EP1521779A1

EP1521779A1 - Compounds that bind to the interferon-gamma, preparation method thereof and medicaments containing same

Info

Publication number: EP1521779A1
Application number: EP03760740A
Authority: EP
Inventors: David Bonnaffe; André Lubineau; Jocelyne Alais; Olivier Gavard; Anna Dilhas; Hugues Lortat-Jacob
Original assignee: Centre National de la Recherche Scientifique CNRS; Commissariat a lEnergie Atomique CEA; Universite Paris Sud Paris 11
Current assignee: Centre National de la Recherche Scientifique CNRS; Universite Paris Sud Paris 11; Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Priority date: 2002-06-19
Filing date: 2003-06-18
Publication date: 2005-04-13
Also published as: CA2489561A1; JP2005533881A; FR2841250A1; AU2003260601A8; FR2841250B1; US20060166927A1; WO2004000887A1; AU2003260601A1

Abstract

The invention relates to a compound that can bind to the interferon-gamma (IFN<), which is selected from molecules having formula (I), in which X denotes a divalent spacer group having a sufficient length to enable each of the two oligosaccharide fragments A and B to bind to one of the peptide sequences 125 to 143 at the C-terminal ends of a homodimer of interferon-? (IFN-?) and n denotes an integer of between 0 and 10, e.g. equal to 0, 1, 2, 3, 4 or 5, and each R denotes independently a hydrogen atom, an SO3<- >group, or phosphate, on the condition that no SO3<- >group is located in position 3 of the glucosamine units of the compound (I). The invention also relates to the method of preparing the compounds, the complexes formed by the aforementioned compounds and the interferon-gamma and medicaments containing said compounds or complexes.

Description

COMPOUNDS BINDING INTERFERON-GAMMA, THEIR PREPARATION METHOD, AND MEDICAMENTS CONTAINING THEM

DESCRIPTION

The invention relates to new compounds or neoglycoconjugates which bind to interferon-gamma.

The invention also relates to the process for the preparation of these compounds, the complexes formed by these compounds and interferon-gamma, and the medicaments comprising these compounds or complexes.

Interferon-gamma (IFNγ) is a polypeptide comprising, for example, 143 amino acids in humans which is part of the family of cyto ines. Cytokines are mediators of cellular communication, which act according to a paracrine, autocrine or sometimes even endocrine process.

In the body, the production of these proteins is finely regulated, and a defect or excess of their synthesis is generally responsible for various pathologies.

From a therapeutic point of view, it may therefore be interesting to increase, or on the contrary to reduce the biological activity of such a protein.

IFNγ, first characterized, on the basis of its antiviral activity, is involved in particular in the control of the immune response and during inflammation.

This cytokine is also cytotoxic or cytostatic for transformed cells and induces the synthesis of oxygen radicals. It regulates expression a large number of molecules in the pericellular space, in particular cell surface molecules, as well as a large number of compounds of the extracellular matrix. IFNγ therefore plays an important role, among other things, in defense mechanisms, such as the immune response and inflammation, in cell growth and differentiation, in the phenomena of cell adhesion and migration (1).

Therapeutics linked to cytokines, such as IFNγ, consist either in administering this type of molecule, or, on the contrary, in inhibiting their activities.

Thus, the multiple activities mentioned above and observed in vitro have given rise to numerous clinical trials in various pathologies, such as cancer (2), chronic granulomatosis (3), rheumatoid arthritis (4) , bacterial or parasitic infections (5), hepatitis (6) or fibroproliferative diseases, such as systemic sclerosis (7). However, the clinical efficacy of IFNγ has not been clearly demonstrated so far, and its main indication remains limited to a rare disease: chronic granulomatosis (8).

Conversely, in certain inflammatory or autoimmune pathologies (9), or to reduce the rejection of the graft after transplantation, it may be advantageous to inhibit the biological activity of the cytokine. For this, antibodies or receptors in soluble form have been developed and tested in animal models (10).

Developing a therapy based on the use of IFNγ poses technical problems important, linked in particular to its low half-life in vivo and its low bioavailability.

The obstacle of low bioavailability of IFNγ can be overcome by using local application methods, but these methods do not allow deep organs to be reached systemically, moreover, the problem of low half - life in vivo remains intact.

By way of example, such methods of local administration of IFNγ: mention may be made of the inhalation of IFNγ for the treatment of lung cancer, its nebulization in the treatment of the allergic response, or its encapsulation in liposomes.

The study of the cellular response to IFNγ can help explain the difficulties of therapeutic use.

Indeed, the cellular response to IFNγ depends on the type of cells stimulated, the local concentration of IFNγ and the other regulatory factors to which the cell is exposed concomitantly.

In particular, it has been shown that, independently of its cellular receptor, IFNγ was also capable of binding to oligossacharides of the heparin or heparan sulphate (HS) type, with a high affinity (5 to 10 nM) (11) .

In vivo, in animals, heparan sulfate effectively fixes IFNγ, and this interaction controls the plasma elimination of the cytokine, its accumulation in various organs, and its location in the tissues. In particular, after an intravenous injection, the IFNγ is eliminated by a biexponential process, during which 90% of the cytokine disappears from the blood circulation during the first 5 to 10 minutes, with a particularly short half-life time, similar 1 minute.

These results demonstrate that a large proportion, namely approximately 90% of the injected IFNγ, is rapidly fixed by molecules of the heparin / heparan sulfate type,

10 in particular on the surface of the vascular endothelium (12). In addition, autoradiographic observation of tissue sections shows that IFNγ does not have identical access to all tissues.

It accumulates in the liver, kidney and spleen,

15 but, for example, not in the muscle. In addition, within the same tissue, it is not homogeneously distributed and is concentrated in areas rich in heparan sulfate. Such local concentrations are detected, for example, in the hepatic sinusoids - on the surface

20. hepatocytes and endothelial cells -, in the renal glomeruli or in the red pulp of the spleen (13).

It therefore appears clearly that the interaction of the cytokine with HS considerably limits the accessibility to different compartments in

25 vivo, and the difficulties encountered during the therapeutic use of IFNγ (14) are probably linked in part to these interactions. These studies also show that heparin sulfates are responsible for significant local accumulation of cytokine.

30 in the tissues. Finally, it has also been shown that in in vivo, IFNγ, alone, is rapidly inactivated by proteolytic degradation of its C-terminal end (12).

In order to provide a solution to the problems mentioned above, it has been proposed to associate IFNγ with a heparin molecule. This association allows a much slower plasma elimination and a wider tissue distribution of the cytokine and induces, in addition, an increase in activity by a mechanism of protection of the C-terminal domain, against proteolytic degradations.

Furthermore, the injection of heparin alone makes it possible to displace the cytokine accumulated in the tissues by endogenous HS, and therefore to reduce or suppress its activity. However, the use of a heparin molecule to protect IFNγ and increase its bioavailability, or on the contrary to suppress its local action, raises difficulties which arise from the activities of heparin, itself, and , in particular, its anticoagulant properties. On heparan sulfates (HS), the interaction site for IFNγ was characterized. It consists of highly sulfated octasaccharide domains separated by a larger, less sulfated 7 kD domain.

Figure 1 shows a dimeric complex of IFNγ and heparan sulfate. The two octasaccharide domains are represented by bold lines in FIG. 1.

