Arisanschinins A-E, Lignans from Schisandra arisanensis Hay

Four new oxygenated dibenzocyclooctadiene lignans, arisanschinins A-D (1-4), and a new 1,4-bis( phenyl)-2,3-dimethylbutane lignan, arisanschinin E (5), together with 15 known compounds, were isolated from the EtOAc-soluble fraction of the aerial parts of Schisandra arisanensis Hay. The structures of 1-5 were elucidated on the basis of extensive spectroscopic analyses, including 2D NMR (HMQC, HMBC, and NOESY) experiments. The configurations of the biphenyl and octadiene moieties were deduced from circular dichroism(CD) and NOESY spectra, respectively. Compound 1 showed significant inhibition of alpha-glucosidase in vitro. The radical-scavenging activities of these compounds were evaluated using DPPH.