EP2951200A1

EP2951200A1 - Kiss1r receptor agonist compounds and use thereof for inducing ovulation in mammals

Info

Publication number: EP2951200A1
Application number: EP14702555.5A
Authority: EP
Inventors: Massimiliano Beltramo; Vincent Aucagne; Alain CARATY; Agnès Delmas; Mathieu GALIBERT
Original assignee: Centre National de la Recherche Scientifique CNRS; Institut National de la Recherche Agronomique INRA
Current assignee: Centre National de la Recherche Scientifique CNRS; Institut National de Recherche pour lAgriculture lAlimentation et lEnvironnement
Priority date: 2013-01-31
Filing date: 2014-01-31
Publication date: 2015-12-09
Also published as: US9884891B2; FR3001455A1; FR3001455B1; BR112015018283A2; US20150361138A1; WO2014118318A1

Abstract

The invention relates to a KISS1R agonist peptide compound capable of inducing ovulation in a female mammal, chosen from a pseudopeptide having the C-terminal sequence: -XaaΨ[Tz]Xaa2-Xaa3-Xaa4-NH₂ (SEQ ID NO: 3), where Ψ[Τz] represents a 1,4-disubstituted 1,2,3-triazole group replacing the peptide bond between the Xaa1 residue and the Xaa2 residue, Xaa1 represents Gly or Ala, Xaa2 represents Leu or an aliphatic α-aminoacyl analogue residue, Xaa3 represents Arg, Arg(Me) or a positively charged α-aminoacyl analogue residue, and Xaa4 represents Tyr, Phe, Trp or an α-aminoacyl analogue residue such as aryl alanine; an analogue of the pseudopeptide of sequence SEQ ID NO: 3 in which the amide peptide bond between Xaa2 and Xaa3 and/or between Xaa3 and Xaa4 is replaced with an isosteric bond; or a salt thereof.

Description

AGONIST COMPOUNDS OF THE KISS1 RECEPTOR AND THEIR USE FOR INDUCING

OVULATION IN MAMMALS

The present invention is in the field of induction and synchronization of ovulation in mammals. More particularly, it relates to a peptide compound agonist of the KISS1 R receptor capable of inducing / synchronizing such ovulation, as well as the use of such a compound as a medicament, in particular for inducing this ovulation, and a veterinary composition and / or pharmaceutical container.

In particular, the compound according to the invention has applications in the field of animal husbandry, in particular with a view to programming breeding throughout the year, for example sheep, goats, or cattle. Although the latter species is not of the spawning type, dairy cows nevertheless show a decline in fertility and a KISS1 R receptor agonist could be used to restore better fertility. Moreover, the compound according to the invention also has applications in the therapeutic field, in particular for reducing the problems of infertility, and in particular in the human clinic for the treatment of reproductive pathologies, in particular in the context of the implementation of medically assisted procreation techniques. Other applications of this compound are the treatment of other pathologies, such as hypothalamic amenorrhea and delayed puberty, and all other pathologies that require an increase in the secretion of GnRH (for Gonadotropin Releasing Hormone) and gonadotropins.

In the field of breeding, the control of reproduction is an important issue, in order to optimize the availability of products, such as meat, milk or its derivatives, throughout the year. For example, sheep and goat farming are subject to strong seasonal variations in productivity, due to the seasonal nature of reproduction and the course of lactation. The methods currently used to induce ovulation at any time of the off-season and / or to synchronize ovulation within herds are based on the use of steroid hormones, such as progesterone or oestradiol, prostaglandin F2a and PMSG (for Pregnant Mare Serum Gonadotropin). These methods, however, do not allow complete control of ovulation. In addition, the estrogen hormones used are pollutants that are not easily degraded, accumulate in the soil and water, and pose a threat to human health. The treatment of animals with such hormones also presents important constraints for the breeders, who are obliged to respect very strict specifications. For example, the methods currently used to induce ovulation in sheep provide for the implantation for 12 to 24 days of a vaginal sponge containing progesterone, combined with co-treatment with an injection. intramuscular serum gonadotropin PMSG at the time of removal of the sponge. Such treatment is binding to implement.

In human clinics, the treatments currently available for assisted procreation have some undesirable side effects, such as ovarian hyperstimulation. These treatments also use hormones to induce ovulation, and therefore act either in the pituitary gland or in the gonads. It is the same for the treatments intended to cure the hypothalamic amenorrhea or delayed puberty.

There remains a need for alternative treatments, implementing a nonsteroidal molecule capable of triggering / synchronizing ovulation in both ruminants, so that they can program their reproduction and milk production throughout the year, improve yields of artificial insemination, optimize herd profitability, and reduce infertility problems in herds, than in humans, to induce gonadotropin release more naturally than current hormone treatments, thereby reducing risk of ovarian hyperstimulation syndrome. The present invention aims at remedying the disadvantages of the treatments proposed by the prior art for inducing / synchronizing ovulation. in female mammals, in particular to those described above, by proposing a non-steroidal compound which makes it possible to achieve such induction / synchronization of ovulation in an efficient manner, which has a low remanence in the environment, and constraints of reduced use.

For this purpose, the present inventors have been interested in the neurotransmission system formed by a receptor, KISS1 R, also called KISS1 receptor, or GPR54 (GenBank accession number, for the human receptor: NM-032551 .4, Gl: 189163516 ), and its endogenous ligands, called kisspeptides (or kisspeptins), derived from the cleavage of a precursor peptide, KISS1 (GenBank accession number, for the human peptide: NM_002256.3, Gl: 1 16829963; NP_002247.3 , Gl: 16829964; for the murine peptide: AB666166.1, Gl: 384367966; BAM1 1250.1, Gl: 384367967; for the ovine peptide: AFW03832.1, Gl: 41 1 100741), which are neurotransmitters having the ability to to stimulate KISS1 R (Kotani et al., 201 1).

In the present description, the abbreviation KISS1 R will be used to designate both the human receptor and the receptor of other species (indicated by the abbreviation Kissl r in the official nomenclature). A complete list of synonyms used to designate the KISS1 R is available on the IUPHAR website.

More particularly, the kisspeptide (kisspeptin) essentially responsible for the biological stimulation activity of KISS1 R is the decapeptide named kisspeptin-10, or KP10. The sequences of the mouse-derived kisspeptin-10 (mKP10, of sequence SEQ ID NO: 1, in which the C-terminal end is modified by amidation) and of the human-derived kisspeptin-10 are known ( hKP10, of sequence SEQ ID NO: 2, in which the C-terminal end is modified by amidation). The kisspeptin-10 derived from the ewe is in particular identical to mKP10. The activation of KISS1 R by these ligands, and more particularly by the

KP10, induces a very powerful stimulatory effect on the release of hormones LH and FSH in mammals, this effect resulting from an increase in the secretion of GnRH (for Gonadotropin Releasing Hormone) (Caraty and Franceschini, 2008). In particular, it has been shown that KP10, administered to ewes intravenously at the end of the follicular phase, is capable of inducing a peak of LH which is followed, 21 hours later, by ovulations synchronized to the hour (Caraty et al., 2007). It has also been shown that during the period of sexual rest (seasonal anestrus), prolonged infusion of KP10 is able to reactivate the gonadotropic axis and induce ovulation (Sébert et al., 2010). These results thus demonstrated the feasibility of controlling ovulation of farm animals by stimulating the KISS1 R / KP10 system. The human KISS1 R and that of the ewe also have a very high degree of homology, with more than 60% identity, and kisspeptides (kisspeptins) show similar in vivo activity in primates and ewes (Seminara et al. al., 2006, Caraty et al., 2007), which makes it possible to envisage an application in human therapy.

Compared to steroid hormones, KP10 has the advantages of being very quickly eliminated from the body and easily destroyed in the natural environment, leaving only amino acids as residues. Moreover, it presents a mechanism of action, resulting in a triggering of the secretion of the hormone LH, hormone necessary for the induction of ovulation, completely different from that of current treatments, and allowing a more localized action and fine by avoiding unwanted side effects.

However, since KP10 is rapidly degraded and excreted by the body, it has a limited duration of action. The present inventors have therefore aimed to develop compounds derived from KP10 which have a prolonged and controlled duration of action in the body, while maintaining similar environmental degradability properties to those of KP10. The invention also aims that these compounds are capable of effectively inducing ovulation in a female mammal, including in off-season, by a small number of administrations, in particular by a single injection. A further object of the invention is that these compounds have a low cost of preparation.

It has now been discovered by the present inventors that such advantageous results are achieved by particular peptide compounds in which, inter alia, a peptide bond between a glycine residue and the adjacent residue, located in a region near the C-terminus of the compound, is replaced by a disubstituted 1,2,3-triazole ring. In the present description, the positions of the amino acids in the peptides are conventionally defined in themselves, the numbering beginning at the N-terminus of the peptide, appearing on the left in all the sequences, while the C-terminal end appears on the right.

