EP1284982A2

EP1284982A2 - Method for treating plant material, compositions comprising n-acylglucosamine derivatives, use of said compounds as biologically protective agents, and treated plant material, in particular seeds

Info

Publication number: EP1284982A2
Application number: EP01936594A
Authority: EP
Inventors: Michel Minier; Bruno Kokel; Chadi o Madame KHOURY KHOURY; Christelle Arles; Hélène VERGNEAU
Original assignee: Universite Pierre et Marie Curie Paris 6
Current assignee: Universite Pierre et Marie Curie Paris 6
Priority date: 2000-05-19
Filing date: 2001-05-18
Publication date: 2003-02-26
Also published as: JP2004522693A; AU2001262470A1; FR2809104B1; WO2001087902A2; WO2001087902A3; CA2409135A1; FR2809104A1

Abstract

The invention concerns a method for treating plant material by applying a compound of formula (I') wherein: A6, A4 and A3, independently of one another, represent OH or OR5 or OC(O)R5 or O-SO2-R5 or O-(CH2)n-NR6-CmH2m+1 or -NHC(O)R5 or O-(CH2)n-NR6-C(O)-CmH2m+1 or O-(CH2)n-S-CmH2m+1 or S-R6 or NR6R7 or NR6R7R8+X- where R¿5? represents a C1-C18 linear or branched alkyl chain; n ranges between 1 and 17 and m ranges between 0 and 16 and n+m < 18; R6, R7 and R8 represent, independently of one another, H or a C1-C12 linear or branched alkyl chain; and X?-¿ a mineral or organic anion; and wherein R'¿2? represents a C1-C4 linear or branched alkyl chain or an ethynyl group or NR'3R'4, where R'3 and R'4 represent independently of each other CiH2i+1, i ranging between 0 and 4, the anomeric carbon hydroxyl being in position α or β, except for compounds where A6, A4 and A3 represent OH.

Description

Method for treating plant material, compositions comprising derivatives of the N-acylglucosamine type, use of these compounds as bio-protective agents, and treated plant material, in particular seeds.

The subject of the present invention is a process for treating plant material as well as compounds derived from an N-acylglucosamine, compositions comprising derivatives of N-acylglucosamine and their use in particular for phytosanitary purposes. In particular, the present invention relates to a process for treating plant seeds, with a view to ensuring their protection against their deterioration during aging, and in particular during their storage.

Many factors, including temperature, humidity, fungi, microorganisms and oxygen pressure have the effect of damaging the seeds during storage. The germination capacity of seeds can itself be affected by these factors.

It is known to treat the seeds by coating, before their storage to avoid their deterioration. For example, document PCT / FR 96/00200 describes compositions comprising on the one hand a film-forming substance and on the other hand an antioxidant.

There is however a need for "bioprotective" products of plant material. The term “bioprotective” is intended to mean compounds having a beneficial activity for plant material, for example progerminative, antifungal, storage stabilizer, in the case of seeds, or else stimulating the natural defenses of the plant, while being biodegradable.

Certain derivatives of N-acetyl-glucosamine (NAG) are known.

The preparation of some of them is described in Femandez-Bolanos et al., Anales de Quimica (1982) 423, and JP 49 20 763 (1974): these are 2-acetamido-2-deoxy- (6) O -octanoyl D-glucopyranose (C8-NAG) and 2-acetamido-2-deoxy- (6) O-palmitoyl D-glucopyranose (C16-NAG). The Applicant has demonstrated that it is possible to treat the plant material and for example the seeds against their deterioration, in particular during their storage by treating them with at least one compound of formula I or I 'below:

⁽ H in which A ₆ , A and A ₃ , independently of one another, represent OH or OR ₅ or OC (O) R ₅ or O-SO ₂ -R ₅ or 0- (CH ₂ ) _n - NR ₆ -C _m H _{2m + 1} or -NHC (O) R ₅ or O- (CH ₂ ) _n -NR ₆ -C (O) -C _m H _{2m + 1} or 0- (CH ₂ ) _n -SC _m H _{2m + 1} or S- Rβ or NRβR7 or NR ₆ R ₇ Rs ⁺ X ^" where R5 represents a linear or branched C1 to Cι ₈ alkyl chain, n is between 1 and 17 and m is between 0 and 16 and n + m <18, Rβ, R7 and R ₈ are independently of one another are H or a linear or branched alkyl chain Ci-C- | _2, and X ^"a mineral or organic anion, and in which R ' ₂ represents a linear or branched C1 to C ₄ alkyl chain or an ethynyl group or NR' ₃ R ', where R' ₃ and R ' ₄ represent independently of each other CiH ₂ i ₊ ι i going from 0 to 4, the hydroxyl of the anomeric carbon being in position α or β, with the exception of the compounds where A ₆ , A and A ₃ represent OH,

in which Ri represents R or CO-R where R represents a linear or branched C ₅ to C ₈ alkyl chain and R ₂ represents a linear or branched C 1 to C ₄ alkyl chain or an ethynyl group or -NR ₃ R where R3 represents CpH ₂ p ₊ ι, p ranging from 0 to 4 and R ₄ represents C _q H ₂ q + ι, q ranging from 0 to 4.

The term “mineral or organic anion” means any anion that is acceptable in such a process and in particular halide (chloride, bromide, iodide), phosphate, sulfate, acetate, carbonate, or benzoate, for example.

Preferably, in formula I or I ′ of the compounds according to the invention, the alkyl chain (s) is (are) linear (s).

Preferably, R ₅ represents a linear or branched C ₃ -C ₁₃ alkyl chain. In a preferred variant, in formula I ', two of A ₃ , A ₄ and A ₆ represent, independently of one another, OC (O) R ₅ where R ₅ represents a linear or branched C alkyl chain ₃ to C ₁₃ , and the third among A ₃ , A ₄ and Aβ represents OH. More preferably, R5 represents a linear or branched C ₃ to C ₈ alkyl chain. In another preferred variant, in formula I ', two among A ₃ , A ₄ and Aβ represent OH and the third among A ₃ , A ₄ and Aβ represents OCOR ₅ where R ₅ represents a linear or branched C ₃ alkyl chain to C ₁₃ . More preferably, in formula I ', R' ₂ represents CH ₃ .

Preferably, Ri represents COR. More preferably, Ri represents CO-C ₇ Hι ₅ , COC ₅ H _t ι, COC9H ₁₉ or COC11H23, and among these, in particular COC Hι ₅ or COC ₉ H ₁₉ . More preferably, R ₂ represents CH ₃ . In the previous formulas, the two anomeric forms α and β are present. In the aqueous phase, the α and β forms can coexist.

