AZAFLUORENONES FROM OXANDRA cf. MAJOR AND BIOGENETIC CONSIDERATIONS

Abstract

The stem bark of Oxandra ef. major, whieh eontains large amounts of 7,7'-bisdehydroaporphine alkaloids, has also yielded three eommonplaee steroids, retieuline, four known aporphinoids and the new azafluorenones darienine, maeondine and ursuline. Three biogenetie hypotheses are diseussed in the light of the struetures of the azafluorenones found to date in the Annonaeeae.