Thus, it is proposed by the present invention a peptide compound agonist KISS1 R, selected from:

a pseudo-peptide, capable of binding KISS1 R, having the C-terminal sequence:

-Xaa [Tz] Xaa2-Xaa3-Xaa4-NH ₂ (SEQ ID NO: 3)

Ψ [Τζ] represents a 1,2,3-triazole-1,4-disubstituted group of formula (I):

replacing the peptide bond between the residue Xaa1 and the residue Xaa2, the C-terminal end at the residue Xaa4 is modified by amidation,

Xaa1 represents Gly or Ala,

Xaa2 represents Leu or a similar aliphatic α-amino acyl residue, such as Ile, Val, Ala (cPr), Nie or Nval, Xaa3 represents Arg, whose -NH ₂ function is optionally substituted by a methyl group, or a positively-charged pos-like cc-amino acyl residue, such as Arg (asymme ₂ ), Lys, optionally substituted, or Orn, where appropriate substituted, Xaa4 represents Tyr, Phe, Trp or a cc-amino acyl residue of similar aryl alanine type, such as 1 -, 2- or 3-naphthylalanine, 2- or 3-thienylalanine, 2- or 3-membered -furylalanine, 2-, 3- or 4-fluorophenylalanine, 2-, 3- or 4-chlorophenylalanine, 2-, 3- or 4-bromorophenylalanine, 2-, 3- or 4-cyanophenylalanine, 2- 3- or 4-iodophenylalanine, 2-, 3- or 4-methylphenylalanine or 2-, 3- or 4-trifluoromethylphenylalanine,

an analogue of the pseudo-peptide of sequence SEQ ID NO: 3 in which the peptide amide bond between Xaa2 and Xaa3 and / or between Xaa3 and Xaa4 is replaced by an isosteric bond,

- or one of their salts.

The disubstituted 1,2,3-triazole ring is advantageously an inexpensive and easily accessible isostere, so that the process for synthesizing such a compound is advantageously inexpensive to implement. This synthesis can also be easily achieved by conventional peptide synthesis techniques, for example solid phase in Fmoc / tBu strategy.

The peptide compound according to the invention advantageously has, with respect to KP10, a prolonged lifespan in the body, more particularly in the blood serum, while retaining a stimulating efficiency of KISS1 R that is as important, or even better, as well as minimal environmental remanence. It makes it possible in particular to significantly increase the blood level of the LH hormone in mammals, including during the anestrus period, by a limited number of administrations, moreover by a route of administration which is particularly compatible with use in breeding, in particular by means of a single injection, for example intramuscular or subcutaneous.

In the present description, the term "C-terminal region" will be used to denote the region of the peptide compound of sequence SEQ ID NO: 3, and by the term "N-terminal region", the remaining region of the compound.

In particular embodiments of the invention, Xaa1 represents Gly, Xaa2 represents Leu and Xaa3 represents Arg, whose -NH ₂ function is optionally substituted with a methyl group.

The peptide compound according to the invention may have a size of from 5 to 54 amino acids, preferably from 5 to 16 amino acids, more preferably from 7 to 12 amino acids, and preferably 9, 10 or 1 1 amino acids.

In particular embodiments of the invention, particularly advantageous in terms of half-life length in the blood serum, the peptide compound has one or more of the following characteristics:

at least the N-terminal amine function is modified by substitution with a group chosen from linear alkanoyls, in particular C 1 -C 6, preferably C 2 -C, benzoyl groups and tetramethylguanidinium groups,

at least the N-terminal amino function is replaced by an azide function, or by a 1,4-disubstituted 1,2,3-triazole group of formula (I);

at least one amino acid, more particularly the N-terminal region, is linked to one or more polyalkylene glycol chains, preferably polyethylene glycol, and / or to one or more lipid chains, such as a palmitoyl group, and / or groups binding to serum albumin. Such modifications advantageously make it possible to increase the half-life of the peptide compound in the body. In particular embodiments, at least one amino acid is linked to a polyethylene glycol chain, linear or branched, of molecular weight between 5 and 40 kDa; at least the N-terminal amine functional group is substituted by an alkyl group, especially chosen from linear, preferably C 1 -C 6, alkyls, in particular by a methyl group, or by a benzyl group.

The peptide compound according to the invention can be cyclized, by any conventional cross-linking in itself between the side chains of two amino acids of its N-terminal region and / or its N-terminal amine function, in particular by formation of a amide, a triazole, an alkene, a disulfide bridge, a bis-thioether, etc.

In particular embodiments of the invention, the peptide compound is chosen from:

a pseudo-peptide of sequence:

H-Tyr-Asn-Trp-Asn-Ser-Phe-Xaa [Tz] Xaa2-Xaa3-Xaa4-NH ₂ (SEQ ID NO: 4) 1 2 3 4 5 6 7 8 9 10 where Ψ [Τζ], Xaa1 , Xaa2, Xaa3 and Xaa4 are as defined above, and the C-terminus at residue Xaa4 is modified by amidation,

an analogue of said pseudo-peptide of sequence SEQ ID NO: 4 capable of binding KISS1 R, or a salt thereof.

By analog of the pseudo-peptide of sequence SEQ ID NO: 4 capable of binding KISS1 R, is meant any pseudo-peptide having the C-terminal sequence SEQ ID NO: 3, and whose sequence is distinguished from the sequence SEQ ID NO By one or more modifications at the level of the N-terminal region, in particular by addition, substitution, by a natural or non-natural amino acid, including D enantiomers, and / or deletion, of one or more acids amines, and / or by a modification of the N-terminus and / or of any functional group carried by the side chain of an amino acid, and / or by the replacement of a peptide bond by an isosteric bond, any in retaining the ability to bind KISS1 R.

The ability of peptide compounds to bind KISS1 R can be controlled in different ways. It may in particular be controlled by an in vivo test, by measuring the concentration of LH in ewe blood samples to which the test molecule has been injected, for example according to the protocol described hereinafter in the present description. An increase in this concentration, relative to an untreated control, indicates an ability of the analog to bind KISS1 R.

Moreover, this ability can be controlled by in vitro test, by measuring the amount of intracellular calcium in a cell line expressing KISS1 R after incubation with the test molecule. Indeed, the stimulation of KISS1 R leads to the activation of two distinct intracellular pathways, which induce the increase of the intracellular concentration of calcium ions: by release of the intracellular stores, following the production of IP3, and by entry following the opening of the ion channels (for example TRPC) of the plasma membrane of the cell, calcium ions present in the extracellular medium. An example of such a test, called calcium mobilization, is described in detail hereinafter in the present description. An increase in the amount of intracellular calcium, relative to an untreated control, then testifies to the ability of the analog to bind KISS1 R.

Particular analogues of the pseudo-peptide of sequence SEQ ID NO: 4, in particular having a half-life in the blood serum greater than that of KP10, correspond to one or more of the following characteristics: at least one acid The amine of Tyr1, Asn2 and Trp3 is substituted with a lysine, the amine function of which is preferably substituted by one or more groups selected from an alkanoyl group, in particular an acetyl group, a polyalkyleneglycol chain, preferably polyethylene glycol, and a chain. lipid, such as a palmitoyl group or other group allowing interaction with serum albumin; at least the amino acid Tyr1 is replaced by its enantiomer D.

Particular peptide compounds according to the invention are analogs of the pseudo-peptide of sequence SED ID NO: 4, differing from the latter but retaining a serine residue (Ser) two positions upstream of Xaa1, that is, in most cases, in position 5.

Other peptide compounds according to the invention have a threonine (Thr) residue at this position.

Particular peptide compounds according to the present invention are: H-Tyr-Asn-Trp-Asn-Ser-Phe-G (Tz) Leu-Arg-Tyr-NH ₂ (SEQ ID NO: 5)

wherein the C-terminus is modified by amidation and the peptide bond between glycine at position 7 and leucine at position 8 is substituted with a 1,4-disubstituted 1,2,3-triazole group,

Ac-Tyr-Asn-Trp-Asn-Ser-Phe-G ^ [Tz] Leu-Arg-Tyr-NH ₂ (SEQ ID NO: 6)

wherein in addition to amidation at the C-terminus and substitution of the peptide bond between glycine and leucine by a 1,4-disubstituted 1,2,3-triazole group, the N-terminus is modified by acetylation,

Ac-Tyr-Asn-Trp-Asn-Ser-Phe-GlyΨ [Tz] Leu-Arg (Me) -Tyr-NH2 (SEQ ID NO: 7) in which, besides amidation at the C-terminus and the substitution of the peptide bond between glycine and leucine by a 1,4-disubstituted 1,2,3-triazole group, the N-terminus is modified by acetylation and the arginine residue at position 9 is modified by methylation, Ac-Tyr-Asn-Lys (Ac) -Asn-Ser-Phe-GlyΨ [Tz] Leu-Arg (Me) -Tyr-NH2 (SEQ ID NO: 8) in which, in addition to amidation at the C-terminus -terminal and the substitution of the peptide bond between glycine and leucine by a 1,4-disubstituted 1,2,3-triazole group, the N-terminus is modified by acetylation, the arginine residue in position 9 is modified by methylation and the lysine residue at position 3 is modified by acetylation,

Αο-ΤγΓ-Α8η-ΤΓρ-Α8Π-8ΘΓ-ΡΙΐΘΨ | Τ ^ζ ] ΟΙγΨ [Τ ^ζ ] ίΘυ-ΑΓ9-ΤγΓ-ΝΗ2 (SEQ ID NO: 9) in which, besides amidation at the C-terminus and substitution of the peptide bond between glycine and leucine by a 1,4-disubstituted 1,2,3-triazole group, the N-terminus is modified by acetylation and the peptide bond between phenylalanine in the 6-position and glycine at the 7-position is also substituted by a 1,4-disubstituted 1,2,3-triazole group.

In particular, as explained above, particularly advantageous peptide compounds according to the present invention are such that at least one amino acid is linked to a unit capable of binding to serum albumin. It has been observed by the present inventors that, surprisingly, such a characteristic has the effect of very significantly increasing the duration of action of the peptide compound in the body. Preferably, the unit capable of binding serum albumin is attached to an amino acid located in the N-terminal region of the peptide compound.

