New triterpenoidal saponins acylated with monoterpenic acid from Albizia adianthifolia

Four new triterpenoidal saponins acylated with monoterpenic acid, i.e., adianthifoliosides C, D, E, and F (1-4), besides the two known julibroside III and the monodesmonoterpenyl elliptoside A, were isolated from the roots of Albizia adianthifolia. Their structures were elucidated on the basis of extensive 1D- and 2D-NMR studies and mass spectrometry as 3-O-{O-α-L- arabinopyranosyl-(1 → 2)-O-β-D-fucopyranosyl-(1 → 6)-O-[β-D-glucopyranosyl-(1 → 2)]-β-D-glucopyranosyl)-21-O-{(2E, 6S)-6-{{4-O-[(2E,6S)-2,6-dimethyl-6-(β-D-quinovopyranosyloxy)octa-2, 7-dienoyl]-β-D-quinovopyranosyl}oxy}-2-(hydroxymethyl)-6-methylocta-2, 7-dienoyl}acacic acid 28-{O-α-L-arabinofuranosyl-(1 → 4)-O-[β-D-glucopyranosyl-(1 → 3)]-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl} ester (1), 21-O-{(2E,6S)-6-{{4-O-[(2E,6S)-2, 6-dimethyl-6-(β-D-quinovopyranosyloxy)octa-2,7-dienoyl]-β-D- quinovopyranosyl}oxy}-2-(hydroxymethyl)-6-methylocta-2,7-dienoyll-3-O-{O-β- D-xylopyranosyl-(1 → 2)-O-β-D-fucopyranosyI-(1 → 6)-2-(acetylamino)-2-deoxy-β-D-glucopyranosyl}acacic acid 28-{O-α-L-arabinofuranosyl-(1 → 4)-O-[β-D-glucopyranosyl-(1 → 3)]-O-a-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl} ester (2), 21-O-{(2E,6S)-6-{{3-O-[(2E,6S)-2,6-dimethyl-6-(β-D- quinovopyranosyloxy)octa-2,7-dienovl]-β-D-quinovopyranosyl}oxy}-2, 6-dimethylocta-2,7-dienoyl}-3-O-{O-β-D-xylopyranosyl-(1 → 2)-O-β-D-fucopyranosyl-(1 → 6)-2-(acetylamino)-2-deoxy-β-D- glucopyranosyl}acacic acid 28-{O-α-L-arabinofuranosyl-(1 → 4)-O-[β-D-glucopyranosyl-(1 → 3)]-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl} ester (3), and 3-O-{O-α-L- arabinopyranosyl-(1 → 2)-O-β-D-fucopyranosyl-(1 → 6)-O-[β-D-glucopyranosyl-(1 → 2)]-β-D-glucopyranosyl}-21-O-{(2E, 6S)-2,6-dimethyl-6-(β-D-quinovopyranosyloxy)octa-2,7-dienoyl}acacic acid 28-{O-α-L-arabinofuranosyl-(1 ß→ 4)-O-[β-D-glucopyranosyl- (1 → 3)]-O-α-L-rhamnopyranosyl-(1 → 2)-β-D-glucopyranosyl} ester (4).