Design, synthesis and biological evaluation of honokiol derivatives as influenza neuraminidase inhibitors.

Honokiol, a natural polyphenol, which was reported to have satisfactory influenza neuraminidase (NA) inhibitory activity, was structurally modified. Twenty-three compounds were synthesized and the -effects in the epoxidation and hydrolyzation reactions were studied. The derivatives were evaluated for NA inhibitory activity and the benzoylhydrazone derivatives showed much better anti-NA activity than honokiol. Structure-activity relationship analysis suggested that the polyphenols exhibited better anti-NA activity than monophenols and biphenols. Furthermore, probable binding mode of drug with target revealed that the most active compound had much stronger interactions with the active site of NA than honokiol suggesting the potent anti-influenza virus activity.