Three New Arylbenzofuran Lignans from Arctium lappa and Their Anti-Tobacco Mosaic Virus Activity

Three new (1-3), together with two known (4 and 5) arylbenzofuran lignans were isolated from the seed of Arctium lappa. Their structures were elucidated by spectroscopic methods, including extensive 1D- and 2D-NMR techniques. Compounds 1-3 were evaluated for their anti-tobacco mosaic virus (Anti-TMV) activity. The results showed that compounds 1-3 showed potential anti-TMV activities with inhibition rates of 33.5%, 32.8%, and 34.2%, at the concentration of 20 mu M, respectively. These rates are higher than that of positive control.