Only the octasaccharide domains bind to the dimeric form of IFNγ, the central domain bridging the two ends. Document FR-A-2 736 832 (WO-A-97/03700) describes an agent which modulates the activity of interferon-γ comprising a group of formula AXB, in which A and B independently represent an oligosaccharide group carrying an anionic charge sufficient, for example, in the form of sulphate groups to confer on said oligosaccharide group an affinity for part of the C-terminal end of human interferon-γ containing the peptide sequence 125-131, and X is a spacer arm of sufficient length to allow groups A and B to each bind to one of said peptide sequences of the C-terminal ends of a homodimer of interferon-γ. The compound described in this document has the following drawbacks:

The molecules designated by A and B are fragments of depolymerization of heparin or of sparse sulfate. It may be recalled here that these molecules are characterized by very great structural heterogeneity, and that there is no method for obtaining molecules of this type of defined structure, from natural sources. The compound described in this document therefore in fact represents a mixture of molecules of various structures. Likewise for segment X which, depending on the case, may also be a fragment of depolymerization of heparan sulfate.

Such a molecule does not necessarily have C2 symmetry (the fragments A, X and B are "in lines", or oriented in the same direction, or else arranged in a "parallel" manner) and therefore does not respect the symmetry of the protein it's supposed to bind to.

Furthermore, these molecules are of animal origin and have the disadvantage of carrying possible transmissible infectious agents. There is therefore a need for a molecule which, linked to IFNγ, makes it possible, among other things, to protect the latter against any degradation, increases its bioavailability, as well as its half-life duration, or, capable of displacing the IFNγ accumulated by heparan sulfates in tissues.

In other words, there is a need for a molecule which, associated with IFNγ, has an action substantially similar to that of heparin, without exhibiting the drawbacks associated with the latter. The object of the invention is to provide a molecule capable of binding to IFNγ, which meets, among other things, the needs indicated above.

The object of the invention is also to provide a molecule capable of binding to IFNγ, which does not have the drawbacks, limitations, defects and disadvantages of analogous molecules of the prior art, in particular heparin and which resolves the problems of the prior art.

This object and others still are achieved, in accordance with the invention, by providing a compound capable of binding to the interferon-γ IFNγ corresponding to the following formula (I):

in which X is a divalent spacer group of sufficient length to allow the two oligosaccharide fragments A and B to each bind to one of the peptide sequences 125 to 143 of the C-terminal ends of an interferon-γ homodimer (IFNγ), n represents an integer from 0 to 10, for example and equal to 0.1, 2, 3, 4, or 5 and each R independently represents a hydrogen atom, an SO ₃ ^"group , or a phosphate group, provided that no SO ₃ ^"group is found in position 3 of the glucosamine units of compound (I).

Preferably, all R's represent a group

SO ₃ ^" or all R groups represent a phosphate group.

The molecule according to the invention is new. It is not identical to any natural molecule, nor to any of the molecules synthesized in the prior art and in particular in application FR-A-2 736 832 (O-A-97/03700).

Indeed, the molecule according to the invention has a specific structure due, first of all, to the fact that the two oligosaccharide groups, placed on either side of the spacer group X, are in an arrangement which can be qualified "symmetrical" or "antiparallel" with respect to the spacer arm, while both in the natural molecules of heparin and heparan sulfate, as in synthetic heparins and in similar molecules described in the prior art, both oligosaccharide groups are in a "parallel" or "asymmetrical" arrangement. These molecules therefore do not respect the symmetry of the protein on which they are capable of binding. In other words, the natural molecules and the molecules of the prior art, whether they are heparin, heparan sulfate, or molecules analogous thereto ^' are completely, completely asymmetrical, that is to say that they come in a form of type "1212", while the molecules of the invention are in an antiparallel form of type "1221", that is to say having a symmetry of type C2.

Furthermore, the molecules of the invention are fundamentally distinguished from natural molecules and molecules of the prior art by another essential structural characteristic in the sense that the molecules according to the invention do not contain a sulfate group in position 3 of the units glucosamine.

Because this sulfate group is responsible for a preponderant part of the anticoagulant activity of heparin, the molecules according to the invention therefore do not have one of the main drawbacks of the molecules of the prior art linked to their anticoagulant activity .

The molecule according to the invention, which can be defined as being a "structural mimic" of heparan sulfate or heparin, in which heparin-type oligosaccharides are linked by a hydrophilic spacer (X) of modular length, is specifically binds to IFNγ like HS.

The compound according to the invention therefore possesses, and even beyond, all the advantageous properties of heparin: namely, inter alia, the fact of protecting the IFNγ molecule against attacks by proteases, the increase in bioavailability of IFNγ, the ability to dissociate, by competition, an iFNγ / heparan sulfate complex, without having the essential drawback: namely, the anticoagulant activity. The molecules according to the invention, finally, are entirely synthetic molecules, unlike molecules of the prior art, represented, for example, by the document FR-A-2 736 832, in which the "terminal" oligosaccharide fragments are of natural origin, as in most cases, as the spacer arm. The disadvantages presented by the molecules of document FR-A-2 736 832 have already been described above, in particular as regards the natural, animal origin of the fragments which constitute them.

The molecules according to the invention, because of their specific structure, therefore appear to solve the problems of molecules used for the same purposes in the prior art. Advantageously, the spacer group has a length o from 15 to 150 A, preferably from 33 to 50 A.

Affinity for the cytokine is optimal for a length of 33 to 50, for example 50 A.

Generally, the spacer group consists of a carbon chain, preferably from 1 to 120 C, one or more of the carbon atoms of which are optionally replaced by a heteroatom chosen from N, S, P and O, an S0 group, or a aryl group, said carbon chain carrying, optionally, one or more anionic groups preferably chosen from sulphate, phosphate and carboxylic groups, etc.

Advantageously, and in particular due to the process used to synthesize the compounds according to the invention, the spacer group X is derived from a polyglycol chosen, preferably, from poly (alkylene glycol) of which the alkylene group comprises from 1 to 4 C, such as poly (ethylene glycol).

Thus, the spacer group will be able to respond to the

where m is generally an integer from 5 to 32.

And the compounds according to the invention will thus preferably correspond to the following formula (II):

(II)

in which n and m have the meaning already given above.

The compounds of formula (II), which are particularly preferred, are those in which n = 0 and m = 5 (11a); n = 0 and m = 10 (Ilb); n = 0 and m = 32 (Ile); n = 1 and m = 5 (Ild); n = 1 and m = 10 (Ile); n ≈ 1 and m = 32

(Ilf); n = 2 and m ≈ 5 (Ilg); n = 2 and m ≈ 10 (Ilh); n = 2 and m = 32 (Ili).

The invention also relates to a process for preparing the compounds corresponding to formula (II), in which the radical coupling of two compounds is carried out water soluble precursors of oligosaccharides of formula (III):

(M)

in which n is an integer from 0 to 10, for example equal to 0, 1, 2, 3, 4 or 5, and R 1 and R ₂ represent a protecting group for the hydroxyl group chosen, preferably, from p-methoxybenzyl groups and benzyl, with a dithiol precursor compound of the spacer group of formula:

in which m is an integer from 5 to 32, to obtain a compound of formula (IV):

then, the thioether functions are oxidized to sulfones and the final deprotection of the compound (IV) is carried out to give the final compound of formula (II):

(II)

R 1 is preferably a p-methoxybenzyl group and R ₂ is a benzyl group.

