Compound of formula in which: A may be -X 1 - or -X 1 -OC(R 9)(R 10)-, in which X 1 may be an alkyl group having from 1 to 5 carbon atoms, optionally substituted with one or more alkyl groups having from 1 to 5 carbon atoms or one or more alkoxy groups having from 1 to 3 carbon atoms, and R 9 and R 10, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms or an alkoxy group having from 1 to 3 carbon atoms, Y is OH R 1 and R 2, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms or an alkoxy group having from 1 to 3 carbon atoms, R 3, R 4 and R 8, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 3 carbon atoms, a halogen atom, -OH, -N(R')(R"), -N(R')COR", -CN, -CONR'R", -SO 2 NR'R", -SO 2 R', nitro and trifluoromethyl; with R' and R", which may be identical or different each other, represented by hydrogen and an alkyl group having from 1 to 5 carbon atoms, R 5 may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 3 carbon atoms, a halogen atom, -OH,-N(R')(R"), -N(R')COR", nitro and trifluoromethyl, or R 5 together with one from among R 6 and R 7 forms a ring having 5 or 6 carbon atoms; with R' and R", which may be identical or different each other, represented by hydrogen and an alkyl group having from 1 to 5 carbon atoms, R 6 and R 7, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, or together form a group C=O, or one from among R 6 and R 7, together with R 5, forms a ring having 5 or 6 carbon atoms, with the proviso that when Y is -OH, A is different from an alkyl group having 1 carbon atom, optionally substituted with one or more alkyl groups having from 1 to 5 carbon atoms, or alternatively at least one of the groups from R 1 to R 8 is different from hydrogen. A may be -X 1 - or -X 1 -OC(R 9)(R 10)-, in which X 1 may be an alkyl group having from 1 to 5 carbon atoms, optionally substituted with one or more alkyl groups having from 1 to 5 carbon atoms or one or more alkoxy groups having from 1 to 3 carbon atoms, and R 9 and R 10, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms or an alkoxy group having from 1 to 3 carbon atoms, X 1 may be an alkyl group having from 1 to 5 carbon atoms, optionally substituted with one or more alkyl groups having from 1 to 5 carbon atoms or one or more alkoxy groups having from 1 to 3 carbon atoms, and R 9 and R 10, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms or an alkoxy group having from 1 to 3 carbon atoms, Y is OH R 1 and R 2, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms or an alkoxy group having from 1 to 3 carbon atoms, R 3, R 4 and R 8, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 3 carbon atoms, a halogen atom, -OH, -N(R')(R"), -N(R')COR", -CN, -CONR'R", -SO 2 NR'R", -SO 2 R', nitro and trifluoromethyl; with R' and R", which may be identical or different each other, represented by hydrogen and an alkyl group having from 1 to 5 carbon atoms, R 5 may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, an alkoxy group having from 1 to 3 carbon atoms, a halogen atom, -OH,-N(R')(R"), -N(R')COR", nitro and trifluoromethyl, or R 5 together with one from among R 6 and R 7 forms a ring having 5 or 6 carbon atoms; with R' and R", which may be identical or different each other, represented by hydrogen and an alkyl group having from 1 to 5 carbon atoms, R 6 and R 7, which may be identical or different each other, may be hydrogen, an alkyl group having from 1 to 5 carbon atoms, or together form a group C=O, or one from among R 6 and R 7, together with R 5, forms a ring having 5 or 6 carbon atoms, with the proviso that when Y is -OH, A is different from an alkyl group having 1 carbon atom, optionally substituted with one or more alkyl groups having from 1 to 5 carbon atoms, or alternatively at least one of the groups from R 1 to R 8 is different from hydrogen.