Ligulariatinside A, a new sesquiterpene glycoside from roots of Ligularia veitchiana

A new sesquiterpene glycoside, ligulariatinside A (1), along with nine known compounds, dibutyl phthalate (2), 1-O-(9Z,12Z-octadecadienoyl) glycerol (3), bis (2-ethylhexyl) phthalate (4), 4-hydroxy-3-methoxyphenylpropanol (5), dihydrosyringenin (6), caffeic acid (7), 6β-hydroxy-7(11)-eremophilen-12,8α-olide (8), together with the mixture of 6β,8β-dihydroxyeremophil-7(11)-en-12,8α-olide (9) and 6β,8α-dihydroxy-eremophil-7(11)-en-12,8β-olide (10) were isolated from roots of L. veitchiana. Structures of these compounds were elucidated by comprehensive analyses of HRESIMS, 1D NMR, and 2D NMR spectroscopic data. Compounds 2 and 4 are not likely natural compounds but contaminants. All isolated compounds were tested for antibacterial activity. Compounds 1, 5, 6, together with the mixture of 9 and 10, showed mild activity against Vibrio anguillarum, with MIC values of 50, 50, 100, and 200 μg/mL, while compound 7 showed moderate activity against Vibrio anguillarum, with a MIC value of 25 μg/mL.