New dihydrobenzoxanthone derivatives with bacterial neuraminidase inhibitory activity isolated from Artocarpus elasticus

•Investigation of A. elasticus lead to new dihydrobenzoxanthones inhibiting BNA.•Eight compounds, including two new, were characterized by spectroscopic methods.•Kinetic parameters determined by Michaelis-Menten equation double reciprocal plots.•Binding affinities between the BNA and compounds were measured by FS quenching.•The binding site was found by molecular docking experiments.