(+)-Tephrodin - A New Flavone from Tephrosia purpurea

1 Muiva-Mutisya L., Macharia B., Heydenreich M., Koch A., Akala H.M., Derese S., Omosa L.K., Yusuf A.O., Kamau E., Yenesew, A. Phytochem. Lett., in press. 2 Vleggar R., Smalberger T.M., de Waal H.L. Tetrahedron Lett. 13 (1972) 703 However, in contrast to the levorotatory tephrodin found by Vleggar et al. our compound showed dextrorotatory behaviour ([α]D 20 = +4.7°). This suggests that both compounds must be stereoisomers. To clarify the relative configuration of our compound experimental data are compared with theoretical quantum chemical calculations (DFT B3LYP 6311G**). For configurational and conformational analysis the coupling constants between H-3“ and both protons H-2“ (2.3 and 1.0 Hz, resp.) can be used: O O O