Three new triterpenoid saponins from the seeds of Aesculus turbinata

Three new triterpenoid saponins, named isoescins VIIa (1), VIa (2), and VIIIa (3), were isolated from the seeds of Aesculus turbinata and identified by spectroscopic analysis and chemical hydrolysis. Their structures were established as 21beta-O-tigloyl-28-O-acetylprotoaescigenin 3beta-O-beta-d-galactopyranosyl(1 --> 2)]beta-d-glucopyranosyl(1 --> 4)]-beta-d-glucopyranosiduronic acid (Isoescin VIIa, 1), 21beta-O-(2-methylbutyryl)-28-O-acetylprotoaescigenin 3beta-O-beta-d-glucopyranosyl(1 --> 2)] beta-d-glucopyranosyl(1 --> 4)]-beta-d-glucopyranosiduronic acid (Isoescin VIa, 2), and 21beta-O-angeloyl-28-O-acetylbarringtogenol C 3beta-O-beta-d-glucopyranosyl(1 --> 2)] beta-d-glucopyranosyl(1 --> 4)]-beta-d-glucopyranosiduronic acid (Isoescin VIIIa, 3).