Crystalline constituents of euphorbiaceae—XII : Isolation and structural elucidation of three new lignans from the leaves of Phyllanthus niruri Linn.

Three more new lignans from the hexane extract of Phyllanthus niruri Linn. are now reported besides phyllanthin and hypophyllanthin. The structure of niranthin is now established as 3,3′,4′,9,9′-pentamethoxy-4,5-methylenedioxy-8,8′-butyrolignan (2). Nirtetralin and phyltetralin are shown to be 1-phenyl tetralins. On the basis of NMR and mass spectra, nirtetralin is assigned the structure (7) and phyltetralin (11).