According to one of its aspects, the present application aims to cover a process for treating vegetable matter. In a particular application, it may be a process for treating seeds intended in particular to prevent their deterioration during aging, in particular during storage. In the case of seeds, the method may consist in coating or film-coating said seeds, prior to their storage, with a composition incorporating an effective amount of at least one compound of the invention. There are numerous compositions for coating or coating the seeds in the form of concentrate, dilutable or ready-to-use compositions. These usual generally aqueous compositions are commercially available. Sepiret (designation of compositions sold by SEPPIC), and green clay constitute such usual compositions. The active compounds of the invention are incorporated into these usual compositions. The compositions of the invention may be in the form of an aqueous slurry. However, the compounds of the invention were applied in aqueous or hydroalcoholic solution.

By plant material is meant not only seeds, seeds but also standing plants, roots, tubers, onions, and plant cell cultures. Preferably, according to the invention, seeds or seeds are treated.

In the case of coating, this process allows the fixing of a precise and just sufficient quantity of active agent at the level of the seed. It allows to put into practice on a large scale, economically, the contribution of active compounds, antifungals, progermatives which can improve the conservation and / or favor the germination of seeds at the time of their sowing and the emergence of plants.

According to a particular characteristic of this process, the aforementioned coating or lamination of the seeds is carried out either by spray-drying, or by churning.

Spray-drying is a known process for coating solid forms dry.

It consists here of spraying the moving seeds with an aqueous film-forming composition as described above while a flow of air permanently ensures the drying of the seeds. The churning technique is a process also known for the film-coating or coating of solid forms by the wet method and consists here of agitating the seeds inside a rotary mixer in the presence of a film-forming composition as described above. Other modes of application than the coating methods provided above can be implemented, in particular on plant material other than seeds, and for example spraying, soil treatment, spreading and watering .

In this case, the compounds of the invention are incorporated in the usual compositions for spray treatment, soil treatment, spreading, or watering.

Preferably, in the process of the invention, the application is carried out at a rate of 0.1 mg to 100 mg of compound of formula I or I 'per gram of seed, preferably 1 mg to 5 mg. In addition, when the application is carried out using an aqueous slurry, this can comprise 1 to 40, preferably 5 to 20 mg of compound of formula l / g of aqueous slurry, or 1 to 40, of preferably 3.5 to 15% of at least one compound of formula I or I 'in the slurry by weight of dry extract. Thus, the present invention also relates to compositions, for phytosanitary use in particular, comprising at least one compound of the invention as active agent. Thus, the present invention relates to compositions comprising at least one compound of formula I or I 'above and a support acceptable for its phytosanitary use. Preferably, in the compositions of the invention, the compound of formula I or I ′ is present in proportions ranging from 1 to 97% of compound, by weight of dry extract in the composition.

In addition, certain compounds of the invention are new. The present invention relates to the compounds of formula I with the exception of those for which R ₁ represents CO (CH ₂ ) ₆ CH ₃ or CO (CH ₂ ) ₁₄ CH ₃ and R ₂ is CH ₃ , and the compounds of formula I 'with the exception of those for which A ₆ , A ₄ and A ₃ represent OH, compounds where R ' ₂ represents CH3, A ₃ and A4 represent OH and A ₆ represents OC (O) (CH ₂ ) ₆ CH3 or OC (O) (CH ₂ ) ι ₄ CH ₃ , and compounds where R ' ₂ represents CH ₃ , A ₄ and A ₆ represent OH and A ₃ represents OC (O) (CH ₂ ) ₆ CH ₃ or OC (O) (CH ₂ ) ιoCH ₃ or OC (O) (CH ₂ ) ₁₄ CH ₃ .

The compounds of formula I of the invention can be prepared according to the following general scheme: Reaction: monoesterification on C6 of the NAG motif

NAG

illustrated here for the products where R ₂ is CH ₃ and R is COC _n -ιH _{2n +} ι whose implementation is within the reach of those skilled in the art, as well as the variants making it possible to obtain the other derivatives of the NAG referred to by the formula I. For the purification, it can thus be implemented by the following stages: hydrolysis of unreacted acyl chloride, evaporation of the DMF by the vane pump at T = 60 ° C. , washing with water until neutral in order to pass the carboxylic acid and the unreacted NAG into the aqueous phase, trituration with pentane in order to remove any organic impurity and optionally washing with ether, in particular .

Certain compounds of formula I ', illustrated here by the compound where R' ₂ is CH ₃ and A ₆ is OCO (CH ₂ ) _n CH ₃ A ₃ and A4 are OH according to the invention can be prepared according to one of the routes A or B of the following general diagram:

NAG

Track B

where Pi is a protective group, for example the benzyl group.

In general, usual methods are within the reach of those skilled in the art with regard to all the compounds of the invention; the text of application PCT / FR 99 02861, in Fernandez-Bolanos et al., Anales de Quimica (1982) 423 and Shulman et al. Carbohydrate Research 27 (1973) 141-147, being cited here for reference.

Thus, to prepare the monoesters, the carbon C1 can be protected by an appropriate group (for example benzyl for the ester), we proceed to esterification with the corresponding reagent (acid chloride) and then deprotects. For ether, a suitable protecting group is allyl. For the diesters in C4 and C6, the procedure is the same with a larger amount of the reagent. To triester it, with excess reagent. To prepare the C3 monoesters, the method described by Femandez-Bolanos et al., Anales de Quimica (1982) 423 can be used.

To produce the monoesters in C4, one protects in C1 for example with a benzyl, and in C6 (mesylation) one esterifies and one deprotects.

To make the diesters at C3 and C4, after having protected at C1, one protects at C6 with an appropriate group (mesyl for example), is esterified in excess and deprotected.

To make the diesters in C3 and C6, protect in C1, then use, for example, benzoic aldehyde or acetone to protect C4 and C6, esterify in C3, deprotect in C6, esterify and deprotect in C1.

Usually, the corresponding reagents are acid chloride to prepare esters, halides, for example alkyl bromide to prepare ethers, corresponding alkylsulfonyl chlorides (R5 SO ₂ Cl) to prepare the compounds where A ₃ , A ₄ or A ₆ represent OSO ₂ R ₅ .

It also relates to the use of the compounds more specifically as an antifungal or germinative.

At certain concentrations, as will appear from the examples, the compounds of the invention, incorporated into a film-coating composition, can provide both antifungal protection and promotion of germination, significantly.

