight relative to the total weight of the composition, and preferably ranging from 0.1 % to 10% by weight relative to the total weight of the composition.

This composition may be in any galenical form normally used in the cosmetic or pharmaceutical field, and especially in the form of an optionally gelled aqueous or aqueous-alcoholic solution, a dispersion, optionally a two-phase dispersion, of the lotion type, an emulsion obtained by dispersion of a fatty phase in an aqueous phase (O/W) or vice versa (W/O), or a triple (W/O/W or 0/W/O) emulsion or a vesicular dispersion of ionic and/or nonionic type; aqueous or oily gels. These compositions are prepared according to the usual methods. According to this invention, a composition in the form of an emulsion, especially an oil-in-water or water-in-oil emulsion, is preferably used. The composition may be more or less fluid and may have the appearance of a white or coloured cream, an ointment, a milk, a lotion, a serum, a paste, a gel or a mousse. It may optionally be applied in aerosol or spray form. It may also be in solid form, for example in stick form.

When the composition is an emulsion, the proportion of the fatty phase may range from 5% to 80% by weight and preferably from 8% to 50% by weight relative to the total weight of the composition. The emulsifier and the coemulsifier may be present in a proportion ranging from 0.3% to 30% by weight and preferably from 0.5% to 20% by weight relative to the total weight of the composition.

The composition according to the invention may constitute a makeup composition, preferably a skincare composition, and especially a cleansing, protecting, treating or care cream for the face, the hands, the feet, the major anatomical folds or the body (for example day creams, night creams, makeup-removing creams, foundation creams or anti-sun creams); a fluid foundation, a makeup-removing milk, a protective or care body milk or an anti-sun milk; a skincare lotion, gel or mousse, such as a cleansing lotion.

The composition according to the invention is advantageously an anti-ageing, in particular care, composition intended for treating and/or combating, cosmetically, the external signs of skin ageing; the composition is more particularly a care composition for mature skin.

The invention is illustrated in greater detail by the following non-limiting examples. Example 1 : Synthesis of 1 -(C-[3-D-glucopyranosyl)-4-(3-methoxy-4-hvdroxy- phenyl)butan-2-one (compound 1 )

3.6 mmol of glucose were solubilized in 25 ml of an H ₂ 0/EtOH mixture (in a ¼ volume or weight ratio); after solubilization, 5.4 mmol of tetrahydrocurcumin (1 .5 eq.) were added, then 14 mmol (4 eq.) of sodium hydrogen carbonate were added,. The mixture was stirred for 12 hours at 90°C. The reaction medium was then concentrated in order to result in an oily yellow mixture which was solubilized in 30 ml of water and extracted with 3 x 30 ml of CH ₂ CI ₂ then with 3 x 30 ml of diethyl ether. The aqueous phase was concentrated, then filtered over a cake of silica, and eluted with a 90/10 Ch^C /MeOH mixture. Compound 1 was obtained with a yield of 68%. The ¹ H and ¹³ C NMR analyses are in accordance with the expected structure. Example 2: Synthesis of 1 -(C-[3-D-glucopyranosyl)-4-(3-methoxy-4-hvdroxy- phenvPbutan-1 -ol (compound 2)

3 mmol (1 .1 g) of compound 1 from Example 1 were solubilized in 30 ml of methanol, then 4 mmol (1 .3 eq.) of NaBH ₄ were added and the mixture was stirred for 3 hours at ambient temperature (23°C). 30 ml of acetone were then added and the stirring of the reaction medium was maintained for 1 hour at ambient temperature. The reaction mixture was filtered over a bed of silica and eluted with the CH ₂ Cl ₂ /MeOH (8/2) mixture. The filtrate was concentrated under vacuum, taken up in 20 ml of water, then acidified to pH 2-3 with a 1 N HCI aqueous solution. This solution was then extracted with 2 ^χ 30 ml of CH ₂ CI ₂ , then with 2 ^χ 30 ml of diethyl ether. The aqueous phases were combined, concentrated, then purified over silica gel with a CH ₂ Cl ₂ /MeOH (9/1 ) eluent; the yellow oil obtained was taken up in a minimum amount of water in order to be freeze- dried. Compound 2 was then obtained in the form of a white powder with a yield of 61 %. The ¹ H and ¹³ C NMR analyses are in accordance with the expected structure.

Example 3: Synthesis of 1 -(C-3-D-xylopyranosyl)-4-(3-methoxy-4-hvdroxy- phenyl)butan-2-one (compound 6)

In 50 ml of anhydrous methanol, 5 g (1 eq.) of C-3-D-xylopyranoside-n-propan-2-one were reacted with sodium methylate at 30% in methanol (7.55 ml, 1 .5 eq.), then 6.69 g (1 .05 eq.) of 4-benzyloxy-3-methoxybenzaldehyde were added.

The reaction medium was stirred for 15 hours at ambient temperature (25°C), then was diluted in dichloromethane and then washed with an aqueous solution of NH ₄ CI. The organic phase was then dried over sodium sulphate and then concentrated under vacuum. The light brown oil obtained was purified over silica gel so as to obtain the corresponding intermediate (B) (pale yellow solid, yield of 30%).

The reaction intermediate (B) obtained (2 g, 1 eq.) was solubilized in a water/ethanol mixture (5 ml/50 ml). Palladium-on-carbon at 10% (400 mg, 0.78 equivalent) was then added, as was cyclohexene (10 ml, 20.5 equivalents). The reaction medium was brought to reflux for 5 hours, and then left to cool to ambient temperature so as to be filtered and concentrated under vacuum. Thus, 1.57 g (1 .57 g, slightly greenish- yellow oil) corresponding to compound 6 were obtained.

