摘要：In this study, twelve neuraminidase (NA) inhibitory compounds 1 – 12 were isolated from heartwood of Caesalpinia sappan on the basis of their biological activities against three types of viral NAs. Of isolated homoisoflavonoids, sappanone A ( 2 ) showed the most potent NAs inhibitory activities with IC50 values of 0.7 µ M [H1N1], 1.1 µ M [H3N2], and 1.0 µ M [H9N2], respectively, whereas saturated homoisoflavonoid ( 3 ) did not show significantly inhibition. This result revealed that α,β-unsaturated carbonyl group in A-ring was the key requirements for viral NAs inhibitory activity. In our enzyme kinetic study, all NA inhibitors screened were found to be reversible noncompetitive types.
