Flavonoids from the roots of Campylotropis hirtella

Eight new flavonoids, including three pterocarpene derivatives, hirtellanines C-E, two flavanones, hirtellanines F and G, three isoflavanones, hirtellanines H-J, as well as four known compounds were isolated from the roots of Campylotropis hirtella. The structures of the new compounds were elucidated by spectroscopic analyses, including 2D-NMR techniques. Pharmacological investigation indicated that the new compounds, particularly hirtellanines D and G, possessed potent immunosuppressive activities and low relative cytotoxicities.