The compositions of the invention can comprise at least one film-forming agent. A film-forming substance suitable in the context of the present invention generally consists of a polymer allowing the formation of a film permeable to water and gas exchanges, biodegradable and without phytotoxic effect for plant material.

As polymer capable of being used for this purpose, mention will be made more particularly of cellulose derivatives, in particular cellulose esters or ethers such as, for example, methylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, cellulose acetophthalate, acetate of cellulose or ethylcellulose; natural polysaccharides such as in particular modified starches, gums such as guar gum, xanthan gum or gum arabic, alginates, chitosans; as well as vinyl or acrylic derivatives.

Other active agents can be incorporated into the compositions. Thus, as an antioxidant agent capable of being used in the context of the present invention, mention will be made more especially of ascorbic acid and its salts (in particular calcium and sodium); tocopherols, especially vitamin E; polyamines, such as, for example, spermine, spermidine, putrescine, agmatine, cadaverine; flavonoids such as, for example, quercetin, myricetin, kaempferol, catechin, luteolin; carotenoids, in particular β-carotene; phenolic compounds such as, for example, thymol, carvacrol, zingerone, 6-gingerol, hydroxytyrosol, butylhydroxyanisole, butylhydroxytoluene; amino acids such as arginine, histidine, cysteine, tryptophan, lysine, threonine and magnesium methioninate; squalene or monoterpenes such as, for example, limonene, carvone, dihydrocarvone, pulegone, isopulegol, isolimonene, or their carbonyl esters, in particular methyl limonate, pulegolactone, limonone; zinc-based substances, such as, for example, zinc gluconate, zinc glycerophosphate, zinc aspartate, zinc glucoheptonate; or selenium-based substances, such as sodium selenate, sodium selenite. They can also contain at least one antioxidant agent, for example chosen from ascorbic acid and its salts; polyamines and especially spermine; zinc-based substances and in particular zinc gluconate; as well as their mixtures.

Preferably, the compositions of the invention are aqueous and therefore, preferably, active agents will be chosen, in particular water-soluble film-forming polymers, in particular from those mentioned above.

Advantageously, the compositions according to the invention can also comprise at least one plasticizing substance, in an amount by weight, expressed relative to the dry matter of the composition, of between 0% and 50%, preferably between 5% and 30 %.

These plasticizing substances make it possible to improve the spreading qualities of the main film, as well as its physical properties.

Among the plasticizing substances which may be used for this purpose, mention will be made more particularly of glycerol, sorbitol, glycols, and their aliphatic ethers or esters; preferably nonionic surfactants in the form of carbohydrate or glycerol esters or ethers or also more or less ethoxylated alcohols and fatty acids.

As the compounds of the invention can have surfactant properties, in particular as nonionic surfactants, the incorporation of these compounds in the compositions of the invention can make it possible to reduce the level of usual surfactant. As the compounds of the invention are biodegradable, this reduction has a certain advantage from the point of view of the biodegradability of the compositions applied.

According to a particular characteristic, the compositions according to the invention may also comprise one or more additives chosen from dyes and fillers usually used to modify the properties of the coating material and the protection of said material, in an amount by weight, expressed relative to the dry matter of the composition, between 0% and 90%, preferably between 5% and 70%. Among the dyes which may be used for this purpose, the following dyes may be mentioned, for example, in soluble or in the form of lacquers: methyl violet 2B, cochineal red, orange yellow S, as well as pigments such as mica-titanium, titanium dioxide, iron oxide, zinc oxide, l magnesium oxide, black 7 or else pigment pastes containing for example red 48, red 1 12, blue 15, green 7 dispersed in a suitable solvent.

By way of example of a filler, mention will be made in particular of opacifying agents such as, for example, talc, mica, cellulose; water repellents such as fatty acids and their derivatives, silicone polymers and wetting agents promoting the spreading of the film-forming composition, and therefore making it possible to improve the coverage and the appearance of the coated seeds.

By way of example, ethoxylated alkylphenols or phosphoric esters of fatty acids can be used as wetting agents. A phytosanitary composition according to the invention can be either in liquid form with a dry matter content of between 10% and 70%, preferably between 20 and 40%, or also in dry form, that is to say in form of powders or granules, preferably water-dispersible. Such a composition can be prepared by known methods widely described in the literature to which a person skilled in the art may refer, and in particular to patents FR-A2,548,675 and US-4,665,648.

After re-dissolving the dry forms or rediluting the abovementioned liquid forms, different active materials, such as in particular fungicides, insecticides, herbicides, molluscids, repellents or growth substances, may be added to the phytosanitary compositions according to the invention.

These active ingredients may be added in an amount by weight, expressed relative to the dry matter of the composition, of between 1% and 50%, preferably between 3% and 30%. In a particular preferred embodiment of the compositions of the invention, these therefore consist of a coating or film-coating composition in which at least one compound of formula I or i 'is incorporated. Advantageously, the composition of the invention is used for the above-mentioned film-coating treatment in an amount by weight of between 2 and 50 expressed in grams of dry matter per kilogram of seed.

In the case of a coating treatment, the amount of composition used can be between 100 and 1000 grams of dry matter per kilogram of seed.

According to another aspect, the present application aims to cover the seeds treated with the phytosanitary compositions described above in particular by means of the above methods.

The invention will be better understood on reading the following examples which are given purely by way of illustration and cannot therefore limit the scope of the invention.

In these examples, the percentages are given by weight, unless otherwise indicated.

Example 1

2-acetamido-2-deoxy- (6) O-octanoyl D-glucopyranose (C8-NAG)

2.5 g of NAG were added to 30 ml (0.88 g) of pyridine in the DMF solvent (30 ml). To this stirred suspension and cooled by an ice and salt bath, octanoyl chloride (2 ml) was slowly incorporated for one hour. The solution obtained was left overnight at room temperature and then 5 ml of water were introduced in order to hydrolyze the remains of unreacted alkyl chloride. Evaporation under reduced pressure was then carried out to give an orange gum.

After evaporation of the solvents, the orange gum is taken up in ethyl acetate. This organic phase is then washed with basic water (saturated Na ₂ CO ₃ solution) and then with water until neutral. This extraction allows octanoic acid (in the form of sodium octanoate) and NAG which have not reacted to pass into the aqueous phase. After evaporation of the ethyl acetate, a very slightly colored powder is obtained. The yield is estimated at around 40%. Recrystallization of this product from a dichloromethane / pentane mixture makes it possible to obtain the pure product (very fine white powder) according to NMR, therefore to within 5%.

1) ¹³ C NMR spectrum

The deuterated solvent is DMSO. The chemical shifts are expressed in ppm.

