New anti-pulmonary fibrosis prenylflavonoid glycosides from Epimedium koreanum

Four new prenylflavonoid glycosides, namely koreanoside H-K (1-4), together with eleven known ones (5-15) were isolated from the leaves of Epimedium koreanum Nakai. Their structures were elucidated by 1D NMR, 2D NMR, HR-ESI-MS, IR and UV. The identification of the sugar moieties was carried out by means of acid hydrolysis and HPLC analysis of their derivatives. It is worth noting that compound 3 and compound 4 were elucidated to contain fucose and quinovose moieties, which were two extremely rare sugar units from the genus Epimedium. The anti-pulmonary fibrosis activity of the new compounds was evaluated using A549 cell line. Compounds 1, 2 and 4 showed significant anti-pulmonary fibrosis activities.