Compound of following formula: where: - R 1, R 2 and R 3 are each a methoxy group, - R 4 is a hydrogen atom, - R 5 and R 6 are the same and each represent a hydrogen or fluorine atom, and advantageously each represent a hydrogen atom, and - A is a ring selected from the group comprising aryl and heteroaryl groups, said groups possibly being: • either fused to a 5 to 7-membered heterocycle, optionally comprising one or more unsaturations and optionally substituted by one or more C 1 to C 4 alkyl groups, • or substituted by one or more groups selected from among halogens, and the groups -B 2, C 1 to C 4 alkyls, C 2 to C 4 alkenyls, C 2 to C 4 alkynyls, aryl, heteroaryl, -COOH, -NO 2, methylenedioxy, -NR 7 R 8,-NHCOR 7, - CONR 7 R 8, -NHCOOR 9, -OSi(C 1 to C 4 alkyl) 3, -NHSO 2 R 9, C 1 to C 4 alkoxy optionally substituted by one or more fluorine atoms, -OCONR 7 R 8, -OSO 2 CF 3, -OSO 2 R 9, -SO 2 R 9, -OSO 3 H, -OPO(OR 10) 2, -ONR 7 R 8, OR 11,-SO 2 NR 12 R 13, -SO 2 NHCOR 14, -OCOR 15, -OCOOR 16, -SR 17 and-OCO(CH 2) n C 6 H 4 N[(CH 2) m Cl] 2 with n = 1 to 4 and m = 1 to 3, where: ◆ R 7 and R 8 are each independently a hydrogen atom or C 1 to C 4 alkyl group, aryl or heteroaryl group, and are advantageously a hydrogen atom or C 1 to C 4 alkyl group, ◆ R 9 is a C 1 to C 4 alkyl group, aryl or heteroaryl group, and is advantageously a C 1 to C 4 alkyl group, ◆ R 10 is a hydrogen atom or C 1 to C 4 alkyl group or a benzyl group, ◆ R 11 is a hydrogen atom, O-protector group, a sugar selected from among glucose, mannose, arabinose or galactose, an amino sugar or amino acid, the free OH and NH 2 groups of sugars, amino sugars and amino acids optionally being able to be substituted by an O-protector and N-protector group respectively, ◆ R 12 and R 13 are each independently a hydrogen atom, C 1 to C 4 alkyl group, aryl or heteroaryl group, ◆ -COR 14 represents the remainder of an amino acid molecule linked to the -SO 2 NH- group or R 14 is a C 1 to C 4 alkyl group, ◆ R 15 is a hydrogen atom, C 1 to C 4 alkyl group, aryl or heteroaryl group, or a group -(CH 2) m CO 2 H or -(CH 2) m NR 7 R 8 with m = 1 to 3, ◆ R 16 is a C 1 to C 4 alkyl group, aryl or heteroaryl group, or a group -(CH 2) m CO 2 H or -(CH 2) m NR 7 R 8 with m = 1 to 3, and ◆ R 17 is a hydrogen atom or C 1 to C 4 alkyl group, or aryl group, and the pharmaceutically acceptable salts thereof, with the exception of the compounds of following formulas: - R 1, R 2 and R 3 are each a methoxy group, - R 4 is a hydrogen atom, - R 5 and R 6 are the same and each represent a hydrogen or fluorine atom, and advantageously each represent a hydrogen atom, and - A is a ring selected from the group comprising aryl and heteroaryl groups, said groups possibly being: • either fused to a 5 to 7-membered heterocycle, optionally comprising one or more unsaturations and optionally substituted by one or more C 1 to C 4 alkyl groups, • or substituted by one or more groups selected from among halogens, and the groups -B 2, C 1 to C 4 alkyls, C 2 to C 4 alkenyls, C 2 to C 4 alkynyls, aryl, heteroaryl, -COOH, -NO 2, methylenedioxy, -NR 7 R 8,-NHCOR 7, - CONR 7 R 8, -NHCOOR 9, -OSi(C 1 to C 4 alkyl) 3, -NHSO 2 R 9, C 1 to C 4 alkoxy optionally substituted by one or more fluorine atoms, -OCONR 7 R 8, -OSO 2 CF 3, -OSO 2 R 9, -SO 2 R 9, -OSO 3 H, -OPO(OR 10) 2, -ONR 7 R 8, OR 11,-SO 2 NR 12 R 13, -SO 2 NHCOR 14, -OCOR 15, -OCOOR 16, -SR 17 and-OCO(CH 2) n C 6 H 4 N[(CH 2) m Cl] 2 with n = 1 to 4 and m = 1 to 3, • either fused to a 5 to 7-membered heterocycle, optionally comprising one or more unsaturations and optionally substituted by one or more C 1 to C 4 alkyl groups, • or substituted by one or more groups selected from among halogens, and the groups -B 2, C 1 to C 4 alkyls, C 2 to C 4 alkenyls, C 2 to C 4 alkynyls, aryl, heteroaryl, -COOH, -NO 2, methylenedioxy, -NR 7 R 8,-NHCOR 7, - CONR 7 R 8, -NHCOOR 9, -OSi(C 1 to C 4 alkyl) 3, -NHSO 2 R 9, C 1 to C 4 alkoxy optionally substituted by one or more fluorine atoms, -OCONR 7 R 8, -OSO 2 CF 3, -OSO 2 R 9, -SO 2 R 9, -OSO 3 H, -OPO(OR 10) 2, -ONR 7 R 8, OR 11,-SO 2 NR 12 R 13, -SO 2 NHCOR 14, -OCOR 15, -OCOOR 16, -SR 17 and-OCO(CH 2) n C 6 H 4 N[(CH 2) m Cl] 2 with n = 1 to 4 and m = 1 to 3, ◆ R 7 and R 8 are each independently a hydrogen atom or C 1 to C 4 alkyl group, aryl or heteroaryl group, and are advantageously a hydrogen atom or C 1 to C 4 alkyl group, ◆ R 9 is a C 1 to C 4 alkyl group, aryl or heteroaryl group, and is advantageously a C 1 to C 4 alkyl group, ◆ R 10 is a hydrogen atom or C 1 to C 4 alkyl group or a benzyl group, ◆ R 11 is a hydrogen atom, O-protector group, a sugar selected from among glucose, mannose, arabinose or galactose, an amino sugar or amino acid, the free OH and NH 2 groups of sugars, amino sugars and amino acids optionally being able to be substituted by an O-protector and N-protector group respectively, ◆ R 12 and R 13 are each independently a hydrogen atom, C 1 to C 4 alkyl group, aryl or heteroaryl group, ◆ -COR 14 represents the remainder of an amino acid molecule linked to the -SO 2 NH- group or R 14 is a C 1 to C 4 alkyl group, ◆ R 15 is a hydrogen atom, C 1 to C 4 alkyl group, aryl or heteroaryl group, or a group -(CH 2) m CO 2 H or -(CH 2) m NR 7 R 8 with m = 1 to 3, ◆ R 16 is a C 1 to C 4 alkyl group, aryl or heteroaryl group, or a group -(CH 2) m CO 2 H or -(CH 2) m NR 7 R 8 with m = 1 to 3, and ◆ R 17 is a hydrogen atom or C 1 to C 4 alkyl group, or aryl group, and the pharmaceutically acceptable salts thereof, with the exception of the compounds of following formulas: