Alopecuroides A–E, Matrine-Type Alkaloid Dimers from the Aerial Parts of Sophora alopecuroides

Five new matrine-type alkaloid dimers, alopecuroides A–E, were isolated from the aerial parts of Sophora alopecuroides. Alopecuroides A and B represent the first dimeric matrine-type alkaloids possessing a cyano group and an epoxy moiety. Alopecuroides C and D are dimeric matrine-type alkaloids connected via C-2–C-9′ and C-10–C-3′ bonds, respectively. The chemical structures of alopecuroides A–E were elucidated by spectroscopic methods combined with single-crystal X-ray diffraction analysis. The anti-inflammatory effects of alopecuroides A–E were evaluated, and alopecuroide B exhibited the most significant activity, better than that of matrine, the representative compound from S. alopecuroides.