Three New Lupane Saponins fromBupleurum Fruticescens

The methanol extract of the aerial parts of Bupleurum fruticescens has yielded three new saponins identified as 3-O-(O-α-L-rhamnopyranosyl-(1→4)-O-[β-D-glucopyranosyl-(1→6)] -O-β-D-glucopyranosyl) 3β -hydroxy -lup -20(29)-ene -23,28-dioic acid (2), 3-O-(O-α-L-rhamnopyranosyl-(1→4)-O-β-D-glucopyranosyl) 3β-hydroxy-lup- 20 (29) -ene- 23, 28-dioic acid 28-O-β-D-glucopyranosyl ester (3) and 3-O-(O-α-L-rhamnopyranosyl-(1→4) -O[β-D-glucopyranosyl—(1→6)] -O-β-D-glucopyranosyl) 3β-hydroxy- lup-20(29) -ene- 23.28-dioic acid 28-O-β-D-glucopyranosyl ester (4). These compounds were named fruticesaponin A, fruticesaponin B and fruticesaponin C. respectively and their structure elucidation was mainly achieved on the basis of NMR spectroscopy. In addition, betulin (1), isorhamnetin-3-O-rutinoside (5) and rutin (6) were identified.