FR2641537A1 - OXYSTERYL PHOSPHATES, SYNTHESIS AND USE AS A PHARMACEUTICAL AGENT - Google Patents

Abstract

Oxysteryle phosphates according to formula (I), where R1 is an oxysteryle radical; where R2 is H or a radical derived from: (a) a natural or synthetic nucleotide structure, (b) a non-nucleotide anticancer agent, (c) an immunodepressive or immunostimulant agent, (d) a component showing an affinity for specific receptors or sites; and where R3 is selected from: -O-H, and salts and pharmaceutically acceptable acide derivatives thereof. Application to the pharmaceutical industry.

Description

 The present invention relates to oxysteryl phosphates, their method of synthesis and their use especially as anti-cancer agents or immunosuppressive agents.

 Recently, the pharmacological properties of oxidized derivatives have been discovered at various positions of the skeleton or side chain of cholesterol or its biogenetic precursors such as desmosterol and lanosterol (see "Polyoxygenated sterols and triterpenes: chemical structures and biological activities"). B. LUU in "Biological activities of oxysterols", INSERM Editions, Vol 166, 1988, pages 23-40).

These derivatives have a cytotoxic activity on cancer cells, this activity is selective since at determined concentrations, they are cytotoxic for cancer cells and without action on non-tumor cells. The mechanism of this action, of which one of the targets is the cell membrane, is original compared to that of known classical anticancer drugs whose action is generally at the level of cell division. For more explanation, see the article cited above and the article "Inhibitory effect of an oxygenated cholesterol on the induction and progression of DMBA mammary carcinoma in the rat" OH Iversen, A. Kolberg , I. Smith-Kielland, A. Stabursvik,
Wirchows, Arch. (Cell, Path.), 1986, 51, 313-320.

 These compounds are also capable of inhibiting lymphocyte activation (blastogenesis and allogeneic stimulation, in particular). This immunosuppression causes inhibition of the appearance of IL-2 receptors on the surface of lymphocytes and the production of this growth factor. These oxysterols have an activity similar to that of immunodepressants commonly used in clinical trials such as cyclosporin A and dexamethasone; but their mechanism of action is different: they intervene at the membrane level by affecting the activation of protein kinase C.

 These products, however, have such a low solubility in the aqueous phase that it is difficult to use their property in vivo, especially in the treatment of cancerous tumors or in the prevention of organ transplant rejection.

 In order to improve the solubility of these products, attempts have been made to use detergents and complexing agents but without any interesting results.

A second solution was to graft hemisuccinate groups to increase the water solubility of these compounds. The corresponding alkaline salts made it possible to test the properties of said compounds in vivo (see "In vivo antitumor activity of water-soluble derivatives of 7-hydroxycholesterols" of S. Rong, C. Bergmann, B. Luu, J.
G.Ourisson, CR Acad. Sci. 1985, 30th, 89-94). However, these derivatives have disadvantages: firstly, their solubility in bi-distilled water remains relatively low (1 to 2%), whereas their solubility in physiological solute is even lower; on the other hand. their pH is not compatible with some therapeutic treatments. Finally, their toxicity is high because the LD-50 is of the order of 200 mg / kg.

 Therefore, one of the aims of the present invention is in particular to provide compounds derived from oxysterols which are significantly more soluble than hemisuccinates and which have, if possible, improved therapeutic properties.

 Another object of the present invention is to provide compounds of the above type allowing the combination of oxysterols above and compounds having a complementary action in the field of immunomodulators and anticancer.

 Another object of the present invention is to provide soluble compounds, derived from oxysterols above, which are associated with molecules for targeting said oxysterols to specific sites.

où R1 est un radical oxystéryle, où R2 est H ou un radical dérivé de
a) une structure nucléotidique naturelle ou synthétique,
b) un agent anti-cancéreux non nucléotidique,
c) un agent immunodépresseur ou immunostimulant,
d) un composant ayant une affinité pour des récepteurs ou des sites spécifiques où R3 est choisi parmi : -O-H ou ses sels notamment alcalins, et dérivés d'acides pharmaceutiquement acceptables.These and other objects which will become apparent, are achieved by means of oxysteryl phosphates of formula 1:

where R1 is an oxysteryl radical, where R2 is H or a radical derived from
a) a natural or synthetic nucleotide structure,
b) a non-nucleotide anti-cancer agent,
c) an immunosuppressive or immunostimulatory agent,
d) a component having an affinity for specific receptors or sites where R3 is selected from: -OH or its particularly alkaline salts, and pharmaceutically acceptable acid derivatives.

dans laquelle --- indique une possible double liaison,vindique une liaison cis ou trans, dans laquelle R 1 l, R 12' R 13 représentent indépendamment H ou CH3, dans laquelle R4, R5 et R6 représentent indépendamment H, =O, -OH, R4 n'existant pas si la position 24-25 est occupée par une double liaison, de préférence l'un au moins des R4, R5, R6 est une fonction oxygénée.The oxysterols, from which the oxysteryl radicals are derived, correspond to the family of compounds described in the article by B. LUU in "Biological activities of oxysterols," JP Beck, A. Crastes de Paulet
Editors, Symposium INSERT9, vol. 166, 1988, pp. 23-40. Among these compounds, mention should be made of polyoxygenated compounds of ergosterol, derivatives of ganoderic acid, derivatives of stigmastane, derivatives of hippuristanols and pentacyclic triterpenes including maytenfolic acid,
More specifically, the oxysteryl R1 group has the following formula derived from cholesterol

in which --- indicates a possible double bond, vindicates a cis or trans bond, wherein R 1 1, R 12 'R 13 independently represent H or CH 3, wherein R 4, R 5 and R 6 independently represent H, = O, - OH, R4 does not exist if the position 24-25 is occupied by a double bond, preferably at least one of R4, R5, R6 is an oxygen function.

 The phosphate group is advantageously fixed in position 3.

 Among the preferred compounds are the compounds wherein R 1 is hydroxy-3-cholesterol, 7-hydroxycholesterolyl, 7,22-dihydroxycholesterolyl, 22,25-dihydroxycholesterolyl, 7,25-dihydroxycholester. -3 yle.

The radical R 2 can be a radical derived from a nucleotide structure, in particular derivatives of natural nucleotides with a purine ring or pyrimidine such as
- adenine
- thymine
- guanine
- uracil
cytosine or synthetic agents, in particular halogenated derivatives such as 5-fluorouracil, or nucleotide derivatives known for their anti-cancer, anti-viral or immunomodulatory activity.

où R' est un groupement méthyle, éthyle, propyle, isopropyle, hydroxy, méthoxy, éthoxy ou fluor où R" est ùn groupement hydroxy, N3 ou CN.The radical R2 can be in particular

wherein R 'is a methyl, ethyl, propyl, isopropyl, hydroxy, methoxy, ethoxy or fluorine group where R "is a hydroxy, N3 or CN group.

 The most conclusive tests are those where R 'is hydrogen, methyl or fluorine and / or R "is hydroxy.

The radical R2 can also be drifted
a non-nucleotide anti-cancer agent,
an immunostimulatory peptide such as MDP and its derivatives,
immunosuppressants of various classes such as corticosteroids, dexamethasone for example or peptides such as cyclosporine.

 Finally, the radical R2 may be an element ensuring the targeting of the molecule on specific receptors or sites, so it may be a simple or complex carbohydrate radical intended to target galactose receptors for example.

 Agents such as antibodies or antigens can also be used to target the complementary elements.

In certain cases, the radical R2 may be grafted via a grafting element in particular
to allow grafting of the molecules from which R 2 is derived which do not have OH functions, or
- To allow to separate the molecules and limit the steric effects of bulky radicals.

 The R2 radical may be a simple ose, which makes it possible to significantly increase the solubility of the compound in a nonionic and non-toxic manner.

 The radical R 2 can also be simply a hydrogen or a corresponding salt.

 The radical R3 is essentially intended to ensure good solubilization of phosphates according to the invention while respecting the pH constraints of the biological media to be treated; it is generally such that there is formation of an anion or a pair of ions once in the biological medium to be treated.

