Two New Benzofuran Derivatives, Corylifonol and Isocorylifonol from the Seeds of Psoralea corylifolia

Abstract

The seeds of Psolalea corylifolia were extracted with ether and 60% EtOH, successively.The latter extract was found to contain the known constituents psoralen, angelicin, corylifolinin, bukuchiol, phydroxybenzoic acid, and astragalin, together with two new benzofuran derivatives.corylifonol and isocorylifonol.Their structures have been elucidated by spectral evidence and chemical transformation.The seeds of Psoralea corylifolia have been used as Chinese medicine for the treatment of uterine hemorrhage,l skin-photosensitizing activity, 2 coronary vasodilatory and inhibitory effect of Hella cell.3The studies of the chemical constituents of this seed are extensive and interesting components including coumarins,d flavonoids. 3.5 and terpenoids,e were o b s e ~e d .Above mentioned components are all isolated from ether or chloroform extract of the seed of P.corylifolia after defat.The polar fraction has not yet been investigated.In connection with our interests in coumarins and flavonoids and the seed of this plant as an important chinese medicine, we have investigated the polar portion of this seed.psoralen (1),3 angelicin (2),3 corylifolinin,sc bukuchiols6 phydroxybenzoic acid, 7 and astragalin,a together with two new benzofuran derivative, corylifonol (3a) and isocorylifonol (4a), were isolated.The identification of known compounds was based on comparison of physical data with those reported in the literature and structural elucidation of corylifonol and isocorylifonol were based on the following evidence.