Vitamin C complexes

1. A conjugate formed from at least one molecule of 5-(1,2-dihydroxy-ethyl)-3,4-dihydroxy-5H-furan-2-one of formula (IV)

enantiomers, diastereoisomers, or racemic mixtures thereof, bound covalently to at least one hydrocarbon radical of formula (A) as follows:

in which:

m 1 =1, 2, 3, 4, 5 or 6;

m 2 =0, 1, 2, 3, 4, 5 or 6; and

 represents the site of binding to the molecule of 5-(1,2-dihydroxy-ethyl)-3,4-dihydroxy-5H-furan-2-one of the formula (IV) or the enantiomer, diastereoisomer, or racemic mixture thereof, the at least one hydrocarbon radical of the formula (A) being fixed by a covalent bond to at least one hydroxyl group of the 5-(1,2-dihydroxy-ethyl)-3,4-dihydroxy-5H-furan-2-one of the formula (IV).

2. The conjugate as claimed in claim 1 , wherein the hydrocarbon radical comprises from 12 to 40 carbon atoms.

3. The conjugate as claimed in claim 1 , wherein the hydrocarbon radical is the radical of formula (A) in which m l represents 1 and m 2 represents 2, or m 1 represents 0 and m 2 represents 0, or m 1 represents 1 and m 2 represents 0.

4. The conjugate as claimed in claim 1 , wherein the conjugate is represented by the following formula (I):

in which:

R 1 , R 2 , R 3 and R 4 , which may be identical or different, represent independently of one another a hydrogen atom or a hydrocarbon radical of formula (A) as claimed in claim 1 , and

at least one of the groups R 1 , R 2 , R 3 and R 4 are not a hydrogen atom.

5. The conjugate as claimed in claim 1 , wherein the conjugate is represented by the following formula (IA):

in which:

R 2 , R 3 and R 4 , which may be identical or different, represent independently of one another a hydrogen atom or the hydrocarbon radical of the formula (A) as claimed in claim 1 , and

R′ 1 represents the hydrocarbon radical of the formula (A) as claimed in claim 1 .

6. The conjugate as claimed in claim 5 , wherein all three of R 2 , R 3 and R 4 represent a hydrogen atom.

7. A method of preparing a conjugate as claimed in claim 1 , the method comprising:

condensation of:

at least one molecule of an acyl halide of the following formula (III)

in which X is a halogen atom, and m 1 and m 2 are as defined for the hydrocarbon radical of formula (A) as claimed in claim 1 , and of

the at least one molecule of 5-(1,2-dihydroxy-ethyl)-3,4-dihydroxy-5H-furan-2-one of the formula (IV) as claimed in claim 1 .

8. A method of preparing the conjugate as claimed in claim 1 , the method comprising:

an esterification reaction between:

the at least one molecule of 5-(1,2-dihydroxy-ethyl)-3,4-dihydroxy-5H-furan-2-one of the formula (IV) as claimed in claim 1 , and

at least one molecule of an acid of the following formula (II):

in which m 1 and m 2 are as defined for the hydrocarbon radical of the formula (A) as claimed in claim 1 .

9. A method of preparing the conjugate as claimed in claim 1 , the method comprising:

reaction between:

at least one molecule of 5-(1,2-dihydroxy-ethyl)-3,4-dihydroxy-5H-furan-2-one of the following formula (IV′):

in which R, R′ and R″ represent a hydrogen atom or a protective group; and

at least one molecule of a compound of the following formula (VIII):

in which m 1 and m 2 are as defined for the hydrogen radical of the formula (A) as claimed in claim 1 ; and Z is a hydrogen atom or a group —SO 2 —CH 3 .

10. The conjugate as claimed in claim 1 formulated as a gel with at least one oil.

11. Nanoparticles of the conjugate as defined in claim 1 .

12. The nanoparticles as claimed in claim 11 , wherein the conjugate is 6-squalenoyl-vitamin C.

13. The nanoparticles as claimed in claim 11 , wherein the conjugate is 2-squalenyl-vitamin C.

14. The nanoparticles as claimed in claim 11 , wherein the conjugate is 3-squalenyl-vitamin C.

15. The nanoparticles as claimed in claim 11 , wherein the nanoparticles have an average size in the range from 30 nm to 500 nm.

16. A method of preparing the nanoparticles as claimed in claim 11 , the method comprising at least:

dispersion of the conjugate in at least one organic solvent at a concentration sufficient to obtain, on adding the corresponding mixture, with stirring, to an aqueous phase, instantaneous formation of nanoparticles in suspension in said aqueous phase, and

isolation of said nanoparticles.

17. A cosmetic, dermatological or food composition comprising as active substance at least one conjugate as claimed in claim 1 and/or nanoparticles of the conjugate as defined in claim 1 together with at least one physiologically acceptable vehicle.

18. A cosmetic process for treating the signs of aging of the skin of the body and/or of the face using the conjugate as claimed in claim 1 and/or nanoparticles of the conjugate as defined in claim 1 .

19. A cosmetic process for stimulating the synthesis of collagen and/or for stimulating the synthesis of glycosaminoglycans using the conjugate as claimed in claim 1 and/or nanoparticles of the conjugate as defined in claim 1 .

20. A medicament comprising as active substance at least one conjugate as claimed in claim 1 and/or nanoparticles of the conjugate as defined in claim 1 .

21. A process for treating burns and/or wounds using the conjugate as claimed in claim 1 and/or nanoparticles of the conjugate as defined in claim 1 .

22. A method of cosmetic treatment of the skin of the body and/or of the face and/or of the scalp, the method comprising:

administering the composition as defined in claim 17 .