The present invention relates to novel direct dyes and compositions comprising them for dyeing keratin fibers especially human hair. The novel dyes of the present invention have benzothiophene structure providing intensive and homogeneous dyeing on keratin fibers, especially human hair.

A family of covalent kinetic stabilizer compounds that selectively and covalently react with the prominent plasma protein transthyretin in preference to more than 4000 other human plasma proteins is disclosed. A contemplated compound corresponds in structure to Formula I, below, where the various substituents are defined within, and ##STR00001##
reacts chemoselectively with one or two of four Lys-15 -amino groups within the transthyretin tetramer. The crystal structure confirms the binding orientation of the compound substructure and the conjugating amide bond. A covalent transthyretin kinetic stabilizer exhibits superior amyloid inhibition potency, compared to a non-covalent counterpart, and inhibits cytotoxicity associated with amyloidogenesis.

A family of covalent kinetic stabilizer compounds that selectively and covalently react with the prominent plasma protein transthyretin in preference to more than 4000 other human plasma proteins is disclosed. A contemplated compound corresponds in structure to Formula I, below, where the various substituents are defined within, and

##STR00001##

reacts chemoselectively with one or two of four Lys-15 -amino groups within the transthyretin tetramer. The crystal structure confirms the binding orientation of the compound substructure and the conjugating amide bond. A covalent transthyretin kinetic stabilizer exhibits superior amyloid inhibition potency, compared to a non-covalent counterpart, and inhibits cytotoxicity associated with amyloidogenesis.