Chemical constituents from Cynanchum paniculatum (Bunge) Kitag

Abstract Twenty-nine compounds, including five acetophenone derivatives ( 1–5 ), three phenanthroindolizidine alkaloids ( 12–14 ), seven pentacyclic triterpenoids ( 15–21 ) and five C 21 steroidal sapogenins ( 22–26 ), were isolated from the root of Cynanchum paniculatum (Bunge) Kitag. Their structures were determined by spectroscopic methods and comparison with reported data. Moreover, the chemotaxonomic relationships were also discussed. As a result, acetophenone derivatives, pentacyclic triterpenoids and C 21 pregnane sapogenins can be recognized as chemotaxonomic markers for Cynanchum genus, and C. paniculatum has close relationships with some species of genus Cynanchum .