Triterpenoid Saponins From the Root Bark of Haplocoelum congolanum

Two undescribed triterpenoid saponins together with 5 known ones were isolated from the root bark of Haplocoelum congolanum Hauman. Their structures were elucidated by spectroscopic methods including one-dimensional and two-dimensional nuclear magnetic resonance experiments in combination with mass spectrometry as 3- O-(4- O-[3-hydroxy-3-methylglutaryl])-α-l-arabinopyranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-α-l-arabinopyranosyloleanolic acid and 3- O-α-l-arabinofuranosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-[β-d-glucopyranosyl-(1→4)]-α-l-arabinopyranosyloleanolic acid.