Inhibitory activity against tobacco mosaic virus (TMV) replication of pinoresinol and syringaresinol lignans and their glycosides from the root of Rhus javanica var. roxburghiana

Four new diepoxylignan glycosides, pinoresinol-4'-O-6' '-O-(E)-feruloyl]-beta-D-glucopyranoside (1), pinoresinol-4'-O-4' ',6' '-O-(E)-diferuloyl]-beta-D-glucopyranoside (2), pinoresinol-4'-O-3' ',6' '-O-(E)-diferuloyl]-beta-D-glucopyranoside (3), and syringaresinol- 4'-O-4' ',6' '-O-(E)-diferuloyl]-beta-D-glucopyranoside (4), together with three known compounds, pinoresinol (5), syringaresinol (6), and pinoresinol-4'-O-beta-D-glucopyranoside (7), were isolated from the n-butanol extract of Rhus javanica var. roxburghiana, and their structures were established using various spectroscopic techniques. Three glycosides (2-4) of the lignans showed moderate inhibition of multiplication of the tobacco mosaic virus.