Three new isobenzofurans from the roots of Nicotiana Tabacum and their bioactivities.

Three new isobenzofurans (1-3), together with four known phenylpropanoids (4-7) were isolated from the roots of Nicotiana tabacum. Their structures were determined by means of HRESIMS and extensive 1D and 2D NMR spectroscopic studies. Compounds 1-6 were tested for their anti-tobacco mosaic virus (anti-TMV) activities and cytotoxicity activities. The results showed that compounds 5 and 6 exhibited high anti-TMV activities with inhibition rates of 35.1 and 33.4%, respectively. The cytotoxicities of compounds 1-7 against five human tumor cell lines (NB4, A549, SHSY5Y, PC3 were also tested. Compounds 1-7 showed weak inhibitory activities against some tested human tumor cell lines with IC50 values in the range of 3.8-9.6 μM.