title: Substituted 2,6-bis(benzimidazol-2-yl)pyridines: a novel chemical class of pestivirus inhibitors that targets a hot spot for inhibition of pestivirus replication in the RNA-dependent RNA polymerase.
abstract: 2,6-Bis(benzimidazol-2-yl)pyridine (BBP/CSFA-0) was identified in a CPE-based screening as a selective inhibitor of the in vitro bovine viral diarrhea virus (BVDV) replication. The EC50-values for the inhibition of BVDV-induced cytopathic (CPE) effect, viral RNA synthesis and the production of infectious virus were 0.3±0.1μM, 0.05±0.01μM and 0.3±0.04μM, respectively. Furthermore, BBP/CSFA-0 inhibits the in vitro replication of the classical swine fever virus (CSFV) with an EC50 of 0.33±0.25μM. BBP/CSFA-0 proved in vitro inactive against the hepatitis C virus, that belongs like BVDV and CSFV to the family of Flaviviridae. Modification of the substituents on the two 1H-benzimidazole groups of BBP resulted in analogues equipotent in anti-BVDV activity (EC50=0.7±0.1μM), devoid of cytotoxicity (S.I.=142). BBP resistant BVDV was selected for and was found to carry the I261M mutation in the viral RNA-dependent RNA polymerase (RdRp). Likewise, BBP-resistant CSFV was selected for; this variant carries either an I261N or a P262A mutation in NS5B. Molecular modeling revealed that I261 and P262 are located in a small cavity near the fingertip domain of the pestivirus polymerase. BBP-resistant BVDV and CSFV proved to be cross-resistant to earlier reported pestivirus inhibitors (BPIP, AG110 and LZ37) that are known to target the same region of the RdRp. BBP did not inhibit the in vitro activity of recombinant BVDV RdRp but inhibited the activity of BVDV replication complexes (RCs). BBP interacts likely with the fingertip of the pestivirus RdRp at the same position as BPIP, AG110 and LZ37. This indicates that this region is a "hot spot" for inhibition of pestivirus replication.
authors.affiliation: Rega Institute for Medical Research, Katholieke Universiteit Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium.
authors.forename: Simone
authors.initials: S
authors.lastname: Musiu
authors.affiliation: Institut für Pharmazie, Abteilung Pharmazeutische Chemie, Universität Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Pürstinger
authors.affiliation: Institut für Pharmazie, Abteilung Pharmazeutische Chemie, Universität Innsbruck, Innrain 80/82, A-6020 Innsbruck, Austria.
authors.forename: Sylvia
authors.initials: S
authors.lastname: Stallinger
authors.affiliation: CODA-CERVA, Groeselenberg 99, B-1180 Bruxelles, Belgium.
authors.forename: Robert
authors.initials: R
authors.lastname: Vrancken
authors.affiliation: CODA-CERVA, Groeselenberg 99, B-1180 Bruxelles, Belgium.
authors.forename: Andy
authors.initials: A
authors.lastname: Haegeman
authors.affiliation: CODA-CERVA, Groeselenberg 99, B-1180 Bruxelles, Belgium.
authors.forename: Frank
authors.initials: F
authors.lastname: Koenen
authors.affiliation: Rega Institute for Medical Research, Katholieke Universiteit Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium.
authors.forename: Pieter
authors.initials: P
authors.lastname: Leyssen
authors.affiliation: Rega Institute for Medical Research, Katholieke Universiteit Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium.
authors.forename: Mathy
authors.initials: M
authors.lastname: Froeyen
authors.affiliation: Rega Institute for Medical Research, Katholieke Universiteit Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium. Electronic address: Johan.Neyts@rega.kuleuven.be.
authors.forename: Johan
authors.initials: J
authors.lastname: Neyts
authors.affiliation: Rega Institute for Medical Research, Katholieke Universiteit Leuven, Minderbroedersstraat 10, B-3000 Leuven, Belgium.
authors.forename: Jan
authors.initials: J
authors.lastname: Paeshuyse
mesh_terms: D000818:Animals; D000998:Antiviral Agents / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D001562:Benzimidazoles / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D002417:Cattle; D002460:Cell Line; D006692:Classical Swine Fever Virus / Q000187:drug effects* / Q000201:enzymology; D030241:Diarrhea Virus 1, Bovine Viral / Q000187:drug effects* / Q000201:enzymology; D024882:Drug Resistance, Viral; D004791:Enzyme Inhibitors / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D016174:Hepacivirus / Q000187:drug effects / Q000201:enzymology; D008958:Models, Molecular; D009154:Mutation; D011487:Protein Conformation; D011725:Pyridines / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology* / Q000633:toxicity; D012324:RNA-Dependent RNA Polymerase / Q000037:antagonists & inhibitors*; D014779:Virus Replication / Q000187:drug effects*
chemical_list: C500137:2,6-bis(benzimidazol-2-yl)pyridine; D000998:Antiviral Agents; D001562:Benzimidazoles; D004791:Enzyme Inhibitors; D011725:Pyridines; D012324:RNA-Dependent RNA Polymerase
keywords: Bovine viral diarrhea virus; RNA-dependent RNA polymerase; Substituted 2,6-bis(benzimidazol-2-yl)pyridine inhibitors