Stryphnosides A–F, six new triterpene glycosides from the pericarps of Stryphnodendron fissuratum

Six new triterpene glycosides stryphnosides A–F (1–6) were isolated from the pericarps of Stryphnodendron fissuratum (Leguminosae). The structures of 1–6 were determined on the basis of extensive spectroscopic analysis, including two-dimensional (2D) NMR data, and the results of hydrolytic cleavage. The sugar moieties of 3–6 are very unique in structure having not only novel sugar sequences but also the terminal α-l-arabinopyranosyl unit with a 1C4 conformation. Stryphnosides C (3)–F (6) are the first representative of naturally occurring glycosides with the 1C4 terminal α-l-arabinopyranosyl group.