Synthesis and Biological Evaluation of NH(2)-Sulfonyl Oseltamivir Analogues as Influenza Neuraminidase Inhibitors

A series of NH(2)-sulfonyl oseltamivir analogues were designed, synthesized, and their inhibitory activities against neuraminidase from H5N1 subtype evaluated. The results indicated that the IC(50) value of compound 4a, an oseltamivir analogue via methyl sulfonylation of C5-NH(2), was 3.50 μM. Molecular docking simulations suggested that 4a retained most of the interactions formed by oseltamivir carboxylate moieties and formed an additional hydrogen bond with the methylsulfonyl group. Meanwhile, 4a showed high stability towards human liver microsomes. More importantly, 4a without basic moieties is not a zwitterion as reported on the general structure of neuraminidase inhibitors. This research will provide valuable reference for the research of new types of neuraminidase inhibitors.