Flavanone O-glycosides from the rhizomes of Dryopteris sublaeta

The aim of this study was to look for the chemical constituents from the rhizomes of Dryopteris sublaeta. The fresh plant was extracted twice with boiling water, the extract was concentrated to small volume under reduced pressure at 50 degrees C. The concentrated material was partitioned with ether, ethyl acetate and n-butanol. The fraction of ethyl acetate was repeatedly chromatographied over silica gel and Sephadex LH-20 columns. Structures of pure compounds were established on the basis of their physiochemical and spectral data. Nine compounds were obtained and identified as sublaetentin A (1), sublaetentin B (2), sublaetentin C (3), sublaetentin D (4), matteuorienate A (5), matteuorienate C (6), arbutin (7), 3-methoxy-4-hydroxyphenyl-1-O-beta-D-glucopyranoside (8) and 3,4-dimethoxyphenyl-1-O-beta-D-glucopyranoside (9). Compounds 1 - 4 are new compounds, the others were isolated from this plant for the first time.