The water-soluble compound precursor of oligosaccharides whose formula is given above (III) is prepared by the following successive steps: a) a disaccharide of formula (V):

is subjected to an oxidative cleavage of the group Ri, preferably paramethoxybenzyle, to give a disaccharide "acceptor" of formula:

b) in parallel, a disaccharide of formula (V), above, is subjected to an isomerization of the allyl group to 1-propenyl, followed by a hydrolysis of the enol ether formed and an activation of the hydroxyl group in the form of trichloroacetamidate to give a “donor” disaccharide, of formula (VIb):

c) the acceptor disaccharide (Via) and the donor disaccharide (VIb) are coupled to obtain the tetrasaccharide (n = 0) of formula (VII), with complete alpha stereospecificity; d) optionally, steps a) to c) are repeated, taking as the starting product for step a), the tetrasaccharide prepared in c), to obtain the hexa (n = 1) and octa (n ≈ 2) saccharide of formula (VII):

e) optionally, steps a) to c) are repeated, taking as starting material, for step a), the octasaccharide prepared in d), to obtain a hexadecasaccharide (n = 6) of formula (VII); f) deacetylation, reduction of the azide function, sulfation and saponification are carried out in order to obtain the water-soluble compound, oligosaccharide (III) precursor sought.

The disaccharide of formula (V) is preferably prepared by a coupling reaction between a compound of formula (VIII):

and a compound of formula (IX)

Finally, the compound of formula (IX) is prepared from the compound of formula (X) and the compound of formula (VIII) is prepared from the compound of formula (XI):

A preferred process for preparing the compound (XI) is to carry out the acetylation of the compound of formula:

at -40 ° C in dichloromethane as solvent, with pyridine as base, acetyl chloride as acylating agent, and 4-dimethylaminopyridine as catalyst.

The compound of formula (XI) is obtained with a very high yield, generally greater than or equal to 95%, and high purity since the furano derivatives are only present in trace amounts in a proportion generally close to or less at 2%.

This avoids, according to the invention, a difficult purification. In all that follows, the therapeutic uses of the compound according to the invention can use one but also several compounds according to the invention. The invention further relates to the compound (I) and the preferred compounds (II), and (IIa) to (Ili) for use as a medicament, generally, the compound (I) and the compounds (II) and (IIa) to (Ili) being new. In other words, the invention relates to the use of the compound (I) and of the compounds (II) and (IIa) to (IIi) in general for preparing a medicament.

When used, only the compounds according to the invention can be used to modulate, for example inhibit, the activity of exogenous or endogenous interferon-γ.

The invention therefore also relates to the compound (I) and to the compounds (II) and (IIa) to (Ili) for use as a modulator, for example an inhibitor, that is to say reducing or suppressing activity endogenous or exogenous interferon-γ.

The invention relates, in addition, to compound (I) and to compounds (II) and (IIa) to (Ili) (alone (s): that is to say without other active principle of different structure) for a use in the treatment of diseases linked to, or characterized by the presence of proinflammatory cytokines such as IFN-γ, these are for example autoimmune, inflammatory or degenerative diseases such as multiple sclerosis, glomerulonephritis, Crohn's disease and rheumatoid arthritis, transplant rejection, etc. The invention thus also relates to compound (I) and to compounds (II) and (IIa to (II)) alone for use in a treatment which complements the immunosuppressive treatments used, for example, to avoid rejection of transplants.

The invention also relates to the use of (I) (alone) and of compounds (II) and (IIa) to (Ili) for preparing a medicament intended for the treatment of disorders, pathologies, related to the activity, in particular excessive endogenous or exogenous interferon-γ and the use of (I) to prepare a medicament intended for the treatment of diseases linked to, or characterized by the presence of pro-inflammatory cytokines such as IFN-γ, it s 'acts for example ^" autoimmune, inflammatory, or degenerative diseases such as multiple sclerosis, glomerulonephritis, Crohn's disease, and rheumatoid arthritis, transplant rejection, etc.

The invention also relates to the use of a compound (I) and of compounds (II) and (IIa) to (Ili) for preparing a medicament intended for a treatment complementary to the immunosuppressive treatments used, for example, to avoid rejection of transplants.

The invention further relates to a medicament containing a compound (or more compounds) of formula (I) or of formula (II) or (IIa) to (Ili), alone (s) (i.e. - say without other active compound); to a composition containing the compound (or more compounds) of formula (I), (II), (IIa) to (Ili), alone (s) and a pharmaceutically acceptable vehicle for use in the treatment of diseases linked to or characterized by the presence of pro-inflammatory cytokines such as IFN-γ (these are example of autoimmune, inflammatory, or degenerative diseases such as multiple sclerosis, glomerulonephritis, Crohn's disease and rheumatoid arthritis, transplant rejection, etc .; to a composition containing the compound (or more compounds) of formula (I), (II), (IIa) to (Ili) alone and a pharmaceutically acceptable vehicle for use in a treatment complementary to the immunosuppressive treatments used, for example example, to avoid rejection of transplants. In this connection, it should be recalled that interferon-gamma is a proinflammatory cytokine, the presence of which characterizes a certain number of pathologies linked to inflammation. In such situations, it is useful to suppress or reduce the biological activity of the endogenous interferon-gamma. In animals, experimental models have proven the advantage of such a strategy (inhibition of interferon-gamma) using inhibiting monoclonal antibodies, or a soluble form of the cytokine receptor. As an example, we can cite autoimmune or degenerative diseases (multiple sclerosis,

Glomerulonephritis, Crohn's disease, Rheumatoid arthritis ... etc). Likewise, the inhibition of interferon-gamma can be an effective complement to the immunosuppressive treatments for example by cyclosporine used for example to avoid rejection of grafts.

Medicines containing the compound (or compounds) (I) alone (s) can be administered in doses which can be determined beforehand by routine experiments, depending in particular on the desired effect. These doses can range, for example, from 0.1 to 200 mg per individual per day, preferably from 1 to 50 mg.

The invention further relates to a medicament containing, in addition to the compound (I) or the preferred compounds (II) from (IIa to (II)), interferon-γ.

Such a medicament contains in combination the compound (I) and the interferon-γ, preferably at a rate of

0.05 to 1 mg of interferon-γ and from 1 to 50 equivalents of compound (I). In this medicine, the compound (I) (e.g.

(II) or (IIa to (Ili)) and the interferon-γ is preferably in the form of a complex of the compound (I) and the interferon-γ. Said complex makes it possible to increase the bioavailability of the cytokine and protects it from proteolytic degradations.

In other words, the compound (I) prevents the capture of interferon-γ by endogenous sparse sulfate molecules, present, for example, in the extracellular matrix and on the surface of many cells, and therefore allows its maintenance and transport in general traffic.

In addition, the compound (I) protects the interferon-γ against degradations capable of reducing or canceling its activity, and it makes it possible to maintain the interferon-γ in its most active form, until the moment of its action on competent cells.

The invention therefore relates to: the complex of compound (I) (or (IIa) to (Ili)) and of interferon-γ for use as a medicament. Indeed, this complex is new and its therapeutic use has never been mentioned; the complex, above, for use as an immunostimulant. Immunostimulatory effects include, for example, the antiproliferative effect in cancers and the activation of immune defenses in infectious diseases, for example viral, bacterial or parasitic, or the ability to block the synthesis of collagen in fibrosis of organs, etc.

And the invention will therefore relate to the above complex for use in the treatment of a disease chosen from cancer, infectious diseases, for example viral, bacterial or parasitic, and organ fibrosis.

The invention relates generally to a medicament containing said complex, as well as the use of the complex for the treatment of a disease, as mentioned above. The invention also relates to the use of the complex, in general, to prepare a medicament and, in particular, to the use of the complex to prepare a medicament intended for the treatment of a disease, as mentioned above. . The invention further relates to a composition containing said complex and a pharmaceutically acceptable vehicle for use in the treatment of a disease selected from cancer, infectious diseases, for example viral, bacterial or parasitic, and fibrosis of organs. The invention will now be described in detail in the following description, of a particular embodiment of the present invention, in which the spacer group consists essentially of a polyglycol, in particular of a polyethylene glycol.

