Sesquiterpenoids and phenolics from Crepis conyzifolia.

From the roots of Crepis conyzifolia, two new and two known guaianolides were isolated together with three known phenylpropanoids. Structures of the new compounds were established as 8beta-hydroxy-4beta, 15-dihydrozaluzanin C and 4beta, 15, 11beta, 13-tetrahydrozaluzanin C-3-O-beta-glucopyranoside by spectral methods. The identity of 8-epiisolippidiol and dentalactone was also discussed.