Two new prenylated flavonol glycosides from Epimedium koreanum Nakai leaves and their anti-pulmonary fibrosis activities

Two new prenylated flavonol glycosides, namely Desmethylicaritin-3-O-β-D-glucopyranosyl-(1→3)-α-L(4″-O-acetyl) rhamnopyranosyl-7-O-β-D(6''''-O-acetyl)-glucopyranoside (1) and 5,7,3',4'-tetrahydroxyl-8-(3,3-dimethylallyl)-flavonol-3-O-α-L-rhamnopyranoside (2), and one with no NMR spectral data reported (3) were isolated from Epimedium koreanum Nakai. Their structures were elucidated by 1D, 2D NMR and HRESIMS analysis. The identification of the sugar moieties was carried out by means of acid hydrolysis and HPLC analysis of their derivatives. The anti-pulmonary fibrosis activities result showed that compound 2 had significant inhibitory effects on A549 cell fibrosis, which was similar to that of the positive control drug, pirfenidone.