Steroidal glycosides from the underground parts of Helleborus caucasicus
2008
Bassarello, C. | Muzashvili, T. | Skhirtladze, A. | Kemertelidze, E. | Pizza, C. | Piacente, S.
Four polyhydroxylated and polyunsaturated furostanol glycosides (1-4), named caucasicosides A (1), B (2), C (3) and D (4), were isolated from the MeOH extract of the underground parts of Helleborus caucasicus, along with four spirostanol derivatives, a furostanol glycoside, a furospirostanol glycoside, 20-hydroxyecdysone and the bufadienolides hellebrigenin and deglucohellebrin. The structures of 1-4 were elucidated as furosta-5,20(22),25(27)-triene-1β,3β,11,26-tetrol 26-O-β-D-glucopyranoside (1), 26-O-β-D-glucopyranosylfurosta-5,20(22),25(27)-triene-1β,3β,11,26-tetrol 3-O-α-L-rhamnopyranosyl-(1 leads to 2)-β-D-glucopyranoside (2), 26-O-β-D-glucopyranosyl-22-methoxyfurosta-5,25(27)-diene-1β,3β,11,26-tetrol 3-O-α-L-rhamnopyranosyl-(1 leads to 2)-β-D-glucopyranoside (3), 26-O-β-D-glucopyranosylfurosta-5,20(22),25(27)-triene-1β,3β,26-triol 3-O-β-D-xylopyranosyl-(1 leads to 3)-α-L-rhamnopyranosyl-(1 leads to 2)-4-O-sulfo-α-L-arabinopyranoside (4). Structure elucidation was accomplished through the extensive use of 1D- and 2D NMR experiments including 1H-1H (COSY, 1D-TOCSY) and 1H-13C (HSQC, HMBC) spectroscopy along with ESI-MS and HR-ESI-MS. The aglycones of 1-4 have never been reported before.
显示更多 [+] 显示较少 [-]