 The ionization state of R3 and its associated ions depends on the desired pH.

 The most interesting compounds will be described in more detail in the examples.

 The compounds according to the present invention can be synthesized according to the techniques described for the synthesis of oligodeoxyribonucleotides and phospholipids "Synthesis of oligodeoxyribonucleotide by continuous flow, phosphotriester method on Kieselguhr / polyamide support" by M.J. Gait, H.W.D. Matthes, M. Singh, B.S. Sproat and R.C.

Titmas ", Nucleic Acid Res., 1982, 10, 6243-6254," Current methods of phosphorylation of biological molecules ", LA Slatin, Synthesis, 1977 (November), 737-753, and" A simple and effective chemical phosphorylation procedure ". Biomolecules, W. Bannworth, A. Trzeciak, Helv Chim Acta, 1987, 10, 1-12.

The use of bifunctional phosphorylating reagents, in particular those described in the article "Preparation of ribonucleoside 3'-O-phosphoramidites and their application to the automated solid phase synthesis of oligonucleotides" by N. Usman, RT Pon, KK Ogilvie,
Tetrahedron Lett., 1985, No. 38, 4567-4570, has proved particularly advantageous.

 The invention also relates to a process for preparing a compound of formula I in which the compound of formula I is deprotected, some of whose reactive functions have been protected during synthesis.

 Among the protective groups, there must be mentioned more particularly the protective groups of the phosphite or phosphate group such as CNCH2CH2- groups.

 Similarly, in the case where the coupled compound is a nucleotide, it is necessary to eliminate the protective groups, in particular OH functions.

 These protected compounds I can be obtained by phosphorylation, direct or indirect, simultaneous or successive, of the compounds R1-OH, and R2-OH where the reactive functions of R2 and R1 have been protected, and then coupling optionally the phosphorylated compound with the non-reactive compound. phosphorylated.

où R8 et Rg sont des groupements dialcoyle amino semblables ou différents dont les groupements alcoyles semblables ou différents ont de 1 à 7 atomes de carbone et sont de préférence ramifiés où R 10 est un groupement protecteur tel que CNCH2C H2-
Le composé intermédiaire ainsi obtenu de formule V

permet d'obtenir un très grand nombre de dérivés en couplant ledit composé de formule V avec un composé présentant une fonction -OH, dont on aura protégé les éventuelles autres fonctions réactives, en présence de tétrazole ou d'un composé susceptible de former des paires d'ions avec les amines secondaires suivit d'une oxydation du triester de phosphite obtenu.Advantageously, using a process comprising the phosphorylation step which consists in reacting the compound R 1 OH wherein R 1 has the same value as in formula 1, with a phosphine of formula IV

where R8 and Rg are similar or different amino dialkyl groups of which the same or different alkyl groups have 1 to 7 carbon atoms and are preferably branched where R 10 is a protecting group such as CNCH2C H2-
The intermediate compound thus obtained of formula V

allows to obtain a very large number of derivatives by coupling said compound of formula V with a compound having an -OH function, which will be protected any other reactive functions, in the presence of tetrazole or a compound capable of forming pairs of ions with the secondary amines followed by oxidation of the obtained phosphite triester.

 Examples of such syntheses are detailed in the experimental section.

 Another object of the present invention is to provide a pharmaceutical composition which contains as active principle at least one of the phosphates according to formula 1.

 These phosphates can be used alone or as an active ingredient in combination with other active ingredients and with vectors commonly used in this type of therapy. These compositions are more particularly intended for the fight against cancer or to induce an immunodepression that is useful especially in the prevention of transplant rejection.

 The present invention further relates to a process for the preparation of anti-cancer and / or immunosuppressive pharmaceutical compositions containing compounds of formula I.

 These compositions are produced by mixing, alone or in combination with other active ingredients, compounds of formula I with the vectors commonly used in the art, and in particular the aqueous vectors, in particular the phosphates according to the invention, have a good solubility in physiological solutions this allows their use for the preparation of compositions to be administered by intravenous or intraperitoneal injection.

