WO2013045704A2

WO2013045704A2 - Dye composition comprising a glycosyl iridoid compound and a particular aldehyde or imine, dyeing process and devices therefor

Info

Publication number: WO2013045704A2
Application number: PCT/EP2012/069366
Authority: WO
Inventors: Hervé David; Gwenaëlle JEGOU
Original assignee: L'oreal
Priority date: 2011-09-29
Filing date: 2012-10-01
Publication date: 2013-04-04
Also published as: JP2014528401A; FR2980705A1; WO2013045704A3; JP6612027B2; KR102071728B1; FR2980705B1; KR20140072150A

Abstract

The present invention relates to a composition for dyeing human keratin fibres, comprising, in a cosmetically acceptable medium: * a compound of the iridoid family of formula (I) below, or a plant extract comprising the same: in which R₁: hydrogen, methyl, hydroxymethyl, aldehyde; -CO₂R₄ in which R₄: hydrogen, C₁-C₂ alkyl; sugar; R₂: a hydrogen atom, a hydroxyl radical, sugar radical; R₃: hydrogen, hydroxyl, alkyloxy; R: sugar radical (aldose or derivative); integer ranging from 1 to 5; the compound(s) of formula (I) having optionally undergone a preliminary step consisting in replacing the radical R with a hydrogen atom, performed using an enzyme; ** at least one aldehyde or imine compound of formulae (i) and (ii), and also oxidized oligo- or polysaccharide comprising at least one aldehyde or imine function: with n equal to 0 or 1; X: O, NR'₁; A: COOH, optionally substituted aryl, cationic or non-cationic, saturated or unsaturated 5- or 6-membered heterocycle, comprising one or two heteroatoms, optionally substituted, alkyl, alkenyl; A2 divalent alkylene; the compounds possibly being, in the case of aldehydes, in acetal or hemiacetal form. The invention also relates to a process using such a composition, and also to multi-compartment devices.

Description

DYE COMPOSITION COMPRISING A GLYCOSYL IRIDOID COMPOUND AND A PARTICULAR ALDEHYDE OR IMINE, DYEING PROCESS AND DEVICES THEREFOR

The present invention relates to a dye composition comprising, in a cosmetically acceptable medium, at least one compound from the glycosyl iridoid family extracted from plants, optionally deglycosylated beforehand, and at least one particular aldehyde or imine compound, and also to a dyeing process using such a composition.

Increasing interest has been shown in recent years for natural compounds that can be used as hair dyes.

For example, patent application EP 440 494 discloses a hair dyeing process using a composition comprising at least one compound of (seco)iridoid-glycoside or non-glycosyl (seco)iridoid (also known as aglycone), extracted from plants such as Rubiaceae, Euphorbiaceae, Valerianaceae, Cornaceae, Gentianaceae, Caprifoliaceae, Oleaceae, Ericaceae, Loganiaceae, etc.

The problem encountered with such colorations is that they are not particularly strong or require repeated application of the composition over several days or several weeks in order to obtain a satisfactory coloration.

Furthermore, it is difficult to achieve natural shades, which is a desired advantage. What is more, when such shades are achieved, it is not uncommon to observe a substantial colour change over time.

The aim of the present invention is thus to overcome the drawbacks described above.

Specifically, it has been discovered, surprisingly, that the colour build-up can be substantially improved using compounds of non-glycosyl iridoid type and derivatives thereof, and, in general, any natural extract containing the same, by combining this compound with a particular aldehyde or imine compound.

It has also been found that the structure of treated fibres is not impaired by the coloration according to the invention.

One subject of the present invention is thus a composition for dyeing human keratin fibres comprising, in a cosmetically acceptable medium:

^* a compound of the iridoid family of formula (I) below, optical or geometrical isomers thereof, mineral or organic acid salts thereof, solvates thereof, or a plant extract comprising the same:

in which:

Ri represents a hydroxymethyl radical, a group -CO2R4 in which R₄ represents a hydrogen atom or a CrC₂ alkyl radical; a sugar radical;

R₂ represents a hydrogen atom, a hydroxyl radical or a sugar radical;

R₃, which may be identical or different, represent a hydrogen atom, a hydroxyl radical, a (CrC₄)alkyloxy radical; the number of hydroxyl groups not being greater than 2;

R represents a sugar radical;

n is an integer between 1 and 5;

the sugar radical is a derivative obtained from an aldose or an aldose derivative: the compound(s) of formula (I) having optionally undergone a preliminary step that consists in replacing the radical R with a hydrogen atom, performed by means of an enzyme;

** at least one aldehyde or imine compound chosen from the following formulae (i) and (ii) below, optical or geometrical isomers thereof, organic or mineral acid salts thereof, solvates thereof, and also oxidized oligo- or polysaccharide comprising at least one aldehyde or imine function:

(i) (ii)

in which formulae (i) and (ii):

m is an integer equal to 0 or 1 ,

X represents an oxygen atom, NR"-i with R' representing a hydrogen atom or a C1-C10 alkyl radical;

when X represents an oxygen atom, the compounds may also be:

o in the form of a 5- or 6-membered cyclic or acyclic acetal resulting from the condensation of an additional primary monoalcohol (R'₃OH) in which R'₃ represents a C1-C5 alkyl radical or a symmetrical 1 ,2- or 1 ,3-diol containing a C₂-C₃ alkyl chain, o in the form of a hemiacetal resulting from the condensation of a hydroxyl group present on A or A-i when A or A-i represents an alkyl radical and when n is equal to 0;

the radicals R'i and R'₂, independently of each other, represents a hydrogen atom or an unsubstituted linear Ci-C₆ alkyl radical;

the monovalent radical A and divalent radical A-i represent a group chosen from:

^* a hvdroxycarbonyl group (-CO-OH):

^* a CR aryl group optionally substituted with at least:

a hydroxyl group,

- a C1-C4 alkyl radical,

an aryl-ethylenyl radical, the aryl group being C₆ and optionally substituted with at least one C1-C2 alkyl or C1-C2 alkoxy radical,

a group -CO-OR 4 or -O-COR 4 in which R'₄ represents a C1-C2 alkyl radical or a phenyl group;

- a group -COOH, in acid or salified form,

a group -OR'₅ in which R'₅ represents a Ci-C₈ alkyl radical optionally substituted with at least one hydroxyl group, an ammonium group -N⁺R"₆ with R"₆, which may be identical or different, representing a C C₂ alkyl radical, a group -SiR'₇ with R'₇, which may be identical or different, representing a C C₂ alkyl radical; a benzyl radical (-CH₂-C₆H₆),

according to one particular variant, two radicals -OR'₅ located ortho to the C₆ aryl group may form a 5- or 6-membered heterocycle by means of the two radicals R'₅,

a group -N(R'₈)₂ in which R'₈, which may be identical or different, represent a Ci-C₆ alkyl radical optionally substituted with a hydroxyl group, a carboxylic group (-COOH) in acid or salified form, or a sulfonic group (-S0₃H) in acid or salified form; the radicals R'₈ possibly forming a saturated or unsaturated 5- or 6- membered heterocycle with the nitrogen atom that bears them, optionally comprising another heteroatom chosen from O, N and NR'₉ in which R'₉ represents a Ci-C₂ alkyl radical; the heterocycle being optionally substituted with a hydroxyl group,

a group -COR'10 in which R'₁₀ represents a C₆ aryl group fused to a 6-membered hydrocarbon-based ring optionally substituted with at least one C C₂ alkyl radical,

- an -SR'n in which R'n represents a C C₂ alkyl radical, a halogen atom preferably chosen from chlorine and bromine, a group -0-S0₂-C₆H₆,

a group -S0₃H,

an unsaturated cationic or non-cationic 5- or 6-membered heterocycle comprising one or two heteroatoms chosen from O, N and NR'₁₂ in which R'₁₂ represents a C C₂ alkyl group optionally fused to a saturated or unsaturated, aromatic or non-aromatic 5- or 6-membered ring, one of the heteroatoms possibly being included in the two rings; the heterocycle or the fused ring possibly being substituted with at least one Ci-C₂ alkoxy radical,

the said aryl group being optionally fused to a 5- or 6-membered heterocyclic group, comprising one or two heteroatoms chosen from O, N and NR'₁₃ in which R'₁₃ represents a CrC₄ alkyl radical, the heterocycle being optionally fused to a C₆ aryl group,

the said aryl group being optionally fused to a C₆ aryl group optionally substituted with at least one Ci-C₂ alkoxy group;

* a cationic or non-cationic, saturated or unsaturated, aromatic or non- aromatic 5- or 6-membered heterocyclic group, comprising one or two identical or different heteroatoms preferably chosen from O, N and NR'₁₄ with R'₁₄ representing a hydrogen atom, a Ci-C₆ alkyl radical or a C₆ aryl radical optionally substituted with a group (R'i₅)₂NCO- or (R'₁₅)CO-NH- in which R'₁₅, which may be identical or different, represent a Ci-C₂ alkyl radical;

the said heterocyclic group being optionally fused to a 6-membered aryl group which is itself optionally substituted with at least one C C₂ alkyl, d-C₄ alkoxy or phenoxy group;

the said heterocyclic group being optionally substituted with at least: o a hydroxyl group,

o a Ci-C₂ alkyl radical optionally substituted with a hydroxyl radical; o an amino radical -N(R'₁₆)2 in which R'₁₆, which may be identical or different, represent a C C₄ alkyl radical optionally substituted with a hydroxyl group, the radicals R'i₆ possibly forming a saturated or unsaturated 5- or 6- membered heterocycle with the nitrogen atom that bears them, optionally comprising another heteroatom chosen from O, N and NR'₁₇ in which R'₁₇ represents a C C₂ alkyl radical;

o a C₆ aryl radical optionally substituted with at least one group -COOH, R'₁₈CONH- with R'₁₈ representing a C C₂ alkyl radical; the said C₆ aryl radical being optionally linked to a nitrogen atom of the heterocyclic group; when the aryl radical is not substituted with a radical mentioned previously, the carbon atoms are substituted with a hydrogen atom;

^* a linear or branched C-rC-in alkyl radical, or a C?-C n alkenyl radical, comprising one or more conjugated or non-conjugated carbon-carbon double bonds; the said alkyl or alkenyl radical being optionally substituted with at least one hydroxyl group;

the divalent radical A₂ represents a linear C-I-C-IO alkylene chain connecting two radicals A-i via a carbon, oxygen or nitrogen atom;

• the compounds of formulae (i) and (ii) comprising, where appropriate, a cosmetically acceptable anion or mixture of anions An, ensuring the electrical neutrality of the formulations. Another subject of the present invention is represented by a process for dyeing human keratin fibres, in which such a composition is used.

Another subject of the invention consists of a multi-compartment device comprising a first compartment containing at least one compound of formula (I) or the plant extract comprising the same, the said compound having undergone a preliminary step that consists in replacing the radical R with a hydrogen atom; and a second compartment containing at least one compound of formula (i) or (ii), an oxidized oligo- or polysaccharide comprising at least one aldehyde or imine function.

Another subject also consists of a multi-compartment device comprising a first compartment containing at least one compound of formula (I) or the plant extract comprising the same; and a second compartment containing at least one compound of formula (i) or (ii), an oxidized oligo- or polysaccharide comprising at least one aldehyde or imine function, and an enzyme for replacing the radical R of formula (I) with a hydrogen atom.

Lastly, a final subject of the invention is represented by a multi-compartment device comprising a first compartment containing at least one compound of formula (I) or the plant extract comprising the same; and a second compartment containing at least one compound of formula (i) or (ii), an oxidized oligo- or polysaccharide comprising at least one aldehyde or imine function; and a third compartment containing an enzyme for replacing the radical R of formula (I) with a hydrogen atom. The composition according to the invention makes it possible to obtain varied, shampoo-fast colorations, which do not degrade the hair.

Other features and advantages of the invention will become more clearly apparent on reading the description and the examples that follow.

It should be noted that, unless otherwise indicated, the limits of the ranges of values given in the description are included within the ranges.

The human keratin fibres treated via the process according to the invention are preferably the hair.

In the text hereinbelow, the terms "at least one" and "one or more" are considered as being synonymous.

The mineral acid salts are more particularly hydrochlorides, hydrobromides, sulfates and phosphates; the organic acid salts are more particularly citrates, succinates, tartrates, lactates, tosylates, benzenesulfonates and acetates.

The solvates are more particularly hydrates.

Compounds of formula (I) or plant extract comprising the same As indicated previously, the composition comprises, in a cosmetically acceptable medium, at least one compound of the abovementioned formula (I), or a plant extract comprising the same. Preferably, Ri represents a hydrogen atom, a hydroxymethyl radical, a hydroxycarbonyl radical, a methoxycarbonyl group or an ethoxycarbonyl group.

Preferably, R₂ represents a hydrogen atom or a hydroxyl radical.

