Isolation of two new antiinflammatory biflavanoids from Sarcophyte piriei

Two new flavano flavanone glycosides, diinsininol (1) and diinsinin (2), have been isolated from the rhizome of Sarcophyte piriei, together with one known flavanone glycoside, naringenin 5-glucoside. Their structures were elucidated on spectroscopic evidence as 5,7,3',4'-tetrahydroxyflavanyl-7-O-beta-glucosyl-(4 beta-8;2 beta-O-7)-eriodictyol (1) and 5,7,3',4'-tetrahydroxyflavanyl-7-O-beta-glucosyl-(4 beta-8;2 beta-O-7)-naringenin (2), respectively. The compounds were tested for their ability to inhibit prostaglandin synthesis, with 1 and 2 giving IC50 values of 9.20 mu M and 13.14 mu M, respectively, and in the inhibition of platelet-activating-factor-induced exocytosis, IC50 values of 49 and 39 mu M.