Finally, according to the present invention, sterols have been made soluble by attachment on a hydroxyl linkage of a phosphate group of formula VI

 The following nonlimiting examples allow the skilled person to better know the implementation parameters of the invention.

Example 1 Phosphorylation of Polyoxygenated Sterols
1 mmol of 7-triethylsilyoxycholesterol was coevaporated with anhydrous acetonitrile (3 x 50 ml) and then dissolved in 30 ml of CH 2 Cl 2.

0.5 ml of bis (diisopropylamine) -2-cyanoethyl phosphine and 70 mg of tetrazolide diisopropylamine are then added. They are allowed to react at room temperature and under argon for two hours. Once the reaction is complete, a rapid chromatography of the reaction mixture on silica gives the corresponding product in a yield of 98% (eluent hexaneXether ethyl with 1% triethylamine) .This phosphorylation is schematized by the following reaction.

Example 2 Coupling of the Nucleotide with Phosphorylated Polyoxygenated Sterols
I mmol of a previously obtained phosphorylated sterol and 1 mmol of a protected nucleotide were coevaporated separately with anhydrous acetonitrile (3 x 50 ml). The sterol thus obtained is then dissolved in 5 ml of ethyl ether and added in 50 ml of a solution of acetonitrile containing 1 mmol of nucleotide and 0.5 mmol of tetrazole.

After 6 hours of reaction, the phosphite triester thus obtained is oxidized to a phosphate triester with m-chloroperbenzoic acid (2 hours). The product is purified by chromatography on silica (eluent: methanol / methylene chloride / triethylamine - yield 60%). This coupling is schematized by the following reaction

Example 3: Detection of Sterol and Nucleotide Drotective Groups

All the protecting groups are deprotected by the action of HCl at 0.36% in THF at 0 ° C. for two hours. A reaction mixture is poured into 200 ml of dichloromethane and the organic phase is washed with NaCl solution to pH 7. Chromatography on silica gives the protected product (eluent: methanol / methylene chloride mixture, yield 90%). This deprotection is schematized by the
next reaction

Example 4 Deprotection of the phosphate protecting group
The previously obtained product is dissolved in methanol and a 25% ammonia solution is added in order to have a final concentration of 5% ammonia. After stirring for 2 hours, the mixture is evaporated to dryness.

The diester phosphate salt is obtained by passing the product through a Dowex 50 ion exchange column (Na + form) in 100% yield. This deprotection is carried out by the following reaction

Example 5: Biological tests of the compounds according to the present invention.

To simplify the description of the subsequent tests, the following notations were chosen
JB 69 (or 69): sodium salt of the ester of monophosphoric acid of 7 P hydroxycholesterol and 2-deoxyuridine,
JC 40 (or 40): sodium salt of the ester of monophosphoric acid of 7 p, 25 dihydroxycholesterol and 2-deoxyuridine,
7BOHC: 7 hydroxycholesterol (compound of the prior art),
78.25 OHC: 78.25 dihydroxycholesterol (compound of the prior art).

 In preliminary tests, the 7O-hydroxychole-steryl phosphate and 5-fluorouracil gave results in vivo (Krebs II carcinoma, P388 leukemia) higher than those obtained with the metal salts of 7-hydroxycholesteryl bis-hemisuccinate .

Toxicity on lymphomas
a) trypan blue count
This technique was used to measure the cytotoxic activity of 69 on murine and human lymphomas. After 48 hours of culture in a medium containing 2% FBS (fetal calf serum), different murine lymphomas (RD121-4, EL-4, YAC) are completely lysed at oxysterol concentrations (69 or 7ssOHC) of 20%. p.N1 (Table 1).