Preferably, R₃, which may be identical or different, represent a hydrogen atom, a hydroxyl group, a methoxy group, an ethoxy group or an n-butyloxy group.

Preferably, R represents a radical derived from a C₆ aldose, such as allose, altrose, galactose, glucose, gulose, idose, mannose or talose, preferably glucose. As regards the aldose derivatives, the deoxy derivatives are preferred, for instance rhamnose, and also diholosides, in particular maltose.

In accordance with an even more particular embodiment of the invention, R represents a radical derived from glucose, rhamnose or maltose, and preferably derived from glucose.

In accordance with a particularly advantageous embodiment of the invention, the compound of formula (I) is geniposide (Ri represents a methoxycarbonyl group) or geniposic acid or a salt thereof (Ri represents a hydroxycarbonyl group in acid or salified form).

The compounds of formula (I) are generally found in plant extracts originating from the following plants: Abelia grandiflora, Adenorandia kalbreyeri, Adina polycephala, Aeginetia indica var. gracilis, Asperula sp, Asystasia bella, Aucuba japonica, Avicennia marina, Bartsia trixago, Buddleja Americana, Buddleja crispa, Buddleja japonica, Canthium schimperianum, Castilleja wightii, Chaenorhinum minus, Clerodendrum serratum, Coprosma sp, Cornus officinalis, Craibiodendron henryi, Cremaspora triflora, Crucianella sp, Daphniphyllum calycinum, Daphniphyllum humile, Daphniphyllum macropodum, Eremostachys glabra, Escallonia sp, Eucommia ulmoides, Feretia apodanthera, Galium humifusum, Galium verum, Gardenia jasminoides, Garrya elliptica, Globularia dumulosa, Hedyotis corymbosa, Hygrophila difformis, Ixeris chinensis, Lamiastrum galeobdolon (Lamium galeobdolon), Lamiophlomis rotata (Phlomis rotata), Leonotis nepetaefolia, Linaria sp, Morinda coreia, Mussaenda pubescens, Nepeta cilicia, Nepeta nuda ssp. Albiflora, Odeontites verna, Oldenlandia corymbosa, Paederia scandens, Pedicularis chinensis, Pedicularis condensata, Pedicularis dolichocymba, Penstemon confertus, Penstemon deutus, Penstemon richardsonii, Penstemon serrulatus, Pithecoctenium crucigerum, Plantago alpina, Plantago carinata, Plantago lagopus, Plantago lanceolata, Plantago subulata, Premna barbata, Randia dumetorum, Rhododendron latoucheae, Rothmannia withfieldii, Rubia peregrina, Rubia tinctorum, Saprosma scortechinii, Scrophularia korainensis, Scrophularia lepidota, Scrophularia ningpoensis, Scyphiphora hydrophyllacea, Swida controversa, Syringa vulgaris, Tarenna kotoensis, Tecoma heptaphylla, Thevetia gaumeri, Thevetia peruviana, Verbascum laxum, Verbascum nigrum, Verbascum phlomoides, Verbascum salviifolium, Verbascum sinuatum, Verbascum thapsus, Verbascum undulatum, Veronica derwentiana, Vitex nigrum, Wendlandia formosana.

Preferably, the plant extract used is Gardenia jasminoides.

It should be noted that the term "extract" denotes juices or powders obtained via one or more extraction, enrichment or concentration operations and optionally drying, starting with natural plant substances.

These compounds of formula (I) are extracted from plants, in a manner known per se.

Thus, in the case of the aerial parts, they are washed, if necessary, ground and then macerated in a suitable solvent, in particular ethanol or water, and then filtered, concentrated and optionally dried.

In the more particular case of fruit, it is optionally frozen, and washed with water to remove the impurities present. They may optionally be sterilized, in particular with a solution comprising ethanol and chlorine.

For the actual extraction, the fruit is thawed, if necessary, and pressed, for example using a specially adapted hydraulic press.

The juice recovered may then, where appropriate, undergo a step of concentration and drying.

In the case of Gardenia jasminoides, commercial extracts with varied contents of compound of formula (I) exist.

The content of compound of formula (I) in the dry extract ranges from 0.1 % to 70% by weight.

The content of compound of formula (I) in the composition is between 0.001 % and 10% by weight relative to the weight of the composition.

It should be noted that the compound(s) of formula (I) have undergone, prior to or simultaneously with the dyeing process, a step consisting in replacing the radical R with a hydrogen atom.

This reaction may be performed by any means known to those skilled in the art and may especially be performed using an enzyme chosen, for example, from isolase and β- glucosidase derived, for example, from sweet almond (EEC 3.2.1 .21 ).

Thus, in the case where the operation takes place simultaneously with the dyeing process, the enzyme is added to the composition just before its application to the fibres.

In the case where the operation takes place before the application to the fibres, the enzyme is added to a buffered (acetate, pH between 5.5 and 6) aqueous solution of compound of formula (I). Preferably, the concentration of compound of formula (I) ranges between 10 and 30 mM. The enzyme is generally used at a concentration ranging between 5-100 units/ml (one enzymatic unit and is in general defined by the number of μηηοΙ of substrate hydrolysed per minute). The operation usually takes place at a temperature close to room temperature (between 20 and 45°C) and over a period ranging from 1 to 5 hours.

The reaction product may be used directly, or alternatively the compound obtained may be extracted, for example by employing a solvent such as ethyl acetate.

Additional dyes

The dye composition may also contain additional dyes other than the above- mentioned compounds of formula (I).

Among these additional dyes, mention may be made of natural or synthetic direct dyes, oxidation dyes with bases optionally combined with couplers, and also combinations thereof.

These direct dyes may be chosen, for example, from neutral, acidic or cationic nitrobenzene direct dyes, neutral, acidic or cationic azo direct dyes, tetraazapentamethine dyes, neutral, acidic or cationic quinone and in particular anthraquinone dyes, azine direct dyes, triarylmethane direct dyes, indoamine direct dyes and natural direct dyes.

Among the natural direct dyes, mention may be made of lawsone, juglone, alizarin, purpurin, carminic acid, kermesic acid, purpurogallin, anthragallol protocatechaldehyde, indigo, isatin, curcumin, spinulosin, apigenidin, chlorophylls, chlorophyllines, orceins, hematin, hematoxylin, brazilin, brazileine, safflower colorants (for instance carthamine), flavonoids (with, for example, morin, apigenidin and sandalwood), anthocyans (such as apigeninidin), carotenoids, tannins, sorghum and cochineal carmine, or mixtures thereof. Extracts or decoctions containing these natural dyes and in particular henna-based poultices or extracts, may also be used.

Among the oxidation bases, mention may be made of para-phenylenediamines, bis(phenyl)alkylenediamines, para-aminophenols, bis-para-aminophenols, ortho- aminophenols and heterocyclic bases, and the addition salts thereof.

Among these couplers, mention may be made especially of meta- phenylenediamines, meta-aminophenols, meta-diphenols, naphthalene couplers and heterocyclic couplers, and the addition salts thereof.

The oxidation base(s) present in the dye composition are each generally present in an amount of between 0.001 % and 10% by weight and preferably between 0.005% and 6% by weight relative to the total weight of the dye composition.

The coupler(s) are each generally present in an amount of between 0.001 % and 10% by weight and preferably between 0.005% and 6% by weight relative to the total weight of the dye composition.

In general, the addition salts of the oxidation bases and couplers that can be used within the context of the invention are especially chosen from the addition salts with an acid such as the hydrochlorides, hydrobromides, sulfates, citrates, succinates, tartrates, lactates, tosylates, benzenesulfonates, phosphates and acetates.

Aldehyde/imine compounds As indicated previously, the composition also comprises at least one aldehyde or imine compound chosen from the abovementioned formulae (i) and (ii), and also oxidized oligo- or polysaccharide comprising at least one aldehyde or imine function. According to a first variant of the invention, the compounds of formulae (i) and (ii) are such that X represents an oxygen atom.

Compounds (i) and (ii) may also be in the form of a 5- or 6-membered cyclic or acyclic acetal resulting from the condensation of an additional primary monoalcohol (R'₃OH) in which R'₃ represents a CrC₅ alkyl radical or a symmetrical 1 ,2- or 1 ,3-diol containing a C₂-C₃ alkyl chain.

These compounds may also be in the form of a hemiacetal resulting from the condensation of a hydroxyl group present on A or A-i when A or A-i represents an alkyl radical and when n is equal to 0. It should be noted that the electrical neutrality of formulae (i) and (ii), is verified, if necessary, by means of an organic or mineral anion or mixture of anions that can equilibrate the charge(s) of the said compounds, selected, for example, from a halide such as chloride, bromide, fluoride or iodide; a hydroxide; a sulfate; a hydrogen sulfate; an alkyl sulfate in which the linear or branched alkyl moiety is Ci-C₆, such as the methyl sulfate or ethyl sulfate ion; carbonates and hydrogen carbonates; salts of carboxylic acids, such as formate, acetate, citrate, tartrate and oxalate; alkylsulfonates for which the linear or branched alkyl moiety is Ci-C₆, such as the methylsulfonate ion; arylsulfonates for which the aryl moiety, preferably phenyl, is optionally substituted by one or more C1-C4 alkyl radicals, such as, for example, 4-tolylsulfonate; and alkylsulfonates such as mesylate.

The nonionic or anionic oxidized polysaccharide comprise one or more aldehyde groups and optionally one or more anionic groups. These anionic groups are preferably carboxylic or carboxylate groups.

The nonionic or anionic oxidized polysaccharide used may be represented by formula (II) below:

P-(CHO)m (COOX)n (II)

in which:

P represents a polysaccharide chain consisting of monosaccharides comprising 5 carbon atoms or more than 5 carbon atoms, preferably 6 or more than 6 carbon atoms and more particularly 6 carbon atoms.

X is chosen from a hydrogen atom, the ions derived from an alkali metal or an alkaline- earth metal such as sodium or potassium, ammonia, organic amines such as monoethanolamine, diethanolamine, triethanolamine and 3-amino-1 ,2-propanediol and basic amino acids such as lysine, arginine, sarcosine, ornithine and citrulline,

m + n is greater than or equal to 1 , M is such that the degree of substitution of the polysaccharide with one or more aldehyde groups (DS(CHO)) is within the range from 0.001 to 2 and preferably from 0.005 to 1 .5. n is such that the degree of substitution of the polysaccharide with one or more carboxylic groups (DS(COOX)) is within the range from 0 to 2 and preferably from 0.001 to 1 .5.

The term "degree of substitution DS(CHO) or DS (COOX) of the polysaccharides according to the invention" means the ratio between the number of carbons oxidized as an aldehyde or carboxylic group for all the repeating units and the number of elemental monosaccharides (even opened by preoxidation) constituting the polysaccharide.

The groups CHO and COOX may be obtained during the oxidation of certain carbon atoms, for example in position C2, C3 or C6, of a saccharide unit containing 6 carbon atoms. Preferably, the oxidation may take place at C2 and at C3, more particularly from 0.01 % to 75% by number and preferably from 0.1 % to 50% by number of the rings having possibly been opened.

The polysaccharide chain, represented by P, is preferably chosen from inulins, celluloses, starches, pectins, guar gums, xanthan gums, pullulan gums, alginate gums, agar-agar gums, carrageenan gums, gellan gums, gum arables, xyloses and tragacanth gums, and derivatives thereof.

The term "derivative" means the compounds obtained by chemical modification of the mentioned compounds. They may be esters, amides or ethers of the said compounds.

The oxidation may take place according to a process known in the art, for example according to the process described in FR 2 842 200, in document FR 2 854 161 or in the article "Hydrophobic films from maize bran hemicelluloses" by E. Fredon et al., Carbohydrate Polymers 49, 2002, pages 1 to 12. Another oxidation process is described in the article "water soluble oxidized starches by peroxide reaction extrusion" Industrial Crops and Products 75 (1997) 45-52 - R. E. Wing, J. L. Willet. These oxidation processes are simple to perform, are efficient and do not generate any toxic by-products or byproducts that are difficult to remove.

The peroxide may be an alkali metal or alkaline-earth metal percarbonate or perborate, an alkyl peroxide, peracetic acid or hydrogen peroxide. The amount of peroxide in the reaction medium is generally between 0.05 and 1 molar equivalent per glucose unit of the polysaccharide.

A single phthalocyanin or a mixture of phthalocyanins, for example a mixture of cobalt phthalocyanin and of iron phthalocyanin, may be used as catalyst. The amount of catalyst depends on the desired degree of substitution. In general, a small amount, for example an amount corresponding to 0.003 to 0.016 molar equivalent per 100 glucose units of polysaccharide, is suitable for use.

The process may also be performed by placing the polysaccharide in pulverulent form in contact with the catalyst dissolved in a small volume of water and with the peroxide. This process is referred to as a "semi-dry" process.