An example of such a unit is y - (/ V-hexadecanoyl-L-glutamyl), also named Y - (/ V-hexadecanoyl-Glu-OH). It is in particular known from the prior art that the use of a γ-glutamyl spacer group between the amino acid and a group capable of binding to serum albumin, such as a hexadecanoyl group (also called palmityl), increases the affinity of said group with serum albumin (Knudsen et al., 2000). Any other motif capable of binding serum albumin, known in itself to those skilled in the art, may also be used in the context of the invention, for example a acide-carboxylate fatty acid (Zarandi et al., 2006), Albu-tag (Dumelin et al., 2008) or a cyclopeptide (Dennis et al., 2002, Angelini et al., 2012). Examples of such units, and associated spacer arms for their binding to a residue of the peptide compound according to the invention are in particular TTDS- (y- (/ V-hexadecanoyl-Glu-OH)) or else 2- ( succinamido) -6- (4- (4-iodophenyl) butanamido) hexanoate. When the peptide compound according to the invention is an analogue of the pseudo-peptide of sequence SEQ ID NO: 4, preferably a unit able to bind serum albumin is introduced at least at position 1, at position 2 and / or in position 3 of the peptide compound, that is to say at the level of Tyr1, Asn2 and / or Trp3, or residues which are analogous thereto. When the pattern capable of binding serum albumin is set at position 1, the unit is preferably attached to the N-terminal amino function. When the unit capable of binding to serum albumin is attached to the 2 or 3 position of the peptide compound, the residue concerned, for example the residue Asn2 or the residue Trp3, is preferably substituted by a lysine residue, on the chain. side of which is fixed the pattern capable of binding serum albumin.

Another aspect of the invention is the use of a peptide compound having one or more of the above-described characteristics as a medicament, and more particularly for inducing ovulation in a female mammal. This mammal may especially be a farm animal such as a sheep, a goat, a bovine, a pig, an equine, etc., a pet, such as a dog or a cat, or, for example, a wild animal, as found in zoos and animal parks, etc. ; otherwise, this mammal can be a human being. More generally, the invention relates to the use of such a peptide compound to stimulate KISS1 R, in order to increase the secretion of GnRH, and consequently to stimulate the release of LH and / or FSH hormones in a patient. mammal.

The peptide compound according to the invention may especially be used in the context of the treatment of pathological conditions resulting from low circulating levels of LH and FSH, for example pathological conditions resulting from insufficient pituitary stimulation. More generally, it can be used for the treatment of pathologies related to a reduction in the activity of the hypothalamic-pituitary-gonad axis, such as amenorrhea of hypothalamic origin or puberty delays.

Other applications of the peptide compound according to the invention are in particular the treatment of certain forms of cancer, sensitive to steroid hormones, or the delay of aging by stimulating the secretion of GnRH (Zhang et al., 2013).

The peptide compound according to the invention is preferably administered in the form of injection, which may for example be carried out intramuscularly, intravenously, subcutaneously, or intradermally. For example, the treatment may consist of a single injection of the compound to the mammal to be treated.

The administration can also be performed orally. The dose of the peptide compound administered according to the invention may be between 1 μ9 and 1 mg, in particular between 1 μg and 250 μg, depending on the mammal and the molecular mass of the compound. For example, for an ewe, the administered dose may be about 10 μg.

According to another aspect, the present invention relates to a veterinary or pharmaceutical composition, in particular for inducing ovulation in a female mammal, which contains a peptide compound corresponding to one or more of the above characteristics, in a pharmaceutically acceptable vehicle.

This composition is preferably in a form that can be administered intramuscularly, subcutaneously, intravenously or intradermally, or in an orally administrable form.

The features and advantages of the invention will emerge more clearly in the light of the following examples of implementation, provided for illustrative purposes only and in no way limitative of the invention, with the support of FIGS. 1 to 10, in which:

FIG. 1 is a graph showing, as a function of time, the amount of peptide remaining intact after incubation at 39.degree. C. in ovine serum, for the peptide compound C2 according to the invention and for the comparative compounds Comp.1 and Comp.3, this quantity being expressed in% of the HPLC peak area at time t = 0; FIGS. 2a to 2i are graphs showing the fluorescence intensity, in arbitrary units, as a function of the concentration of compound, obtained in an intracellular calcium mobilization test showing the activation of KISS1 R by the compound, for the following compounds according to the invention: FIG. 2a, compound C1; Figure 2b, compound C2; Figure 2c, compound C3; Figure 2d, compound C4; Figure 2e, compound C5; Figure 2f, compound C6; Figure 2g, compound C7; for Comparative Comp.2 in Figure 2h; for the Comparative Comp.3 in Figure 2i; and, in all the figures, the comparative compound Comp.1; FIG. 3 shows the concentration of LH measured in blood samples taken from ewes during the anoestrus period, at different times before and after the intravenous administration of physiological solutions containing respectively 5 nmol / ew of the compounds Comp. or Comp.3, and physiological solution alone (T), the moment of administration being indicated by an arrow in the figure; said concentration of LH being expressed as a percentage with respect to the maximum concentration of LH measured after injection of 5 nmol / ew of Comp.1 taken as reference (% of the maximum stimulation of Comp.1);

FIG. 4 shows the concentration of LH measured in blood samples taken from oestrus ewes, at different times before and after the intravenous administration of physiological saline containing respectively 5 nmol / ewe of the comparative compound Comp. 1, compounds according to the invention C1, C4 and C6, and physiological solution alone (T), the moment of administration being indicated by an arrow in the figure; said concentration of LH being expressed as a percentage with respect to the maximum concentration of LH measured after injection of 5 nmol / ew of Comp.1 taken as reference (% of the maximum stimulation of Comp.1);

FIGS. 5a to 5i are graphs showing the fluorescence intensity, in arbitrary units, as a function of the concentration of compound, obtained in an intracellular calcium mobilization test showing the activation of KISS1 R by the compound, for the following compounds according to the invention: FIG. 5a, compound C8; Figure 5b, compound C9; Figure 5c, compound C10; Figure 5d, compound C1 1; Figure 5e, compound C12; Figure 5f, compound C13; Figure 5g, compound C14; Figure 5h, compound C15; Figure 5i, compound C16; and, in all the figures, for the comparative compound Comp.1;

FIGS. 6a to 6d show the concentration of LH measured in blood samples taken from ewes during the anoestrus period, at different times before and after the intravenous administration of physiological solutions containing respectively 5 nmol / ewe of the compounds: Figure 6a, Comp.1; Figure 6b, Comp.3; Figure 6c, C1; Figure 6d, C2;

FIG. 7 is a histogram showing the area under the curve (AUC) calculated for each curve of FIGS. 6a to 6d;

FIGS. 8a and 8b show the concentration of LH measured in blood samples taken from ewes during the anoestrus period, at different times before and after the intravenous administration of physiological solutions respectively containing the compounds according to the invention: Figure 8a, C2; Figure 8b, C8, in concentrations of 1 nmol / ewe, 5 nmol / ewe and 15 nmol / ewe; FIGS. 9a and 9b are histograms showing the area under the curve (AUC) calculated for each of the curves respectively of FIGS. 8a and 8b;

and FIG. 10 shows the concentration of LH measured in blood samples taken from sheep during the oestrus period, at different times before and after the injection of a physiological solution containing the compound according to the invention C8 at a concentration 15 nmol / ewe, on the one hand, intravenously (iv), and on the other hand, intramuscularly (im).

EXAMPLE 1 Synthesis of Peptide Compounds in Accordance With the invention

1 .1 / General procedure

The peptide syntheses are carried out on solid phase in Fmoc / iBu strategy, at a scale of 0.1 mmol. The solid support used is a ChemMatrix® resin functionalized by a Rink amide arm.

Automated peptide elongation is performed using Applied Biosystem's 433A synthesizer. The standard Fastmoc® synthesis program provided by the manufacturer is used with a simple coupling followed by a step of acetylation with acetic anhydride after each coupling. The couplings are carried out using 10 equivalents of protected amino acid, 9.5 equivalents of HCTU (2- (6-chloro-1H-benzotriazol-1-yl) -1,3-hexafluorophosphate, 3-tetramethylaminium) and 20 equivalents of di-isopropylethylamine in N-methyl-2-pyrrolidone (NMP). Deprotection of the Fmoc group is carried out using a 20% solution of piperidine in NMP. The protective groups of the side chains used are Arg (Pbf), Arg (Me, Pbf), Asn (Trt), Ser (iBu), Trp (Boc), Tyr (iBu), Hyp (iBu), Thr (Bu).

The 1,4-disubstituted, 1,2-triazole, 1,2-triazole (<// [4- (1,2,3-triazol-1-yl)], abbreviated ψ [Τζ]) pseudopeptide linkages are formed by copper (I) catalysed cycloaddition between an alkyne and an azide (CuAAC), in solution (route A) or on a solid support (route B), according to the general reaction schemes below:

In the case of the introduction of several bonds ([Tz] consecutive, the formation of the first triazole is carried out on a solid support by cycloaddition with a / V-Fmoc-amino alkyne.The Fmoc group is then deprotected under standard conditions, then the amine is converted to azide with the aid of a diazo transfer reagent The formation of the second triazole is then carried out by cycloaddition with a γ-Fmoc α-amino alkyne, according to the general reaction scheme below ( track C): way (C)

The crude triazolopeptide is finally released from the resin with a solution of TFA / H ₂ 0 // Pr ₃ SiH / phenol, 87.5 / 5 / 2.5 / 5 for 2 h. The peptide is precipitated in cold Et ₂ 0, centrifuged and then washed 3 times with Et ₂ 0.

It is then purified by RP-HPLC (nucleosil C1 8 300 A column, 5μιτι, 1 0 * 250 mm, 3 ml / min, eluent A = H ₂ O + 0.1% TFA, eluent B = CH ₃ CN + O, 1% TFA).

