AH receptor antagonists

1. A compound of formula (Ia), (Ib), or (Id):

2. A process for the preparation of a compound according to claim 1 comprising reacting an indanone and an aromatic aldehyde according to the scheme

in which,

for formula (Ia): R 1 and R 2 =CH 3 ; R 3 -R 8 and R 11 =H; R 9 and R 10 =methoxy;

for formula (Ib): R 1 and R 2 =CH 3 ; R 3 , R 6 -R 11 =H; R 4 and R 5 =methoxy; and

for formula (Id): R 1 , R 2 and R 9 =CH 3 ; R 3 -R 4 , R 6 -R 8 and R 11 =H; R 10 =butoxy; and

R 5 =methoxy.

3. A pharmaceutical formulation comprising a compound of formula (I):

in which

R 1 and R 2 independently of one another are C 1 -C 12 -alkyl;

R 3 to R 11 independently of one another are hydrogen, C 1 -C 12 -alkyl, hydroxyl or C 1 -C 12 -alkoxy; and

the broken line represents either a double bond or two hydrogens.

4. The pharmaceutical formulation according to claim 3 in which R 1 and R 2 are methyl.

5. The pharmaceutical formulation according to claim 3 , wherein the compound of formula (I) is compound of formula (Ia), (Ib), (Ic), or (Id):

6. The pharmaceutical formulation according to claim 3 , wherein the compound of formula (I) is in a sufficient amount (a) for reducing or preventing a translocation of an AhR into a cell nucleus, (b) for reducing or preventing a UVB-induced gene expression, (c) for reducing or preventing a gene expression induced or inducible by polycyclic aromatic hydrocarbons and/or (d) for reducing or preventing UVB-induced or UVB-inducible skin damage.

7. The pharmaceutical formulation according to claim 6 for reducing or preventing gene expression induced or inducible by polycyclic aromatic hydrocarbons, wherein the polycyclic aromatic hydrocarbon is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 6-formylindolo[3,2-b]carbazole (FICZ).

8. The pharmaceutical formulation according to claim 6 for reducing or preventing UVB-induced or UVB-inducible skin damage, wherein the skin damage is skin cancer, skin ageing, skin inflammation, or sunburn.

9. A pharmaceutical formulation for reducing or preventing a gene expression induced or inducible by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) comprising a compound of formula (I):

in which

R 1 and R 2 independently of one another are C 1 -C 12 -alkyl;

R 3 to R 11 independently of one another are hydrogen, C 1 -C 12 -alkyl, hydroxyl or C 1 -C 12 -alkoxy; and

the broken line represents either a double bond or two hydrogens.

10. A skin protection agent, photoprotective agent, and/or AhR antagonist comprising a compound of formula (I):

in which

R 1 and R 2 independently of one another are C 1 -C 12 -alkyl;

R 3 to R 11 independently of one another are hydrogen, C 1 -C 12 -alkyl, hydroxyl or C 1 -C 12 -alkoxy; and

the broken line represents either a double bond or two hydrogens; and one or more UV filters.

11. The skin protection agent, photoprotective agent, and/or AhR antagonist according to claim 10 in which R 1 and R 2 are methyl.

12. The skin protection agent, photoprotective agent, and/or AhR antagonist according to claim 10 , wherein the compound of formula (I) is a compound of formula (Ia), (Ib), (Ic), or (Id):

13. A method (a) for reducing or preventing a translocation of an AhR into a cell nucleus, (b) for reducing or preventing a UVB-induced gene expression, (c) for reducing or preventing a gene expression induced or inducible by polycyclic aromatic hydrocarbons and/or (d) for reducing or preventing UVB-induced or UVB-inducible skin damage comprising applying to the skin a compound of formula (I):

in which

R 1 and R 2 independently of one another are C 1 -C 12 -alkyl;

R 3 to R 11 independently of one another are hydrogen, C 1 -C 12 -alkyl, hydroxyl or C 1 -C 12 -alkoxy; and

the broken line represents either a double bond or two hydrogens.

14. The method according to claim 13 in which R 1 and R 2 are methyl.

15. The method according to claim 13 , wherein the compound of formula (I) is a compound of formula (Ia), (Ib), (Ic), or (Id):

16. The method of claim 13 for reducing or preventing gene expression induced or inducible by polycyclic aromatic hydrocarbons, wherein the polycyclic aromatic hydrocarbon is 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) or 6-formylindolo[3,2-b]-carbazole (FICZ).

17. The method of claim 13 for reducing or preventing UVB-induced or UVB-inducible skin damage, wherein the skin damage is skin cancer, skin ageing, skin inflammation, or sunburn.

18. A method for reducing or preventing a gene expression induced or inducible by 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) comprising applying to the skin a compound of formula (I):

in which

R 1 and R 2 independently of one another are C 1 -C 12 -alkyl;

R 3 to R 11 independently of one another are hydrogen, C 1 -C 12 -alkyl, hydroxyl or C 1 -C 12 -alkoxy; and

the broken line represents either a double bond or two hydrogens.

19. A cosmetic method of protecting the skin comprising applying to the skin a compound of formula (I):

in which

R 1 and R 2 independently of one another are C 1 -C 12 -alkyl;

R 3 to R 11 independently of one another are hydrogen, C 1 -C 12 -alkyl, hydroxyl or C 1 -C 12 -alkoxy; and

the broken line represents either a double bond or two hydrogens.

20. The cosmetic method according to claim 19 , wherein R 1 and R 2 are methyl.

21. The cosmetic method according to claim 19 , wherein the compound of formula (I) is a compound of formula (Ia), (Ib), (Ic), or (Id):