LIGNANS AND NEOLIGNANS FROM STEMS AND FRUITS OF PIPER WIGHTII

Two new neolignans, (7R,8R,3'R)-7-acetoxy-3',4'-dimethoxy-3,4-methylenedioxy-6'oxo-Delta-(1',4',8')-8.3'-lignan (1) and (7R,8R,3'R)-7-hydroxy-3',4'-dimethoxy-3,4-methylenedioxy-6'oxo-Delta-(1',4',8')-8.3'-lignan (2) were isolated from the petroleum ether extract of stems of Piper wightii Miq. The structures were elucidated on the basis of their spectroscopic analysis and chemical transformation. Additionally five known neolignans, isodihydrofutoquinol A (3) and B (4), lacifolin C (5) and D (6) and wallichinine (7) and two known alpha,alpha'-diaryl-beta,beta'-dimethyltetrahydrobenzofuran lignans, calopiptin (8) and machilin G (9), were isolated for the first time from Piper wightii. The new neolignan 2, isodihydrofutoquinol B (4), lancifolin C (5) and wallichinine (7) were also isolated from the methanolic extract of fruits of the same species alongwith gelbelgin (10), also a known lignan of the tetrahydrobenzofuran type.