The pure triazolopeptide is analyzed by HPLC (using either a Nucleosil C1 8 300 Å, 5 μιη, 4.6 × 250 mm, 1 mL / min column, or a Chromolith HighResolution RP-1.8 column, 4.6 × 100 mm. , 3mL / min) and MALDI-TOF mass spectrometry (matrix: cc-cyano-4-hydroxy cinnamic acid, instrument: Ultraflex, Bruker Daltonics, Germany). When nothing is specified in the description, the theoretical and experimental values given correspond to the monoisotopic ion.

1 .21 Intermediaries of synthesis

- (S) -2-azido-4-methylpentanoic acid (1):

This compound is synthesized following the protocol described in Goddard-Borger and Stick, 2007.

- / V-Fmoc-prop-2-ynylamine (2):

This compound is synthesized following the protocol described in Pokorski et al., 2007.

(S) -1-phenylbut-3-yn-2-amine (3):

This compound is synthesized following the protocol described in Reginato et al., 1996.

N-Fmoc- (S) -1-phenylbut-3-yn-2-amine (4):

(S) -1-phenylbut-3-yn-2-amine (3) (1.45 g, 10 mmol, 1 eq.) And NaHCO ₃ (1.3 g, 15 mmol, 1.5 eq.) are dissolved in CH ₃ CN / H ₂ O (1: 1, 50 ml). After addition of Fmoc-OSu (3.71 g, 11 mmol, 1.1 eq.), The solution is stirred for 16 h at room temperature. The reaction medium is then diluted with 100 ml of AcOEt. The organic phase is washed with an aqueous solution of 1M NaHCO ₃ (2 × 20 ml) then dried over MgSO ₄ and concentrated under reduced pressure. The residue obtained is then purified by flash chromatography to obtain the compound (4) in the form of a white solid (3.2 g, 8.8 mmol, 88%). 1 H NMR (500 MHz, CDCl ₃ ) δ = 7.78 (d, J = 7.6 Hz, 2H), 7.64 - 7.53 (m,

2H), 7.42 (t, J = 7.5, 2H), 7.36-7.23 (m, 9H), 5.01-4.95 (m, 1H), 4.81-4.75 (m, 1H), 4.52-4.43 (m, 1H). ), 4.42 - 4.35 (m, 1H), 4.25 - 4.19 (m, 1H), 3.07-2.94 (m, 2H), 2.32 (d, J = 2.4 Hz, 1H).

¹³ C NMR (125 MHz, CDCl ₃ ) δ = 155.39, 144.01, 141.55, 136.20, 130.04, 128.60, 127.95, 127.28, 125.28, 125.21, 120.22, 82.52, 72.88, 67.12, 47.43, 44.51, 41.68.

1.31 Formation of triazole by CuAAC in solution

Fmoc-Gly <// [Tz] Leu-OH (5):

(S) -2-Azido-4-methylpentanoic acid (1) (1.1 g, 7 mmol, 1 eq) and the

/ V-Fmoc-prop-2-ynylamine (2) (2.0 g, 7.35 mmol, 1.05 eq) are dissolved in a DMF / iBuOH / H ₂ O mixture (5: 4: 1, 36 ml). ) under an argon atmosphere. After addition of Pr ₂ Net (1.2 ml, 7 mmol, 1 eq) followed by CuBr (Me ₂ S) (144 mg, 0.7 mmol, 0.1 eq), the reaction mixture is stirred for 20 min. at room temperature. The solution is then diluted with 150 ml of a 1M aqueous solution of NaHCO ₃ and then washed with Et ₂ (2 × 20 ml). The aqueous phase is acidified with an aqueous solution of 6M HCl to pH 2, then extracted with AcOEt (4 x 50 ml). The organic phases are combined, dried over MgSO ₄ and then concentrated on a rotary evaporator. The product (5) is obtained as a pale green solid (3.01 g, 6.9 mmol, 98%), and is used as an automated SPPS building block without additional purification step. 1 H NMR (500 MHz, CDCl ₃ ) δ = 7.79 - 7.72 (m, 3H), 7.59 - 7.50 (m,

2H), 7.44-7.35 (m, 2H), 7.35-7.21 (m, 2H), 5.72-5.68 (s, 1H), 5.49-5.43 (m, 1H), 4.57-4.43 (m, 3H), 4.39 - 4.34 (m, 1H), 4.22 - 4.16 (m, 1H), 2.15-1.88 (m, 2H), 1.41-1.32 (m, 1H), 0.96 (d, J); = 6.4 Hz, 3H), 0.90 (d, J = 6.6 Hz, 3H). 1 ³ C NMR (125 MHz, CDCl ₃ ) δ = 171.76, 156.89, 143.96, 143.80,

141 .46, 127.92, 127.26, 125.32, 125.07, 120.18, 67.40, 47.25, 41.58, 41.45, 36.14, 24.93, 22.80, 21.45.

1 .4 / Formation of triazole by CuAAC on solid support

According to the general synthesis method used, the alkyne compound (0.4 mmol, 4 eq.) And CuBr (Me ₂ S) (82 mg, 0.4 mmol, 4 eq.) Are dissolved in 10 ml of NMP under an atmosphere of argon. After addition of iPr ₂ Net (70 μl, 0.4 mmol, 4 eq.), The solution is aspirated into a syringe provided with a sintered polypropylene, and containing the resin bearing the azide peptide (0.1 mmol). The reaction medium is stirred for 2 hours at room temperature. The resin is then washed successively with NMP (3 x 2 min), CH ₂ Cl ₂ (2 x 2 min), 1 M pyridinium chloride in CH ₂ Cl ₂ / MeOH 95: 5 (2 x 2 min). ), CH ₂ Cl ₂ (2 x 2 min) then DMF (2 x 2 min). The continuation of the elongation is carried out by standard SPPS.

1 .5 / Introduction of the modification Y- (A / -hexadecanoyl-L-qlutamyl) Modification on the N-terminal residue

According to the general mode of synthesis used, the resin bearing the modified peptide provided with an unprotected N-terminal amino function (50 μιτιοΙ) is coupled after the automated SPPS elongation with Fmoc-Glu-OiBu (10 equivalents). protected amino acid, 9.5 equivalents of HCTU and 20 equivalents of di-isopropylethylamine in NMP). Deprotection of the group Fmoc is performed using a solution of 20% piperidine in NMP. The hexadecanoic acid is then coupled (10 equivalents of acid, 9.5 equivalents of HCTU and 20 equivalents of di-isopropylethylamine in a NMP / CH ₂ CI ₂ 1: 4 mixture). The crude Y- (/ V-hexadecanoyl-L-glutamyl) -triazolopeptide is finally released from the resin with 5 ml of a solution of TFA / H ₂ 0 // Pr ₃ Si H / phenol, 87.5 / 5/2, 5/5 for 2 hours. The resin is rinsed with TFA (2x5mL for 5 min), and the filtrates are concentrated at room temperature using a rotary evaporator to a volume of about 1 mL. The peptide is precipitated by dilution with 40 mL Et ₂ 0 precooled to -80 ° C, then centrifuged and washed 2 times with Et ₂ 0. It is then purified and analyzed according to standard protocols.

Modification on the side chain of the residue in position 2 or 3

According to the general synthesis method used, a derivative of Fmoc-L-lysine provided with a Dde group on its side chain, Fmoc-Lys (Dde) -OH, is introduced at position 2 or 3 during the SPPS. After the automated synthesis, the resin bearing the modified peptide provided with an amine N-Dde function (50 μιτιοΙ) is treated with 10 ml of a 2% hydrazine solution in NMP (2 × 5 min) to remove the Dde group, then the resin carrying the modified peptide provided with an unprotected amine function (50 μιτιοΙ) is treated according to a protocol identical to that used for the introduction of the modification in position 1.

1 .6 / Comparative Peptide Compound Comp.1 (mKP10)

The peptide compound Comp.1, of sequence SEQ ID NO: 1: H-Tyr-Asn-Trp-Asn-Ser-Phe-Gly-Leu-Arg-Tyr-NH ₂ , of chemical formula: is prepared by standard SPPS.

HPLC (Nucleosil): t _R = 19.2 min (gradient: 20-40% MeCN / H ₂ 0)

0.1% TFA in 30 min); UV detection (λ = 280 nm); MS: m / z observed 1318.6 ([MH] + calculated for C ₆ H 18 N ₁₇ O ₁₅ = 1318.6).

1 .71 Peptide compound Comp.2 (hKP10)

The peptide compound Comp.2, of sequence SEQ ID NO: 2:

H-Tyr-Asn-Trp-Asn-Ser-Phe-Gly-Leu-Arg-Phe-NH ₂ ,

of chemical formula:

is obtained from the supplier Genecust (Dudelange, Luxembourg) 1 .8 / Compound Compound Comp.3

The Comp.3 peptide compound, of sequence SEQ ID NO: 10:

Ac-Tyr-Asn-Trp-Asn-Ser-Phe-Gly-Leu-Arg-Tyr-NH ₂ ,

corresponding to mKP10 in which the N-terminus is modified by acetylation, and chemical formula:

is prepared by standard SPPS.

HPLC (Nucleosil): t _R = 21.9 min (gradient: 20-40% MeCN / H ₂ O +)

0.1% TFA in 30 min); UV detection (λ = 280 nm); MS: m / z observed = 1360.6 ([MH] + calculated for C ₆ H ₈₄ N ₁₉ O ₁₄ = 1360.6).

