Covalently attached ferulic acid in a proteoglycan from rice bran

Abstract A water-soluble proteoglycan, precipitated with ammonium sulfate from the hot-water extract of rice bran, contained ferulic acid, which was liberated by alkaline treatment. Evidence for the linkage between the carboxyl group of ferulic acid and the proteoglycan was obtained by the characterization of ferulic acid hydroxamate after treatment of the proteoglycan with hydroxylamine.