Abstract: The present invention relates to derivatized polyphenols, wherein all of the reactive phenolic hydroxyl functional groups are completely esterified or etherified, as demonstrated by the absence of free hydroxyl groups in an infrared absorption spectrum of the derivatized product. Due to their increased stability, the derivatized polyphenols can be used in cosmetic and pharmaceutical formulations more effectively, targeting and releasing active anti-oxidant polyphenols via natural biological degradative mechanisms in situ in the targeted areas.

Abstract: A process for extracting essentially oligomeric catechin polyphenols from a potentilla plant, including the steps: treating at least part of the plant with a polar organic solvent to form a first extract, evaporating the first extract to dryness at a temperature of not more than 60.degree. C. to form an evaporation residue, adding water to the evaporation residue to form an aqueous solution, exhaustively extracting the solution with a water-immiscible solvent capable of dissolving oligomeric catechin polyphenols to form an organic solution, evaporating the organic solution to dryness at a temperature of not more than 60.degree. C. to form a second extract of essentially oligomeric catechin polyphenols. The second extract can be used as a compound having a free radical-scavenging action and/or action against UV rays.

Abstract: Process for esterifying a polyphenolic oligomer extract of plant origin by the action of an acid chloride, the compositions obtained by this process and their use in human therapy or in cosmetics are described. The extract is placed in a liquid medium which is not a solvent for the extract but which is a solvent for the ester(s) to be obtained, so as to obtain a suspension. At least one aliphatic tertiary amine of low boiling point is added to the suspension in the presence of a catalytic amount of at least one organic base other than pyridine. At least one fatty acid chloride is introduced into this mixture, the reaction mixture being stirred at a temperature below 40.degree. C. and then concentrated by evaporation in order to obtain an esterified extract.