More preferentially, the polysaccharide is obtained by oxidation of inulin, cellulose, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, methylcellulose, starch, starch acetate, hydroxyethyl starch, hydroxypropyl starch, guar gum, carboxymethyl guar gum, carboxymethylhydroxypropyl guar gum, hydroxyethyl guar gum, hydroxypropyl guar gum, xylose, xanthan gum or carrageenan gum, or mixtures thereof.

The polysaccharides that are the most particularly preferred in the invention are those corresponding to formula (II) in which P represents a polymer chain derived from inulin and from starch; m is such that the degree of substitution of the polysaccharide with one or more aldehyde groups (DS(CHO)) is within the range from 0.005 to 2.5; n is such that the degree of substitution of the polysaccharide with one or more carboxylic groups (DS(COOX)) is within the range from 0.001 to 2.

As examples of compounds of formulae (i) and (ii), oxidized oligo- and polysaccharide comprising at least one aldehyde or imine function, which are particularly suitable for performing the invention, mention may be made of the following compounds, salts thereof, isomers thereof and solvates thereof, these compounds being alone or as mixtures:

yde

y enza e y e e

Structure Chemical name Structure Chemical name

2-(pyrrolidin-1-

2-(1H-imidazol-1- yl)pyridine-3- yl)benzaldehyde a¹ carbaldehyde

oxidized starch

Preferably, the composition comprises at least one compound of formula (i).

Advantageously, formula (i) is such that:

^* m is 0 or 1 ;

* the radicals R'i and R'₂, independently of each other, represent a hydrogen atom or an unsubstituted linear Ci-C₆ alkyl radical;

^* X represents an oxygen atom;

A represents:

^* a linear or branched Cs-C n alkyl radical, optionally substituted with at least one hydroxyl group;

^* a C₂-C₈ alkenyl radical comprising a carbon-carbon double bond;

^* a hydroxycarbonyl group (-COOH);

^* a CR aryl group optionally substituted with at least:

o a hydroxyl group,

o a C1-C4 alkyl radical,

o a group -CO-OR 4 or -O-COR 4 in which R'₄ represents a C1-C2 alkyl radical,

o a group -OR'₅ in which R'₅ represents a Ci-C₆ alkyl radical, o an aryl-ethylenyl radical, the aryl group being C₆ and optionally substituted with at least one C1-C2 alkyl or d-C₂ alkoxy radical,

o an unsaturated cationic or non-cationic 5- or 6-membered heterocycle comprising one or two heteroatoms chosen from O, N and NR'₁₂ in which R'i₂ represents a C C₂ alkyl group optionally fused to a saturated or unsaturated, aromatic or non-aromatic 5- or 6-membered ring, one of the heteroatoms possibly being included in the two rings; the heterocycle or the fused ring possibly being substituted with at least one C C₂ alkoxy radical, - the said aryl group being optionally fused to a 5- or 6-membered heterocyclic group, comprising one or two heteroatoms chosen from O, N and N R'₁₃ in which R'₁₃ represents a Ci-C₄ alkyl radical;

^* a cationic or non-cationic, saturated or unsaturated, aromatic or non-aromatic 5- or 6-membered heterocyclic group, comprising one or two identical or different heteroatoms preferably chosen from O, N and N R'₁₄ with R'₁₄ representing a hydrogen atom, a CrC₆ alkyl radical or a C₆ aryl radical optionally substituted with a group (R'^NCO- or (R'i₅)CO-N H- in which R'₁₅ represent a CrC₂ alkyl radical;

- the said heterocyclic group being optionally fused to a 6-membered aryl group which is itself optionally substituted with at least one Ci-C₂ alkyl or C1-C4 alkoxy group;

- the said heterocyclic group being optionally substituted with at least:

o a hydroxyl group,

o a C1-C2 alkyl radical optionally substituted with a hydroxyl radical,

o an amino radical -N(R'₁₆)2 in which R'₁₆, which may be identical or different, represent a C1-C4 alkyl radical optionally substituted with a hydroxyl group, the radicals R'i₆ possibly forming a saturated or unsaturated 5- or 6-membered heterocycle with the nitrogen atom that bears them, optionally comprising another heteroatom chosen from O, N and N R'₁₇ in which R'₁₇ represents a CrC₂ alkyl radical,

^* the compounds of formula (i) comprising, where appropriate, a cosmetically acceptable anion or mixture of anions An, ensuring the electrical neutrality of the formulations;

^* the compound(s) of formula (i) possibly being in acetal or hemiacetal form, as described previously.

As examples of preferred compounds (i), mention may be made of the following compounds, isomers thereof, salts thereof or solvates thereof, these compounds being alone or as a mixture:

1 -butyl-1 H-indole-3- A¹ 2-hydroxy-3,4- dimethoxy-6- carbaldehyde methylbenzaldehyd e

More particularly, the content of compound(s) of formula (i) or (ii), or of oxidized oligo- or polysaccharide comprising at least one aldehyde or imine function is between 0.001 % and 30% by weight relative to the weight of the composition.

As examples of preferred oxidized oligo- or polysaccharide, mention may be made of the following compounds:

- oxidized starch (Rn 9047-50-1 ), starch known under the following trade names: Caldas 10; Caldas 5; Caldas 5H; Caldas 5S; Caldas C 5; Caldas C 5GP; Caldas C 5GT; Caldas No. 5; DAS 100; Dialdehyde starch; Dialdehydostarch; Formamyl; Periodate starch; Polyaldehyde starch; Starch dialdehyde; Sumstar; Sumstar 150; Sumstar 190

- oxidized cellulose (Rn 9032-52-4) known under the names 2,3-Dialdehyde cellulose; 2,3-Dialdehydocellulose; Aldehydocellulose; Cellulose 2,3-dialdehyde; Cellulose dialdehyde; Dialdehyde cellulose;

- oxidized inulin (Rn 82446-43-3 );

- dextran dialdehyde (Rn 37317-99-0 ).

Amine

In accordance with one embodiment of the invention, the composition may comprise at least one primary or secondary amine or addition salts thereof, ammonia or hydroxylamine, or mixtures thereof.

In general, the addition salts of these amine compounds that may be used in the context of the invention are especially chosen from addition salts with an acid, such as hydrochlorides, hydrobromides, sulfates, citrates, succinates, tartrates, lactates, tosylates, benzenesulfonates, dodecylbenzenesulfonat.es, phosphates and acetates, and preferably the hydrochlorides, citrates, succinates, tartrates, phosphates and lactates.

In particular, the primary or secondary amine(s) that may be used in the context of the invention are chosen from the amines of formula (III) that will be detailed below, amino polymers, purine bases, and also the addition salts thereof, and combinations thereof.

In particular, formula (III) is as follows:

R'₇R'₈NH (III)

in which formula (III) R'₇ and R'₈ represent, independently of each other:

- a hydrogen atom;

- a linear, branched and/or cyclic, saturated and/or unsaturated, aromatic or non- aromatic C1-C2₀ hydrocarbon-based radical, which may contain from 1 to 5 carbon-carbon double bonds and/or may be optionally substituted, optionally interrupted with one or more heteroatoms and/or with one or more groups comprising at least one heteroatom or group comprising at least one heteroatom (preferably chosen from oxygen, nitrogen, sulfur, C=0, C=S, SO and S0₂ or combinations thereof); the said hydrocarbon-based radicals R'₇ and R's possibly forming, with the nitrogen atom to which each is attached, a saturated or unsaturated 5- or 7-membered heterocycle, which is optionally substituted, optionally aromatic, optionally fused to a 6-membered aromatic or heteroaromatic nucleus, optionally comprising another nitrogen or non-nitrogen heteroatom; the hydrocarbon- based radical not comprising any nitro, nitroso, peroxo or diazo functions.

The compounds of formula (III) are advantageously not oxidation bases or oxidation couplers employed in the dyeing of keratin fibres.

Among the groups present as substituents of the heterocyclic hydrocarbon-based groups, mention may be made of the following groups:

carboxylic, sulfonic, phosphonic, in acid or salified form,

hydroxyl, CrC₄ alkoxy, (CrC₈)alkoxycarbonyl,

(Ci-C₄)alkylsulfonate, (CrC₈)alkylphosphonate,

tri(CrC₄)alkylsilyl, tri(CrC₄)alkoxysilanyl,

amino, (di)(Ci-C₄)alkylamino, tri(Ci-C₄)alkylammonium,

thiol, (Ci-C₄)alkylthio,

aminosulfonyl, (di)(Ci-C₄)alkylaminosulfonyl,

aminocarbonyl, (di)(Ci-C₄)alkylaminocarbonyl,

(Ci-C₄)alkylcarbonylamino,

guanidine,

ureido (N(R)₂-CO-NR'-) in which the radicals R and R', independently of each other, represent a hydrogen atom or a C C₄ alkyl or (Ci-C₄)alkylsulfonylamino radical;

phenyl, indolyl, pyrrolyl, imidazolyl, optionally substituted with one or more Ci-C₂ alkyl or hydroxyl.

Preferably, the groups present as substituents are chosen from the following groups: carboxylic in acid or salified form; hydroxyl; C C₄ alkoxy; (CrC₈)alkoxy carbonyl; thiol; (CrC₄)alkylthio; amino; mono- and di(Ci-C₄)alkylamino; aminocarbonyl; mono- and di(C C₂)alkylaminocarbonyl; (Ci-C₄)alkylcarbonylamino; phenyl, indolyl, pyrrolinyl, imidazolyl optionally substituted with one or more C C₂ alkyl or hydroxyl.

In particular, the amine(s) of formula (III), which may be identical or different, comprise from 1 to 5 primary and/or secondary amine functions; the amine(s) not comprising any N-N bonds. Also, the amine(s) of formula (III) do not comprise more than two heteroatoms bonded together.

Preferably, the amine(s) are compounds of formula (III), more particularly chosen from the compounds of formulae (Ilia) to (llli), (llli') below, and also the addition salts thereof.

o amino acids and/or derivatives of general formula (Ilia):

in which formula (Ilia):

- R₉ represents a hydrogen atom, a linear or branched Ci-C₆ alkyl radical, preferably substituted with one or more hydroxyl, hydroxycarbonyl, thiol, (CrC₄)alkylthio, amido, amino or guanidine groups, a phenyl radical, optionally substituted with one or more hydroxyl, an indolyl radical optionally substituted with one or more hydroxyl, an imidazolyl radical, a pyrrolinyl radical optionally substituted with a Ci-C₂ alkyl group; or an unsubstituted phenyl radical;

- R"₉ denotes a hydrogen, a C C₄ alkyl radical or an unsubstituted phenyl radical;

- Rio represents a hydrogen or a C C₄ alkyl radical;

- R"₉ and R₉ possibly forming, together with the nitrogen atom to which they are attached, a saturated 5- or 6-membered heterocycle.

Examples of compounds of formula (Ilia) that may be mentioned most particularly include asparagine, cysteine, glutamine, histidine, lysine, methionine, phenylalanine, proline, pyrrolysine, serine, threonine, tryptophan and tyrosine, and the addition salts thereof.

According to another variant, the compounds of formula (Ilia) are advantageously chosen from 2-amino-2-methylpropanoic acid; omethyl-D,L-phenylalanine; D,L-o (hydroxymethyl)alanine; D,L-a-methyl-meta-tyrosine; a-methyl-D,L-tryptophan; D,L-o methylhistidine dihydrochloride; L-2-methylserine; (S)-2-methylcysteine dihydrochloride; (S)-2-methyl-2-pyrrolidinecarboxylic acid.

o esters derived from amino acids and/or derivatives of general formula

(1Mb)

in which formula (1Mb):

- R₉ represents a hydrogen atom, a linear or branched Ci-C₆ alkyl radical, preferably substituted with one or more hydroxyl, hydroxycarbonyl, (Ci-C₄)alkoxycarbonyl, thiol, (C C₄)alkylthio, amido, amino or guanidine groups, a phenyl radical, optionally substituted with one or more hydroxyl, an indolyl radical optionally substituted with one or more hydroxyl, an imidazolyl radical, a pyrrolinyl radical optionally substituted with a Ci-C₂ alkyl group; or an unsubstituted phenyl radical;

- R"₉ represents a hydrogen, a C C₄ alkyl radical or an unsubstituted phenyl radical;

- Rio represents a hydrogen or a C C₄ alkyl radical;

- R"₉ and R₉ possibly forming, together with the nitrogen atom to which they are attached, a saturated 5- or 6-membered heterocycle. - Ri i represents:

- a linear or branched, saturated or unsaturated Ci-Ci₈ hydrocarbon-based radical optionally comprising from 1 to 5 conjugated or unconjugated carbon-carbon double bonds, optionally substituted as indicated previously, optionally interrupted with one or more heteroatoms and/or with one or more groups comprising at least one heteroatom, preferably chosen from oxygen, nitrogen, sulfur, C=0, C=S, SO and S0₂ or combinations thereof; the alkyl radical not comprising any nitro, nitroso, peroxo or diazo functions;

- an unsubstituted benzyl radical.