This description is made in conjunction with the accompanying drawings in which: FIG. 1 represents an IFNγ / HS dimer complex or molecule according to the invention; 0 FIG. 2 is a graph which gives the% inhibition I for different molecules according to the invention defined by the length L of the spacer arm o (in A) and of the number of saccharides of the oligosaccharide groups (tetra, hexa 5 or octasaccharide ). The compounds according to the invention can be defined as structural mimics of heparin or heparan sulfate or also as neoglycoconjugates corresponding, in particular, to formula (II). 0

(not)

In these structural mimics, tetra with octasaccharides, of the heparin type, are linked by a hydrophilic spacer of modular length, for example a polyglycol type spacer. The molecules according to the invention bind specifically to IFNγ, in the manner of Heparan-Sulphate, as described in FIG. 1.

The development of a process for the preparation of the compounds according to the invention faced essentially four problems:

1. Have a high-efficiency coupling between the spacer and the oligosaccharides which always require significant synthetic effort.

2. Master the stereochemistry of the bond between the spacer and the first glucosamine unit of oligossacharide. This stereochemistry must be alpha, since it is the stereochemistry that is naturally found in the polymer of Heparan-Sulphate (HS).

3. Master the alpha stereochemistry of all the glycosidic bonds in the oligosaccharide.

4. Have effective access to L-Iduronic acid, which is a rare sugar that cannot be isolated in sufficient quantity from natural sources for synthetic needs.

In the following, we describe the synthesis of the compounds according to the invention, emphasizing each time the solutions provided by the method of the invention to each of the synthesis problems listed above.

1. Development of an efficient coupling to a poly (ethylene glycol) (PEG) spacer. For the coupling between the oligosaccharides and the spacer, use is preferably made, according to the invention, of a conventional reaction in organic chemistry: the radical coupling of a thiol on an alkene (19). This method has been successfully tested with alpha-allyl glucosaminide 2 and the dithiol derivatives of PEG 3a-c. (diagram 1).

Diagram 1

2. Control of the stereoselectivity of the anomeric alkylation reaction,

To prepare compound 2, the anomeric alkylation method, developed by R. R. SCHMIDT (20) and already used in the laboratory (21) was chosen. The reaction of the alkoxide from hemiacetal 5a with the allyl bromule 6 leads exclusively, in dichloromethane, to the beta stereoisomer.

Surprisingly, it has been found that the addition of tetrabutylammonium iodide reverses the stereochemistry and leads mainly to the alpha isomer in alpha / beta ratios of up to 98/2

(22) (diagram 2). This procedure specific to the invention, unexpectedly leading to the alpha isomer, is neither described nor suggested in the prior art. The reaction conditions for the glucosamine 5a derivative were optimized and applied as such to the other substrates. The optimization concerns the temperature, the ratio of the reactants, the concentrations, etc. Thus, these reaction conditions were applied to other sugars and to another electrophile: benzyl bromide 7. He was thus able It should be shown that this reversal of stereoselectivity of the anomeric alkylation reaction with tetrabutylammonium salts was general.

6.8: R '- CH = CH ₂ 5a, 8a, 9a R ₁ -0Ac, R ₂ = H, R ₃ = NHAc, R = Ac 5c, _18c: = H, R ₂ = OAc, R ₃ = 0Ac, R = Ac

7, 9: R ' ^≈ Ph 5b, 8b: R _t = OAc, R ₂ = H, R ₃ OAc, R = Ac 5d, 8d: R _t = OBn, R ₂ = H, R _g = 0Bn, R = Bn

Diagram 2

3. Preparation of octasaccharide tetra, precursors of heparin fragments.

There are many methods for preparing long fragments of heparin or mimes (23).

Due to the essential step of the process of the invention, it is imperative to prepare fragments having an allyl group in anomeric position, for the couplings to the spacer, which leads to the development of a specific process. Indeed, it was necessary to use a highly convergent method, based on the preparation of a suitably protected disaccharide which allows generating a donor disaccharide and an acceptor disaccharide, so as to prepare a tetrasaccharide, the latter itself being able to serve as a base for the preparation of hexa and octasaccharides. The stereochemistry constraints of the oligosaccharide couplings, the desired sulfation patterns, as well as the need for the allyl group in the anomeric position have led to considering disaccharide 10 as the basic brick of the synthesis (diagram 3).

Diagram 3

3. 1. Synthesis of basic disaccharide 10.

3. 1. 2. New accesses to L-iduronic acid (24).

L-Iduronic acid is a rare sugar that it is impossible to isolate in sufficient quantity from natural sources for synthetic needs. It is therefore essential to have effective methods for preparing derivatives of this compound (25). Although the addition of organometallic to aldehyde 12 (26) is postponed to occur with a very low diastereoselectivity (27), a study has been undertaken within the framework of the invention. nucleophiles precursors of carboxylate groups on this compound (diagram 4).

Diagram 4

First, the addition of vinyl organometallic was studied and it was surprisingly found that under certain conditions, it was possible to obtain the diastereoisomers ido and gluco 13a and 14b in 50/50 proportions . This result is particularly interesting from the perspective of the development of the combinatorial synthesis of glycosaminoglycan fragments containing glucuronic and iduronic acids.

It was then found that the proportion of L-ido stereoisomer increased with the size of the nucleophile, reaching 100% stereoselectivity with (PhS) ₃ CLi. This completely stereoselective addition of tris- (phenylthio) methyllithium to the aldehyde 12 is the key step in the preparation of the pyranosic derivative of L-iduronic acid 17.

Another remarkable improvement of the process of scheme 5 given in scheme 5bis is the acetylation of the crystals of compound 15 by proceeding at -40 ° C. in dichloromethane as solvent, with pyridine as base, acetyl chloride as acylating agent and 4-dimethylaminopyridine as catalyst. Under these conditions, the mixture 17 (: β 2/98) is obtained with 98% yield and the furano derivatives 16 are only present in trace amounts (2%). This improvement is spectacular because under the conditions described above (25) the derivatives 16 were obtained with a 40% yield which required difficult purification and recycling by deacetylation.

The overall yield of the preparation of this synthon, commonly used for the preparation of heparin fragments, from diaceone glucose 11 is 65%, which is much higher than the previously described methods which lead to overall yields of 25 to 30% (diagram 5).

K _g ∞ ;, MeOH 80% after recycling of the furanose derivatives

Diagram 5

K, OQ ₃ , MeOH 80% after recycling of juranose derivatives

Diagram 5bis

3. 1. 3. Access to the disaccharide 10.

Having developed various accesses to synthons of L-iduronic acid, it is then necessary to prepare a derivative of 2-azido glucose allowing the preparation of base brick 10. In conventional syntheses involving an azido group in position 2 , this group is introduced first, then the group protecting the anomeric position via a glycosylation reaction. As we already had very efficient access to alpha allyl-N-acetyl glucosaminide 8a alpha (see diagram 4), we decided to use the tri lylazide developed by VASELLA (28) to introduce the azido group on compound 18 whose anomeric position is already protected by an allyl group (diagram 6).

Diagram 6

In order to demonstrate that it is possible to use synthon 13a to prepare heparin-type oligosaccharides, a specific methodology has been developed to transform it into donor 26, in which all the protective groups of base disaccharide 10 are introduced before the coupling reaction (diagram 7).

This methodology was also applied in part to the glucuronic synthon 14a, and made it possible to prepare a glucuronic acid donor having protective groups close to 26.

