[The isolation and identification of qianhucoumarin B and qianhucoumarin C from Peucedanum praeruptorum].

Five compounds were isolated from the traditional Chinese medicine Qianhu, roots of Peucedanum praeruptorum. Their structures were identified as 3'-angeloyloxykhellactone (IX), qianhucoumarin B (X), qianhucoumarin C (XI), Pd-III (XIII) and peucedanocoumarin III (XV). Among them, X and XI are new compounds, their absolute configurations were elucidated by chemical correlation with khellactones, as 3'(S)-acetoxy-4'(S)-hydroxy-3',4'-dihydroseselin(X) and 3'(S)-hydroxy-4'(S)-acetoxy-3',4'-dihydroseselin (XI). Compound IX was isolated from plants for the first time.