The NMR, NMR and mass spectra are in accordance with the structure of the expected product.

Example 4: Synthesis of 1 -( C-3-D-xylopyranosyl)-2-hvdroxy-4-(3-methoxy- 4-hydroxyphenyl)butane (compound 5)

Compound 6 obtained in Example 3 (1 .57 g, 1 eq.) was solubilized in ethanol (20 ml) and then sodium borohydride (0.182 g, 1 eq.) was added in small portions. The medium was stirred at ambient temperature for 12 hours. Acetone was then added in order to destroy the excess sodium borohydride, followed by aqueous hydrochloric acid (1 N) in order to adjust the pH to 2. The reaction medium was then concentrated under vacuum, taken up in water and then washed twice with ethyl acetate. The aqueous phase was then extracted with butanol, and the organic phases were combined and concentrated under vacuum. The crude product obtained was purified over silica gel in order to obtain 0.53 g (yield of 34%) of a slightly yellow oil corresponding to the pure compound 5. The NMR, NMR and mass spectra are in accordance with the structure of the expected product. Example 5: Evaluation of the antioxidant activity of the compounds of the invention with respect to a UVA-induced oxidative stress on keratinocytes.

The technique for evaluating the antioxidant activity of the compounds used according to the invention is carried out in accordance with a well-known method (J. of Photo- chemistry and Photobiology B: Biology 57 (2000) 102-1 12 TOBI et a/.: Glutathione modulates the level of free radicals produced in UVA-irradiated cells). This technique uses a fluorescent probe, a marker of the intracellular overall oxidative stress, 2'-7'- dichlorofluorescin diacetate (DCFH-DA). PRINCIPLE

The use of DCFH-DA as a marker of the oxidative stress is based on its physico- chemical properties. It is an apolar and nonionic molecule capable of diffusing through cell membranes. Once inside the cell, DCFH-DA will be hydrolysed by intracellular esterases to give a non-fluorescent compound: DCFH or 2,7- dichlorofluorescin. In the presence of activated oxygen species, DCFH is rapidly oxidized to give a highly fluorescent compound: DCF or 2,7-dichlorofluorescein.

PROCEDURE: 1 . Treatment of the keratinocytes with a compound of formula (I)

At confluence, the keratinocytes are incubated in the presence of the compound to be tested of formula (I) for 24 hours at 37°C, 5% C0 ₂ , in the culture medium, according to a dose effect (3 concentrations). 2. Incorporation of DCFH-DA

The keratinocytes, pretreated with the compound tested, are rinsed then incubated in the presence of DCFH-DA in the dark.

3. Exposure to UVA After this incubation, the DCFH-DA solution is removed, the cells are then exposed to 2 J/cm ² of UVA.

Observation: an unexposed control plate is stored in the dark at room temperature. 4. Measurement of the fluorescence

The fluorescence of DCF is evaluated immediately after the exposure to UVA, by spectrofluorimetry (excitation: 480 nm; emission: 530 nm).

5. Results:

The results are expressed in Table 1 below, as % of fluorescence relative to the control cells exposed to UVA. The measurement is carried out on 8 samples and the average value is determined.

Table 1

The above results reveal an antioxidant activity of the compound from Example 2 with respect to the UVA-induced oxidative stress with around 21 % protection against UVA- induced oxidative stress.

Thus, the compounds of formula (I) according to the invention induce an active photo- protection of the skin with respect to the untreated control.

Example 6

A face care cream of oil-in-water emulsion type is prepared, comprising (% by weight): Compound from Example 2 0.005% Glyceryl stearate 2% Polysorbate 60 (Tween 60 from ICI) 1 % Stearic acid 1 .4%

Triethanolamine 0.7%

Carbomer 0.4%

Liquid fraction of shea butter 12% Perhydrosqualene 12%

Antioxidant qs

Fragrance, preservative qs Water qs 100%

A similar composition is prepared with the compounds from Examples 1 , 3 and 4.

After application to the face, the composition makes it possible to protect the skin from UVA-induced stress.

Example 7

An anti-ageing gel for the skin is prepared, comprising (% by weight):

Compound from Example 2 2%

Hydroxypropyl cellulose (Klucel H from Hercules) 1 % Antioxidant qs

Fragrance, preservative qs

Isopropanol 40%

Water qs 100%

A similar composition is prepared with the compound from Examples 1 , 3 and 4.

After application to the face, the composition makes it possible to protect the skin from UVA-induced stress.

Example 8

A sun composition is prepared, comprising: - Cyclohexadimethylsiloxane 3%

- Mixture of dimethicone copolyol, cyclopentasiloxane and water

(10/88/2) (DC 5225C from Dow Corning) 1 %

- α,ω-Dihydroxylated polydimethylsiloxane/cyclopentadimethylsiloxane mixture (14.7/85.3) (Dow Corning 1501 FL from Dow Corning) 2%

- 15 nm titanium dioxide (MICRO TITANIUM DIOXIDE MT-100 T V from Tayca) 1 %

- acrylic acid/stearyl methacrylate copolymer polymerized

in an ethyl acetate/cyclohexane mixture

(PEMULEN TR-1 POLYMER from Noveon) 0.4%

Propylene glycol 6%

Glycerol 6%

C12/C15 alkyl benzoate (TEGOSOFT TN from Goldschmidt) 4% Butylmethoxidibenzoylmethane 2.5%

Ethylhexyl triazone 2%

2-Ethylhexyl 2-cyano-3,3-diphenylacrylate 10%

Drometrizole trisiloxane 4%

Ethanol 18%

Compound from Example 2 0.5%

Water qs 100% A similar composition is prepared with the compound from Examples 1 , 3 and 4.

After application to the face, the composition makes it possible to protect the skin from UVA-induced stress.