Light-protection agents

1. A method for achieving a light or UV screening effect on the skin of a patient, comprising applying to the skin a compound of formula I

where R 1 and R 2 are

H or

OR 11 , where each OR 11 is independently

OH,

straight-chain or branched C 1 - to C 20 -alkoxy,

straight-chain or branched C 3 - to C 20 -alkenyloxy,

straight-chain or branched C 1 - to C 20 -hydroxyalkoxy, where one or more hydroxyl groups is bonded to a primary or secondary carbon atom and alkyl chains of said hydroxyalkoxy moiety optionally being interrupted by oxygen, or

a C 3 - to C 10 -cycloalkoxy group or C 3 - to C 12 -cycloalkenyloxy group, having rings optionally bridged by —(CH 2 ) n — groups, where n=1 to 3, or

mono- and/or oligoglycosyl,

with the proviso that at least one of R 1 or R 2 is OR 11 ,

R 3 is OR 11 , and

R 4 to R 7 and R 10 are each independently,

H,

straight-chain or branched C 1 - to C 20 -alkyl,

straight-chain or branched C 3 - to C 20 -alkenyl,

straight-chain or branched C 1 - to C 20 -hydroxyalkyl, where the hydroxyl group is bonded to a primary or secondary carbon atom and alkyl chains of said hydroalkyl moieties optionally being interrupted by oxygen, or

C 3 - to C 10 -cycloalkyl groups or C 3 - to C 12 -cycloalkenyl groups, having rings optionally bridged by —(CH 2 ) n — groups, where n=1 to 3, and

R 8 and R 9 are each independently

H,

OR 11 ,

straight-chain or branched C 1 - to C 20 -alkyl,

straight-chain or branched C 3 - to C 20 -alkenyl,

straight-chain or branched C 1 - to C 20 -hydroxyalkyl, where the hydroxyl group is bonded to a primary or secondary carbon atom and alkyl chains of said hydroxyalkyl moieties optionally being interrupted by oxygen, or

C 3 - to C 10 -cycloalkyl or C 3 - to C 12 -cycloalkenyl, having rings optionally bridged by —(CH 2 ) n — groups, where n=1 to 3.

2. A method according to claim 1 wherein R 4 to R 7 and R 10 are H.

3. A method according to claim 1 wherein R 3 is

OH or

straight-chain or branched C 1 - to C 20 -alkoxy, or

mono- and/or oligoglycosyl, and

R 1 or R 2 are

OH,

straight-chain or branched C 1 - to C 20 -alkoxy or

mono- and/or oligoglycosyl.

4. A method according to claim 1 , wherein R 3 is methoxy, ethoxy or ethylhexyloxy.

5. A method according to claim 1 , wherein R 1 or R 2 is methoxy, ethoxy or ethylhexyloxy.

6. A method according to claim 1 , wherein R 1 or R 2 is glucosyl.

7. A method according to claim 1 , wherein compound according to claim 1 wherein R 3 is a straight-chain or branched C 1 - to C 20 -alkoxy group, and R 8 and R 9 are identical and are H or straight-chain or branched C 1 - to C 20 -alkoxy.

8. A method according to claim 7 , wherein R 3 is methoxy, ethoxy or ethylhexyloxy.

9. A method according to claim 7 , wherein R 8 and R 9 is methoxy, ethoxy or ethylhexyloxy.

10. A method according to claim 8 , wherein R 8 and R 9 is methoxy, ethoxy or ethylhexyloxy.

11. A method according to claim 1 , wherein at least one of R 1 to R 3 is OH, and at least one of R 1 and R 2 is OH.

12. A method according to claim 1 , wherein the compound of formula I is applied in the form of a pharmaceutical composition.

13. A method according to claim 12 , wherein the pharmaceutical composition is in encapsulated form.

14. A method according to claim 12 , wherein the pharmaceutical composition further comprises an additional UV filter.

15. A method according to claim 14 , wherein the additional UV filter is 3-(4′-methylbenzylidene)-dl-camphor, 1-(4-tert-butylphenyl)-3-(4-methoxy-phenyl)propane-1,3-dione, 4-isopropyldibenzoylmethane, 2-hydroxy-4-methoxybenzophenone, octyl methoxycinnamate, 3,3,5-trimethyl-cyclohexyl salicylate, 2-ethylhexyl 4-(dimethylamino)benzoate, 2-ethylhexyl 2-cyano-3,3-diphenylacrylate, or 2-phenylbenzimidazole-5-sulfonic acid or a potassium, sodium or triethanolamine salt thereof.

16. A method according to claim 12 , wherein the pharmaceutical composition further comprises at least one antioxidant.

17. A method according to claim 12 , wherein the pharmaceutical composition comprises a cosmetically or dermatologically suitable excipient.

18. A method according to claim 1 , wherein the compound of the formula I is prepared by reacting a 2-hydroxyacetophenone compound with a lithium compound and subsequently a keto compound.

19. A method of stabilizing a UV filter comprising adding thereto a compound of formula I

where R 1 and R 2 are

H or

OR 11 , where each OR 11 is independently

OH,

straight-chain or branched C 1 - to C 20 -alkoxy,

straight-chain or branched C 3 - to C 20 -alkenyloxy,

straight-chain or branched C 1 - to C 20 -hydroxyalkoxy, where one or more hydroxyl groups is bonded to a primary or secondary carbon atom and alkyl chains of said hydroxyalkoxy moiety optionally being interrupted by oxygen, or

a C 3 - to C 10 -cycloalkoxy group or C 3 - to C 12 -cycloalkenyloxy group, having rings optionally bridged by —(CH 2 ) n — groups, where n=1 to 3, or

mono- and/or oligoglycosyl,

with the proviso that at least one of R 1 or R 2 is OR 11 ,

R 3 is OR 11 , and

R 4 to R 7 and R 10 are each independently,

H,

straight-chain or branched C 1 - to C 20 -alkyl,

straight-chain or branched C 3 - to C 20 -alkenyl,

straight-chain or branched C 1 -to C 20 -hydroxyalkyl, where the hydroxyl group is bonded to a primary or secondary carbon atom and alkyl chains of said hydroalkyl moieties optionally being interrupted by oxygen, or

C 3 - to C 10 -cycloalkyl groups or C 3 - to C 12 -cycloalkenyl groups, having rings optionally bridged by —(CH 2 ) n — groups, where n=1 to 3, and

R 8 and R 9 are each independently

H,

OR 1 ,

straight-chain or branched C 1 - to C 20 -alkyl,

straight-chain or branched C 3 - to C 20 -alkenyl,

straight-chain or branched C 1 - to C 20 -hydroxyalkyl, where the hydroxyl group is bonded to a primary or secondary carbon atom and alkyl chains of said hydroxyalkyl moieties optionally being interrupted by oxygen, or

C 3 - to C 10 -cycloalkyl or C 3 - to C 12 -cycloalkenyl, having rings optionally bridged by —(CH 2 ) n — groups, where n=1 to 3.