Diagram 7

When it is desired to prepare GAGs: glycosaminoglycans having only L-iduronic acid, the stereoselective access to the thiorthoester 13c is much more profitable than the non-stereoselective addition leading to 13a and 14a. It has been shown that synthon 17 could be transformed in one step into donor 27. This compound couples with good yields to acceptor 21 to lead to disaccharide 22, in which it remains to install the protective groups' on the part iduronic acid, which takes place in a few steps (diagram 8).

Diagram 8

3. 2. Effective strategy for obtaining oligosaccharides.

From the disaccharide 10, the acceptor disaccharide 25 is easily prepared by oxidative cleavage of the paramethoxybenzyl group by DDQ: dichlorodycyanoquinone.

The donor disaccharide 26 (29) is, for its part, prepared by isomerization of the allyl to 1-propenyl with an iridium-based catalyst, (30), then hydrolysis of the ethenol ether, thus formed, catalyzed by mercury salts, which allows the release of the anomeric position, which is then activated in the form of trichloroacetimidate (scheme 9).

Diagram 9

The coupling of the acceptor disaccharide 25 and the donor disaccharide 26 at -40 ° C., in the presence of TBDMSOTf, leads with excellent yield to tetrasaccharide 27, with total alpha stereoselectivity. By applying the same operations to tetrasaccharide 27 as to disaccharide, it is possible to prepare, with very good yields, acceptor tetrasaccharide 28 and donor tetrasaccharide 29 (diagram 10) which make it possible to obtain hexa and octasaccharides 30 and 31. This methodology extends without problem to the preparation of a hexadecasaccharide or a dodecasaccharide.

Figure 10 4. Preparation of neocon ugués.

The protected oligosaccharides are transformed into partially deprotected and water-soluble compounds by: deacetylation, reduction of the azido function, sulfation, then saponification (diagram 11).

Figure 11

Compounds 32-34 are thus obtained, soluble in water and ready for coupling to bisthioPEGs. Under UV irradiation from a medium pressure lamp, the expected product is formed, but accompanied by secondary products, presumably from an oxidation of the benzyl groups which are eliminated by reverse phase chromatography C18. The final deprotection of neoglycoconjugates is carried out by hydrogenolysis, on palladium hydroxide on charcoal in the presence of phosphate buffer pH 7, after oxidation of the thioethers to sulfone to avoid poisoning of the catalyst (diagram 12).

0

Figure 12

The products thus synthesized have been tested for their ability to bind to IFNγ. 5 The use of a real-time molecular interaction analysis system (BIAcore) offers the possibility to identify and quantify very quickly the affinities existing between different molecules.

This device uses an optical detection system, the surface plasmon resonance phenomenon, to measure the concentration of molecules that have reacted on the surface of a biosensor ("sensor chip"). Biotinilated heparin is immobilized on a "sensor chip" previously activated with streptavidin. It is then possible to measure the interaction of IFNγ, injected in continuous flow on the surface of this sensor, with the immobilized heparin. The interaction between heparin and IFNγ causes a change in mass at the surface of the sensor, which is recorded as a function of time. In a second step, the IFNγ is previously incubated with the various synthesized products, then the complexes are injected onto the surface of the biosensor. The capacity of the products tested is then measured to inhibit the interaction of IFNγ / heparin.

The results are shown in FIG. 2, and indicate that a molecule containing a spacer arm of 5 nm (50 A), connecting two octasaccharides, has a very high affinity for the cytokine.

The same is true for molecules containing a 33 A and 114 A spacer arm which also have the capacity to interact with IFNγ, but with affinities, however less.

The invention will now be described with reference to the following example, given by way of illustration and not limitation. Example 1

In this example, the synthesis of compounds according to the invention is described: namely, neoglycoconjugates fixing the interferon, in which the group or spacer arm is derived from poly (ethylene glycol) s of variable lengths and the two oligosaccharides of ends are constituted by trisulfated disaccharides. The starting product of the synthesis is compound 8α, prepared according to LUBINEAU A.; ESCHER S.; ALAIS J.; BONNAFFE D., Tetrahedron Lett. 1997, 38, 4,087 - 4,090, that is to say according to the following operating mode 1: Operating mode 1:

Commercial glucosamine hydrochloride is peracetylated in a mixture of acetic anhydride (20 equivalents) and pyridine (30 equivalents). After evaporation of the reagents and coevaporation with toluene, the mixture is crystallized from an ethyl acetate / petroleum ether mixture to yield peracetylated glucosamine with a yield of 90%. The crystals recovered are treated with 1.1 equivalent of hydrazine acetate in anydre THF (concentration 0.3 M) for 20 h at 20 ° C. The THF is then evaporated at room temperature under reduced pressure, the residue coevaporated with toluene and the residual oil directly chromatographed on silica gel with an AcOEt / petroleum ether / CH ₂ Cl ₂ mixture (8/1/1 to 8 / 0/2). The free compound in the anomeric position is obtained with 75% yield. It is then dissolved in the necessary volume of CH ₂ C1 ₂ to have a concentration of 0.5 M and added dropwise to a mixture of tetrabutylammonium bromide (2 eq.), NaH (1.5 eq) and allyl bromide (20 eq.) Cools to -20 ° C. The temperature is then allowed to rise to 20 ° C. over 12 h and the reaction is stopped by adding 0.5 equivalent of acetic acid. The reaction medium is evaporated under reduced pressure and the residue directly chromatographed on silica (eluent: toluene / acetone 1/0 to 7/3) to yield compound 8a with a yield of 88%.

Compound 8a α is treated with eight equivalents of Ba (OH) ₂ in water at 100 ° C overnight, the pH is then lowered to 3 by adding sulfuric acid, the mixture centrifuged to precipitate barium sulfate , the supernatant collected, then evaporated under reduced pressure and coevaporated with water to remove the acetic acid formed. Salt 18 is neutralized with potassium carbonate and directly treated with TfN ₃ , following the protocol described in ALPER PB; HUNG SC; ONG CH, Tetrahedron Lett. 1996, 37, 6 029-6032, that is to say according to the following procedure 2: Procedure 2: 15 equivalents of NaN _{3 are} dissolved in the minimum of water necessary and cooled to 0 ° C. then an equivalent volume of dichloromethane and 2 equivalents of triflic anhydride are added dropwise. After 2 hours with vigorous stirring at 0 ° C., the mixture is left to settle and the organic phase is recovered, which is washed with an equivalent volume of saturated sodium bicarbonate solution. The organic phase is then directly added to an aqueous solution of salt 18 and 0.01 equivalent of copper sulphate. The minimum amount of methanol necessary to obtain a homogeneous mixture is then added. After 4 hours of reaction to 20 ° C, an equivalent of butylamine is added to destroy the excess triflylazide.

The resulting solution is deposited on silica gel 70-200 μ by evaporation and the compound 19 eluted with a MeOH / CH ₂ Cl ₂ 8/2 mixture.

After evaporation under reduced pressure, the residue is dissolved in anhydrous acetonitrile and treated with benzaldehyde dimethylacetal in the presence of camphorsulfonic acid. After two hours at room temperature, the solution is neutralized by adding an aqueous solution of sodium bicarbonate and the compound extracted with diethyl ether. After purification by chromatography on silica gel (petroleum ether / AcOEt), the compound 20 is treated with benzyl bromide in the presence of NaH in DMF. After dilution with diethyl ether, washing of the organic phase with water and evaporation, the residue is treated at 50 ° C., with a 60% acetic acid solution, for two hours. After evaporation and coevaporation with toluene, the residue is chromatographed on silica gel (petroleum ether / AcOEt). The resulting diol is dissolved in pyridine ^anhydrous and one equivalent of acetyl chloride is added at -20 ° C, then the temperature is allowed to rise to 0 ° C. The reaction is completed overnight. The pyridine is then evaporated under reduced pressure, the residue is dissolved in diethyl ether, then the organic phase obtained is washed with a dilute solution of HCl, water and a sodium bicarbonate solution. The organic phase is then dried, evaporated and chromatographed on silica gel with a mixture of petroleum ether and AcOEt. We obtain thus compound 21 with an overall yield of 75% since 8a a.

