Identification of Dimethylmatairesinol as an Immunoglobulin E-suppressing Component of the Leaves of Cinnamomum camphora

Immunoglobulin E (IgE) plays an important role in allergic diseases. In this study, we found that a methanol extract of leaves of the camphor tree Cinnamomum camphora (C. camphora) reduced the amount of IgE secreted by human myeloma U266 cells. When the methanol extract was fractionated by extraction with organic solvents, the ethyl acetate fraction showed the highest activity. The fraction was further separated into several subfractions by...