Chromone Derivatives from the Stems of Sichuan Local Sun Cured Tobacco and Their Anti-TMV Activity

Two new chromone derivatives ( 1 and 2 ), together with four known ( 3–6 ) ones, were isolated from the stems of a local sun cured tobacco (Fenghuang tobacco, widely cultivated in Shifang prefecture, Sichuan Province). Their structures were elucidated by spectroscopic methods, including extensive 1D and 2D NMR techniques. Compounds 1 and 2 were tested for their anti-tobacco mosaic virus (anti-TMV) activity. The results showed that compounds 1 and 2 exhibited high anti-TMV activities with inhibition rates of 35.8 and 28.6% at the concentration of 20 μM. These rates are close to that of the positive control.