Five new homoisoflavonoids from the tuber of Ophiopogon japonicus

Five new homoisoflavonoids, ophiopogonanone C (1), ophiopogonanone D (2), ophiopogonone C (3), ophiopogonanone E (4) and ophiopogonanone F (5), and six known compounds were isolated from an ethanol extract of the tubers of Ophiopogon japonicus (Thunb) Ker-Gawl. Spectroscopic analyses were used to elucidate the structures of these compounds.