Two New Sesquineolignans from the Bark of Illicium dunnianum

Abstract

Two new sesquineolignans, named dunnianol (1) and isodunnianol (2), respectively, were isolated from the bark of Illicium dunnianum together with the known biphenylneolignan, magnolol (3). Compounds 1 and 2 have a similar triphenyl-type neolignan structure to that of macranthol (4), which we previously isolated from the pericarps of I. macranthum. Their structures were elucidated by means of the detailed analysis of their ¹H-and ¹³C-nuclear magnetic resonance spectra of 1, 2, and their acetylation and methylation products, including two-dimensional NMR spectra, comparing with those of magnolol, isomagnolol and macranthol.