Structure Elucidation of Two Triterpenoid Saponins from Leaves of Schima superba Gardn. et Champ

摘要

Two new oleanane-type triterpenoid saponins with two angeloyls at C-21, C-22, and a branch of tetrasaccharide moiety (Rha, Cal, Glc, GlcA, or Rha, Xyl, Glc, GlcA) at C-3 were isolated from leaves of Schima superba Gardn. et Champ. Their structures were established using one- and two-dimensional NMR and high resolution electrospray ionization mass spectrometry as 21,22-di-O-angeloyl-R_1-bamgenol-3-O-{β-d-glucopyranosyl-(1→2)-β-d-galactopyranosyl-(1 → 2)-[α-l-rhamnopyranosyl-(1 → 4)] }-β-d-glucuronopyranoside, named schi-masuoside A(1), 21,22-di-O-angeloyl-R_1-barrigenol-3-O-{β-d-glucopyranosyl-(1 →2)-β-d-xylopyranosyl-(1 → 2)-[α-l-rhamnopyranosyl-(1 → 4)] }-β-d-glucurono-pyranoside, named schimasuoside B (2). There are strong antifungal effect of their mixture on Magnaporthe oryzae.