2 "to 7" 8 "

Displacement (Corresponding carbon):

173.2 (C 1 "), 169.6 (C 1 '), 91, 0 (CH 1), 71, 4 (CH 3), 70.6; 69.5; 64.0 (CH 4, CH 5, CH ₂ 6), 54.4 (CH 2), 38.0 (CH ₂ 2 "), 33.7 (CH ₂ 3"), 31, 4 (CH ₂ 4 "), 28.7 (CH ₂ 5 "), 24.7 (CH ₂ 6"), 22.9 (CH ₃ 2 '), 22.3 (CH ₂ 7 "), 14.2 (CH ₃ 8").

2) ¹ H NMR spectrum ppm (ppm) = 0.86 (t; 3H; CH ₃ 8 "), 1.25 (m; 8H; CH ₂ from 7" to 4 "), 1.52

(m; 2H; CH ₂ 3 "), 1.83 (s; 3H; CH ₃ 2 '), 2.29 (t; 2H; CH ₂ 2"), 3.07 to 4.32 (m; 8H ; CH; CH ₂ ; OH), 4.9 (m; 1 H; OH), 6.55 (d; 1 H; OH), 7.66 (d; 1 H; NH) 3) Mass spectrum

In chemical ionization mode, the peaks [M + H] ⁺ and [M + HH ₂ O] ⁺ at 348 and 330 respectively confirm the molecular mass of 347 g / mol of C8-NAG.

4) Elementary analysis

The results, presented in the table below, show that the product is only pure at 8%.

5) Determination of the Critical Micellar Concentration: The surface tension γ of the liquid in contact with air is measured at 25 ° C by the Wilhelmy plate method (digital tensiometer Krϋss K10 ST). This consists of immersing a platinum blade vertically in a liquid, then gradually withdrawing it according to the tension exerted by the liquid film on the blade. The maximum value read before the complete removal of the blade represents the surface tension expressed in mN / m. After calibration of the device, the surface tensions of solutions containing increasing amounts of the product were read and the measurements repeated three times. The critical micellar concentration is obtained from the conventional diagrams γ = f (Log C) where C represents the concentration expressed in mol / 1.

The evolution of the surface tension γ (in mN / m) of an aqueous solution (volume = 10 ml) was followed as a function of the quantities of product (C in mol / l) dissolved. The results obtained are illustrated in Figures 1. The critical micelle concentration corresponds to the concentration above which the surface tension becomes constant. First of all, the surfactant nature of the molecules is noted, confirmed by the lowering of the surface tension from 71 to 39 mN / m for concentrations ranging from 0 to 6 mM (or 2.08 g / l).

For C8-NAG, CMC = 6.10 ^'3 mol / l and γ - γ ₀ = 32 ± 2 mN / m. γ - γ ₀ designates the lowering of the surface tension of water (γo) when C = CMC.

Example 2

2-acetamido-2-deoxy- (6) O-stearoyl D-glucopyranose (C18-NAG). The synthesis of Example 1 is suitable for obtaining the compound in

Ci ₈ , 2-acetamido-2-deoxy- (6) O-stearoyl D-glucopyranose. We used

3.8 ml of stearoyl chloride.

One night after the addition of the acyl chloride under the same conditions as for Example 1, the reaction medium became milky white. The solvents were evaporated. The drying was completed by lyophilization and made it possible to recover 3 g of a very fine white powder whose melting point is of the order of 170 ° C.

Example 3 Synthesis of 2-acetamido-2-deoxy- (6) O-decanoyl D-glucopyranose (C10-NAG).

The procedure was the same as in the previous examples. The addition of acyl chloride (2.15 g of decanoyl chloride) to the NAG (2.5 g) was carried out for 1 to 2 hours with stirring, in the presence of 0.88 g of pyridine in 30 ml of DMF in an ice and salt bath (-10 to -20 ° C), and under an inert atmosphere (argon). The solution obtained was left for fifteen hours at room temperature, still with stirring and under argon.

The solution, which became clear, was then hydrolyzed with 5 ml of water and the solvent was evaporated with a vane pump at T = 60 ° C. 30 ml of water were added to the yellow-orange gum. After a waiting time about 1 hour, gelation was observed. The particles being colloidal, washing with water was done by successive centrifugations (up to 5) at 4500 rpm for 30 minutes until neutral. The white pellets were then triturated with pentane, then washed with ether. A fine white powder was then obtained.

The yield obtained is of the order of 35 to 40%.

This low yield can be attributed to the simultaneous formation of diester in C1 and C6, eliminated during washing with ether. Characterization The deuterated solvent used is DMSO. The chemical shifts are expressed in ppm.

2 "to 9" 10 "

1. ¹ H NMR spectrum

The solvent used is deuterated DMSO. δ (ppm) = 0.85 (t; 3H; CH ₃ 10 "), 1.24 (s; 12H; CH ₂ from 9" to 4 "), 1.51 (m; 2H; CH ₂ 3") , 1.82 (s; 3H; CH ₃ 2 '), 2.28 (t; 2H; CH ₂ 2 "), 3.05 to 4.31 (several m; 6H; 4 CH cycle; CH ₂ 6) , 4.76 (d; 1 H; OH), 4.89 (m; 1 H; CH cycle), 5.19 (d; 1 H; OH), 6.57 (d; 1 H; OH), 7, 69 (d; 1 H; NH) 2. ¹³ C NMR spectrum

The solvent used is deuterated DMSO. δ (ppm) = 14.21 (CH ₃ 10 "), 22.35 (CH ₂ 9"), 22.91 (CH ₃ 2 '), 24.73 (CH ₂ 8 "), 28.71 to 29 , 12 (CH ₂ 7 "to 5"), 31, 53 (CH ₂ 4 "), 33.70 (CH ₂ 3"), 36.14 (CH ₂ 2 "), 54.38 (CH 2), 64.02 to 70.52 (CH 4, 5, 6), 71, 38 (CHOH 3), 90.94 (CHOH 1), 169.60 (CHO 1 '), 173.19 (CHO 1 ").

3. Determination of the Critical Micellar Concentration CMC = 8.10 ^-5 mol / l and γ-γ ₀ = 40 + 2 mN / m.

Example 4

Synthesis of 2-acetamido-2-deoxy- (6) O-dodecanoyl D-glucopyranose (C12-NAG)

The procedure was the same as in the previous examples.

The addition of lauroyl chloride (2.47 g) to the NAG flask (2.5 g) and pyridine (0.88 g) in DMF (30 ml) was carried out as for Example 3. The solution obtained was left for fifteen hours at room temperature, still with stirring and under argon. The solution, which had become clear, was then hydrolyzed with 5 ml of water and the solvent was evaporated. 30 mL of water was added to the yellow-orange gum. After a waiting time of approximately 1 h, gelling was observed: the particles are such that two different procedures for washing with water can be chosen. The whole was filtered on frit No. 3, or treated by the method by successive centrifugations as in Example 3.

The white solid (obtained whatever the method) was then triturated with pentane, then washed with ether. A fine white powder was obtained. The yield of this reaction is of the order of 35 to 40%. Characterization

2 "to 11" 12 "

1. ¹ H NMR spectrum The solvent used is deuterated DMSO. δ (ppm) = 0.83 (t; 3H; CH ₃ 12 "), 1.12 (s; 16H; CH ₂ from 11" to 4 "), 1.49 (m; 2H;

CH ₂ 3 "), 1.80 (s; 3H; CH ₃ 2 '), 2.26 (t; 2H; CH ₂ 2"), 3.03 to 4.29 (several m;

6H; 4 CH cycle; CH ₂ 6), 4.75 (d; 1 H; OH), 4.92 (m; 1 H; CH cycle), 5.17

(d; 1H; OH), 6.55 (d; 1 H; OH), 7.68 (d; 1 H; NH) 2. ¹³ C N NMR spectrum (ppm) = 14.13 (CH ₃ 12 " ), 22.28 (CH ₂ 11 "), 22.83 (CH ₃ 2 '), 24.66 (CH ₂ 10"),

28.65 to 29.19 (CH ₂ 9 "to 5"), 31.49 (CH ₂ 4 "), 33.62 (CH ₂ 3"), 37.69 (CH ₂ 2 "),

54.31 (CH 2), 63.95 to 70.44 (CH 4, 5, 6), 71, 31 (CHOH 3), 90.86 (CHOH

1), 169.52 (CHO 1 '), 173.11 (CHO 1 ") 3. Determination of the Critical Micellar Concentration

CMC = 10 ^"6 mol / l and γ-γ ₀ = 13 + 2 mN / m. Example 5

Synthesis of 2-acetamido-2-deoxy- (6) 0-myristoyl D-glucopyranose C14-NAG

The procedure was similar to the previous examples. The addition of myristoyl chloride (2.79 g) took place in a water bath at T = 40 ° C for 1 hour. The flask was left at this temperature for about fifteen hours, still with stirring and under argon.

The solution, which had become clear, was then hydrolyzed with 5 ml of water, and the solvent was evaporated. 30 ml of water was added to the yellow gum. About 1 hour later, gelation was observed: washing with water was carried out by successive centrifugations (4 are sufficient) at 4500 rpm for 30 minutes. The white solid was then triturated with pentane, then washed with ether.

The yield of this reaction is between 35 and 40%. Characterization

2 "to 13" 14 "

1. R spectrum

The solvent used is deuterated DMSO. δ (ppm) = 0.85 (t; 3H; CH ₃ 14 "), 1.24 (s; 20H; CH ₂ from 13" to 4 "), 1.51 (m; 2H; CH ₂ 3") , 1.82 (s; 3H; CH ₃ 2 '), 2.28 (t; 2H; CH ₂ 2 "), 3.09 to 4.31 (several m; 6H; 4 CH cycle; CH ₂ 6), 4.76 (d; 1 H; OH), 4.90 (m; 1 H; CH cycle), 5.19 (d; 1 H; OH), 6.57 (d; 1 H ; OH), 7.69 (d; 1H; NH).

2. NMR spectrum ¹³ C δ (ppm) = 14.20 (CH ₃ 14 "), 22.35 (CH ₂ 13"), 22.90 (CH ₃ 2 '), 24.72 (CH ₂ 12 ") , 28.72 to 29.27 (CH ₂ 11 "to 5"), 31, 55 (CH ₂ 4 "), 33.69 (CH ₂ 3"), 54.37 (CH 2), 63.99 to 70.52 (CH 4, 5, -6), 71, 37 (CHOH 3), 90.94 (CHOH 1), 169.58 (CHO l '), 173.17 (CHO 1 ")

Example 6

2-acetamido-2-deoxy- (6) O-hexanoyl D-glucopyranose (C6-NAG)

Procedure

The reaction was carried out according to the same protocol as for the preceding products with 1.52 g of hexanoyl chloride.

After hydrolysis of the clear solution with 5 ml of water, the solvent was evaporated and 10 ml of water added in order to obtain the precipitation of the product. The whole was then filtered on a No. 3 frit and then washed with water until neutral. The white solid was then triturated with pentane, then washed with ether. A white powder is obtained. Characterization

2 "to 5" 6 "

1. ¹ H NMR spectrum

The solvent used is deuterated DMSO. δ (ppm) = 0.86 (t; 3H; CH ₃ 6 "), 1.26 (s; 4H; CH ₂ 5" and 4 "), 1.52 (m; 2H; CH ₂ 3"), 1.82 (s; 3H; CH ₃ 2 '), 2.25 (t; 2H; CH ₂ 2 "), 3.13 to 4.32 (several m; 6H; 4CH cycle; CH ₂ 6), 4 , 75 (d; 1 H; OH), 4.89 (m; 1 H; CH cycle), 5.19 (d; 1 H; OH), 6.57 (d; 1 H; OH), 7, 69 (d; 1H; NH).

Example 7 2-acetamido-2-deoxy- (6) O-hexanoyl D-glucopyranose (C6-NAG)

In order to obtain regioselective monoesterification on the hydroxyl carried at C6, the hydroxyl carried at C1 is protected by a benzyl group before esterifying. To esterify, a solution of 1.75 g of hexanoyl chloride in

2 ml of dichloromethane was added dropwise at room temperature for 2 hours to a solution of 3.11 g of benzyl NAG in 50 ml of anhydrous pyridine. The solution was stirred at room temperature for 48 h. In order to stop the reaction, the unreacted hexanoyl chloride was hydrolyzed with 5 mL of water. The pyridine was evaporated. The brown oily residue obtained was dissolved in 100 mL of chloroform. This organic phase was washed with 20 ml of water in order to pass the pyridinium chloride and most of the unreacted starting material into the aqueous phase. The organic phase was then washed with 20 ml of a saturated solution of sodium hydrogen carbonate in order to pass the hexanoic acid into the aqueous phase in the form of sodium hexanoate. The organic phase was dried over MgSO ₄ and then evaporated. The residual brown oil was triturated in pentane several times until a fine powder was obtained. The powder was isolated by decantation, dried under vacuum and then dissolved in 100 ml of ether. The starting material and part of the monomer have not been soluble in ether and formed a white solid which was collected by vacuum filtration and dried. The ethereal phase was evaporated. The solid obtained was recrystallized from an ether / pentane mixture to obtain a 90% pure product with a yield of approximately 25%. This product was then debenzylated by hydrogenation at atmospheric pressure with a palladium on carbon catalyst.