<Tb>

<SEP> Lymphomas <SEP> RDM-4 <SEP> Lymphoma <SEP> LIIOLT4
<tb> cxyslem (s <SEP> hL-in.s
<tb><SEP> X <SEP> 11arc <SEP> 100X <SEP> 100%
<tb><SEP> 10pM <SEP> 20% <SEP> 100%
<tb><SEP> 7OTC
<tb><SEP> 100% <SEP> tu0% <SEP> i <SEP> 100% <SEP> 0%
<tb><SEP> 1011M <SEP> 80% <SEP> 40% <SEP> 0%
<tb><SEP> 725 <SEP> OHC
<tb><SEP> 20pM <SEP> 100%
<tb><SEP>10; M <SEP> 1001: <SEP> 0%
<tb> Table 1: t inhibition on different lymphomas after 48 h of
culture in 2 Z SVF
Human lymphoma (Molt 4) is much more sensitive to 69 than to 7POHC (under the same culture conditions). 7.25 OHC is more active than 7BOHC and 69 on murine lymphomas, which can be explained by the activity probably conferred by the hydroxyl at position 25.

b) release of chromium 51
Various types of lymphoma were labeled with 51 chromium and then lysed cholesterol derivatives to study cytotoxicity during the first 2 to 4 hours of culture. The lysis of lymphomas is demonstrated by the release of chromium 51 in the culture medium after 2 hours (or 4 hours of incubation). the results are collated in table 2

<tb><SEP> 0% <SEP> SVF
<tb><SEP> -Cholesterol <SEP> + Cholesterol (63M) <SEP> 2% FCS <SEP> 10% FCW
<tb><SEP> 20M <SEP> 83% <SEP> 85% <SEP> 41% <SEP> 13%
<tb> 69 <SEP> 10M <SEP> 80% <SEP> 6% <SEP> 0 <SEP> 7%
<tb><SEP> 5M <SEP> 52% <SEP> 5% <SEP> 0 <SEP> 0
<tb> 70HC <SEP> 10M <SEP> 11% <SEP> 9% <SEP> 1 <SEP> 5
<Tb>
Table 2:% release of 5ICr (after 2 hours of incubation)
69 exhibits extremely rapid cytotoxic activity, whereas free 7P0HC which is not soluble in aqueous medium requires 24 to 48 hours of culture to exert a cytotoxic action. Compared with 69, even a very high dose of 7e, OHC (50 μM) is not toxic to lymphomas during the first 2 to 4 hours of culture whereas concentrations 10 times lower (511M) are toxic on 24 hours of culture. 69, which is soluble in aqueous medium (more than 30.0 in physiological saline) therefore has faster kinetics of action than its non-phosphorylated counterparts.

 From Table 2, it also appears that the cytotoxic action of 69 is highly dependent on the concentration of FBS in the culture medium (as well as 7ssOHC and 7ss, 25 OHC). The addition of cholesterol in the culture medium partially reverses the cytotoxic action of oxysterols: non-soluble or water-soluble derivatives.

 The addition of BSA hardly modifies the cell inhibition obtained with the insoluble oxysterols. On the other hand; The activity of the water-soluble derivatives is very strongly dependent on the concentration of BSA. 1% of BSA completely reverses the cytotoxic action of 69 to 40 μm.

This difference in behavior between 7 OHC and its water-soluble derivative could be explained by the presence of the phosphate group which would promote serum albumin binding.

c) Incorporation of 3H thymidine
In parallel with cytotoxicity assays determined by trypan blue counting and chromium salting, experiments were performed with incorporation of 3 H Thymidine: another method for estimating cell proliferation. The results obtained are summarized in Table 3

<tb><SEP> SVF <SEP> 2% <SEP> | <SEP> SVF <SEP> 10% <SEP>
<tb><SEP> 20 <SEP> 10 <SEP> 3000
<tb><SEP> 10 <SEP> 10 <SEP> 300
<tb> 69 <SEP> 5 <SEP> 1000 <SEP> 120
<tb> (11M) <SEP>: <SEP> 2.5 <SEP>: <SEP> 300 <SEP> 100
<tb><SEP> 20 <SEP> 10 <SEP> 60
<tb><SEP> 0 <SEP> 50 <SEP> 80
<tb> 70HC <SEP> 5 <SEP> 70 <SEP><SEP> go <SEP>
<tb> (iiM) <SEP> 2.5 <SEP> 75 <SEP> 80
<Tb>
Table 3: Percentage of incorporation of 3H Thymidine
EL-4 lymphoma in culture 48 h in a medium containing 2 or 10% FCS (with addition of 3 H Thymidine 6 hours before the end of the culture).

