Table 1: Antiviral activity and cytotoxicity of naphthoimidazole derivatives (3a-j), derivative A [28] was reported for comparison; NM 108 and ribavirin were used as positive controls.

Compound MDBK (aCC50) BVDV (bEC50)
3a 37.5±3.5 16.2±2.6
3b 11.6 >11.6
3c >100 >100
3d >100 >100
3e 11.8 >11.8
3f 2.8 >2.8
3g >100 >100
3h 4.7 >4.7
3i >100 >100
3j >100 >100
A >100 0.3
NM 108 >100 1.5±0.2
Ribavirin >100 18±2

aCompound concentration (µM) required to reduce the viability of mock-infected MDBK cells by 50%, as determined by the MTT method.
bCompound concentration (µM) required to achieve 50% protection of MDBK cells from the BVDV-induced cytopathogenicity, as determined by the MTT method.