According to one particular variant, R₉ and Rn may optionally form a saturated 5- membered carbon-based ring.

Preferably, Rn represents a linear or branched, optionally substituted C1-C10 alkyl radical; a benzyl radical; and even more preferably a linear or branched C1-C4 alkyl radical optionally substituted with at least one hydroxyl group, preferably from 1 to 2 hydroxyl groups; a benzyl radical.

As examples of formula (1Mb), mention may be made of methoxytyrosine, 2- ethylpiperidine carboxylate; D, L-phenylalanine methyl ester; L-cystine dimethyl ester dihydrochloride; L-leucine methyl ester; methyl 2-amino-3-methylbutyrate; L-phenylalanine ethyl ester hydrochloride; L-glutamic acid diethyl ester hydrochloride; ethyl (S)-2-amino-3- methylbutanoate hydrochloride; D,L-serine methyl ester hydrochloride; tyrosine methyl ester hydrochloride; L-cysteine ethyl ester hydrochloride; L-histidine methyl ester hydrochloride; methyl (S)-pyrrolidine-2-carboxylate hydrochloride; methyl 2-aminoacetate hydrobromide; ethylglycine; H-D,L-alanine ethyl ester hydrochloride; D,L-tyrosine ethyl ester hydrochloride; methyl 2-(phenylamino)acetate; ethyl glutamate; bis(a,3-tert-butyl) D,L-aspartate hydrochloride; ethyl L-oaminoisocaproate hydrochloride; benzyl glycinate para-toluenesulfonate; D,L-alanine ethyl ester hydrochloride; 5-hydroxy-D,L-tryptophan methyl ester hydrochloride; D,L-threonine methyl ester hydrochloride; D,L-proline tert- butyl ester; D, L-phenylalanine methyl ester hydrochloride.

o amides and thioesters derived from amino acids and/or derivatives of general formula (lllc):

(me)

in which formula (lllc):

- R₉ represents a hydrogen atom, a linear or branched Ci-C₆ alkyl radical, preferably substituted with one or more hydroxyl, (CrC₄)alkoxycarbonyl, hydroxycarbonyl, thiol, (C C₄)alkylthio, amido, amino or guanidine groups, a phenyl radical, optionally substituted with one or more hydroxyl, an indolyl radical optionally substituted with one or more hydroxyl, an imidazolyl radical, a pyrrolinyl radical optionally substituted with a C1-C2 alkyl group; - R"₉ represents a hydrogen or a C1-C4 alkyl radical optionally substituted with a hydroxysulfonyl radical;

- R1₀ represents a hydrogen or a C1-C4 alkyl radical;

- R"₉ and R₉ possibly forming, together with the nitrogen atom to which they are attached, a saturated 5-membered heterocycle;

- R12 represents:

^* a hydrogen atom;

^* a Ci-C₆ alkyl radical, preferably substituted with one or more hydroxyl, thiol, (C C₄)alkylthio, amido or amino, a phenyl radical, optionally substituted with one or more hydroxyl, an indolyl radical optionally substituted with one or more hydroxyl, an imidazolyl radical, a pyrrolinyl radical optionally substituted with a C1-C2 alkyl group;

- X represents a sulfur or nitrogen atom.

According to one particular variant, R₉ and R12 may optionally form a saturated 5-, 6- or 7-membered carbon-based ring.

In the case where X represents a nitrogen atom and R12 represents an alkyl radical defined as previously and most particularly an amino acid residue and/or the corresponding methyl or ethyl ester thereof chosen from alanine, arginine, asparagine, aspartate, cysteine, glutamate, glutamine, glycine, histidine, lysine, methionine, phenylalanine, proline, pyrrolysine, serine, threonine, tryptophan, tyrosine, valine, leucine or isoleucine, the compound of formula (I lie) represents a dipeptide or an oligopeptide.

As examples of compounds of formula (III c), mention may be made of 3- aminodihydrothiophene-2-one hydrochloride; D,L-homocysteine thiolactone; D,L-leucyl- D,L-alanine, aspartame; (S)-pyrrolidine-2-carboxamide; [N-(-acetamido)]-2- aminoethanesulfonic acid; D,L-alanyl-D,L-phenylalanine; 2-(2-aminoacetamido)-3-(4- hydroxyphenyl)propanoic acid; 2-(2-aminoacetylamino)acetic acid; (R)-3-aminoazepan-2- one; glycinamide hydrochloride; L-Leucine amide hydrochloride; 2-aminopropanediamide; 2-(2-amino-3-methylbutanamido)propanoic acid; L-tyrosyl-L-alanine; L-valyl-L- phenylalanine; sarcosyl-L-phenylalanine; L-tyroyl-3-alanine; glycyl-L-proline; glycyl-D,L- valine; 2-aminomalonamide; L-methionamide hydrochloride; 2-amino-3- methylbutanamide; D-alaninamide hydrochloride; L-tyrosinamide hydrobromide; aspartate acid amide; L-tyrosine amide hydrochloride; L-arginine amide dihydrochloride; lysine amide dihydrochloride; threonine amide hydrochloride; isoleucine amide hydrochloride; histidine amide dihydrochloride; D,L-alanine amide hydrochloride; 2-amino-3-(4- hydroxyphenyl)propionamide; D,L-tryptophanamide hydrochloride; N-hydroxy-L-arginine acetate (H-ARG-NH2 2AcOH); asparagine amide hydrochloride; L-glutamic acid α,γ- diamide hydrochloride; D-phanylalanine amide; D-leucinamide hydrochloride; L-glutamic acid oarmide; L-methionineamide; L-cystine bisamide hydrochloride; glycinamide acetate; D-lysine amide dihydrochloride; glycinamide; L-isoglutamine γ-methyl ester hydrochloride; D-arginine amide dihydrochloride; (S)-pyrrolidine-2 carboxamide; prolylhistamine hydrochloride.

o Amino compounds of general formula (Hid):

(Hid)

Ί which formula (llld):

Ri3, Ri4_> Ri5 and Ri₆ represent, independently of each other:

^* a hydrogen atom;

^* a linear, branched and/or cyclic, saturated and/or unsaturated C1-C2₀ hydrocarbon- based radical, which may contain from 1 to 5 optionally aromatic carbon-carbon double bonds, optionally substituted as indicated previously, optionally interrupted with one or more heteroatoms and/or with one or more groups comprising at least one heteroatom, preferably chosen from oxygen, nitrogen, sulfur, CO, C=S, SO and S0₂ or combinations thereof, optionally bearing at least one hydroxyl or C1-C2 alkoxy group, the said radicals R1₃ and R14 or R₁₄ and Ri₅ or R₁₅ and Ri₆ possibly forming, with the carbon atoms which each is attached, a saturated or unsaturated 5- or 7-membered heterocycle, optionally substituted as indicated previously, which is optionally aromatic, optionally comprising another identical nitrogen or non-nitrogen heteroatom; the alkyl radical not comprising any nitro, nitroso, peroxo or diazo functions; more particularly an optionally substituted C1-C1₀ alkyl radical; and preferably a linear or branched Ci-C₈ alkyl radical optionally substituted with at least one hydroxyl group, preferably from 1 to 2 hydroxyl groups, a hydroxycarbonyl radical, a ureido radical, a (CrC₄)alkoxycarbonyl radical; an unsubstituted phenyl radical;

X represents a nitrogen, oxygen or sulfur atom;

Ri7 represents:

^* a hydrogen atom;

^* a linear or branched, saturated or unsaturated Ci-Ci₈ hydrocarbon-based radical, optionally comprising from 1 to 5 conjugated or non-conjugated carbon-carbon double bonds, optionally substituted as indicated previously, optionally interrupted with one or more heteroatoms and/or with one or more groups comprising at least one heteroatom, preferably chosen from oxygen, nitrogen, sulfur, CO, C=S, SO and S0₂ or combinations thereof; the alkyl radical not comprising any nitro, nitroso, peroxo or diazo functions; more particularly, R₁₇ represents a hydrogen, an optionally substituted linear or branched C1-C1₀ alkyl radical; and preferably a hydrogen, a linear or branched C1-C4 alkyl radical optionally substituted with at least one hydroxyl group, preferably from 1 to 2 hydroxyl groups;

R18 represents:

^* a hydrogen atom;

^* a linear or branched Ci-C₈ alkyl radical, optionally substituted as indicated previously, optionally interrupted with one or more heteroatoms and/or with one or more groups comprising at least one heteroatom, preferably chosen from oxygen, nitrogen, sulfur, CO, C=S, SO and S0₂ or combinations thereof, optionally bearing at least one hydroxyl or CrC₂ alkoxy group; the alkyl radical not comprising any nitro, nitroso, peroxo or diazo functions;

- o is an integer between 0 and 5.

According to another variant of the invention, the radicals Ri₆ and Ri₇ may optionally form, with the carbon atom for R₁₆ and the atom X for the radical Ri₇ to which each is attached, a saturated or unsaturated 5- or 6-membered heterocycle, optionally substituted as indicated previously, optionally aromatic, optionally comprising another nitrogen or non- nitrogen heteroatom.

According to another variant of the invention, the radicals Ri₈ and Ri₅ may optionally form, with the nitrogen atom for R₁₈ and the carbon atom for the radical Ri₅ to which each is attached, a saturated or unsaturated 5- or 6-membered heterocycle, optionally substituted as indicated previously, optionally aromatic, optionally comprising another nitrogen or non-nitrogen heteroatom.

As examples of compounds of formula (llld), mention may be made of L-2- aminohexanoic acid amide hydrochloride; L-phenylalanine amide; (S)-(+)-aminosuccinic acid; (R)-2-(methylamino)succinic acid; ethyl nipecotate; 3-piperidine carboxylic acid; 3- phenyl-3-alanine; ethyl 3-aminobutyrate; 2-carboethylamine; D,L-3-aminoadipic acid; β- alanine ethyl ester hydrochloride; ethyl 3-amino-3-ureido-N-butyrate; dimethyl (S)- aminosuccinate hydrochloride; β-L-alanine methyl ester hydrochloride; 4- carboxyethoxypiperidine; 4-aminobutyric acid; D,L-3-aminoadipic acid; 4- (methylamino)butyric acid hydrochloride; ethyl γ-aminobutyrate hydrochloride; hexahydronicotinamide; piperidine-4-carboxamide; 3-carbamoyl-2,2,5,5- tetramethylpyrrolidine.

o Amino compounds of general formula (llle):

(llle)

in which formula (llle):

- Ri3, Ri4, Ri5, Ri6 and Ri₈ have the same meaning as previously.

- Rig represents:

* a hydrogen atom;

^* a linear or branched Ci-C₈ alkyl radical, optionally substituted as indicated previously, optionally interrupted with one or more heteroatoms and/or with one or more groups comprising at least one heteroatom, preferably chosen from oxygen, nitrogen, sulfur, CO, C=S, SO and S0₂ or combinations thereof, optionally bearing at least one hydroxyl or Ci-C₂ alkoxy group; the alkyl radical not comprising any nitro, nitroso, peroxo or diazo functions;

- p is an integer between 0 and 7; - u is an integer equal to 1 or 2. When u is equal to 2, then the radical Ri₈ represents a hydrogen.

According to another variant of the invention, the radicals Ri₃ and Ri₄ may optionally form, with the carbon for R₁₃ and Ri₄ to which these substituents are attached, a saturated 5- or 6-membered heterocycle.