1 .9 / Peptide compound C1

The peptide compound C1, of sequence SEQ ID NO: 5: H-Tyr-Asn-Trp-Asn-Ser-Phe-GlyΨ [Tz] Leu-Arg-Tyr-NH2, of chemical formula:

is prepared according to the route B described above by introducing the azide function by automated coupling of -azido acid (1). The formation of triazole by CuAAC on a solid support is carried out with the alkyne (2), following the general procedure.

HPLC (Nucleosil): t _R = 17.8 min (gradient: 20-40% MeCN / H ₂ 0.1% TFA in 30 min); UV detection (λ = 276 nm); MS: m / z observed 1341.6 ([MH] + calculated for C ₆₄ H ₈₄ N ₁₉ O ₁₄ = 1341.6).

1 .10 / Peptide compound C2

Peptide compound C2, of sequence SEQ ID NO: 6: Ac-Tyr-Asn-Trp-Asn-Ser-Phe-G ^ [Tz] Leu-Arg-Tyr-NH ₂ , of Chemical Formula:

is prepared according to route B, introducing the azide function by automated coupling of -azido acid (1). The formation of triazole by CuAAC on a solid support is carried out with the alkyne (2), following the general procedure. The rest of the synthesis is done by classical SPPS.

HPLC (Nucleosil): _R = 20.5 min (gradient: 20-40% MeCN / H ₂ O + 0.1% TFA in 30 min); UV detection (λ = 277 nm); MS: observed m / z = 1384.7 ([MH] + calculated for ΟββΗββΝυ δ = 1384.6).

1 .1 1 / Peptide compound C3

Peptide compound C3, of sequence SEQ ID NO: 7: Ac-Tyr-Asn-Trp-Asn-Ser-Phe-GlyΨ [Tz] Leu-Arg (Me) -Tyr-NH2, of chemical formula:

is prepared by introducing triazole according to route A, using the compound Fmoc-Glyi> [Tz] Leu-OH (5). HPLC (Nucleosil): _R = 14.3 min (gradient: 25-40% MeCN / H ₂ 0.1% TFA in 30 min); UV detection (λ = 280 nm); MS: m / z observed 1398.7 ([MH] + calculated for = 1398.7).

1 .12 / Peptide compound C4

Peptide compound C4, of sequence SEQ ID NO: 8:

Ac-Tyr-Asn-Lys (Ac) -Asn-Ser-Phe-GlyΨ [Tz] Leu-Arg (Me) -Tyr-NH 2, of chemical formula:

is prepared by introducing triazole according to route A, using the compound Fmoc-Glyi> [Tz] Leu-OH (5).

HPLC (Nucleosil): _R = 12.9 min (gradient: 20-40% MeCN / H ₂ O + 0.1% TFA in 30 min); UV detection (λ = 280 nm); MS: m / z observed = 1382.7 ([MH] + calculated for C ₆ H ₉₂ N ₁₉ O ₁₆ = 1382.7).

1 .13 / Peptide Compound C5 Peptide Compound C5, of Sequence SEQ ID NO: 9:

Ac-Tyr-Asn-Trp-Asn-Ser-PheΨ [Tz] GlyΨ [Tz] Leu-Arg-Tyr-NH2, of Chemical Formula:

is prepared as follows.

The first triazole (Glyi /> [Tz] Leu) is formed according to route B, introducing the azide function by automated coupling of -azido acid (1). The formation of triazole by CuAAC on a solid support is carried out with the alkyne (2), following the general procedure. The second triazole (Phei> [Tz] Gly) is formed according to route C. After deprotection of the Fmoc group, the resin is stirred for 1 hour with the transfer reagent of diazo 1 H-imidazole-1-sulfonyl azide.H ₂ SO ₄ (135 mg, 0.5 mmol, 5 eq), and K ₂ CO ₃ (140 mg, 1 mmol, 10 eq) dissolved in DMF / H ₂ O (3/7, 3 mL). After washing the resin, the resulting supported azidopeptide is engaged in a solid supported CuAAC reaction with the alkyne (4), following the general procedure. The rest of the synthesis is done by classical SPPS.

HPLC (Nucleosil): _R = 15.9 min (gradient: 25-40% MeCN / H ₂ O + 0.1% TFA in 30 min); UV detection (λ = 280 nm); MS: m / z observed = 1408.7 ([MH] + calculated for C ₆ H 18 N ₁₇ O ₁₃ = 1408.7).

1 .14 / Peptide compound C6

The peptide compound C6, of sequence:

Ac-DTyr-DTrp-Asn-Thr-Phe-GlyΨ [Tz] Leu-Arg (Me) -Trp-NH ₂ , of chemical formula:

is prepared by introducing tnazole according to route A, using the compound Fmoc-Gly [Tz] Leu-OH (5).

HPLC (Nucleosil): t _R = 28.4 min (gradient: 20-40% MeCN / H ₂ O + 0.1% TFA in 30 min); UV detection (λ = 280 nm); MS: m / z observed = 1321.7 ([MH] + calculated for = 1321, 7).

1 .15 / Peptide compound C7

The peptide compound C7, of sequence:

Αο-θΤγΓ-Ηγρ-Α5η-ΤήΓ-Ρήβ-ΟΙγΨ [Τζ] ίβυ-ΑΓ9 (Μβ) -ΤΓρ-ΝΗ ₂ , of chemical formula:

is prepared by introducing the triazole according to the A route described above, using the compound Fmoc-Glyi /> [Tz] Leu-OH (5).

HPLC (Nucleosil): _R = 21.3 min (gradient: 20-40% MeCN / H ₂ O + 0.1% TFA in 30 min); UV detection (λ = 280 nm); MS: m / z observed = 1248.6 ([MH] + calculated for C60H82N17O13 = 1248.6). 1 .16 / Peptide compound C8

The peptide compound C8, of sequence SEQ ID NO: 1 1:

Αο-ΤγΓ-ίγ5 (γ- (Λ / -ήθΧ3θΙέθ3ηογΙ-ΟΙυ-ΟΗ)) - ΤΓρ-Α5η-8θΓ-Ρήθ-ΟΙγΨ [Τζ] ίθυ-ΑΓ9-ΤγΓ-ΝΗ in which y - (/ V-hexadecanoyl-Glu -OH) represents a unit formula (II):

is prepared according to route B, introducing the azide function by automated coupling of -azido acid (1). The formation of triazole by CuAAC on a solid support is carried out with the alkyne (2), following the general procedure. Following the elongation synthesis is continued by conventional SPPS, then the modification y - (/ V-hexadecanoyl-Glu-OH) is introduced following the general procedure for positions 2/3.

HPLC (Nucleosil): t _R = 19.9 min (gradient: 45-75% MeCN / H ₂ O + 0.1% TFA in 30 min); UV detection (λ = 280 nm); MS: m / z observed = 1766.0 ([MH] + calculated for C89H128N2OO18 = 1766.0).

1 .17 / Peptide compound C9

The peptide compound C9, of sequence SEQ ID NO: 12: γ- (Λ / -ήθΧ3άέθ3ηογΙ-ΟΙυ-ΟΗ) -ΤγΓ-Α5η-ΤΓρ-Α5η-8θΓ-Ρήθ-ΟΙγΨ [Τ ^ζ ] ίθυ-ΑΓ9-ΤγΓ-ΝΗ ₂ , wherein y - (/ V-hexadecanoyl-Glu-OH) represents a unit of formula (II) above is prepared according to route B, introducing the azide function by automated coupling of Γα-azido acid (1) . The formation of triazole by CuAAC on a solid support is carried out with the alkyne (2), following the general procedure. The continuation of the elongation synthesis is continued by standard SPPS, then the modification y - (/ V-hexadecanoyl-Glu-OH) is introduced following the general procedure for position 1.

HPLC (Chromolith): t _R = 6.15 min (gradient: 20-40% MeCN / H ₂ O + 0.1% TFA in 6 min); UV detection (λ = 280 nm); MS: m / z observed = 1710.0 ([MH] + calculated for C₁HH ^ olc = 1710.0).

1 .18 / Peptide compound C10

The peptide compound C10, of sequence SEQ ID NO: 13: γ- (Λ / -ήθΧ3άέθ3ηογΙ-ΟΙυ-ΟΗ) ΤγΓ-Α5η-ΤΓρ-Α5η-8θΓ-Ρ ^ή θ-ΟΙγΨ [Τ ^ζ ] ίθυ-ΑΓ9-ΤΓρ- ΝΗ ₂ , wherein y - (/ V-hexadecanoyl-Glu-OH) represents a unit of formula (II) above is prepared according to route B, introducing the azide function by automated coupling of -azido acid (1) . The formation of triazole by CuAAC on a solid support is carried out with the alkyne (2), following the general procedure. Further synthesis is continued by conventional SPPS, and then the modification y - (/ V-hexadecanoyl-Glu-OH) is introduced following the general procedure for position 1.

HPLC (Chromolith): t _R = 4.3 min (gradient: 45-75% MeCN / H ₂ O + 0.1% TFA over 6 min); UV detection (λ = 280 nm); MS: observed m / z = 1732.9 ([MH] + calculated for = 1732.9).

