7a-O-methyldeguelol, a modified rotenoid with an open ring-C, from the roots of Derris trifoliata - Yenesew, A; Mushibe, E K; Induli, M; Derese, S; Midiwo, J O; Kabaru, J M; Heydenreich, M; Koch, A; Peter, M G (Phytochemistry, 2005)