Furthermore, derivative 17 is prepared according to LUBINEAU A.; GAVARD O.; ALAIS J.; BONNAFFE D., Tetrahedron Lett. 2000, 307 - 311, that is to say according to the following operating mode 3: Operating mode 3:

Commercial diacetoneglucose, dissolved in anhydrous dimethyl formamide (concentration of 0.5 M), is treated with 1.2 equivalents of benzyl bromule and 1.3 equivalents of NaH. After 1 h at 20 ° C., the excess NaH is destroyed with isopropanol. The reaction mixture is then diluted with ethyl ether and the organic phase washed three times with water. After evaporation, the residue is taken up in 60% acetic acid until a concentration of 0.1 M is reached. After two hours at 50 ° C., the mixture is evaporated and then coevaporated with toluene under reduced pressure. Chromatography on silica gel

(eluent: petroleum ether / ethyl acetate 9/1 to 2/8) allows the desired diol to be obtained with 98% yield. This diol is dissolved in dichloromethane (concentration of 0.25 M), then the same volume of water is added, 0.5 equivalents of tetrabutylammonium hydrogen sulfate, 0.5 equivalents of NaHCO ₃ then, after having lowered the temperature at 0 ° C, 2 equivalents of NaI0 ₄ in small portions. The temperature is then allowed to rise to the ambient level and then the mixture is stirred for 1 hour. After decantation, the organic phase is recovered which is evaporated and then taken up in ethyl ether. The organic phase is washed three times with water, dried over magnesium sulfate, filtered and evaporated. The residue is filtered through silica gel (eluent: ethyl acetate) and compound 12, obtained quantitatively, is used directly, after evaporation and co-evaporation with toluene, in the subsequent step. A solution of tris-phenylthiomethyl-lithium is prepared in the following manner: 1.2 equivalents (relative to the aldehyde) of tris-phenylthiomethane are dissolved in the quantity of THF necessary to obtain a concentration of 0.8 M, the temperature is lowered to -78 ° C and the mixture put under mechanical stirring, then 1.1 equivalents (relative to the aldehyde) of n-butyllithium in solution in hexane are added. A yellow precipitate appears and stirring is continued at -78 ° C for 1 h 30. The aldehyde, dissolved in THF (0.6 M concentration) is then added dropwise. The mixture is stirred at -78 ° C. for one hour and then the temperature is allowed to rise to room temperature over 16 hours and the reaction is stopped by adding a saturated solution of ammonium chloride. The resulting solution is extracted three times with ethyl ether, the organic phase is dried over magnesium sulfate, evaporated and then chromatographed on silica gel (eluent petroleum ether / ethyl acetate 9/1 to 6/4). Compound 13c is thus obtained with 92% yield.

Tris-phénylethioorthoester 13c obtained above is dissolved in the volume of methanol necessary to obtain a concentration of 0.05 M was then added l / ^10th volume of water and / ^10th volume of dichloromethane and then 1.7 CuO equivalents and 4 CuCl ₂ equivalents. After one hour at room temperature, the mixture is filtered through Celite 545 and evaporated at room temperature under reduced pressure. The residue is taken up in CH ₂ C1 ₂ and the organic phase is washed with a saturated NaCl solution, filtered through phase separator paper and evaporated. The mixture is purified by chromatography on silica (eluent: petroleum ether / AcOEt 8/2 to 5/5), product 14 is thus obtained with a yield of 94%. The product 14 is then treated with a 90% trifluoroacetic acid solution for 30 minutes at room temperature (initial concentration of the reagent: 0.35 M). The reaction medium is evaporated under reduced pressure and then coevaporated twice with water. An oil is thus obtained which crystallizes. These crystals of compound 15 are suspended in dichloromethane (concentration 0.2 M) and the temperature is lowered to -40 ° C, 9 equivalents of pyridine, 0.01 equivalent of 4-dimethylaminopyridine and 5 equivalents of chloride are then added. acetyl. After 1 hour of stirring at -40 ° C, the temperature is allowed to rise to ambinate, diluted with dichloromethane and the organic phase is washed with a saturated solution of NaHCO ₃ , water, 1 M sulfuric acid. and water. This gives mixture 17 (α / β 2/98) with a yield of 98%.

The derivative 17 is converted into donor 27 according to JACQUINET J. C.; PETITOU M.; DUCHAUSSOY P.; LEDERMAN I.; CHOAY J.; TORRI G.; SINAY P., Carbohydrate Res. 1984, 130, 221, that is to say according to the following procedure 4: Procedure 4:

The mixture 17 is dissolved in anhydrous dichloromethane (0.1 M concentration), then 1/10 ^th by volume of anhydrous ethyl acetate is added and the mixture is left to react for 24 hours in the presence of 1.3 equivalents of TiBr ₄ . The mixture is diluted with CH ₂ C1 ₂ and washed with ice water. The organic phase is filtered on silicone paper and then concentrated. The product 27 thus obtained is used directly in the next step. The coupling of 21 (1.2 equivalents) with 27 is carried out in dichloromethane at 20 ° C, in the presence of σ sieve 4 A and silver triflate (1.2 equivalents) and carried out, after chromatography on gel of silica with petroleum ether / AcOEt mixture, with disaccharide 22 with a yield of 85%.

Compound 22 was deacetylated in anhydrous methanol in the presence of K ₂ C0 _3, after neutralization with DO EX resin ^® 50 x 8200 H ^+, filtration and evaporation, the residue was suspended in benzene, and then 2, 2 equivalents of Bu ₂ SnO. After 2 hours of azeotropic water entrainment, 3 equivalents of triethylamine and 2.2 equivalents of freshly distilled acetyl chloride are added. A mixture of 3 products is then obtained, the majority of which is compound 24 accompanied by the acetylated compounds in position 6/4 'and 6/2' / 4 '.

After chromatography on silica gel with ^'petroleum ether / AcOEt, the byproducts are deacetylated and again subjected to the acylation reaction: is thus obtained after the recycling composé.24 with 85% yield.

Treatment of the latter with 2 equivalents of paramethoxybenzyl alcohol trichloroacetimidate in dichloromethane in the presence of 0.1 equivalent of trimethylsilyl triflate makes it possible to obtain compound 10 with a yield of 80% accompanied by 20% of 24 n ' having not reacted. These two products 10_ and 24 are easily separable by chromatography on silica gel with petroleum ether / AcOEt mixture.

