Chemical constituents from Inula helenium / 中草药

ABSTRACT

Objective To study the major chemical components from Inula helenium. Methods The compounds were separated and purifid by using a variety of chromatographic techniques including silica gel column chromatography, thin layer chromatography, and high performance liquid chromatography, and the structures of the compounds were verified by nuclear magnetic spectroscopy and literature data. Results A total of 22 compounds were separated from petroleum ether extract of I. helenium and identified separately as alantolactone (1), isoalantolactone (2), 4,4-dimethylsterols (3), 11αH,13-dihydroisoalantolactone (4), 11αH,13-dihydroalantolactone (5), 4(15)-epoxy-isoalantolactone (6), 5α,6α-epoxyalantolactone (7), alloalantolactone (8), isoalloalantolactone (9), friedelin (10), friedelinol (11), erythrodiol (12), β-sitosterol-glucopyranoside (13), lupeol acetate (14), lupeone (15), lupeol (16), δ-amyrin (17), lupeol palitate (18), 5,7,4'-trihydroxy-3',5'-dimethoxy flavane (19), (+)-syringaresinol (20), 3,5,3'-trihydroxy-6,7,4'-trimethoxy flavone (21), and 3,5,6,7,3'-hydroxy-4'-methoxy dihydroflavones (22). Conclusion Compounds 21 and 22 are isolated from this genus for the first time; Compounds 10-15, 17, and 18 are separated from the I. helenium for the first time. After antibacterial test, compounds 1, 2, 4, 5, 7-9 have strong inhibitory effects on Escherichia coli, Staphylococcus aureus, and Bacillus subtilis.