Placoisoflavones A and B, two new cytotoxic isoflavonoids from N.D.Khôi & Yakovlev.

Two previously unreported isoflavonoids, placoisoflavones A and B ( and ), along with five known compounds, calopogonium isoflavone B (), jamaicin (), 6-methoxycalopogonium isoflavone A (), vestitol (), and caviunin () have been isolated from the stems of N.D.Khôi & Yakovlev.