The basic disaccharide 10 is transformed with a 95% yield into donor disaccharide 26 (synthesized by another route in TABEUR C.; MALLET JM; BONO F.; HERBERT JM; PETITOU M.; SINAY P., Bioorg., Med. Chem 1999, 7, 2 003 - 2 012, by isomerization of allyl, in the presence of C ₈ H ₁₄ MePh ₂ PIr ¹ PF _s and cleavage of enol by mercury salts, as described by OLTVOORT JJ; VAN BOECKEL CAA; KONING JH; VAN BOOM JH, Synthesis 1981, 305 - 308, that is to say according to the following operating mode 5: Operating mode 5:

Disaccharide 10 is dissolved in anydre THF so as to have a concentration of 0.06 M. The solution is degassed under vacuum, then 0.013 equivalents of C ₈ H ₁₄ MePh ₂ PIr ^I PF _{6 are added} . The mixture is redegased then left in contact with dihydrogen for 2 minutes and finally redegased then put under an argon atmosphere. After two hours with stirring at room temperature, the mixture is evaporated and then taken up in the volume of acetone necessary to obtain a concentration of 0.05 M, 1.2 equivalents of HgO and 1.1 of HgCl _{2 are then added.} . After two hours with stirring at room temperature, the mixture is filtered under Celite 545, evaporated and taken up in ethyl ether. The ethereal phase is washed with a 10% Kl solution, then with water, dried over magnesium sulphate, filtered, evaporated and finally chromatographed on silica gel (eluent toluene / AcOEt 8/2 to 6/4) to lead to the free disaccharide in the anomeric position with a yield of 97%. Then, a treatment is carried out in dichloromethane with 6 equivalents of trichloroacetonitrile and 2 equivalents of K ₂ C0 ₃ , followed by chromatography on silica gel with the petroleum ether / AcOEt 1% o NEt ₃ mixture. Disaccharide 10, treated with 1.5 equivalents of DDQ in dichloromethane saturated with water, leads after washing the organic phase with a saturated NaHCO _{3 solution} and chromatography on silica gel with petroleum ether / AcOEt mixture and acceptor disaccharide 25 with a yield of 95%.

The coupling of the acceptor disaccharide 25 and the donor disaccharide 26 (1.3 equivalents) is carried out in o dichloromethane at -40 ° C. in the presence of 4 A sieve and of terbutyldimethylsilyl triflate (0.2 equivalents). After addition of the catalyst, the reaction is left for 30 minutes at -40 ° C, then the temperature is allowed to rise to 0 ° C, temperature at which the reaction is stopped by adding 0.2 equivalents of triethylamine. Chromatography on direct silica gel of the reaction mixture with the CH ₂ Cl ₂ / AcOEt / petroleum ether mixture makes it possible to isolate the tetrasaccharide 27 with a yield of 95%.

The latter is then transformed into tetrasaccharides acceptor 28 (90% yield) and donor 29 (95% yield) using the same reaction sequences as for disaccharide 10. Using the same conditions as for the preparation of tetrasaccharide 27, the couplings of the donor disaccharide 26 with the acceptor tetrasaccharide 28 and donor tetrasaccharide 29 with the acceptor tetrasaccharide 28 lead to hexasaccharide 30 and to octasaccharide 31 with yields of 95%. The oligosaccharides 27, 30 and 31 are deacetylated in anhydrous methanol in the presence of 0.5 equivalent of anhydrous K ₂ C0 ₃ . After neutralization of the reaction media with DOWEX 50 X 8 200 H ⁺ and evaporation, the products are purified by chromatography on silica gel and obtained with yields of 86 to 95%. The reduction of the azido groups is carried out with propane dithiol (2 equivalents per azido group) in methanol in the presence of triethylamine (2 equivalents per azido group). After evaporation of the methanol by argon sweeping, the residues are chromatographed on silica gel (CH ₂ Cl ₂ / MeOH) to yield the amino compounds with yields of 90% to 80%. These compounds are then sulfated by the pyridine complex. S0 ₃ (5 equivalents per function to be sulfated) in pyridine for 16 hours at 20 ° C, followed by 24 hours at 55 ° C. The excess sulfating agent is destroyed by 16 equivalents of methanol and the mixture is directly chromatographed on SEPHADEX ^® LH-20

(CH ₂ Cl ₂ / MeOH 1/1), then on a reverse phase column C18 (MeOH / AcOH-Net buffer ₃ 5 mM pH 7.0). After exchange resin on BIORAD ^® AG 50 WX 8 200 Na ^+, the sulfated oligosaccharides were obtained with yields ranging from 80 to 95%. The saponification is carried out for 48 hours at 37 ° C., in the presence of aqueous lithine (26 equivalents per ester to be saponified) and hydrogen peroxide (3 equivalents relative to the lithine). The pH is then brought to 5 by addition of acetic acid (0.75 equivalents relative to the lithine) and the mixture purified by chromatography on a reverse phase column Cl8 (MeOH / AcOH-NEt ₃ buffer 10 mM pH O 2004/000887

48

7.0). After exchange resin on BIORAD ^® AG 50 X 8 200 Na ^+, oligosaccharides from 32 to 34, wherein n respectively = 0, 1 and 2, are obtained in yields of 90% to quantitative. The couplings of oligosaccharides 32 to 34 (2.5 equivalents) on the dithiol spacers derived from polyethylene glycol of variable lengths: namely m = 5, 10 and 32, at a concentration of 0.2 M in water, s' perform under ultraviolet irradiation at 365 nM or by heating in the presence of a radical initiator.

The mixture is directly treated with 8 equivalents of oxone, that is to say with a 0.2 M solution, brought to pH 6 by addition of K ₂ HP0 ₄ . After 4 hours of reaction at 20 ° C., the excess oxidant is reduced by adding a sodium thiosulfate solution and the mixture is directly purified by semi-preparative HPLC on reverse phase C18 (CH ₃ CN / AcOH buffer -NEt ₃ 5 mM pH 7.0). After exchange resin on BIORAD ^® AG 50 WX 8 200 Na ^+, oligosaccharides are resolubilized in 100 uL 40 mM sodium phosphate buffer pH 7 and spokes under hydrogen atmospheric pressure in the presence of a mass equivalent of palladium hydroxide 20% on coal. After 48 hours of reaction at 20 ° C, samples are filtered on celite 545, then desalted on Biogel ^® 10 DG (H ₂ 0). The Illa-i compounds are thus obtained with a yield of 80 to 90% over these three stages. At the same time, oligosaccharides 32 to 34 were quantitatively debenzylated under the same conditions. For compounds la to le, n = 0, for compounds ld to lf, n = 1, and for compounds lg to li, n = 2. For compounds la, ld and lg: m = 5 and the length of the spacer arm is from 33 A, for compounds lb, le, lh: m = 10 and the length o of the spacer arm is 50 A, and for compounds le, lf and li: m ≈ 32 and the length of the spacer arm is 114 A .

1) BnBr, NaH

88% on the three stages

accepted

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Claims

58

1. Compound capable of binding to interferon-gamma (IFNγ) chosen from the molecules corresponding to the following formula (I):

in which X is a divalent spacer group of sufficient length to allow the two oligosaccharide fragments A and B to each bind to one of the peptide sequences 125 to 143 of the C-terminal ends of an interferon-γ homodimere (IFN-γ) and n represents an integer from 0 to 10, for example equal to 0.1, 2, 3, 4 or 5 and each R independently represents a hydrogen atom, an SO ₃ ^"group , or phosphate, provided that no SO ₃ ^"group is found in position 3 of the glucosamine units of compound (I).

2. A compound according to claim 1, in which all the R represent an SO ₃ ^"group or all the R groups represent a phosphate group.

3. Compound according to claim 1, in which σ the spacer group is from 15 to 150 A in length, preferably from 33 to 50 A.

4. Compound according to claim 1, in which the spacer group consists of a carbon chain, preferably from 1 to 120C, one or more of the carbon atoms of which are optionally replaced by a heteroatom chosen from N, S, P and 0 , a group SO ₂ , an aryl group, said carbon chain carrying, optionally, one or more anionic groups.

5. A compound according to claim 4, in which said anionic groups are chosen from sulphate, phosphate and carboxylic groups.

