Stilbene Derivatives from Bletilla striata and Their Antiviral Activity

Two new ( 1 and 2 ), together with five known ( 3 – 7 ) stilbene derivatives, were isolated from the tubers of Bletilla striata . The structures of these new compounds were elucidated by means of spectroscopic methods, while the known compounds were identified by comparison their data with those in the literature. Compounds 1 and 2 were tested for their anti-tobacco mosaic virus (anti-TMV) activities. The results revealed that 1 and 2 exhibited potential anti-TMV activities with inhibition rates of 31.5 and 30.6%, respectively, and these rates were close to that of a positive control. Compounds 1 and 2 were also tested for their anti-rotavirus activities, and compounds 1 and 2 showed potential activities with therapeutic index (TI) values of 15.5 and 16.2, respectively. These values are lower than that of a positive control.