As a follow up of an anti-Flaviviridae project, a new series of variously 
substituted 2-styryl-benzimidazoles were synthesized and tested in vitro for 
biological activity. Compounds were tested in cell-based assays against viruses 
representative of: i) two of the three genera of the Flaviviridae family, i.e. 
Pestiviruses and Flaviviruses; ii) other RNA virus families, such as 
Retroviridae, Picornaviridae, Paramyxoviridae, Rhabdoviridae and Reoviridae; 
iii) two DNA virus families (Herpesviridae and Poxviridae) as well as for 
cytotoxicity tests, run in parallel with antiviral assays,against MDBK, BHK and 
Vero 76 cells. In the series examined, new leads emerged against BVDV, CVB-2 and 
RSV. Compounds 11, 12, 17, 18, 24, 31 exhibited anti-BVDV activity in the 
concentration range 1.7-16 microM; among them, compound 17 was the most active, 
with an EC(50) = 1.7 microM. Compounds 18 and 21 were equally active against 
CVB-2, with EC(50) values of 7 - 8 microM, while the derivative 30 was active 
against RSV with EC(50)= 1 microM and represents a new lead compound.