Biphenyl derivatives substituted with an aromatic or heteroaromatic radical, and pharmaceutical and cosmetic compositions containing them

A biphenyl compound substituted with an aromatic or heteroaromatic radical, characterized in that they correspond to the general formula (I) below:

• in which:
• Ar represents an aromatic or heteroaromatic radical chosen from:
• Z being O or S,
• R1 represents —COR9,
• R2 and R3, taken together, form a 5- or 6-membered ring, optionally substituted with at least one methyl,
• R4 represents H, a halogen atom, linear or branched C1-C20 alkyl, —OR10, —OCOR11 or a polyether radical,
• R5 represents H, a halogen atom, linear or branched C1-C20 alkyl, —OCOR11, OR12, mono- or polyhydroxyalkyl, —NO2,
• —(CH2)n—NHCOCH3, —CH═CH—COR13, —(CH2)nCOR13, n being 0 to 6, —O—(CH2)mCOR13, —O—(CH2)mOH, m being 1 to 12, optionally substituted aryl, optionally substituted aralkyl, optionally substituted heteroaryl, a polyether radical or a —CH2— polyether radical,
• R6 represents H, lower alkyl or —OR10,
• R7 represents H, a halogen atom, linear or branched C1-C20 alkyl, —OR10 or —OCOR11 or a polyether radical,
• R9 represents
• R10 represents H or lower alkyl,
• R11 represents lower alkyl,
• R12 represents H, linear or branched C1-C20 alkyl, mono- or polyhydroxyalkyl, or optionally substituted aryl or aralkyl,
• R13 represents H, lower alkyl, —OR10, aryl or
• r′ and r″, which may be identical or different, represent H, OH, lower alkyl, mono- or polyhydroxyalkyl, optionally substituted aryl, an amino acid residue or a peptide residue, or t′ and r″, taken together, form a heterocycle,
• or an optical or geometrical isomer of the said compounds of formula (I).