6. Compound according to claim 4, in which the spacer group is derived from a polyglycol chosen, preferably, from poly (alkylene glycol) in which the alkylene group comprises from 1 to 4 C, such as poly (ethylene glycol) .

7. Compound according to claim 6, in which the spacer group corresponds to the formula:

in which m is an integer from 5 to 32. 8. A compound according to claim 7, corresponding to the following formula (II):

(II) in which n represents an integer from 0 to 10, for example equal to O, 1, 2, 3, 4 or 5, and m is an integer from 5 to 32.

9. Compound (Ha) corresponding to formula (II) according to claim 8, in which n = 0 and m ≈ 5.

10. Compound (Ilb) corresponding to formula (II) according to claim 8, in which n = 0 and m = 10.

11. Compound (Ile) corresponding to formula (II), according to claim 8, in which n ≈ 0 and m ≈ 32.

12. Compound (Ild) corresponding to formula (II), according to claim 8, in which n ≈ 1 and m ≈ 5. 13. Compound corresponding to formula (II), according to claim 8, in which n = 1 and m = 10.

14. Compound (Ilf) corresponding to formula (II), according to claim 8, in which m ≈ 1 and m = 32.

15. Compound (Ilg) corresponding to formula (II), according to claim 8, in which n = 2 and m = 5.

16. Compound (Ilh) corresponding to formula (II), according to claim 8, in which n = 2 and m = 10.

17. Compound (Ili) corresponding to formula (II), according to claim 8, in which n = 2 and m = 32. 18. Process for the preparation of a compound capable of binding to interferon-gamma (IFNγ ) of formula (II) according to claim 8, in which the radical coupling of two water-soluble compounds, oligosaccharide precursors of formula (III) is carried out:

(M)

in which n is an integer from 0 to 10, for example equal to 0, 1, 2, 3, 4 or 5, and Ri and R ₂ represent a group protecting the hydroxyl group chosen, preferably, from the groups p- methoxybenzyl and benzyl, with a dithiol precursor compound of the spacer group of formula:

in which m is an integer from 5 to 32, to obtain a compound of formula (IV):

then, the thioether functions are oxidized to sulfones and the final deprotection of the compound (IV) is carried out to give the final compound of formula (II).

(II)

19. The method of claim 18, wherein R is a p-methoxybenzyl group and R ₂ is a benzyl group.

20. The method of claim 18, wherein the water-soluble compound precursor of oligosaccharides of formula (III) is prepared by the following 5 successive steps: a) a disaccharide of formula (V):

O 2004 0

63

b) in parallel, a disaccharide of formula (V), above, is subjected to an isomerization of the allyl group to 1-propenyl, followed by a hydrolysis of the enol ether formed and an activation of the hydroxyl group in the form of trichloroacetamidate to give a “donor” disaccharide, of formula (VIb): 64

c) the acceptor disaccharide (Via) and the donor disaccharide (VIb) are coupled to obtain the tetrasaccharide (n = 0) of formula (VII), which has complete alpha stereospecificity; d) optionally, steps a) to c) are repeated, taking as the starting product for step a), the tetrasaccharide prepared in c), to obtain the hexa (n = 1) and octa (n = 2) saccharide of formula (VII):

e) optionally, steps a) to c) are repeated, taking as starting material, for step a), the octasaccharide prepared in d), to obtain a hexadecasaccharide (n = 7) of formula (VII); 65

f) deacetylation, reduction of the azide function, sulfation and saponification are carried out to obtain the water-soluble compound, oligosaccharide (III) precursor sought.

21. The method of claim 20, wherein the disaccharide of formula (V) is prepared by a coupling reaction between a compound of formula (VIII):

and a compound of formula (IX)

22. The method of claim 21, wherein the compound of formula (IX) is prepared from the compound of formula (X) and the compound of formula (VIII) is prepared from the compound of formula (XI): es

2 ³ . The method of claim 2 ₂ , wherein the compound of formula:

is prepared by acetylation of the compound of formula ₍ XII ₎

at - ⁴⁰ ° ^C in dichloromethane as solvent, with pridine as low, acetyl chlorue as acylating agent, and 4-dimethylaminopyridine as catalyst.

24. A compound according to any one of claims 1 to 17, for use as a medicine.

25. Use of a compound according to any one of claims l to 17, for preparing a medicament.

26. Compound according to any one of claims 1 to 17, for use as a modulator, for example an inhibitor, of the activity of one endogenous or exogenous interferon-γ.

27. Compound according to any one of claims 1 to 17, for use in the treatment of diseases linked to, or characterized by, the presence of proinflammatory cytokines such as Interferon- γ, for example inflammatory or degenerative autoimmune diseases such as multiple sclerosis, Glomerulonephritis, Crohn's disease and rheumatoid arthritis.

28. Compound according to any one of claims 1 to 17 for use in a treatment complementary to immunosuppressive treatments used for example to avoid rejection of grafts.

29. A medicament containing a compound according to any one of claims 1 to 17. 30. A composition containing the compound according to any one of claims 1 to 17 and a pharmaceutically acceptable vehicle for use in the treatment of diseases linked to, or characterized by the presence of proinflammatory cytokines such as interferon-γ, for example autoimmune or degenerative diseases such as multiple sclerosis, Glomerulonephritis, Crohn's disease, and rheumatoid arthritis.

31. A composition containing the compound according to any one of claims 1 to 17 and a pharmaceutically acceptable vehicle for use in a treatment complementary to immunosuppressive treatments used for example to avoid rejection of grafts.

32. Use of a compound according to any one of claims 1 to 17, for preparing a medicament intended for the treatment of pathologies or disorders related to the activity, in particular excessive, of endogenous or exogenous interferon-γ.

33. Use of a compound according to any one of claims 1 to 17 for preparing a medicament intended for the treatment of diseases linked to, or characterized by, the presence of proinflammatory cytokines such as Interferon-γ, for example auto-inflammatory diseases. inflammatory or degenerative immune systems such as multiple sclerosis, Glomerulonephritis, Crohn's disease and rheumatoid arthritis.

34. Use of a compound according to any one of claims 1 to 17 for preparing a medicament intended for a treatment in addition to the immunosuppressive treatments used for example to avoid rejection of grafts.

35. Medicament containing, in addition to a compound according to any one of claims 1 to 17, 1 γ-interferon.

36. The medicament of claim 35, wherein the compound of any one of claims 1 to 17 and interferon-γ are in the form of a complex of the compound and interferon-γ.

37. Complex of a compound according to any one of claims 1 to 17 and of interferon-γ for use as a medicament.

38. Complex of a compound according to any one of claims 1 to 17 and of interferon-γ for use as an immunostimulan.

39. Complex of a compound according to any one of claims 1 to 16 and of interferon-γ for use in the treatment of a disease chosen from cancer, infectious diseases, for example viral, bacterial or parasitic and organ fibrosis.

40. Composition containing a complex of a compound according to any one of claims 1 to 17 and of interferon-γ, and a pharmaceutically acceptable vehicle, for use in the treatment of a disease chosen from cancer, diseases infectious, for example viral, bacterial or parasitic, and organ fibrosis.

41. A drug containing a complex of a compound according to any one of claims 1 to 17 and of interferon -γ.

42. Use of a complex of a compound according to any one of claims 1 to 17, and of interferon γ, to prepare a medicament.

43. Use of a complex of a compound according to any one of claims 1 to 17, and of interferon γ, for preparing a medicament intended for the treatment of a given disease among cancer, infectious diseases, for example viral, bacterial or parasitic, and organ fibrosis.