New saponins from the seeds of Aesculus chinensis

Abstract

Eight new acylated polyhydroxyoleanene triterpenoidal saponins, aesculiosides A-H (1-8), along with four known ones, have been isolated from the seeds of Aesculus chinensis. On the basis of extensive NMR studies, the structures of the new compounds were determined to be 21-O- tigloylprotoaescigenin 3-O-[β-D-glucopyranosyl-(1→2)][β-D-glucopyranosyl- (1→4)]-β-D-glucuronopyranosyl acid (1), 21-O-angeloylprotoaescigenin 3-O- [β-D-glucopyranosyl-(1←2)[[β-D-glucopyranosyl-(1→)]-β-D- glucuronopyranosyl acid (2), 21,22-O-ditigloylprotoaescigenin 3-O-[β-D- glucopyranosyl-(1→2)][[β-D-glucopyranosyl-(1→4)]-β-D-glucuronopyranosyl acid (3), 21-O-tigloyl-22-O-angeloylprotoaescigenin 3-O-[β-D-glucopyranosyl- (1→2)] [β-D-glucopyranosyl-(1→4)-β-D-glucuronopyranosyl acid (4), 21,22- O-ditigloylprotoaescigenin 3-O-[β-D-glucopyranosyl-(1→2)][β-Δ- glucopyranosyl(1→4)]-methyl β-D-glucuronopyranosate (5), 21-O-tigloyl-22-O- angeloylprotoaescigenin 3-O-[β-D-glucopyranosyl-(1→2)-l]β-D- glucopyranosyl-(1→4)]-methyl β-D-glucuronopyranosate (6), 21-O-tigloyl-28- O-acetylprotoaescigenin 3-O-[β-D-glucopyranosyl-(1→2)][[β-D- glucopyranosyl-(1→4)]-methyl β-D-glucuronopyranosate (7) and 21-O-angeloyl- 28-O-acetylprotoaescigenin 3-O-[β-D-glucopyranosyl-(1→2)][β-D- glucopyranosyl-(1→4)]-methyl β-D-glucuronopyranosate (8).