title: Aminoadamantanes with persistent in vitro efficacy against H1N1 (2009) influenza A.
abstract: A series of 2-adamantanamines with alkyl adducts of various lengths were examined for efficacy against strains of influenza A including those having an S31N mutation in M2 proton channel that confer resistance to amantadine and rimantadine. The addition of as little as one CH2 group to the methyl adduct of the amantadine/rimantadine analogue, 2-methyl-2-aminoadamantane, led to activity in vitro against two M2 S31N viruses A/Calif/07/2009 (H1N1) and A/PR/8/34 (H1N1) but not to a third A/WS/33 (H1N1). Solid state NMR of the transmembrane domain (TMD) with a site mutation corresponding to S31N shows evidence of drug binding. But electrophysiology using the full length S31N M2 protein in HEK cells showed no blockade. A wild type strain, A/Hong Kong/1/68 (H3N2) developed resistance to representative drugs within one passage with mutations in M2 TMD, but A/Calif/07/2009 S31N was slow (>8 passages) to develop resistance in vitro, and the resistant virus had no mutations in M2 TMD. The results indicate that 2-alkyl-2-aminoadamantane derivatives with sufficient adducts can persistently block p2009 influenza A in vitro through an alternative mechanism. The observations of an HA1 mutation, N160D, near the sialic acid binding site in both 6-resistant A/Calif/07/2009(H1N1) and the broadly resistant A/WS/33(H1N1) and of an HA1 mutation, I325S, in the 6-resistant virus at a cell-culture stable site suggest that the drugs tested here may block infection by direct binding near these critical sites for virus entry to the host cell.
authors.affiliation: Department of Pharmaceutical Chemistry, Faculty of Pharmacy, National and Kapodistrian University of Athens , Athens 15771, Greece.
authors.forename: Antonios
authors.initials: A
authors.lastname: Kolocouris
authors.forename: Christina
authors.initials: C
authors.lastname: Tzitzoglaki
authors.forename: F Brent
authors.initials: FB
authors.lastname: Johnson
authors.forename: Roland
authors.initials: R
authors.lastname: Zell
authors.forename: Anna K
authors.initials: AK
authors.lastname: Wright
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Cross
authors.forename: Ian
authors.initials: I
authors.lastname: Tietjen
authors.forename: David
authors.initials: D
authors.lastname: Fedida
authors.forename: David D
authors.initials: DD
authors.lastname: Busath
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives* / Q000138:chemical synthesis* / Q000494:pharmacology; D000547:Amantadine / Q000494:pharmacology; D000818:Animals; D000998:Antiviral Agents / Q000138:chemical synthesis* / Q000494:pharmacology; D004285:Dogs; D024921:Drug Resistance, Multiple, Viral; D057809:HEK293 Cells; D006801:Humans; D053118:Influenza A Virus, H1N1 Subtype / Q000187:drug effects* / Q000235:genetics; D007473:Ion Channels / Q000235:genetics; D061985:Madin Darby Canine Kidney Cells; D009154:Mutation; D012299:Rimantadine / Q000494:pharmacology; D014763:Viral Matrix Proteins / Q000235:genetics; D000086082:Viroporin Proteins
chemical_list: D000218:Adamantane; D000547:Amantadine; D000998:Antiviral Agents; D007473:Ion Channels; D012299:Rimantadine; D014763:Viral Matrix Proteins; C488937:M2 protein, Influenza A virus; D000086082:Viroporin Proteins