¹ H NMR spectrum of 2-acetamido-2-deoxy- (6) O-hexanoyl D-glucopyranose (C6-NAG) The solvent used is deuterated DMSO. δ (ppm) = 0.86 (t; 3H; CH ₃ 6 "), 1.26 (m; 4H; CH ₂ 5" and 4 "), 1.52 (m; 2H; CH ₂ 3"), 1.82 (s; 3H; CH ₃ 2 '), 2.25 (t; 2H; CH ₂ 2 "), 3.13 to 4.32 (several m; 6H; 4CH cycle. CH ₂ 6), 4 , 75 (d; 1 H; OH), 4.89 (m; 1 H; CH cycle), 5.19 (d; 1 H; OH), 6.57 (d; 1 H; OH), 7, 69 (d; 1H; NH).

Example 8

2-acetamido-2-deoxy- (6) O-butyryl D-glucopyranose (C6-NAG)

The procedure was the same as in Example 7, using 1.16 g of butyryl chloride in place of hexanoyl chloride. 1 H-NMR spectrum of 2-acetamido-2-deoxy- (6) O-butyryl D- glucopyranose (C4-NAG)

The solvent used is deuterated DMSO. δ (ppm) = 0.86 (t; 3H; CH ₃ 4 "), 1.52 (q; 2H; CH ₂ 3"), 1.82 (s; 3H; CH ₃ 2 '), 2.25 (t; 2H; CH ₂ 2 "), 3.13 to 4.42 (several m; 6H; 4CH cycle. CH ₂ 6), 4.75 (d; 1 H; OH), 4.89 (m; 1 H; CH cycle), 5.19 (d; 1 H; OH), 6.57 (d; 1 H; OH), 7.69 (d; 1 H; NH).

Example 9

Diester in position C4 and position C6: (C6) ₂ -NAG The procedure is the same as in Example 7, using 3.5 g of hexanoyl chloride. The separation of the diester and the monoester at C6 is obtained by fractional extraction in the solvents (pentane / ether).

Example A

For the treatment (coating or coating) of wheat seeds Triticum aestivum with a composition comprising a coating agent Sepiret 7017 ^® Silver sold by the company SEPPIC, presented in the form of a thick suspension containing 29% of dry matter, an additive according to the invention and a diluent (water) was used. Coating operation: A coating slurry was prepared by diluting the commercial preparation of Sepiret 7017 with demineralized water in the following proportions: 15 g of commercial suspension for 21 g of water. The porridge thus prepared contained between 12% and 14% of dry extract.

The preparations tested on the seeds consisted of this slurry to which various quantities of additive were added, so as to produce preparations titrating between 5 and 50 mg of additive per gram. The additives tested were: N-acetylglucosamine (noted NAG),

2-acetamido-2-deoxy-6-0-octanoyl-D-glucopyranose (C8-NAG), 2-acetamido-2-deoxy-6-0-stearoyl-D-glucopyranose (C18-NAG) and tensio- Hecameg ^® glycosylated active ingredient: methyl-6-0- (N-heptylcarbamoyl) -α-D- glucopyranoside. 4 g of preparation were used to film 1 10 seeds, i.e.

4.5 g of wheat. The application of the coating was carried out by mixing together the seeds and the preparation. The drying was carried out under a stream of hot air: duration: one hour; temperature: 30 - 35 ° C. After this operation, the seeds carried between 0.10 and 0.15 g of dry film coating per gram of wheat. Effects of additives on seed germination and on the development of phytopathogenic fungi.

Lots of 100 wheat seeds naturally contaminated with the phytopathogenic fungi Fusarium roseum and Microdochium nivale were incubated in petri dishes closed with parafilm, at the rate of 5 seeds per dish, after film-coating according to the protocol described above. .

The agar medium consisted of: in g / l of demineralized water: Yeast extract 2, KH2PO4: 1.5; K2HPO4: 1.5; Mg (Sθ4) .7H2θ: 0.3; NaNθ3: 3 and agar: 14. Incubation temperature: 16 ° C.

The antifungal effect was measured by the inhibition of the growth of the hyphae of fungi, after 7 days of incubation, by comparison with the results obtained with film-forming preparations not containing the additives (reference preparations). Contaminated seed is a seed that has given rise to the development of hyphae of the fungus.

The effect on germination was measured by counting the germinated seeds after 7 days. We define, respectively, the Difference of contamination De and

Difference in germination Dg, for a batch of 100 seeds, by:

De = number of contaminated seeds (test) - number of contaminated seeds (ref.)

Dg = number of sprouted seeds (test) - number of sprouted seeds (reference)

The TEA antifungal efficacy rate is also defined by: TEA = (% contaminated seeds reference -% contaminated seeds IOO test (% contaminated seeds reference) and the TEG germination efficiency rate by:

TEG = (% germinated seeds test -% germinated seeds reference xlOO (% germinated seeds reference)

We consider as significant the trials which led to differences Dg or De greater, in absolute value, than 15 seeds.

The table shows a significant antifungal efficacy on the part of C8-NAG at the three concentrations tested: 5, 10 and 50 mg / g as well as for Hecameg (5 mg / g). However, there is an increase significant germination for an average concentration of C8-NAG (10 mg / g) while Hecameg reduces it.

Example B: Coating with C12-NAG alone in solution or in hydroalcoholic suspension.

Film-coating tests were carried out by stirring, for approximately one minute, wheat seeds in suspensions or hydroalcoholic solutions of C12-NAG. These suspensions or solutions were produced by mixing 150 mg of C12-NAG with 4 ml of hydroalcoholic solvent.

The solvents tested were pure water, an aqueous ethanol solution at 50% volume / volume and an aqueous ethanol solution at 95% (v / v).

Lots of 50 seeds, approximately 2 grams, were used. The film-coated seeds were then dried in a stream of hot air at about 30 ° C.

Control manipulations, with other batches of seeds, consisted in carrying out the protocol described above using hydroalcoholic solutions of the same titles, without active compound, in order to control the effect of the simple impregnation of the seeds by the diluents . The control batches and the batches comprising C12-NAG were dried simultaneously under the same current of hot air. Drying was stopped when the control batch regained its initial weight before impregnation.

