Four diarylheptanoids from Hedychium coronarium rhizomes

Several cytotoxic compounds have been identified from the rhizome of Hedychium coronarium (Zingiberaceae), a plant widely distributed in subtropic and tropic areas. To supply some of these active ingredients for chemical modification, its constituents were reinvestigated, leading to the isolation of four new but very minor diarylheptanoids (1-4) together with the major coronarin D. Their structures were elucidated based on spectroscopic analyses.