New Complex Isoflavones in the Roots of Yellow Lupin (Lupinus luteus L., cv. Barpine)

Abstract

Six new isoflavones each having a prenyl (3, 3-dimethylallyl) or a modified prenyl group at C-6 or C-8 of the isoflavone skeleton, lupiwighteone [5, 7, 4'-trihydroxy-8-(3, 3-dimethylallyl)isoflavone, 1], luteone hydrate [5, 7, 2', 4'-tetrahydroxy-6-(3-hydroxy-3-methylbutyl)isoflavone, 3 (already known as a fungal metabolite of luteone)], lupiwighteone hydrate [5, 7, 4'-trihydroxy-8-(3-hydroxy3-methylbutyl)isoflavone, 4], 2, 3-dehydrokievitone hydrate [5, 7, 2', 4'-tetrahydroxy-8-(3-hydroxy3-methylbutyl)isoflavone, 5], hydroxywighteone [5, 7', 4'-trihydroxy-6-(3-hydroxymethyl-3-methylallyl)isoflavone, 6], hydroxyparvisoflavone A [a 2-hydroxymethyl-2-methylpyrano-isoflavone, 7], and a new coumaronochromone, lupilutin [5, 7, 4'-trihydroxy-8-(3-hydroxy-3-methylbutyl)-coumaronochromone, 8], were isolated from the roots of yellow lupin (Lupinus luteus L., cv. Barpine). Together with these new isoflavonoids, the presence of simple isoflavones (genistein and 2'-hydroxygenistein) and complex isoflavones (wighteone, luteone, 2, 3-dehydrokievitone (2), parvisoflavones A and B, and lupinisoflavones A and B) in the yellow lupin roots has also been confirmed.