As examples of compounds (llle), mention may be made of the following acids, enantiomers thereof if they exist, and also the salts thereof, and hydrates thereof: (1 - aminoethyl)phosphonic, (aminomethyl)phosphonic, (1 -aminoethyl-1 -cyclohexyl)- phosphonic, (l -aminopropyl)phosphonic, (l -aminobutyl)phosphonic, iminobis- (methylphosphonic), (1 -amino-2-methylpropyl)phosphonic, (1 -amino-2-phenylethyl)- phosphonic, (1 -amino-1 -methylethyl)phosphonic, (1 -amino-3-methylbutyl)phosphonic, 1 - aminobenzylphosphonic, 1 -aminohexylphosphonic, diethyl(aminoethyl)phosphonic (in particular oxalate salt), tetraethyl(aminomethylene)bisphosphonic (in particular salts thereof), (1 -amino-2,2-dimethylpropyl)phosphonic, N-methylaminomethylphosphonic, (1 - aminopentyl)phosphonic, (1 -amino-2-methylbutyl)phosphonic, (l -aminooctyl)phosphonic, (1 -amino-1 -methylpropyl)phosphonic, (1 -amino-1 ,2- dimethylpropyl)phosphonic, (1 -amino- 1 ,3-dimethylbutyl)phosphonic, (1 -amino-1 -methylbutyl)phosphonic, (1 -amino-1 -cyclo- pentyl)phosphonic, (1 -aminohydroxycarbonyl)propylphosphonic, (1 -amino-1 -methylethyl)- phosphonic, 1 -amino-2-methylbutylphosphonic, 1 -phosphono-2-phenylethylamine, (aminomethyl)phosphonic, 3-aminopropylphosphonic, 2-amino-2-methyl-4-phosphono- butanoic and the ethyl esters thereof, (diethyl(3-aminopropyl)phosphonic (in particular oxalate salt), 3-(N-hydroxyamino)propyl phosphonic, 2-amino-2-methyl-4- phosphonobutyric, diethyl (3-aminopropyl)phosphonate, 2-amino-4-phosphonobutyric, 2- aminoethylphosphonic, 2-amino-3-phosphonopropionic, diethyl (2-aminoethyl)- phosphonate, diethyl (2-aminoethyl)phosphonic, (2-((2-pyrrolidinylcarbonyl)amino)- ethyl)phosphonic, diethyl (2-amino-1 -methyl-2-phenyl)ethylphosphonate, diethyl (2-amino- 2-phenyl)ethylphosphonate, and/or mixtures thereof.

o Amino compounds of general formula (lllf):

(lllf)

in which formula (lllf):

- Ri3, Ri₄, Ri5, Ri6 and Ri₈ have the same meaning as previously. In addition, the radicals Ri₃, Ri₄, Ri₅ and Ri₆, independently of each other, may also represent a hydroxyalkyl radical, a (Ci-C₄)alkoxycarbonyl radical, a carboxaldehyde radical, a (CrC₃)alkoxy

- q is an integer between 1 and 18;

- X represents an oxygen atom, an SH or OH group, or a methylene group optionally substituted with a hydroxyl radical; - when X represents an oxygen atom, then R₁₈ forms a 5- or 6-membered rings optionally substituted with one or more hydroxy(methyl), preferably from 1 to 4 hydroxy(methyl) groups.

According to another variant of the invention, the radicals Ri₆ and Ri₈ or R₁₃ and Ri₈ may optionally form, with the carbon atom for R₁₆ (or for R₁₃) and the nitrogen atom for the radical Ri₈ to which each is attached, a saturated or unsaturated 5- or 6-membered heterocycle, optionally substituted as indicated previously, optionally aromatic, optionally comprising another identical nitrogen or non-nitrogen heteroatom.

According to another variant of the invention, the amine of formula (lllf) may be a β- amino alcohol originating from the reduction of the acid or ester function to an alcohol of one of the 20 esterified or non-esterified amino acids.

As examples of compounds (I I If), mention may be made of the following compounds, enantiomers thereof if they exist, and also the salts thereof and the hydrates thereof: isopropanolamine, isopropylamine, methylethanolamine, methylglucamine, stearamine, tromethamine, promethazine, 1 ,3-dimethylpentylamine, octodrine, spermidine, theanine, octamylamine, 2-amino-1 -phenylpropane-1 ,3- diol, 1 ,3-dihydroxy-2- amino-2-methylpropane, 2-amino-2-(hydroxymethyl)propane-1 ,3-diol tris, 2-amino-1 ,3- dihydroxy-2-ethylpropane, 2-amino-3-methylbutan-1 -ol, 2-amino-2-methylpropan-1 -ol, phenylglycinol, 2-aminopropanol, 2-hydroxyethylamine, 2-aminohexan-1 -ol, 1 -amino-1 - cyclopentanemethanol, histidinol, 2-amino-3-(3-indolyl)propanol, 3-(4-hydroxyphenyl)-2- amino-1 -propanol, β-aminoisobutanol, 2-amino-1-propanol, 2-amino-1 ,3-propanediol, 2- amino-4-methyl-1 -pentanol, 2-amino-3-methyl-1 -butanol, β-aminobenzenepropanol, 2- aminopropan-1 -ol, 2-amino-1 -butanol, 2-amino-4-methylpetan-1 -ol, 3-aminopropanethiol, ethyl 2-amino-4-mercaptobutanoate, 6-hydroxyhexylamine, β-D-galactopyranosylamine, β-D-glucopyranosylamine, 1 -amino-2,5-anhydro-D-mannitol, 1 -amino-1 -deoxy-D-fructose, D-glucosamine, 2-pyrrolidinemethanol, 1 -amino-2,3-dihydroxypropane, 3-propanolamine, 3-[(2-hydroxyethyl)amino]propan-1 -ol, di-β-hydroethylamine, bis(3-hydroxypropyl)amine, N-2'-aminoethyl-N-propanolamine, 4-amino-N-butanol, methyl 3-amino-3-deoxy-a-D- mannopyranoside, N-butyl-4-hydroxybutylamine, 4-amino-4-(3-hydroxypropyl)-1 ,7- heptanediol, 1 -hexylamine, 1 -octylamine, 1 -nonylamine, 1 -decylamine, laurylamine, 1 - tetradecylamine, 1 -hexadecylamine, 3-amino-2-hydroxypropionic acid, 3-amino-2- hydroxy-4-phenylbutanoic acid, 4-amino-3-hydroxybutyric acid, ethyl 4-hydroxy-2- pyrrolidinecarboxylate, and mixtures thereof.

o Amino compounds of general formula (lllg): - R₂o represents:

^* a linear C1-C4 alkyl radical,

^* a linear C1-C4 alkoxy radical,

- o is an integer between 0 and 5,

- v is an integer equal to 1 or 2. When v is equal to 2, then R₁₈ represents a hydrogen.

As examples of compounds (II Ig), mention may be made of aminopropyltriethoxysilane, (aminomethyl)trimethylsilane, 2-(trimethylsilyl)ethanamine, 3- (trimethylsilyl)propan-l -amine, 4-(triethoxysilyl)butan-1 -amine, N-[3-

(trimethoxysilyl)propyl]ethylenediamine, 3-(trimethoxysilyl)propylamine, 3-triethoxysilyl-1 - propanamine and (3-methylaminopropyl)trimethoxysilane, and mixtures thereof,

o Amino compounds of general formula (lllh):

in which formula (lllh):

- Ri3, i4, Ri5, R16 and Ri₈ have the same meaning as previously. In addition, the radicals Ri₃, Ri4, Ri₅ and Ri₆, independently of each other, may also represent a hydroxyl radical, a (CrC₄)alkoxycarbonyl radical, a carboxaldehyde radical, a (CrC₃)alkoxy;

- R21 and R22 represent, independently of each other:

^* a hydrogen atom;

^* a linear, branched and/or cyclic, saturated and/or unsaturated C1-C2₀ hydrocarbon- based radical, which may contain from 1 to 5 carbon-carbon double bonds, optionally substituted as indicated previously, optionally interrupted with one or more heteroatoms and/or with one or more groups comprising at least one heteroatom, preferably chosen from oxygen, nitrogen, sulfur, CO, C=S, SO and S0₂ or combinations thereof, optionally bearing at least one hydroxyl or C1-C2 alkoxy group, more particularly an optionally substituted C1-C1₀ alkyl radical; and preferably a linear or branched C1-C4 alkyl radical optionally substituted with at least one hydroxyl group, preferably from 1 to 2 hydroxyl groups;

- R21 and R22 possibly forming, with the nitrogen atom to which they are attached, a saturated or unsaturated 5- or 7-membered heterocycle, optionally substituted as indicated previously, optionally aromatic, optionally comprising another identical nitrogen or non-nitrogen heteroatom; the alkyl radical not comprising any nitro, nitroso, peroxo or diazo functions,

- w is an integer between 1 and 10.

According to another variant of the invention, the alkyl radicals Ri₆ and R21 may optionally form, with the carbon atom for R₁₆ and the nitrogen atom for the radical R21 to which each is attached, a saturated or unsaturated 5- or 6-membered heterocycle, optionally substituted as indicated previously, optionally aromatic, optionally comprising another nitrogen or non-nitrogen heteroatom. According to another variant of the invention, the alkyl radicals Ri₈ and R₂i may optionally form, with the first nitrogen atom for R₁₈ and the last nitrogen atom for the radical R₂i to which each is attached, a saturated or unsaturated 5- to 14-membered heterocycle, optionally substituted as indicated previously, optionally aromatic, optionally comprising another nitrogen or non-nitrogen heteroatom.

Among the compounds of formula (lllh), mention may be made in particular of the amines below, the enantiomers thereof if they exist, and also the salts thereof and the hydrates thereof: gerontine, N-[3-aminopropyl]-1 ,4- butanediamine, 1 ,4-butanediamine, 4- (ethylamino)-N-butylamine, 2-[3-(2-hydroxy-1 ,1 -bis-hydroxymethylethylamino)propyl- amino]-2-hydroxymethylpropane-1 ,3-diol, 1 ,4,8,1 1 -tetraazacyclotetradecane, 1 ,4- diazacycloheptane, 1 ,3-diamino-2-hydroxypropane, N,N'-bis(2-aminoethyl)propane-1 ,3- diamine, 3-methylaminopropylamine, 1 ,3-diaminopropane, N,N'-dimethyltrimethylene- diamine, 2,2-dimethyltrimethylenediamine, 2,2-dimethyl-1 ,3-diaminopropane, N-(2- hydroxyethyl)-1 ,3-diaminopropane, N-(2-hydroxyethyl)-1 ,3-diaminopropane, cystamine, 1 ,5 diaminopentane, 1 ,6-diaminohexane, lauraminopropylamine, 2-methylheptylamine (2- (N-methyl)heptylamine), ethylenediamine, N,N-bis(2-hydroxyethyl)ethylenediamine, 3- aminoalanine, piperazine-2-carboxylic acid, β-Ν-methylaminoalanine, methyl piperazine-2- carboxylate, ethyl 3-aminoprolinate, 2,4-diamino-N-butyric acid, N-[3- (trimethoxysilyl)propyl]ethylenediamine, or mixtures thereof.

o Amino compounds of general formulae (llli) and/or (llli'):

in which general formulae (llli) and/or (llli'):

- R₂3 and R₂₄ represent, independently of each other:

^* an optionally substituted Ci-C₆ alkyl radical, optionally interrupted with one or more heteroatoms and/or with one or more groups comprising at least one heteroatom, preferably chosen from oxygen, nitrogen, sulfur, CO, SO and S0₂ or combinations thereof; the alkyl radical not comprising any nitro, nitroso, peroxo or diazo functions;

^* an alkylcarbonyl radical (R-CO-) in which R represents a C C₄ alkyl radical;

^* an alkylsulfonyl radical (RS0₂-) in which R represents a C C₄ alkyl radical;

^* a (di)(alkyl)aminosulfonyl radical ((R)₂N-S0₂-) in which the radicals R independently represent a hydrogen or a C C₄ alkyl radical;

^* a (di)(alkyl)aminocarbonyl radical ((R)₂N-CO-) in which the radicals R independently represent a hydrogen or a C C₄ alkyl radical;

^* a halogen atom preferably chosen from bromine, chlorine and fluorine;

^* a Ci-C₄ alkoxy group;

a C₂-C₄ (poly)hydroxyalkoxy group;

^* a hydroxycarbonyl group (HO-CO-); ^* an alkoxycarbonyl group (RO-CO-) in which R represents a C1-C4 alkyl radical;

^* an alkylcarbonylamino group (RCO-NR'-) in which the radical R represents a C C₄ alkyl radical and the radical R' represents a hydrogen atom or a C1-C4 alkyl radical;

^* an alkylsulfonyl radical (RS0₂-) in which the radical R represents a C1-C4 alkyl radical;

- Y represents a carbon or nitrogen atom;

- z, z' and z" represent, independently of each other, a carbon atom, a nitrogen atom or a nitrogen atom substituted with a hydrogen;

- x is an integer between 0 and 2; when x is less than 2, the unsubstituted carbon atom(s) bear a hydrogen atom;

- x is an integer equal to 0 or 1 ; when x' is less than 1 , the unsubstituted carbon atom(s) bear a hydrogen atom.

Among the compounds of formulae (UN) and/or (UN'), mention may be made in particular of the compounds listed below, the enantiomers thereof if they exist, and also the salts thereof and the hydrates thereof: opyridylamine, 2-amino-3-hydroxypyridine, 2 aminonicotinic acid, 2-amino-3-methylpyridine, 6-methoxy-3-pyridylamine, 3- aminopyridine, 3-amino-4-pyridinylamine, 2,5-aminopyridine, γ-pyridylamine, 2,3- dimethylpyridine-4-amine, 4-aminosalicylic acid, methyl para-aminobenzoate, benzocaine, aminobenzoic acid, 4-amino-m-anisic acid, 4-amino-3-hydroxybenzoic acid, methyl 3,4- diaminobenzoate, methyl-4-amino-3-methoxybenzenecarboxylic acid, 2-aminoanisole-4- carboxylic acid, 3-amino-4-hydroxybenzoic acid, ethyl 3-aminobenzoate, 1 -amino-3- carboxybenzene, methyl 2-aminobenzoate, ethyl anthranilate, 1 H-pyrazol-3-ylamine, 3- amino-4-carbethoxy-1 H-pyrazole, 5-amino-1 -ethylpyrazole, 1 H-benzimidazol-2-amine, 2- imidazolamine, 1 -methylbenzimidazol-2-amine, and mixtures thereof.

