Triterpenoid glycosides from the rhizomes of Allium ascalonicum and their anoctamin-1 inhibitory activity

Ten triterpenoid glycosides including two undescribed compounds (1 and 2) were isolated from the methanol extract of Allium ascalonicum rhizomes. These compounds were structurally elucidated to be 3β-O-α-L-rhamnopyranosyl-(1→2)-α-L-arabinopyranosyl-19α-hydroxyolean-12-ene-28-oic acid 28-O-[α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranosyl] ester (1), 3-O-β-D-glucopyranosyl-(1→3)-[α-L-rhamnopyranosyl-(1→2)]-α-L-arabinopyranosyl-3β,19α-dihydroxyoleanane-12-en-28-oic acid (2), lactifoloside C (3), lactifoloside H (4), randiasaponin IV (5), kudinoside G (6), ilexkudinoside W (7), lactifoloside G (8), kudinoside D (9), and ilexkudinoside T (10) by analyzing their HR-ESI-MS, NMR spectral data and by comparison with those reported in the literature. Compounds 1-10 were evaluated for anoctamin-1 (ANO1) inhibitory activity using yellow fluorescent protein reduction assays. At the concentration of 30 µM, compounds 2 and 9 displayed moderate ANO1 inhibitory percentages of 28.9 ± 0.85% and 26.2 ± 0.65%, respectively.