Five new peltogynoids from underground parts of Iris bungei: A mongolian medicinal plant

Five new peltogynoids, irisoids A-E (1-5), have been isolated from the unde rground parts of Iris bungei. The structures of the new compounds were esta blished on the basis of spectroscopic methods and were found to be 1,8,10-t rihydroxy-9-methoxy-[1]benzopyrano-[3,2-c][2]-benzopyran-7(5H)-one (1), 1,8 -dihydroxy-9,10-dimethoxy-[1]benzopyrano-[3,2-c][2]-benzopyran-7(5H)-one (2 ), 1,10-dihydroxy-8,9-dimethoxy-[1]benzopyrano[3,2-c][2]-benzopyran-7(5H)-o ne (3), 1,8-dihydroxy-9,10-methylenedioxy-[1]benzopyrano-[3,2-c][2]-benzopy ran-7(5H)-one (4), and 1,8,11-trihydroxy-9,10-methylenedioxy-[1]benzopyrano -[3,2-c] [2]-benzopyran-7(5H)-one (5). The structure of irisoid B (2) was e stablished unambiguously by X-ray diffraction study.