Oleanolic acid and hederagenin glycosides from Weigela stelzneri
Four previously undescribed and one known oleanolic acid glycosides were isolated from the roots of Weigela stelzneri, and one previously undescribed and three known hederagenin glycosides were isolated from the leaves. Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-α-L-arabinopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-D-xylopyranosyl-(1 → 4)]-β-D-xylopyranosyl-(1 → 4)-β-D-xylopyranosyl-(1 → 3)-α-L-rhamnopyranosyl-(1 → 2)-β-D-xylopyranosyloleanolic acid, 3-O-β-D-glucopyranosyl-(1 → 2)-[β-…
Spirostane-Type Saponins from Dracaena fragrans Yellow Coast
Three steroidal glycosides were isolated from the bark of Dracaena fragrans (L.) Ker Gawl. « Yellow Coast », and a fourth from the roots and the leaves. Their structures were characterized on the basis of extensive 1D and 2D NMR experiments and mass spectrometry, and by comparison with NMR data of the literature. These saponins have the spirostane-type skeleton and are reported in this species for the first time.
Cytotoxic steroidal glycosides from Allium flavum.
Abstract Three new spirostane-type glycosides ( 1 – 3 ) were isolated from the whole plant of Allium flavum . Their structures were elucidated mainly by 2D NMR spectroscopic analysis and mass spectrometry as (20 S ,25 R )-2α-hydroxyspirost-5-en-3β-yl O -β- d -xylopyranosyl-(1 → 3)-[β- d -galactopyranosyl-(1→2)]-β- d -galactopyranosyl-(1→4)-β- d -galactopyranoside ( 1 ), (20 S ,25 R )-2α-hydroxyspirost-5-en-3β-yl O -β- d -xylopyranosyl-(1 → 3)-[β- d -glucopyranosyl-(1→2)]-β- d -galactopyranosyl-(1→4)-β- d -galactopyranoside ( 2 ), and (20 S ,25 R )-spirost-5-en-3β-yl O -α- l -rhamnopyranosyl-(1 → 4)-[β- d -glucopyranosyl-(1→2)]-β- d -glucopyranoside ( 3 ). The three saponins were evaluated f…
Steroidal saponins from Dracaena marginata
Three new steroidal saponins and ten known ones were isolated from the bark of Dracaena marginata, along with two known steroidal saponins from the roots. Their structures were elucidated on the basis of extensive 1D and 2D NMR experiments and mass spectrometry as (25R)-26-(beta-D-glucopyranosyloxy)3beta,22alpha-dihydroxyfurost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-[alpha-L-rhamnopyranosyl-(1 --> 4)]-beta-D-glucopyranoside (1), (25R)-26-(beta-D-glucopyranosyloxy)-3beta,22alpha-dihydroxyfurost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-4-O-sulfo-alpha-L-arabinopyranoside (2), and (25S)-3beta-hydroxyspirost-5-en-1beta-yl O-alpha-L-rhamnopyranosyl-(1 --> 2)-4-O-sulfo-alpha-L…