New anti-pulmonary fibrosis prenylflavonoid glycosides from Epimedium koreanum Nakai

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 spectroscopic techniques including 1D NMR, 2D NMR, HRESIMS, 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 against A549 cell line. Compounds 1 , 2 and 4 showed significant anti-pulmonary fibrosis activities.