1 .19 / Peptide compound C1 1 The peptide compound C1 1, of sequence SEQ ID NO: 14:

Αο-ΤγΓ-Α5η-ίγ5 (γ- (Λ / -ήθΧ3θΙέθ3ηογΙ-ΟΙυ-ΟΗ)) - Α5η-8θΓ-Ρ ^ή θ-ΟΙγΨ [Τ ^ζ ] ίθυ-ΑΓ9-ΤγΓ-ΝΗ2, wherein y - (/ V -hexadecanoyl-Glu-OH) represents a unit of formula (II) above is prepared according to the B route, introducing the azide function by automated coupling of Γα-azido acid (1). The formation of triazole by CuAAC on a solid support is carried out with the alkyne (2), following the general procedure. Following the elongation synthesis is continued by conventional SPPS, then the modification y - (/ V-hexadecanoyl-Glu-OH) is introduced following the general procedure for positions 2/3. HPLC (Chromolith): t _R = 3.05 min (gradient: 45-75% MeCN / H ₂ O + 0.1% TFA over 6 min); UV detection (λ = 280 nm); MS: m / z observed = 1693.9 ([MH] + calculated for C ₈ 2Hi ₂ N ₂ OOi 9 = 1694.0).

1 .20 / C12 Peptide Compound The C12 Peptide Compound, with the Sequence SEQ ID NO: 15: γ- (Λ / -ήθΧ3άέθ3ηογΙ-ΟΙυ-ΟΗ) ΤγΓ-Α5η-ΤΓρ-Α5η-8θΓ-Ρ ^ή θ-ΟΙγΨ [Τζ] ίθυ-ΑΓ9 (Μθ) -ΤγΓ-ΝΗ ₂ , wherein y - (/ V-hexadecanoyl-Glu-OH) represents a unit of formula (II) above is prepared according to the B route, introducing the azide function by automated coupling of -azido acid (1). The formation of triazole by CuAAC on a solid support is carried out with the alkyne (2), following the general procedure. Further synthesis is continued by conventional SPPS, and then the modification y - (/ V-hexadecanoyl-Glu-OH) is introduced following the general procedure for position 1.

HPLC (Chromolith): _R = 3.8 min (gradient: 45-75% MeCN / H ₂ O + 0.1% TFA over 6 min); UV detection (λ = 280 nm); MS: m / z observed = 1723.9 ([MH] + calculated for C86H122N2OO18 = 1723.9).

1 .21 / Peptide compound C13

The peptide compound C13, with the sequence SEQ ID NO: 16: γ- (Λ / -ήθΧ3άέθ3ηογΙ-ΟΙυ-ΟΗ) ΤγΓ-Α5η-ΤΓρ-Α5η-8θΓ-Ρ ^ή θ-ΟΙγΨ [Τζ] ίθυ-ΑΓ9-Ρ ^ή θ -ΝΗ ₂ , wherein y - (/ V-hexadecanoyl-Glu-OH) represents a unit of formula (II) above is prepared according to the B route, introducing the azide function by automated coupling of Γα-azido acid ( 1). The formation of triazole by CuAAC on a solid support is carried out with the alkyne (2), following the general procedure. Further synthesis is continued by conventional SPPS, and then the modification y - (/ V-hexadecanoyl-Glu-OH) is introduced following the general procedure for position 1. HPLC (Chromolith): t _R = 4.25 min (gradient: 45-75% MeCN / H ₂ O + 0.1% TFA over 6 min); UV detection (λ = 280 nm); MS: m / z observed = 1693.9 ([MH] + calculated for C85H120N2OO17 = 1693.9).

1 .22 / Peptide compound C14 Peptide compound C14, of sequence SEQ ID NO: 17:

Αο-ΤγΓ-ίγ5 (ΤΤ08- (γ- (Λ / -ήθΧ3θΙέθ3ηογΙ-ΟΙυ-ΟΗ))) - ΤΓρ-Α5η-8θΓ-Ρήθ-ΟΙγΨ [Τζ] ίθυ-ΑΓ9- Tyr-NH ₂ ,

wherein TTDS is a 1,13-diamino-4,7,10-trioxatridecanesuccinic acid spacer arm and TTDS- (γ- (/ V-hexadecanoyl-Glu-OH)) represents a unit of formula (III):

is prepared according to route B, introducing the azide function by automated coupling of -azido acid (1). The formation of triazole by CuAAC on a solid support is carried out with the alkyne (2), following the general procedure. The continuation of the elongation is continued by SPPS using Fmoc-Lys (Dde) -OH for the 2-position. After the automated synthesis, the resin bearing the modified peptide provided with an amino function N-Dde (50 μιτιοΙ) is treated with 10 mL of a 2% hydrazine solution in NMP (2 x 5 min) for remove the Dde group, then the resin bearing the modified peptide provided with an unprotected amino function (50 μιτιοΙ) is coupled with [1 - / V- (9-fluorenylmethoxycarbonyl) -1, 13-diamino-4 acid , 7,10-trioxatridecanesuccinamic acid (Fmoc-TTDS-OH, 3 equivalents, 3 equivalents of HATU (2- (7-aza-1 / - / - benzotriazol-1-yl) hexafluorophosphate -1, 1, 3 3-tetramethylaminium) and 6 equivalents of di-isopropylethylamine in NMP). The Fmoc group is removed by treatment with a solution of 20% piperidine in NMP. Fmoc-Glu-OiBu is then coupled (10 equivalents of protected amino acid, 9.5 equivalents of HCTU and 20 equivalents of di-isopropylethylamine in NMP). Deprotection of the Fmoc group is carried out using a 20% solution of piperidine in NMP. The hecadecanoic acid is then coupled (10 equivalents of acid, 9.5 equivalents of HCTU and 20 equivalents of di-isopropylethylamine in a NMP / CH ₂ CI ₂ 1: 4 mixture).

The crude TTDS- [Y- (/ V-hexadecanoyl-L-glutamyl)] triazolopeptide is finally released from the resin with 5 mL of a solution of TFA / H ₂ 0 // Pr ₃ SiH / phenol, 87.5 / 5 / 2.5 / 5 for 2 hours. The resin is rinsed with TFA (2 x 5 mL for 5 min), and the filtrates are concentrated at room temperature using a rotary evaporator to a volume of about 1 mL. The peptide is precipitated by dilution with 40 mL Et ₂ 0 previously cooled to - 80 ° C, then centrifuged and washed 2 times with Et ₂ 0. It is then purified and analyzed according to standard protocols.

HPLC (Chromolith): t _R = 3.65 min (gradient: 45-75% MeCN / H ₂ O + 0.1% TFA over 6 min); UV detection (λ = 280 nm); MS: observed m / z = 2068.2 ([MH] + calculated for Cio Hi5 ₃ N ₂₂ 0 ₂₃ = 2068.2). 1 .23 / Peptide compound C15

Peptide compound C15, of sequence SEQ ID NO: 18:

Ac-Tyr-Lys [2- (succinamido) -6- (4- (4-iodophenyl) butanamido) hexanoate] -Trp-Asn-Ser-Phe-G4-TzLeu-Arg-Tyr-N1-,

in which 2- (succinamido) -6- (4- (4-iodophenyl) butanamido) hexanoate represents a unit of formula (IV):

is prepared according to route B, introducing the azide function by automated coupling of -azido acid (1). The formation of triazole by CuAAC on a solid support is carried out with the alkyne (2), following the general procedure. The continuation of the elongation is continued by SPPS using Fmoc-Lys (Dde) -OH for the 2-position. After the automated synthesis, the resin bearing the modified peptide provided with an amino function N-Dde (50 μιτιοΙ) is treated with 10 ml of a 2% hydrazine solution in NMP (2 x 5 min) to remove the Dde group, then the resin bearing the modified peptide provided with an unprotected amino function (50 μιτιοΙ) is treated with succinic anhydride (10 equivalents of anhydride and 20 equivalents of diisopropylethylamine in NMP). HD-Lys (Boc) -OiBu is then coupled (10 equivalents of protected amino acid, 10 equivalents of PyAOP (7-Azabenzotriazol-1-yloxy) hexafluorophosphate tripyrrolidinophosphonium) and 20 equivalents of di-isopropylethylamine in NMP). The crude triazolopeptide is finally released from the resin with 5 mL of a solution of TFA / H ₂ 0 // Pr ₃ SiH / phenol, 87.5 / 5 / 2.5 / 5 for 2 h. The resin is rinsed with TFA (2x5 mL for 5 minutes), and the filtrates are concentrated at room temperature using a rotary evaporator to a volume of about 1 mL. The peptide is precipitated by dilution with 40 mL Et ₂ 0 previously cooled to 0 ° C, then centrifuged and washed 2 times with Et ₂ 0.

The peptide is finally coupled in solution with 4 - (- p-iodophenyl) butanoic acid (3 equivalents) activated in the form of its N-hydroxysuccinimide ester as described in the publication by Trussel et al., 2009. The compound C15 thus obtained is then purified and analyzed according to the standard protocols.

HPLC (Chromolith): t _R = 4.85 min (gradient: 20-40% MeCN / H ₂ O + 0.1% TFA over 6 min); UV detection (λ = 280 nm); MS: observed m / z = 1898.8 ([MH] + calcd for C ₈₈ Hii lN ₆ ₂₁ 0 ₁₉ = 1898.8).

1 .24 / Peptide compound C16

The peptide compound C16, of sequence SEQ ID NO: 19: Αο-ΤγΓ-ίγ5 (ΡΕΟ5000) -ΤΓρ-Α5η-5βΓ-Ρήβ-ΟΙγΨ [Τ ^ζ ] ίβυ ^ -ΤγΓ-ΝΗ ₂ , in which PEG5000 represents a motif of formula: COCH ₂ CH ₂ NH (CH ₂ CH ₂ 0) nMe with -85 <n <-130, with an average molecular weight of about 5000 g / mol, is prepared according to route B, by introducing the azide function by automated coupling of Γα-azido acid (1). The formation of triazole by CuAAC on a solid support is carried out with the alkyne (2), following the general procedure. The continuation of the elongation is continued by SPPS using Fmoc-Lys (Boc) -OH for the 2-position. After the automated synthesis, the triazolopeptide (50 μιτιοΙ) is finally released from the resin with 5 ml of a solution of TFA / H ₂ 0 // Pr ₃ If H / phenol, 87.5 / 5 / 2.5 / 5 for 2 h. The resin is rinsed with TFA (2 x 5 mL for 5 min), and the filtrates are concentrated at room temperature using a rotary evaporator to a volume of about 1 mL. The peptide is precipitated by dilution with 40 mL Et ₂ 0 precooled to -80 ° C, then centrifuged and washed 2 times with Et ₂ 0.

