Sesquiterpenoid derivatives from Ferula ferulioides. IV

Four novel prenyl-furocoumarin type sesquiterpenoid derivatives, 2,3-dihydr o-7-hydroxy-2S*,3R*-dimethyl- 3-[4,8-dimethyl-3(E),7-nonadienyl]-furo [3,2- c]coumarin, 2,3-dihydro-7-hydroxy-2R*,3R*-dimethyl-3-[4,8-dimethyl- 3(E),7- nonadienyl]-furo[3,2-c]coumarin, 2,3-dihydro-7-hydroxy-2S*,3R*-dimethyl-3-[ 4-methyl-5-(4-methyl-2-furyl)-3(E)-pentenyl]-furo[3,2-c]coumarin, and 2,3-d ihydro-7-methoxy-2S*,3R*-dimethyl-3-[4,8-dimethyl-3(E),7-nonadienyl]-furo[3 ,2-c]coumarin were isolated from the roots of Ferula ferulioides. Their str uctures were established by detailed spectral analysis and the biosynthetic pathway leading to these prenyl-furocoumarin type sesquiterpenoids is prop osed based on these structures.