The physicochemical properties of the C12-NAG compounds allow the deposition of significant quantities of the compound. Table 1 summarizes these results: Table 1: Coating tests with pure C12-NAG: dry mass deposited

*: Suspension in the diluent 50% ethanol, then evaporation before coating

Example C

Flax and pea film-coating treatment The procedure was as in Example A.

The film-coating agent is Sepiret Argent 7017 ^® . For flax and peas, 5 and 6 g of this film-coating suspension are respectively required to film 110 seeds.

Different additives can be added to this preparation before the seeds are introduced. This method is very rudimentary and nevertheless offers the advantage of being easy to implement, in particular for testing a range of different film-coating compositions. It is also inexpensive in seeds. It allows you to film by obtaining a dry mass much greater than that achieved by an industrial type laminator (more than 30 times more). Example D

Effect on contamination of pea seeds (Pisum sativum)

Pea seeds contaminated with Botrytis sp. and Ascochyta pinodes were coated with Sepiret Argent 7017® (reference) and with NAG and C8-NAG introduced into the coatings, under the same conditions as above.

The pea seeds used germinated less quickly than those of wheat, the results were increased to 8 days.

The results are presented as a percentage of germinated or contaminated seeds: these figures are to be systematically compared with the results obtained on the batch of seeds serving as a reference. Thus, we indicate the algebraic deviation Δ, in number of seeds of the batch tested compared to the 100 seeds of the reference. At the same time, the effect obtained with respect to the contamination, eff, expressed as a percentage, is calculated as follows:

Eff = (% of contaminated seeds -% of contaminated seeds of the reference) x 100% of contaminated seeds of the reference Thus, an antifungal effect corresponds to a negative value of eff. NAG 50 mg / g: Δ contam. 8 d = + 30; eff. contam. 8 d = + 16% C8NAG 10 mg / g: Δ contam. 8 j = -7; eff. contam. 8 d = -37%

Example E

Germination of phytopathogenic fungal spores in the presence of Cn-NAG. Solutions of Cn-NAG (n = 8, 10, 12 and 14) are produced by dissolving 2 mg of Cn-NAG in 0.4 ml of 95% ethanol.

Each of these solutions is introduced into 40 ml of sterile agar kept liquid at 50 ° C.

The agar is composed of glucose (10 g / l) and Agar-Agar (12.5 g / l). After addition of the Cn-NAG solutions, the agar is poured into sterile Petri dishes. The dishes are then seeded with 0.3 ml of mushroom spore suspensions containing between 2.10 ⁵ and 4.10 ⁵ spores / ml. After incubation for approximately 20 hours at 19 ° C. in the dark, the germination of the spores and the length of the hyphae developed by the fungi are evaluated by observation under a microscope.

The following table shows the results obtained with the Botrytis cinerea (strains A and B) and Fusarium roseum v. graminearum.

Results

There is a significant decrease in the length of the hyphae developed by all fungi in the presence of Cn-NAG. The most marked effect being observed with C14-NAG: between 60 and

70% reduction in length for Botrytis and Fusarium respectively. There is also a relative decrease in the germination rate of spores (between 35 and 50%) for Botrytis.

σ

L: length of hyphae

TG: germination rate of spores

Claims

branched in Ci to C-iβ, n is between 1 and 17 and m is between 0 and

16 and n + m <18, R _Θ , R βt R ₈ represent, independently of one another, H or a linear or branched alkyl chain Ci to Cι ₂ , and X ^" an anion

3. Method according to claim 1 or 2, characterized in that R5 represents a linear or branched C ₃ to C-ι ₃ alkyl chain.

4. Method according to one of claims 1 to 3, characterized in that in formula I ', two among A ₃ , A ₄ and Aβ represent, independently of one another, OC (0) Rs where R ₅ represents a linear or branched alkyl chain C ₃ to C-ι _3, and the third of a _3, a ₄ and Aß is OH.

5. Method according to claim 4, characterized in that R ₅ represents a linear or branched C ₃ to C ₈ alkyl chain.

6. Method according to one of claims 1 to 3, characterized in that in formula I ', two among A ₃ , A ₄ and β represent OH and the third among A ₃ , A ₄ and AQ represents OCOR ₅ where R5 represents a straight or branched alkyl chain C ₃ Cι _3.

7. Method according to one of claims 1 to 6, characterized in that R ' ₂ represents CH ₃ .

8. Method according to claim 1, characterized in that the compound has the formula:

(I) in which Ri represents R or CO-R where R represents a linear or branched C ₅ -C ₁₈ alkyl chain and R ₂ represents a linear alkyl chain or branched in Ci to C ₄ or an ethynyl group, or -NR ₃ R ₄ where R ₃ represents C _p H ₂ p ₊ ι, p ranging from 0 to 4 and R represents C _q H ₂ q + ι, q ranging from 0 to 4.

9. Method according to claim 8, characterized in that Ri represents COR.

10. Method according to one of claims 8 or 9, characterized in that Ri represents COR where R is a linear chain in C5, C ₇ , Cg or C11.

11. Method according to one of claims 8 to 10, characterized in that R2 represents CH ₃ .

12. Method according to one of claims 1 to 11, characterized in that the plant material is a standing plant, a plant cell culture, a root, an onion, a tuber or seeds.

13. Method according to one of claims 1 to 12, characterized in that the plant material is in the form of seed.

14. Method according to one of claims 1 to 13, characterized in that the application is carried out by spraying, spreading, coating or film-coating.

15. Method according to one of claims 1 to 14, characterized in that the application is carried out by coating or film-coating.

16. Method according to one of claims 1 to 15, characterized in that the application is carried out in an amount of 0.1 mg to 100 mg of compound of formula I per gram of seed, preferably 1 mg to 5 mg.

17. Method according to one of claims 1 to 16, characterized in that the application is carried out by application of aqueous spray comprising 1 to 40, preferably 5 to 20 mg of compound of formula l / g of aqueous spray, or 1 to 40, preferably 3.5 to 15% of compound of formula I in the slurry by weight of dry extract.

