Comparative studies of inhibitory activities of chalcones on tomato ringspot virus (ToRSV)

Twenty-one chalcones were investigated and compared at a concentration of 5 mL/ 1 for activity against tomato ringspot nepovirus (ToRSV) infectivity.Although several individual compounds showed anti-viral activity, it was not possible to identify the best group of chalcones for virus inhibition.The most effective inhibitory compounds were Al (2',3',4',4-tetrahydroxychalcone) (69% inhibition), Bl (4',3,4-trimethoxychalcone) (49%), Cl (2\4'-dihydroxy-3,4,5-trimethoxychalcone) (37%), and Dl (2',4'-dihydroxychalcone) (52%).The anti-viral activities of Al, Bl, Cl, and Dl were further examined in time course experiments.In addition, the capacity of chalcones for direct viricidal action and effects on infection due to viral-RNA, rather than virions, were investigated.