Serendipitous discovery of a potent influenza virus a neuraminidase inhibitor.
Mohan, S., Kerry, P.S., Bance, N., Niikura, M., Pinto, B.M.(2014) Angew Chem Int Ed Engl 53: 1076-1080
- PubMed: 24339250 
- DOI: https://doi.org/10.1002/anie.201308142
- Primary Citation of Related Structures:  
4MJU, 4MJV - PubMed Abstract: 
We have previously reported a potent neuraminidase inhibitor that comprises a carbocyclic analogue of zanamivir in which the hydrophilic glycerol side chain is replaced by the hydrophobic 3-pentyloxy group of oseltamivir. This hybrid inhibitor showed excellent inhibitory properties in the neuraminidase inhibition assay (Ki =0.46 nM; Ki (zanamivir) =0.16 nM) and in the viral replication inhibition assay in cell culture at 10(-8) M. As part of this lead optimization, we now report a novel spirolactam that shows comparable inhibitory activity in the cell culture assay to that of our lead compound at 10(-7) M. The compound was discovered serendipitously during the attempted synthesis of the isothiourea derivative of the original candidate. The X-ray crystal structure of the spirolactam in complex with the N8 subtype neuraminidase offers insight into the mode of inhibition.
Organizational Affiliation: 
Department of Chemistry, Simon Fraser University, 8888 University Drive, Burnaby, BC, V5A1S6 (Canada) http://www.sfu.ca/chemistry/groups/pinto/