Use may also be made of the following amines, which may or may not be in salt form: lauroylethylenediamine, octopamine, oleamine, palmitamine, 2-(2- aminoethoxy)ethanol, 2-amino-4,5-dimethylthiazole, hexetidine, mecamylamine, tranylcypromine, triamterene, methyl[2-(3-trimethoxysilylpropylamino)ethylamine], bis(triethoxysilylpropyl)amine, N 1 -(3-(trimethoxysilyl)propyl)hexane-1 ,6-diamine, diethylenetriaminopropyltrimethoxysilane, N-(3-triethoxysilylpropyl)ethylenediamine, N-(3- trimethoxysilylethyl)ethylenediamine.

According to another variant of the invention, the amines are chosen from amino polymers, and also the addition salts thereof. The term "amino polymers" means macromolecules of more or less high molecular weight containing one or more primary or secondary amine functions. The term "polymer" means a compound comprising at least five repeating units linked in sequence via covalent bonds.

The amino polymer may be synthesized:

- via radical reactions (polyacrylates, polymethacrylates, polyvinyls, etc.),

- via condensation reactions (polyesters, polyethers, polyamides, polyurethanes, polydimethylsiloxanes, polypeptides, etc.), - via ring-opening reactions (polyesters, etc.).

It may be of natural origin, optionally chemically modified, for instance polysaccharides (cellulose, dextran, chitosan, guar) and amino or thiol derivatives thereof.

The polymers may be in any type of topology: linear, branched, star or hyperbranched chain (for instance dendrimers), block, random or alternating chains.

The chemical groups may be naturally present on the polymer chain, at the end of the chain, grafted along the main chain or side chains, or on the branches of star or hyperbranched polymers.

The following are most particularly preferred:

1 / polyamino acids containing free OH or NH₂ or SH or COOH groups, for example polylysine,

21 natural or modified polysaccharides containing NH₂ or SH functions,

3/ amino silicones,

4/ synthetic polymers containing NH₂ or SH function is, in particular polyvinyl vinyls substituted with an amine function and polymers made from the commercial monomers below:

and in particular from polylysine; chitosan; polyethoxylated amines such as carboxyPEG-8 amine, carboxyPEG-12 amine or carboxyPEG-24 amine; or combinations thereof.

According to another variant of the invention, the amine(s) are chosen from purine bases, in particular chosen from adenine, adenosine, guanine, guanosine G, thymine, thymidine T, uracil, uridine U, cytosine, cytidine C, addition salts thereof, and combinations thereof.

It would not constitute a departure from the context of the invention to combine several of these variants. Preferably, if the composition comprises one or more amines, they are chosen from ammonia, the compounds of formulae (I l ia), (1 Mb), (l l lc), (l lle) and (ll lg) in particular when R₂o represents a linear C1-C4 alkoxy group, and (U N'), alone or as mixtures.

If the composition comprises one or more primary or secondary amines, ammonia or hydroxylamine, their content represents in the composition between 0.001 % and 65% by weight and preferably between 0.001 % and 30% by weight relative to the weight of the composition.

Enzyme

The composition according to the invention may optionally comprise at least one enzyme, chosen, for example, from isolase, β-glucosidase derived, for example, from sweet almond (EC 3.2.1.21 ), alcohol oxidase (EC 1 .1.3.13), alcohol dehydrogenases EC 1 .1 .1.1 , alcohol dehydrogenases EC 1 .1 .1.2, alcohol dehydrogenases EC 1 .1 .1.71 , aromatic alcohol dehydrogenases EC 1 .1.1.90, also known as aryl alcohol dehydrogenases, aromatic alcohol dehydrogenases EC 1.1.1 .97, 3-hydroxybenzyl alcohol dehydrogenases EC 1 .1.1.97, coniferyl alcohol dehydrogenases EC 1.1.1 .194, cinnamyl alcohol dehydrogenases EC 1.1 .1 .195, methanol dehydrogenases EC 1.1 .1 .244, aromatic alcohol oxidases EC 1.1 .3.7, also known as aryl alcohol oxidases, alcohol oxidases EC 1 .1 .3.13, 4-hydroxymandelate oxidases EC 1 .1.3.19, long-hydrocarbon-chain alcohol oxidases EC 1.1.3.20, methanol oxidases EC 1.1.3.31 , alcohol dehydrogenases EC 1 .1 .99.20, methylglutamate dehydrogenases EC 1.5.99.5, 2-oxo acid decarboxylases EC 4.1 .1.1 , benzoylformate decarboxylases EC 4.1.1.7, phenylpyruvate decarboxylases EC 4.1 .1.43 and threonine aldolases EC 4.1 .2.5. If it is present, the concentration of the enzyme used in the dye composition is between 0.005% and 40% by weight relative to the total weight of the said composition and preferably between 0.05% and 10% by weight relative to the weight of this composition. Salts

The composition comprising the compound(s) of formulae (I) and/or (II) may optionally comprise one or more salts.

When they are present, these salts are generally chosen from organic solvents and/or mineral salts, and also combinations thereof.

In particular, the anions composing these salts may be either inorganic (chloride, carbonate, hydrogen carbonate, sulfate, hydrogen sulfate, silicate, phosphate, hydrogen phosphate, hydroxide, etc.) or organic (aspartate, formate, acetate, lactate, citrate, gluconate, succinate, malate, fumarate, orotate, etc.).

The cations composing these salts, associated with the above anions, may be derived either from alkali metals (preferably lithium, sodium or potassium), from alkaline- earth metals (preferably magnesium or calcium) or from transition metals (scandium, titanium, vanadium, manganese, molybdenum, iron, cobalt, nickel, copper, zinc, silver or gold). Other cations may also form salts, for instance ammoniums. Preferably, the cations will be chosen from alkali metals (lithium, sodium or potassium), alkaline-earth metals (magnesium or calcium), ammoniums, and also the following transition metals: manganese, molybdenum, iron, copper, zinc, silver and gold. When they are present, their content represents from 0.001 % to 40% by weight relative to the weight of the composition, and even more preferentially between 0.001 % and 20% by weight relative to the weight of the composition. Other ingredients

The cosmetically acceptable medium generally comprises at least water or a mixture of water and of at least one organic solvent. Examples of organic solvents that may be mentioned include Ci-C₄ lower alkanols, such as ethanol and isopropanol; polyols such as 1 ,3-propanediol or 1 ,6-hexanediol and polyol ethers, for instance 2-butoxyethanol, propylene glycol, propylene glycol monomethyl ether, diethylene glycol monoethyl ether and monomethyl ether, and also aromatic alcohols, for instance benzyl alcohol or phenoxyethanol, and mixtures thereof.

When they are present, the solvents are preferably present in proportions preferably of between 1 % and 99% by weight relative to the weight of the composition and even more preferentially between 5% and 95% by weight relative to the weight of the composition.

The composition used in the process according to the invention may also contain various adjuvants conventionally used in hair dye compositions, such as anionic, cationic, nonionic, amphoteric or zwitterionic surfactants or mixtures thereof, anionic, cationic, nonionic, amphoteric or zwitterionic polymers or mixtures thereof, mineral or organic thickeners, and in particular anionic, cationic, nonionic and amphoteric polymeric associative thickeners, antioxidants, penetrants, sequestrants, fragrances, buffers, dispersants, conditioning agents, for instance volatile or non-volatile, modified or unmodified silicones such as amino silicones, film-forming agents, ceramides, preserving agents, opacifiers and conductive polymers.

The above adjuvants are generally present in an amount for each of them of between 0.01 % and 20% by weight relative to the weight of the composition.

Needless to say, a person skilled in the art will take care to select this or these optional additional compound(s) such that the advantageous properties intrinsically associated with the dye composition in accordance with the invention are not, or are not substantially, adversely affected by the envisaged addition(s).

The pH of the composition is generally between 3 and 14 approximately, preferably between 4 and 1 1 approximately and more preferentially between 6 and 1 1 . It may be adjusted to the desired value by means of acidifying or basifying agents usually used in the dyeing of keratin fibres, or alternatively using standard buffer systems.

Among the acidifying agents that may be mentioned, for example, are mineral or organic acids, for instance hydrochloric acid, orthophosphoric acid, carboxylic acids, for instance acetic acid, tartaric acid, citric acid or lactic acid, and sulfonic acids.

Among the basifying agents, examples that may be mentioned include aqueous ammonia, alkali metal carbonates and the amines mentioned previously. The composition may be in various forms, such as in the form of a liquid, a cream or gel, powders to be mixed before use to obtain poultices, infusions, or in any other form that is suitable for dyeing keratin fibres, and especially the hair. The ingredients of the abovementioned composition are advantageously stored separately.

In particular, the compound(s) of formula (I) or the plant extract comprising the same, the compound being or not being lysed beforehand; where appropriate, the enzyme for replacing the radical R with a hydrogen atom if compound (I) has not been lysed beforehand; and the aldehyde or imine compound(s) or the oxidized oligo- or polysaccharide(s) containing an aldehyde or imine function are stored separately.

It should also be noted that if one or more amine compounds are present, these compounds are also stored separately from the compounds (I) or from the plant extract comprising the same, which is or is not lysed.

It may also be advantageous to store at least the compound(s) of formula (I) or the lysed or non-lysed plant extract comprising the same in an airtight container.

The composition used in the process according to the invention may also comprise one or more oxidizing agents. In this case, it is referred to as a ready-to-use composition.

Oxidizing agent

In particular, when an oxidizing agent is present, the ready-to-use composition is advantageously obtained by the extemporaneous mixing, before application, of a composition described previously with at least one composition comprising one or more oxidizing agents.

The oxidizing agent is preferably chosen from hydrogen peroxide, urea peroxide, alkali metal bromates or ferricyanides, peroxygenated salts, for instance persulfates, perborates and percarbonates of alkali metals or alkaline-earth metals, such as sodium, potassium and magnesium.

Oxidizing agents that are also suitable for use include those of enzymatic type, for instance 4-electron oxidoreductases (such as laccases), 2-electron oxidoreductases (such as uricase), where appropriate in the presence of the respective donor or cofactor thereof, and peroxidases.

The use of hydrogen peroxide is particularly preferred.

This oxidizing agent is advantageously formed by hydrogen peroxide in aqueous solution (aqueous hydrogen peroxide solution), the titre of which may range more particularly from 1 to 40 volumes and even more preferentially from 5 to 40 volumes.

It should thus be noted that the composition used in the invention may result from the extemporaneous mixing of several compositions.

The composition that has just been described is thus applied to human keratin fibres, in particular the hair. Dyeing process

In accordance with a first embodiment, the applied composition does not comprise any oxidizing agent.

In this case, the ingredients (compound of formula (I) or extract, which is or is not lysed; where appropriate, the enzyme for placing the radical R with a hydrogen atom, the aldehyde or imine compound(s) or the oxidized oligo- or polysaccharide(s) containing an aldehyde or imine function) are stored separately.

This embodiment is especially suitable in the case where the composition does not comprise an oxidation dye (bases or couplers).

In accordance with a second embodiment, the ready-to-use composition that has just been detailed and that is obtained by extemporaneous mixing, before application, of the composition described previously free of oxidizing agent with an oxidizing composition, is applied to the fibres.

This embodiment is particularly suitable in the case where the composition comprises one or more oxidation dyes (bases or couplers) or when it is desired to obtain a lightening effect.

According to a second variant of this embodiment, the composition free of oxidizing agent and an oxidizing composition are applied successively and without intermediate rinsing.

The oxidizing composition used comprises one or more oxidizing agents as defined above.

As regards the organic solvents that may be present in the oxidizing composition, reference may be made to the list indicated previously in the context of the description of the composition according to the invention.

Usually, the pH of the oxidizing composition is less than 7.

The oxidizing composition may take the form of a solution, an emulsion or a gel.

It may optionally comprise one or more additives conventionally used in the field of dyeing human keratin fibres, as a function of the desired galenical form. Once again, reference may be made to the list of additives given above.

Irrespective of the embodiment selected (with or without oxidizing agent, extemporaneous mixing or successive applications of the composition and of the oxidizing agent), the mixture applied to the fibres is left in place for a time generally from about 1 minute to 5 hours and preferably from 10 minutes to 3 hours.

As regards the temperature at which the composition(s) are applied, it is generally between 20 and 200°C and advantageously between 20°C and 55°C.

This operation may thus be performed using, for example, a heating hood, an infrared lamp or a straightening or curling iron.

