ISOPRENYLATED FLAVANONES FROM MORUS-CATHAYANA

Three new 2-prenyl-3-hydroxyflavanones, sanggenols F, G and I, having an ether linkage between C-3 and C-2' and a prenyl (geranyl) side chai n, were isolated along with sanggenol J, regarded as a Diels-Alder typ e adduct between dehydrosanggenol F (diene) and a chalcone (dienophile ) from the root, bark of Morus cathayana. A new 2-farnesyl-3-hydroxyfl avanone, sanggenol H, with an ether linkage between C-3 and C-2', and a new 3-hydroxyflavanone, sanggenol K, were also isolated from the bar k. Their structures were elucidated by spectroscopic methods. (C) 1997 Elsevier Science Ltd.