C-GLYCOSIDIC ELLAGITANNIN METABOLITES IN THE HEARTWOOD OF JAPANESE CHESTNUT TREE (CASTANEA-CRENATA SIEB ET ZUCC)

HPLC comparison of tannins in the bark, sapwood and heartwood of Casta nea crenata showed striking differences of composition, The major tann in of the bark is hamamelitannin, whereas vescalagin and castalagin ar e dominant in the wood. Inner heartwood contained three new C-glycosid ic ellagitannin metabolites, castacrenins A, B and C. Outer heartwood contained dimeric, trimeric (castaneanin A), tetrameric (castaneanins B and C) and pentameric (castaneanin D) C-glycosidic ellagitannins com posed of vescalagin and castalagin units, Castacrenins and castaneanin s are derived from vescalagin and castalagin by intramolecular and int ermolecular dehydration, respectively.