The incorporation of 3H Thymidine reflects the cytotoxic activity of 69, but there is a very strong increase in 3H incorporation.
Thymidine at nontoxic doses of 69.

This could be interpreted by a molecular effect of 69: blocking in S phase during cell proliferation. Cell cycle studies make it possible to evaluate the percentage of cells in each phase of the cycle. After addition of nontoxic doses of 69 on cells
EL-4 cultured for 3 to 6 days, there is an increase in the percentage of cells in G1 and S phases, and a decrease in the percentage of cells in G2 phase. This effect is dose dependent.

Example 6 In Vivo Tests
The antitumor activity of 69 was demonstrated with OFI mice transplanted with KREBS 2 tumor. 100% remission was obtained with two successive ip injections of 1.5 mg of 69, 24 hours after tumor injection. . A similar effect was observed with mice carrying P388 leukemia (5 mg / kg in a single injection).

Example 7 Immunomodulation
a) in vitro
In vitro has a marked immunosuppressive activity, comparable to that of its non-phosphorylated counterpart, 7P0HC. Splenic lymphocytes of C57 B6 mice were stimulated in vitro by a nonspecific mitogen concavalinaline A. The 69 is added at the beginning of the stimulation and the culture is done for 42 hours followed by the addition of> H Thymidine then the cultivation continues for another 6 hours.

Immunosuppression is dependent on the concentration of fetal calf serum (FCS). The results are summarized in Table 4.

<Tb>

<SEP> ConA <SEP> i <SEP> CanA
<tb><SEP> 20 <SEP> RM <SEP> 82% <SEP> 12 <SEP> RM <SEP><SEP> 99% <SEP>
<tb><SEP> 10 <SEP> FM <SEP><SEP> 69% <SEP> 6M <SEP> 97%
<tb> 69 <SEP> 5 <SEP> 11M <SEP> 67% <SEP><SEP> 7.25 <SEP> 3 <SEP> pM <SEP> 95%
<tb><SEP> 2.5 <SEP> - <SEP> 1 <SEP> 1.5MIL <SEP> 77%
<tb> Witness
<tb> stimulated <SEP> 0% <SEP> 0%
<Tb>
Table 4: Percentage inhibition of concanavalin stimulation
A in in vitro immunomodulation assays.

b) Ex vivo
The purpose of the ex vivo assays is to detect 69 activity in vivo in mice treated with it for several days. The activity of the product on animals is then demonstrated by means of experiments carried out in vitro.

 The intraperitoneal LD 50 of 69 is approximately 250 mg / kg. To avoid any phenomenon of acute toxicity, treatment is carried out with a dose of 50 mg / kg spread over two daily injections, for 4 days.

 One day after the end of this treatment, the mice are sacrificed.

Peritoneal cells, spleen, thymus are removed mice per mouse.

The effects of 69 are determined by counting cells in the presence of Trypan blue. The number of cells present in the spleen, the thymus, the peritoneal exudates are determined
compared to the controls, the cellularity of the spleen is unchanged,
in the thymus, the cellularity is significantly diminished compared to the controls, there remains only about 20% of cells, only the cells are affected during this treatment,
in the peritoneal cavity, the number of cells recovered is significantly higher in the treated mice. An increase in the number of macrophages and a neutrophil migration in the abdominal cavity should be noted.

Answers to mitogens
The response to stimulation with different mitogens (concavalinaline
A, lipopolysaccharides) is increased for spleen cells of mice previously treated with 69. Although the cellularity in the thymus decreases by about 60.0, a sharp increase in stimulation is observed up to 300 90 of the treated thymocytes compared to to the thymocytes of the control mice. This phenomenon, similar to that observed in the case of corticolls, could be interpreted as a decrease in pre-thyme cells.