The process according to the invention may advantageously be performed in the presence of a light stimulus. It consists more particularly in applying to the keratin fibres thus treated UVA radiation (in particular an irradiance of between 0.01 and 0.40 milliwatt/cm² and preferably between 0.1 and 0.2 milliwatt/cm², delivered by continuous-spectrum lamps or line- spectrum lamps) and/or UVB radiation (in particular an irradiance of between 0.01 and 0.20 milliwatt/cm² and preferably between 0.01 and 0.1 milliwatt/cm² delivered by continuous-spectrum lamps or by line-spectrum lamps).

Preferably, these compounds are alkali metal, alkaline-earth metal or ammonium, carbonate, hydrogen carbonate, chloride, sulfate, silicate, monobasic phosphate or acetate salts.

According to one preferred variant of the invention, this stimulus is performed by using a composition comprising, in a cosmetically acceptable medium, at least one salt chosen from lithium, sodium, potassium, calcium or ammonium carbonate; sodium or potassium hydrogen carbonate; calcium, lithium or sodium chloride; ammonium, sodium or magnesium sulfate; sodium silicate; monobasic sodium or potassium phosphate; sodium acetate.

The composition advantageously has a salt content ranging from 0.001 % to 40% by weight relative to the weight of the composition, and even more preferentially between 0.001 % and 20% by weight relative to the weight of the composition.

It would not constitute a departure from the context of the present invention to perform several successive steps combining stimuli that are different from each other.

After the leave-on time the keratin fibres may be rinsed with water, optionally washed with a shampoo, rinsed with water and dried or left to dry.

Lastly, a final subject of the invention is represented by a multi-compartment device comprising a first compartment containing at least one compound of formula (I) or the plant extract comprising the same; and a second compartment containing at least one compound of formula (i) or (ii), an oxidized oligo- or polysaccharide comprising at least one aldehyde or imine function; and a third compartment containing an enzyme for replacing the radical R of formula (I) with a hydrogen atom.

Preferably, the lysed or non-lysed compound(s) of formula (I) are stored protected from air, advantageously under an inert atmosphere.

The device may optionally comprise an additional compartment comprising one or more amines, or one or more salts.

The examples that follow illustrate the invention without limiting the scope thereof. Example 1

The extract of Gardenia jasminoides more or less enriched in geniposide is first lysed in the presence of β-glucosidase. The genipin derived from this extract is then isolated by crystallization after 100 kD ultrafiltration. The extract thus obtained is 99% enriched in genipin.

The dye compositions are obtained by dissolving in an aqueous solution buffered to a pH of 9 by sonicator for 30 minutes 5x10^"3 mol% of Gardenia jasminoides extract 99% enriched in genipin and 5x10^"3 or 25x 10^"3 mol% of vanillin.

Each composition is applied to natural grey hair containing 90% white hairs (1 g of lock per 2 g of solution) and the said locks are placed under different application conditions (hotplate, see the table below).

The lock is then rinsed, washed with a shampoo and dried with a hairdryer.

Example 2

The dye composition is obtained by dissolving in a solution buffered to a pH of 9 by sonicator for 30 minutes 5x10^"3 mol% of lysed Gardenia jasminoides extract 93% enriched in genipin and 2.5x10^"2 mol% of oxidized starch.

The composition is applied to natural grey hair containing 90% white hairs (1 g of lock per 2 g of solution) and left in place at 100°C (hotplate) for 5 minutes.

After this leave-on time, the lock is rinsed, washed with a shampoo and dried with a hairdryer.

A green-black coloration is obtained. Example 3

The dye compositions are obtained by dissolving in a solution buffered to a pH of 9 by sonicator for 30 minutes 5x10^"3 mol% of lysed Gardenia jasminoides extract 99% enriched in genipin and 10x10^"3 of vanillin in the presence of a salt or of an amine.

Each composition is applied to locks of natural grey hair containing 90% white hairs (bath ratio (BR): 1 g of lock per 10 g of solution) and the said locks are placed under cellophane at 40°C for 2 hours.

Each lock is then rinsed, washed with a shampoo and dried with a hairdryer.

Example 4

The dye compositions are obtained by dissolving in a medium comprising benzoic acid (1 % by weight), benzyl alcohol (5% by weight), ethanol (15% by weight), an aqueous solution buffered to a pH of 9 (79%) in a sonicator for 30 minutes, 5x10^"3 mol% of lysed Gardenia jasminoides extract 93% enriched in genipin, 10x 10^"3 mol% of ingredient.

Each composition is applied to locks of natural grey hair containing 90% white hairs (bath ratio (BR): 1 g of lock per 10 g of solution) and the said locks are placed under cellophane at 50°C for 30 minutes.

The lock is then rinsed, washed with a shampoo and dried with a hairdryer.

Structure Chemical name

test 9 copper

O test 10 Red violet

OH 0 test 1 1 violet OH

test 12 dark grey

OH test 13 golden

C

Example 5

The dye compositions are obtained by dissolving in an aqueous solution by sonicator for 30 minutes 5x10^"3 mol% of lysed Gardenia jasminoides extract 99% enriched in genipin and 10x10^"3 of vanillin in the presence of salt (saturated solution).

Each composition is applied to locks of natural and/or permanent-waved grey hair containing 90% white hairs (bath ratio (BR): 1 g of lock per 5 g of solution) and the said locks are placed under cellophane at 40°C for 2 hours.

The lock is then rinsed, washed with a shampoo and dried a hairdryer.

Test 26 (NH₄)₂S0₄ dark yellow

Test 27 (NH₄)₂C0₃ yellow-green

Example 6

The dye composition is obtained by dissolving in a medium comprising 1 % by weight of benzoic acid, 5% by weight of benzyl alcohol, 15% by weight of ethanol, an aqueous solution buffered to a pH of 9 (79%) in a sonicator for 30 minutes, 5x10^"3 mol% of lysed Gardenia jasminoides extract 93% enriched in genipin, 10x 10^"3 mol% of ingredient.

The lock is then rinsed, washed with a shampoo and dried with a hairdryer.

Example 7

Each dye composition is obtained by dissolving in an aqueous solution at a pH of 8

(KHC0₃) in a sonicator for 20 minutes, 1.13g% of lysed Gardenia jasminoides extract 93% enriched in genipin, and vanillin (1.56g% if present).

Each composition is applied to locks of natural grey hair containing 90% white hair (1 g of lock per 5 g of solution) and the said locks are placed at 30°C for 60 minutes (hotplate).

The lock is then rinsed, washed with a shampoo and dried with a hairdryer.

The results are the following:

It is clear from the above results, that the colour is more intense with vanillin

Example 8

Preparation of the imine type compound The imine is prepared by reacting vanillin (0.4g%) in a mixture of water (5ml) / ethanol (1 ml), with 3-aminopropanol (0.2g%) in the presence of acetic acid, during 30 minutes at ambient temperature.

The resulting imine is then added to 1.13g% of lysed Gardenia jasminoides extract 93% enriched in genipin, and vanillin (1 .56g% if present).

The pH of the composition is then adjusted to 8 by addition of KHC0₃ and then put in a sonicator during 20 minutes.

The composition is applied to natural grey hair containing 90% white hair (1 g of lock per 6 g of solution) and the said locks are placed for 60 minutes at 40°C (hotplate).

The colour of hair is dark green-blue.

Example 8

The dye composition is obtained by dissolving with a sonicator for 20 minutes, 1 .13g% of lysed Gardenia jasminoides extract 93% enriched in genipin, and oxidized inulin (1.13g%) in an aqueous solution at a pH of 8 (addition of KHC0₃).

Each composition is applied to natural grey hair containing 90% white hair (1 g of lock per 5 g of solution) and the said locks are placed for 60 minutes at 40°C (hotplate).

The hair is coloured in golden yellow.

Claims

Process for dyeing human keratin fibres, in which a composition is applied, comprising, in a cosmetically acceptable medium:

* a compound of the iridoid family of formula (I) below, optical or geometrical isomers thereof, mineral or organic acid salts thereof, solvates thereof, or a plant extract comprising the same:

in which:

R₂ represents a hydrogen atom, a hydroxyl radical or a sugar radical;

R represents a sugar radical;

n is an integer between 1 and 5;

the sugar radical is obtained from an aldose or an aldose derivative:

the compound(s) of formula (I) having undergone, prior to or simultaneously with the dyeing process, a step consisting in replacing the radical R with a hydrogen atom; ** at least one aldehyde or imine compound chosen from the following formulae (i) and (ii) below, optical or geometrical isomers thereof, organic or mineral acid salts thereof, solvates thereof, and also oxidized oligo- or polysaccharide comprising at least one aldehyde or imine function:

(i)

in which formulae (i) and (ii):

m is an integer equal to 0 or 1 ,

X represents an oxygen atom, NR"-i with R"-i representing a hydrogen atom or a C1-C10 alkyl radical;

when X represents an oxygen atom, the compounds may also be: o in the form of a 5- or 6-membered cyclic or acyclic acetal resulting from the condensation of an additional primary monoalcohol (R'₃OH) in which R'₃ represents a Ci-C₅ alkyl radical or a symmetrical 1 ,2- or 1 ,3-diol containing a C₂-C₃ alkyl chain,

o in the form of a hemiacetal resulting from the condensation of a hydroxyl group present on A or A-i when A or A-i represents an alkyl radical and when n is equal to 0;

^* a hvdroxycarbonyl group (-CO-OH):

^* a CR aryl group optionally substituted with at least:

a hydroxyl group,

a C1-C4 alkyl radical,

a group -CO-OR 4 or -O-COR 4 in which R'₄ represents a C C₂ alkyl radical or a phenyl group;

a group -COOH, in acid or salified form,

an -SR'11 in which R'n represents a C C₂ alkyl radical,

a halogen atom preferably chosen from chlorine and bromine, a group -0-S0₂-C₆H₆, a group -S0₃H,

an unsaturated cationic or non-cationic 5- or 6-membered heterocycle comprising one or two heteroatoms chosen from O, N and NR'₁₂ in which R'₁₂ represents a CrC₂ alkyl group optionally fused to a saturated or unsaturated, aromatic or non-aromatic 5- or 6-membered ring, one of the heteroatoms possibly being included in the two rings; the heterocycle or the fused ring possibly being substituted with at least one Ci-C₂ alkoxy radical,

the said aryl group being optionally fused to a 5- or 6-membered heterocyclic group, comprising one or two heteroatoms chosen from O, N and NR'₁₃ in which R'₁₃ represents a Ci-C₄ alkyl radical, the heterocycle being optionally fused to a C₆ aryl group,

the said aryl group being optionally fused to a C₆ aryl group optionally substituted with at least one C C₂ alkoxy group;

^* a cationic or non-cationic, saturated or unsaturated, aromatic or non- aromatic 5- or 6-membered heterocyclic group, comprising one or two identical or different heteroatoms preferably chosen from O, N and NR'₁₄ with R'₁₄ representing a hydrogen atom, a Ci-C₆ alkyl radical or a C₆ aryl radical optionally substituted with a group (R'i₅)₂NCO- or (R'₁₅)CO-NH- in which R'₁₅, which may be identical or different, represent a C C₂ alkyl radical;

- the said heterocyclic group being optionally fused to a 6-membered aryl group which is itself optionally substituted with at least one C C₂ alkyl, d-C₄ alkoxy or phenoxy group;

o a Ci-C₂ alkyl radical optionally substituted with a hydroxyl radical; o an amino radical -N(R'₁₆)2 in which R'₁₆, which may be identical or different, represent a C C₄ alkyl radical optionally substituted with a hydroxyl group, the radicals R'i₆ possibly forming a saturated or unsaturated 5- or 6- membered heterocycle with the nitrogen atom that bears them, optionally comprising another heteroatom chosen from O, N and NR'₁₇ in which R'₁₇ represents a C C₂ alkyl radical,

^* a linear or branched C-rC-in alkyl radical, or a C?-C n alkenyl radical, comprising one or more conjugated or non-conjugated carbon-carbon double bonds; the said alkyl or alkenyl radical being optionally substituted with at least one hydroxyl group; the divalent radical A₂ represents a linear C₁-C₁₀ alkylene chain connecting two radicals A-i via a carbon, oxygen or nitrogen atom;

the compounds of formulae (i) and (ii) comprising, where appropriate, a cosmetically acceptable anion or mixture of anions An, ensuring the electrical neutrality of the formulations.