18. Composition comprising at least one compound of formula I ':

in which A ₆ , A ₄ and A ₃ , independently of one another, represent OH or OR ₅ or OC (0) R ₅ or O-SO2-R5 or 0- (CH ₂ ) n-NR6-C _m H ₂ m ₊ ι or - NHC (0) R ₅ or 0- (CH ₂ ) n-NR6-C (0) -C _m H ₂ m ₊ ι or 0- (CH ₂ ) _n -SC _m H _{2m +} ι or SR ₆ or NR ₆ R ₇ or NR ₆ R ₇ R ₈ ⁺ X ^" where R represents a linear or branched C 1 to C ₈ alkyl chain, n is between 1 and 17 and m is between 0 and 16 and n + m <18, R _6, R ₇ βt R ₈ represent, independently of each other H or a linear or branched C1 to C12 alkyl chain, and X ^" an inorganic or organic anion, and in which R ' ₂ represents a linear or branched C1 to C alkyl chain or an ethynyl group or NR' ₃ R ' ₄ , where R' ₃ and R ' ₄ independently represent one of the other CjH ₂ i + ι i ranging from 0 to 4, the anomeric carbon hydroxyl being in the α or β position, with the exception of the compounds where A ₆ , A ₄ and A ₃ represent OH, and a vehicle support for phytosanitary application e.

19. Composition according to claim 18, comprising at least one compound of formula I:

(I)

in which Ri represents R or CO-R where R represents a linear or branched C ₅ to C ₈ alkyl chain and R ₂ represents a linear or branched C ₁ to C ₄ alkyl chain or an ethynyl group, or -NR3R ₄ where R ₃ represents C _p H _{2p + 1} , p ranging from 0 to 4 and R ₄ represents C _q H ₂ q + ι, q ranging from 0 to 4 and a vehicle support for phytosanitary application.

20. Composition according to claim 19, characterized in that Ri represents COR where R is a linear chain in C ₅ , C, Cg or C-.

21. Composition according to one of claims 18 to 20, characterized in that R ₂ or R ' ₂ represents CH ₃ .

22. Composition according to one of claims 18 to 21, characterized in that the vehicle is a coating or film-coating formulation or an aqueous or hydroalcoholic solution.

23. Composition according to one of claims 18 to 21, characterized in that the compound of formula I is present in proportions ranging from 1 to 97% of compound, by weight of dry extract in the composition. 24. Compounds of formula I ':

(! ') in which A ₆ , A ₄ and A _3> independently of each other, represent

OH OR OR5 OR OC (0) R ₅ OR O-SO2-R5 OR 0- (CH ₂ ) n-NR6-C _m H2m + 1 or - NHC (0) R ₅ or 0- (CH2) n-NR ₆ -C (0) -C _m H _{2m +} ι or 0- (CH ₂ ) nSC _m H _{2m +} ι or SR ₆ or NR ₆ R7 or NR ₆ R ₇ R ₈ ⁺ X ^" where R ₅ represents a linear or branched alkyl chain in Ci to Cιs, n is between 1 and 17 and m is between 0 and 16 and n + m <18, Rβ _, R ₇ and R ₈ represent, independently of one another H or a linear alkyl chain or branched in Ci to C ₁ 2, and X ^" an inorganic or organic anion, and in which R ' ₂ represents a linear or branched alkyl chain in C to C ₄ or an ethynyl group or NR' ₃ R ' ₄ , where R ' ₃ and R' ₄ represent independently of each other H2i + ι i ranging from 0 to 4, the anomeric carbon hydroxyl being in position α or β, with the exception of the compounds where Aβ, A ₄ and A3 represent OH, compounds where R ' ₂ represents CH ₃ , A3 and A4 represent OH and A represents OC (0) (CH ₂ ) 6CH ₃ or OC (0) (CH ₂ ) i4CH ₃ , and compounds where R' ₂ represents CH ₃ , A ₄ and A ₆ represent OH and A ₃ represents OC (0) (CH ₂ ) ₆ CH ₃ or OC (O) (CH ₂ ) ₁₀ CH ₃ or OC (0) (CH ₂ ) ι ₄ CH ₃ . 25. Compounds of formula I:

(I) in which Ri represents R or CO-R where R represents a linear or branched alkyl chain in Cs to C-ι ₈ and R ₂ represents a linear or branched alkyl chain in Ci to C- ₄ or an ethynyl group, or -NR ₃ R ₄ where R ₃ represents C _p H _2P + ι, p ranging from 0 to 4 and R ₄ represents C _q H _2q + ι, q ranging from 0 to 4, with the exception of the compounds where Ri represents CO (CH ₂ ) eCH ₃ or CO (CH ₂ ) ι ₄ CH ₃ and R ₂ is CH ₃ .

26. Use, as phytosanitary agent, of the compound of formula I ':

<0 in which A ₆ , A ₄ and A ₃ , independently of one another, represent OH or OR ₅ or 00 (O) R ₅ or 0-S0 ₂ -R ₅ or 0- (CH ₂ ) n-NR ₆ -C _m H2m + ι or - NHC (0) R ₅ or 0- (CH ₂ ) _n -NR ₆ -C (0) -C _m H _{2m + 1} or 0- (CH ₂ ) nSC _m H ₂ m ₊ ι or SR ₆ or NR ₆ R ₇ or NR ₆ R ₇ R ₈ ⁺ X ^" where R ₅ represents a linear or branched C 1 to C ₈ alkyl chain, n is between 1 and 17 and m is between 0 and 16 and n + m <18, R _6, R ₇ and R ₈ represent, independently of one another, H or a linear or branched alkyl chain in Ci to C-ι ₂ , and X ^" a mineral anion or organic, and in which R ' ₂ represents a linear or branched C1 to C ₄ alkyl chain or an ethynyl group or NR' ₃ R ' _l where R' ₃ and R 'represent independently of each other CjH _{2i +} ι i going from 0 to 4, the hydroxyl of the anomeric carbon being in position α or β, with the exception of the compounds where A $, A ₄ and A ₃ represent OH.

27. Use, as phytosanitary agent, of the compound of formula I:

) Wherein R represents R or CO-R wherein R represents a linear or branched alkyl chain C ₈ to C-ι and R ₂ represents a linear alkyl chain or branched Ci-C4 or an ethynyl group or -NR ₃ R ₄ where R ₃ represents C _p H _2p + ι, p ranging from 0 to 4 and R ₄ represents C _q H _{2q +} ι, q ranging from 0 to 4.

28. Use according to one of claims 26 or 27, characterized in that the compound of formula I or I 'is present in proportions ranging from 1 to 97% of compound, by weight of dry extract in the composition of application. 29. Use of the compound of formula I or the as defined in claim 26 or 27 as a surfactant.

30. Use of a compound of formula I or l as defined in either of claims 26 or 27 as an antifungal.

31. Use of a compound of formula I or l as defined in either of claims 26 or 27 as a progerminative.

32. Use of a compound of formula I or l as defined in either of claims 26 or 27 as an additive for a film-coating or coating composition.

33. Plant material treated by the process according to one of claims 1 to 17.

34. Vegetable material according to claim 33, characterized in that the vegetable material is a seed.