Functional tests: cytotoxicity
LAK: LAK (Lymphokine activated killer) activity is decreased in treated mice,
CTL: the activity of CTL (cytotoxic T lymphocyte) is decreased in the treated mice, IL-1: the IL-1 activity of peritoneal macrophages stimulated or not by LPS, is greatly decreased after treatment with interperitoneal with 69.

 From previous examples, it has been demonstrated that 69 has excellent antitumor and immunosuppressive activity in vitro and in vivo due to its good solubility in aqueous medium (30/0 in physiological saline).

The 69 is therefore a product capable of curing tumor-bearing mice
KREBS 2 but also to modify immune responses after an in vivo treatment of 4 days. It is also worth noting the remarkable activity of 69 for the treatment of human lymphoma.

 Tests on the so-called "40" compound have confirmed the activity of this new family of water-soluble oxygenated phosphates. The cytotoxic activity of 4G is increased in murine lymphomas compared to 69; similarly, the immunosuppressive effect in vitro and ex vivo is accentuated with 40.

Claims (13)

1. oxysteryl phosphates of formula I

 where R1 is an oxysteryl radical, where R2 is H or a radical derived from  a) a natural or synthetic nucleotide structure,  b) a non-nucleotide anti-cancer agent,  c) an immunosuppressive or immunostimulatory agent,  d) a component having an affinity for specific receptors or sites where R3 is selected from: -O-H or its pharmaceutically acceptable salts and acid derivatives.  2. Phosphates according to claim 1, characterized in that the group R1 has the following formula

 in which --- denotes a possible double bond, indicates a cis or trans bond, wherein R 11, R 12, R 13 independently represent H or CH 3, wherein R 4, R 5 and R 6 independently represent H, OH, -OH, R 4 does not exist if the position 24-25 is occupied by a double bond, preferably at least one of R4, R5, R6 is an oxygen function.  3. phosphates according to one of claims 1 and 2, characterized in that said oxysteryl group is 7-hydroxycholesteryl, hydroxycholesteryl, 7,25 dihydroxycholesteryl, 7,22 dihydroxycholesteryl, 22,25 dihydroxycholesteryl, phosphate being fixed in position 3.  4. Phosphates according to one of claims I to 3, characterized in that R2 is a nucleotide.  5. Phosphates according to claim. 4, characterized in that said nucleotide has the formula III

 where R 'is a methyl, ethyl, propyl, isopropyl, hydroxy, methoxy, ethoxy or fluorine group where R "is a hydroxy, N3 or CN group.  6. Phosphates according to claim 5, characterized in that R 'is fluorine, hydroxy or methyl and R "is hydroxy.  Phosphates according to claim 2, characterized in that they have the following formula

 in which R4, R5 and R6 independently represent H or OH,  R 'is H or F,  X is a cation ensuring the neutrality of the compound.  8. Process for the preparation of compounds of formula I, characterized in that the compound of formula I, of which certain reactive functions have been protected during synthesis, is deprotected.  9. Synthesis process according to claim 8, characterized in that the protected compounds I are obtained by phosphorylation. directly or indirectly, concurrently or sequentially, R1-OH compounds, and R2-OH where the reactive functions of R2 and R1 have been protected.  10. Process according to claim 9 for the synthesis of phosphates according to one of claims 1 to 7, characterized in that it comprises the phosphorylation step of reacting the compound R1OH where R1 has the same value as in formula I, with a phosphine of formula IV

  wherein R8 and R9 are similar or different dialkylamino groups of which the same or different alkyl groups have from 1 to 7 carbon atoms and are preferably branched wherein R 10 is a protecting group; to obtain an intermediate compound of formula V:

 and in that the compound V is coupled with a compound R2-OH in the presence of tetrazole, optionally reducing the phosphite triester thus obtained.  He. Pharmaceutical composition characterized in that it contains at least one compound according to one of claims I to 7.  12. Pharmaceutical composition according to claim 11, characterized in that it comprises vectors commonly used in the field of the administration of anti-cancer and immunosuppressive.  13. Composition according to one of claims 11 and 12 in the form of injectable solution.  14. Process for rendering water-soluble sterols, characterized in that a phosphate group of formula VI is attached to a hydroxyl linkage