Process according to the preceding claim, in which the plant extract originates from the following plants: Abelia grandiflora, Adenorandia kalbreyeri, Adina polycephala, Aeginetia indica var. gracilis, Asperula sp, Asystasia bella, Aucuba japonica, Avicennia marina, Bartsia trixago, Buddleja Americana, Buddleja crispa, Buddleja japonica, Canthium schimperianum, Castilleja wightii, Chaenorhinum minus, Clerodendrum serratum, Coprosma sp, Cornus officinalis, Craibiodendron henryi, Cremaspora triflora, Crucianella sp, Daphniphyllum calycinum, Daphniphyllum humile, Daphniphyllum macropodum, Eremostachys glabra, Escallonia sp, Eucommia ulmoides, Feretia apodanthera, Galium humifusum, Galium verum, Gardenia jasminoi^'des, Garrya elliptica, Globularia dumulosa, Hedyotis corymbosa, Hygrophila difformis, Ixeris chinensis, Lamiastrum galeobdolon (Lamium galeobdolon), Lamiophlomis rotata (Phlomis rotata), Leonotis nepetaefolia, Linaria sp, Morinda coreia, Mussaenda pubescens, Nepeta cilicia, Nepeta nuda ssp. Albiflora, Odeontites verna, Oldenlandia corymbosa, Paederia scandens, Pedicularis chinensis, Pedicularis condensata, Pedicularis dolichocymba, Penstemon confertus, Penstemon deutus, Penstemon richardsonii, Penstemon serrulatus, Pithecoctenium crucigerum, Plantago alpina, Plantago carinata, Plantago lagopus, Plantago lanceolata, Plantago subulata, Premna barbata, Randia dumetorum, Rhododendron latoucheae, Rothmannia withfieldii, Rubia peregrina, Rubia tinctorum, Saprosma scortechinii, Scrophularia korainensis, Scrophularia lepidota, Scrophularia ningpoensis, Scyphiphora hydrophyllacea, Swida controversa, Syringa vulgaris, Tarenna kotoensis, Tecoma heptaphylla, Thevetia gaumeri, Thevetia peruviana, Verbascum laxum, Verbascum nigrum, Verbascum phlomoides, Verbascum salviifolium, Verbascum sinuatum, Verbascum thapsus, Verbascum undulatum, Veronica derwentiana, Vitex nigrum, Wendlandia formosana, preferably Gardenia jasminoi^'des.

Process according to any one of the preceding claims, in which the content of compound(s) of formula (I) in the composition is between 0.001 % and 10% by weight relative to the weight of the composition.

Process according to any one of the preceding claims, in which the compounds of formula (i) or (ii) are such that X represents an oxygen atom. Process according to any one of the preceding claims, in which the compound(s) are of formula (i) and such that:

^* n is 0 or 1 ;

^* X represents an oxygen atom;

A represents:

^* a C?-CR alkenyl radical comprising a carbon-carbon double bond;

^* a hydroxycarbonyl group (-COOH);

^* a CR aryl group optionally substituted with at least:

- a hydroxyl group,

- a C1-C4 alkyl radical,

- a group -CO-OR 4 or -0-COR'₄ in which R'₄ represents a C1-C2 alkyl radical,

- a group -OR'₅ in which R'₅ represents a Ci-C₆ alkyl radical,

- an aryl-ethylenyl radical, the aryl group being C₆ and optionally substituted with at least one Ci-C₂ alkyl or CrC₂ alkoxy radical,

- an unsaturated cationic or non-cationic 5- or 6-membered heterocycle comprising one or two heteroatoms chosen from O, N and N R'₁₂ in which R'₁₂ represents a C C₂ alkyl group optionally fused to a saturated or unsaturated, aromatic or non-aromatic 5- or 6-membered ring, one of the heteroatoms possibly being included in the two rings; the heterocycle or the fused ring possibly being substituted with at least one C C₂ alkoxy radical,

- the said aryl group being optionally fused to a 5- or 6-membered heterocyclic group, comprising one or two heteroatoms chosen from O, N and N R'₁₃ in which R'₁₃ represents a C1-C4 alkyl radical;

^* a cationic or non-cationic, saturated or unsaturated, aromatic or non-aromatic 5- or 6-membered heterocyclic group, comprising one or two identical or different heteroatoms preferably chosen from O, N and N R'₁₄ with R'₁₄ representing a hydrogen atom, a Ci-C₆ alkyl radical or a C₆ aryl radical optionally substituted with a group

or (R'₁₅)CO-N H- in which R'₁₅ represent a C C₂ alkyl radical;

- the said heterocyclic group being optionally fused to a 6-membered aryl group which is itself optionally substituted with at least one C C₂ alkyl or C1-C4 alkoxy group;

- the said heterocyclic group being optionally substituted with at least:

o a hydroxyl group,

o a Ci-C₂ alkyl radical optionally substituted with a hydroxyl radical,

o an amino radical -N(R'₁₆)2 in which R'₁₆, which may be identical or different, represent a C1-C4 alkyl radical optionally substituted with a hydroxyl group, the radicals R'i₆ possibly forming a saturated or unsaturated 5- or 6-membered heterocycle with the nitrogen atom that bears them, optionally comprising another heteroatom chosen from O, N and NR'₁₇ in which R'₁₇ represents a CrC₂ alkyl radical,

^* the compound(s) of formula (i) possibly being in acetal or hemiacetal form.

6. Process according to any one of the preceding claims, in which the content of compound(s) of formula (i) or (ii), or of oxidized oligo- or polysaccharide comprising at least one aldehyde or imine function is between 0.001 % and 30% by weight relative to the weight of the composition.

7. Process according to any one of the preceding claims, comprising one or more organic or mineral salts chosen from:

* chloride, carbonate, hydrogen carbonate, sulfate, hydrogen sulfate, silicate, phosphate, hydrogen phosphate, hydroxide or organic anions chosen from aspartate, formate, acetate, lactate, citrate, gluconate, succinate, malate, fumarate, orotate combined with

^* alkali metals, alkaline-earth metals, transition metals such as scandium, titanium, vanadium, manganese, iron, cobalt, nickel, copper, zinc, silver or gold, or ammoniums.

8. Process according to any one of the preceding claims, in which the content of salt(s) ranges between 0.001 % and 40% by weight relative to the weight of the composition and even more preferentially between 0.001 % and 20% by weight relative to the weight of the composition.

9. Process according to the preceding claim, in which the step consisting in replacing the radical R with a hydrogen atom is performed using an enzyme chosen from isolase and β-glucosidase (EC 3.2.1 .21 ).

10. Process according to any one of the preceding claims, in which a temperature of between 30 and 200°C is applied. 1 1 . Process according to any one of the preceding claims, in which UVA radiation is applied, in particular an irradiance of between 0.01 and 0.40 milliwatt/cm² and/or UVB radiation is applied, in particular an irradiance of between 0.01 and 0.20 milliwatt/cm². 12. Multi-compartment device comprising a first compartment containing at least one compound of formula (I) or the plant extract comprising the same, as described in either of Claims 1 and 2, which has undergone a preliminary step consisting in replacing the radical R with a hydrogen atom, and a second compartment containing at least one compound of formula (i) or (ii), an oxidized oligo- or polysaccharide comprising at least one aldehyde or imine function, according to any one of Claims 1 , 4 and 5.

Multi-compartment device comprising a first compartment containing at least one compound of formula (I) or the plant extract comprising the same, as described in either of Claims 1 and 2, and a second compartment containing at least one compound of formula (i) or (ii), an oxidized oligo- or polysaccharide comprising at least one aldehyde or imine function, according to any one of Claims 1 , 4 and 5, and an enzyme for replacing the radical R of formula (I) with a hydrogen atom according to Claim 9.

Multi-compartment device comprising a first compartment containing at least one compound of formula (I) or the plant extract comprising the same, as described in either of Claims 1 and 2, and a second compartment containing at least one compound of formula (i) or (ii), an oxidized oligo- or polysaccharide comprising at least one aldehyde or imine function, according to any one of Claims 1 , 4 and 5, and a third compartment containing an enzyme for replacing the radical R of formula (I) with a hydrogen atom, according to Claim 9.

Composition for dyeing human keratin fibres, comprising, in a cosmetically acceptable medium:

in which:

· Ri represents a hydroxymethyl radical, a group -CO2R4 in which R₄ represents a hydrogen atom or a CrC₂ alkyl radical; a sugar radical;

R₂ represents a hydrogen atom, a hydroxyl radical or a sugar radical;

R₃, which may be identical or different, represent a hydrogen atom, a hydroxyl radical, a (CrC₄)alkyloxy radical; the number of hydroxyl groups not being greater than 2; R represents a sugar radical;

n is an integer between 1 and 5;

the sugar radical is obtained from an aldose or an aldose derivative:

the compound(s) of formula (I) having optionally undergone a preliminary step that consists in replacing the radical R with a hydrogen atom, performed by means of an enzyme;

(i) (ϋ)

in which formulae (i) and (ii):

m is an integer equal to 0 or 1 ,

X represents an oxygen atom, NR"-i with R"-i representing a hydrogen atom or a

C1-C10 alkyl radical;

when X represents an oxygen atom, the compounds may also be:

o in the form of a 5- or 6-membered cyclic or acyclic acetal resulting from the condensation of an additional primary monoalcohol (R'₃OH) in which R'₃ represents a C1-C5 alkyl radical or a symmetrical 1 ,2- or 1 ,3-diol containing a C₂-C₃ alkyl chain,

· the radicals R'i and R'₂, independently of each other, represents a hydrogen atom or an unsubstituted linear Ci-C₆ alkyl radical;

^* a hvdroxycarbonyl group (-CO-OH):

^* a CR aryl group optionally substituted with at least:

- a hydroxyl group,

a C1-C4 alkyl radical,

a group -COOH, in acid or salified form, a group -OR'₅ in which R'₅ represents a Ci-C₈ alkyl radical optionally substituted with at least one hydroxyl group, an ammonium group -N⁺R"₆ with R"₆, which may be identical or different, representing a Ci-C₂ alkyl radical, a group -SiR'₇ with R'₇, which may be identical or different, representing a Ci-C₂ alkyl radical; a benzyl radical (-CH2-C₆H₆),

a group -N(R'₈)2 in which R'₈, which may be identical or different, represent a Ci-C₆ alkyl radical optionally substituted with a hydroxyl group, a carboxylic group (-COOH) in acid or salified form, or a sulfonic group (-S0₃H) in acid or salified form; the radicals R'₈ possibly forming a saturated or unsaturated 5- or 6- membered heterocycle with the nitrogen atom that bears them, optionally comprising another heteroatom chosen from O, N and NR'₉ in which R'₉ represents a C1-C2 alkyl radical; the heterocycle being optionally substituted with a hydroxyl group,

a group -COR'10 in which R'₁₀ represents a C₆ aryl group fused to a 6-membered hydrocarbon-based ring optionally substituted with at least one C1-C2 alkyl radical,

an -SR'11 in which R'n represents a CrC₂ alkyl radical,

a halogen atom preferably chosen from chlorine and bromine, a group -0-S02-C₆H₆,

a group -S0₃H,

an unsaturated cationic or non-cationic 5- or 6-membered heterocycle comprising one or two heteroatoms chosen from O, N and NR'₁₂ in which R'₁₂ represents a CrC₂ alkyl group optionally fused to a saturated or unsaturated, aromatic or non-aromatic 5- or 6-membered ring, one of the heteroatoms possibly being included in the two rings; the heterocycle or the fused ring possibly being substituted with at least one C C₂ alkoxy radical,

the said aryl group being optionally fused to a 5- or 6-membered heterocyclic group, comprising one or two heteroatoms chosen from O, N and NR'₁₃ in which R'₁₃ represents a C1-C4 alkyl radical, the heterocycle being optionally fused to a C₆ aryl group,

^* a cationic or non-cationic, saturated or unsaturated, aromatic or non- aromatic 5- or 6-membered heterocyclic group, comprising one or two identical or different heteroatoms preferably chosen from O, N and NR'₁₄ with R'₁₄ representing a hydrogen atom, a Ci-C₆ alkyl radical or a C₆ aryl radical optionally substituted with a group (R'i₅)₂NCO- or (R'₁₅)CO-NH- in which R'₁₅, which may be identical or different, represent a C C₂ alkyl radical; the said heterocyclic group being optionally fused to a 6-membered aryl group which is itself optionally substituted with at least one Ci-C₂ alkyl, C1-C4 alkoxy or phenoxy group;

o a C1-C2 alkyl radical optionally substituted with a hydroxyl radical; o an amino radical -N(R'₁₆)2 in which R'₁₆, which may be identical or different, represent a C1-C4 alkyl radical optionally substituted with a hydroxyl group, the radicals R'i₆ possibly forming a saturated or unsaturated 5- or 6- membered heterocycle with the nitrogen atom that bears them, optionally comprising another heteroatom chosen from O, N and NR'₁₇ in which R'₁₇ represents a Ci-C₂ alkyl radical,

^* a linear or branched C-rC n alkyl radical, or a C?-C n alkenyl radical, comprising one or more conjugated or non-conjugated carbon-carbon double bonds; the said alkyl or alkenyl radical being optionally substituted with at least one hydroxyl group;

the divalent radical A₂ represents a linear C1-C10 alkylene chain connecting two radicals A-i via a carbon, oxygen or nitrogen atom;