The peptide (2 equivalents) is finally coupled in solution with a commercial polymer (IRIS Biotech Gmbh) with an average mass of about 5000 g / mol activated in the form of its ester of / V-hydroxysuccinimide (5 mM peptide in a 50mM HEPES buffer mixture pH 8.5 and MeCN 9: 1). The compound C16 thus obtained is then purified and analyzed according to the standard protocols.

HPLC (Nucleosil): t _R = 15-17 min (gradient: 35-55% MeCN / H ₂ O + 0.1% TFA in 40 min); UV detection (λ = 280 nm); MS: m / z observed = 6182.2 ([MH] + calcd for n = 106, C ₂₈ H ₅₂₂ N ₂₀ O ₂₂ = 6182.4, mass average, not monoisotopic).

EXAMPLE 2 - Proteolytic degradation test of peptide compounds in ovine serum

To carry out this test, blood was collected from the jugular vein of Ile de France ewes and centrifuged. The supernatant (serum) was stored at -20 ° C until use.

The degradation in this serum of the different peptide compounds according to the invention and comparative peptide compounds is monitored over time. For this purpose, each peptide compound to be analyzed and the internal calibrator (L-phenylalaninol) are dissolved in milliQ water (0.5 mM and 6.6 mM, respectively). The commercial protease inhibitor cocktail (Sigma, P8340) is supplied in solution in DMSO.

Serum and stock solutions of peptide compounds are preheated to 39 ° C for 30 minutes. Each solution of peptide compound (50 μί, ie a final concentration in the serum of 50 μΜ) and the internal calibrant solution (25 μί) are mixed with 425 μί. of serum and incubated at 39 ° C. The monitoring of the kinetics of proteolytic degradation of the compounds is carried out by taking, at various given times, 75 μί. of the solution, which are diluted with 150 μί. of acetonitrile to precipitate the serum proteins. The suspension obtained is centrifuged at 14,000 rpm for 10 min at 4 ° C. 100 μί. supernatant are diluted in 900 μί. 0.1% TFA solution in water, then injected into HPLC for analysis (column: Chromolith® HighResolution RP-18 endcapped, 3 mL / min, gradient: 2-52% MeCN / H ₂ O + 0.1% TFA in 5 min, UV detection, λ = 214 nm). The amount of intact peptide compound after incubation is determined by integration of the peak area, using L-phenylalaninol as internal calibrator. It is expressed in% of the area of the peak at time t = 0.

The value corresponding to 100% of intact peptide compound is obtained by mixing 420 μί. of serum, 5 μί. inhibitor cocktail and 25 μl of the phenylalaninol solution, followed by 50 μl. of peptide compound, then immediately treating the resulting solution according to the protocol described above. For all the compounds tested, the results obtained after 3 hours of incubation in the serum are shown in Table 1 below.

Table 1 - Quantities of intact peptide compounds after 3 hours of incubation in ovine serum, expressed as% of HPLC peak area at time t = 0

These results demonstrate that the compounds according to the invention C2 to C7 all have a lifespan in the ovine serum which is very much extended compared to the comparative natural compounds mKP10 (Comp.1) and hKP10 (Comp.2).

The interest, in terms of elongation of the half-life in ovine serum, of the substitution by a triazole bond of the amide bond between the glycine residue and the leucine residue is furthermore clearly demonstrated by comparison of the kinetics of degradation in the serum obtained for the compound according to the invention C2, and the comparative compound Comp.3, whose structures differ only in the nature of said bond. In particular, these compounds are both provided with an N-terminal γ-acetyl group. These kinetics of proteolytic degradation in ovine serum are illustrated on Figure 1. It is clear from this figure that the peptide compound according to the invention C2 has a significantly longer shelf life compared with that of the comparative peptide compound Comp.3.

EXAMPLE 3 - Intracellular calcium mobilization tests 3.1 / Materials and methods

To carry out the in vitro tests of the activity of the peptide compounds according to the invention and of the comparative compounds, the cell line HEK293A (ATCC, American Type Culture Collection, Manassas, Virginia, USA) was stably transfected with the receptor human KISS1 R (Genbank accession number: NM_032551) For transfection, was used pcDNA3.1 vector (Invitrogen, Cergy Pontoise, France), in which the sequence of human KISS1 R was inserted with a 5 'HA tag in position 957-2150 bp. Transfection and selection of clones were performed as described in literature (Mancini et al., 2009, and Invitrogen website). The KISS1R receptor is coupled to Gq proteins and its activation produces an increase in intracellular calcium concentration. To verify the agonist activity and to measure the EC ₅ o of the peptide compounds according to the invention, the following protocol has been implemented.

HEK293A cells expressing the human KISS1 R receptor were seeded in a 96-well plate (clear plate black) at a concentration of 40,000 cells / well, and placed in an incubator at 37 ° C. After 48 hours, the medium was changed and the cells were incubated with Fluo-4NW fluorescent dye, as specified by the manufacturer (Molecular Probe). To avoid peptide-plastic adhesion, the compounds to be tested were prediluted in a so-called "non-binding" plate (Corning) at a concentration 20 times greater (20X) at the desired final concentration.

After measuring the basal fluorescence, 5 μl of the 20X solution containing the test compound was added to each well (containing 95 μl) to obtain the desired concentration. Variations of Fluorescence was recorded every 7 seconds for 5-7 minutes with a plate reader (PolarStar Optima, BMG Labtech). Activity-concentration curves were generated using the GraphPad Prism 5 software, and the EC ₅ o of each compound was calculated by fitting the curve to a sigmoid.

3.2 / Compounds C1 to C7 according to the invention

The curves obtained are shown in FIGS. 2a to 2g, respectively for the compounds in accordance with the invention C1, C2, C3, C4, C5, C6 and C7, in FIG. 2h for the comparative compound Comp.2 and in FIG. 2i for Comp.3 Comparative Comp. In each of these figures, the curve obtained for the comparative compound Comp.1 also shown for comparison. The results, in terms of EC ₅ o, are shown in Table 2 below.

Table 2 - Effect of Peptide Compounds on Intracellular Calcium Mobilization of Cells Expressing Human KISS1 R These results show that the insertion of a disubstituted 1,2,3-triazole heterocycle as a replacement for the peptide bond between glycine and leucine, according to the invention, increases the stimulation power of the human KISS1 R of the peptide compounds. with the exception of compound C5, which remains active, although to a lesser extent.

3.3 / Compounds C8 to C16 according to the invention

The curves obtained are shown in FIGS. 5a to 5i, respectively for the compounds in accordance with the invention C8, C9, C10, C1 1, C12, C13, C14, C15 and C16. In each figure, the curve corresponding to Comp.1, which has been tested in parallel with each compound, is also represented. The results, in terms of EC ₅ o, are shown in Table 3 below.

Table 3 - Effect of the Peptide Compounds According to the Invention, Modified by a Pattern That Is Bindable to Serum Albumin (C8 to C15) or by a PEG (C16), to the Mobilization of Intracellular Calcium in Cells Expressing KISS1 R human These results show that the insertion of a disubstituted 1,2,3-triazole heterocycle replacing the peptide bond between glycine and leucine, associated with the presence on the peptide compound of a motif capable of binding to the peptide. Serum albumin, or PEG, according to particular embodiments of the present invention, enhances the stimulatory potency of the human KISS1 R peptide compounds, with the exception of the compound C1 1, which remains active however, although less, and the compound C16, which shows a power similar to the Comp.1 comparative compound.

Example 4 - Activity In Vivo Tests 4.1 / 1 ^st Experiment

In this example, the compounds in accordance with the invention C1, C4 and C6 and the comparative compound Comp.1 were tested.

The tests were carried out on Ile de France ewes either during the anoestrus period for the Comp.1 and Comp.3 comparative compounds, or during the estrus period for the Comp.1 comparative compound and for the Compound Compounds. the invention C1, C4 and C6. Eps used in the estrus period were previously treated with a vaginal sponge containing 20 mg of fluorogestone acetate (Chronogest CR sponge, Intervet) to block the secretion of LH and simulate a luteal phase. Five days after sponge placement (for estrus animals) or the day before the test (for anestrus animals), a catheter was placed into the jugular vein of the animal. On the day of the test, the peptide compound to be tested was injected into the catheter at the desired dose (5 nmol / ewe), diluted in 1 ml of physiological saline solution. Heparin-containing saline (3 ml) was injected immediately after the peptide compound to rinse the catheter and bring all of the compound into the bloodstream of the animal.

A negative control (T) consisting of physiological solution alone has also been realized. Before and after the injection of the test compound, blood samples were taken at variable intervals between 10 min and 1 h, for a period of between 3 h and 30 h.

Blood samples were centrifuged, and plasma stored at -20 ° C until used to measure LH concentration, following an RIA method described in the literature (Caraty et al., 2007).

The results obtained, in terms of LH concentration in each blood sample, relative to the maximum concentration of LH measured after injection of 5 nmol / ew of Comp.1 (% of the maximum stimulation of Comp.1), depending on the time, are shown in Figure 3 for compounds Comp.1 and Comp.3 (ewes in anoestrus period) and in Figure 4 for compounds Comp.1, C1, C4 and C6 (sheep during oestrus ).

