ACTIVITY-GUIDED ISOLATION OF CONSTITUENTS OF TEPHROSIA-PURPUREA WITH THE POTENTIAL TO INDUCE THE PHASE-II ENZYME, QUINONE REDUCTASE

An isoflavone, 7,4'-dihydroxy-3',5'-dimethoxyisoflavone (i), and a cha lcone, (+)-tephropurpurin (2), both novel compounds, as well as six co nstituents of known structure, (+)-purpurin (3), pongamol (4), lanceol atin B (5), (-)-maackiain (6), 3-hydroxy-4-methoxy-8,9-methylene-dioxy pterocarpan (7), and (-)-medicarpin (8), were obtained as active compo unds from Tephrosia purpurea, using a bioassay based on the induction of quinone reductase (QR) activity with cultured Hepa 1c1c7 mouse hepa toma cells. Additionally, three inactive compounds of known structure, 3'-methoxydaidzein, desmoxyphyllin B, and 3,9-dihydroxy-8-methoxycoum estan, were isolated and identified. The structure elucidation of comp ounds 1 and 2 was carried out by spectral data interpretation.