Studies on new steroidal saponins from Allii macrostemonis bulbus and their antitumor activities

Two new steroidal saponins(2, 3) and two known compounds(1, 4) were isolated from 75% ethanol extract of Allii macrostemonis bulbus by various spectral methods. The two new steroidal saponins were respectively elucidated as (25S)-26-O-β-D-glucopyranosyl-5α-furostanol-2α,3β,22,26-tetrol-3-O0-β-D-glucopyranosyl(1→2)-[β-D-glucopyranosyl(1→3)]-β-D-glucopyranosyl(1→4)-β-D-galactopyranoside(2) and 26-O-β-D-glucopyranosyl-5α-furostanol-25(27)-ene-3β,22,26-tetrol-3-O-β-D-glucopyranosyl(1→2)-[β-D-glucopyranosyl(1→3)]-β-D-glucopyranosyl-(1→4)-β-D-galactopyranoside(3). Compound 4 was obtained from this medical plant for the first time. The activity experiments of proliferation inhibition on tumor cells were performed by cell counting kit-8(CCK-8) method for compound 2(25S-configuration) and its isomer(compound 1, 25R-configuration). The results show that compounds 1 and 2 have weak inhibition on lung cancer A549 cells, melanoma A375 cells and breast cancer MCF-7 cells as well as certain inhibitory effect on liver cancer HepG2 cells, and the inhibitory effect of compound 1 is stronger than that of compound 2.