Abstract
The chemical constituents of a Japanese sedge "birodo-suge" [Carex fedia Nees var. miyabei (Franchet) T. Koyama] were investigated, and four 3, 5, 4'-trihydroxystilbene (resveratrol 1) oligomers, one dimer, one trimer and two tetramers, were isolated. Their structures were determined by spectroscopic evidence and biogenetic consideration. The dimer was identified as ε-iniferin (2) that had already been identified as a phytoalexin of grape vine leaves. The trimer and the tetramers were structurally new compounds, and were named miyabenols C (for the trimer 5), and A and B (for the tetramers 3 and 4 respectively). The antimicrobial test of 3 (the predominant constituent) revealed that 3 was antibiotic only against Gram positive bacteria.