It is clear from these figures that the compounds according to the invention C1, C4 and C6 are all more active than the Comp.1 and Comp 3 comparative compounds with regard to the increase in the plasma concentration of LH.

More particularly, it is observed in FIG. 3 that the compound having an N-terminal substitution (Comp 3), which is more potent than Comp.1 (mKP10) in vitro, increases in this in vivo test only minimally, the effectiveness and duration of elevation of plasma LH concentration. On the other hand, as can be seen in FIG. 4, the introduction of a triazole unit replacing the peptide bond between the glycine and leucine residues, according to the present invention, significantly increases not only the concentration LH plasma, but also the duration of this increase.

4.2 / 2 ^nd Experimentation

In this example, the compounds in accordance with the invention C1 and C2 and the comparative compounds Comp.1 and Comp.3 were tested.

The tests were carried out on Ile de France ewes during the anestrus period, as indicated above with reference to the 1 ^st Experimentation (no treatment with progesterone). In particular, for all animals, the day before the test, a catheter was placed in the jugular vein of the animal. On the day of the test, the peptide compound to be tested was injected into the catheter at the desired dose (5 nmol / ewe), diluted in 1 ml of physiological saline solution.

The results obtained, in terms of LH concentration in each blood sample as a function of time, are shown in FIGS. 6a to 6d, respectively for compounds Comp.1, Comp.3, C1 and C2. In these figures, the arrow, showing the time "0", indicates the moment of the injection. The duration of action of the compound concerned is symbolized by asterisks, the number of which is proportional to the duration of action of the compound.

It is clear from these figures that the compounds according to the invention C1 and C2 have a duration of action which is prolonged longer in time than the Comparative compounds Comp.1 and Comp.3, of which they respectively differ only by replacement of the peptide bond between the glycine and leucine residues by the 1,2,3-triazole-1,4-disubstituted linkage.

For each of the curves obtained, the area on the curve (AUC) was calculated. The set of values obtained are shown in FIG. 7. It is observed that the compound according to the invention C2 is significantly more active than the comparative compounds with regard to the total increase in the plasma concentration of LH on the whole. the duration of the experiment (9 hours).

4.3 / 3 ^rd Experimentation In this example the compounds according to the invention were tested

C2 and C8, which differ in the presence, in C8, of a motif capable of binding serum albumin at the 2-position of the peptide compound.

The tests were performed on ewes Ile de France during the period of anoestrus, as indicated above in reference to the 1 ^st Experiment (without progesterone treatment). In particular, for all animals, the day before the test, a catheter was placed in the jugular vein of the animal. On the day of the test, the peptide compound to be tested was injected into the catheter at the desired dose, diluted in 1 ml of saline. For each compound, the following three doses were tested: 1 nmol / ew, 5 nmol / ew and 15 nmol / ew.

The results obtained, in terms of LH concentration in each blood sample as a function of time, for each injected dose, are shown in FIGS. 8a and 8b, respectively for compounds C2 and C8. In these figures, the arrow, showing the time "0", indicates the moment of the injection.

It is clear from these figures that the compound according to the invention C8, differing from the compound C2 by the introduction of a pattern capable of binding serum albumin, has an action that is even more prolonged over time, and very significantly, that the compound C2, which has been shown above that it is itself much better than the Comp.1 and Comp.3 comparative compounds.

For each of the curves obtained, the area on the curve (AUC) was calculated. The set of values obtained are shown in FIGS. 9a and 9b, respectively for the compounds C2 and C8. It is observed that the compound according to the invention C8 is even more active than the compound C2 as regards the secretion of LH.

4.4 / 4 ^th Experimentation

In this example, the compound according to the invention C8 was injected, on the one hand intravenously, and on the other hand intramuscularly, to sheep of Ile de France breed in oestrus period.

The ewes were previously treated with a vaginal sponge containing 20 mg of fluorogestone acetate (Chronogest CR sponge, Intervet) to block the secretion of LH and simulate a luteal phase.

In this experiment, it was chosen an exposure time of longer vaginal sponge compared to the 1 ^st experiment, so to better block the endogenous pulsatility of LH. Twelve days after laying the sponge, a catheter was placed in the jugular vein of some of the animals. On the day of the test, compound C8 was injected into the catheter at the desired dose (15 nmol / ewe), diluted in 1 ml of saline. Heparin-containing saline (3 ml) was injected immediately after the peptide compound to flush the catheter and draw all of the compound into the bloodstream of the animal.

In parallel, on other animals, the same day, an intramuscular injection, at the same dose (15 nmol / ewe), was made in the muscles of the animals located between the neck and the shoulder, as practiced in the animals. farms.

Before and after the injection of the test compound, blood samples were taken at variable intervals between 10 minutes and 1 hour, for a period of 10 hours.

Blood samples were centrifuged, and plasma stored at -20 ° C until used to measure LH concentration, following the RIA method described in the literature (Caraty et al., 2007).

The results obtained, in terms of LH concentration in each blood sample, are shown in Figure 10. In this figure, the arrow, showing the time "0", indicates the timing of the injections. These results show that the peptide compound according to the invention C8 is also effective, in vivo, by intramuscular injection, on the secretion of LH in the plasma.

BIBLIOGRAPHIC REFERENCES

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Caraty et al., 2007, Endocrin. 148 (1): 5258-5267

Caraty and Franceschini, 2008, Reprod. Dom. Anim. (Suppl 2): 172-178

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Dumelin et al., 2008, Angew. Chem., Int. Ed., 47: 3196-3201

Goddard-Borger and Stick, 2007, Org. Lett. 9: 3797-3800

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Claims

Peptide agonist compound of the KISS1 R receptor, characterized in that it is chosen from:

a pseudo-peptide presenting the C-terminal sequence:

-Xaa [Tz] Xaa2-Xaa3-Xaa4-NH ₂ (SEQ ID NO: 3) where Ψ [Τζ] represents a 1,2,3-triazole-1,4-disubstituted group of formula (I):

replacing the peptide bond between the residue Xaa1 and the residue Xaa2,

Xaa1 represents Gly or Ala,

Xaa2 represents Leu or a similar aliphatic α-amino acyl residue,

Xaa3 represents Arg, whose -NH ₂ function is optionally substituted by a methyl group, or a positively-charged positively charged α-amino-acyl residue,

Xaa4 represents Tyr, Phe, Trp or an α-aminoacyl residue of the aryl alanine analogue type, an analogue of the pseudo-peptide of sequence SEQ ID NO: 3 in which the peptide amide linkage between Xaa2 and Xaa3 and / or between Xaa3 and Xaa4 is replaced by an isosteric bond, or a salt thereof.

Peptide compound according to claim 1, selected from a pseudo-peptide of sequence:

H-Tyr-Asn-Trp-Asn-Ser-Phe-Xaa [Tz] Xaa2-Xaa3-Xaa4-NH ₂ (SEQ ID NO: 4) 1 2 3 4 5 6 7 8 9 10

an analogue of said pseudo-peptide capable of binding the KISS1R receptor, or a salt thereof.

Peptide compound according to claim 2, consisting of an analogue of said pseudo-peptide of sequence SEQ ID NO: 4, in which at least one amino acid among Tyr1, Asn2 and Trp3 is substituted by a lysine, the amine function of which is preferably substituted by one or more groups selected from an alkanoyl group, a polyalkylene glycol chain, preferably polyethylene glycol, and a lipid chain.

4. A peptide compound according to any one of claims 2 to 3, consisting of an analogue of said pseudo-peptide sequence SEQ ID NO: 4, wherein at least the amino acid Tyr1 is replaced by its enantiomer D.

Peptide compound according to any one of claims 1 to 4, in which at least the N-terminal amino function is modified by substitution with a group chosen from linear alkanoyls, in particular C 1 -C 6 alkanes, a benzoyl group and a tetramethylguanidinium group.

The peptide compound according to any one of claims 1 to 5, wherein at least the N-terminal amino function is replaced by an azide function or a 1,2,3-triazole-1,4-disubstituted group of formula (I).

7. Peptide compound according to any one of claims 1 to 6, wherein at least the N-terminal amino function is substituted by an alkyl group, especially chosen from linear alkyls, preferably C 1 -C 6 alkyl, or by a group. benzyl.

Peptide compound according to any one of claims 1 to 7, wherein at least one amino acid is linked to one or more chains. polyalkylene glycol, preferably polyethylene glycol, and / or one or more lipid chains and / or groups binding to serum albumin.

Peptide compound according to any one of claims 1 to 8, in which at least one amino acid is linked to a unit capable of binding to serum albumin, in particular to a y - (/ V-hexadecanoyl-Glu group. -OH), said amino acid being preferably located in the N-terminal region of said peptide compound.

Peptide compound according to any one of claims 1 to 9 for use as a medicament.

Peptide compound according to claim 10 for use in inducing ovulation in a mammal.

Peptide compound according to claim 10 for use in the treatment of pathologies related to a reduction of hypothalamic-pituitary-gonad axis activity.

13. A peptide compound according to claim 10, for its use for the treatment of cancers sensitive to steroid hormones or for delaying aging,

A peptide compound according to any one of claims 10 to 13, which is administered in the form of injection.

15. A pharmaceutical or veterinary composition, especially for inducing ovulation in a female mammal, characterized in that it contains a peptide compound according to any one of claims 1 to 9 in a pharmaceutically acceptable vehicle.

16. A composition according to claim 15, in a form that can be administered by intramuscular, subcutaneous, intravenous or intradermal injection, or in an orally administrable form.