METHOD FOR OXIDIZING NATURAL MATERIAL HAVING FLAVONOID SKELETON, METHOD FOR PRODUCING NATURAL MATERIAL HAVING FLAVONOID SKELETON, AND METHOD FOR DYEING HAIR

摘要

PROBLEM TO BE SOLVED: To provide a method for oxidizing a natural material having a flavonoid skeleton, and a method for dyeing hair using the oxidized material.;SOLUTION: The natural material having a flavonoid skeleton such as (+)- catechin is oxidized by oxygen gas in a mixed solvent of water and an alcohol under a basic condition to obtain a compound represented by general formula (2), (wherein, R₁₀, R₁₁, R₁₂ and R₁₃ indicate each independently a hydrogen atom, a hydroxy group or a methyl group; R₁₄ indicates a hydrogen atom, a hydroxy group, a galloyl group or a saccharide; R₁₅ indicates a hydrogen atom or a hydroxy group; and X indicates CH₂, C=O or CHOH).;COPYRIGHT: (C)2013,JPO&INPIT