Process for stimulating the colour of pigment elements secreted by certain animal cells and especially by those of the shell of molluscs

摘要

This process consists in amplifying the melanin synthesis of the melanocytes by treating the said tissues or cells in the presence of compounds of the general formula: in which R<1>, R<2> and R<3> are chosen from hydrogen or methyl, ethyl, propyl, isopropyl or sulphonated radicals, preferably encapsulated within infracellular vectors. The process applies to improving the yield of the production of black pearls, to the conversion of white cultured pearls into black pearls as well as to varying the colour of nacres and of pearls.