Chemical constituents from Crepis crocea

Thirteen compounds were isolated from the ethyl acetate fraction of Crepis crocea by column chromatographies on silica gel, Sephadex LH-20 and semi-preparative HPLC. The structures were elucidated on the basis of spectral analysis as tectorone I (1), 8β- (2-methyl- 2-hydroxy-3-oxobutanoyloxy) -glucozaluzanin C (2), tectoroside (3), luteolin-7-O-glucoside (4), cosmosiin (5), esculetin (6), 3,4-dihydroxybenzaldehyde (7), trans-4-hydroxycinnamic acid (8), Caffeic acid (9), methyl p-hydroxyphenyllactate (10), ethylp- hydroxyphenyllactate (11), cis-3,4-dihydroxy-β-ionion (12). All the compounds, except for compounds 4 and 9, were isolated from this plant for the first time, and tectorone I (1) is a new natural product.