Ecdysones from Zoanthus spp. with inhibitory activity against dengue virus 2

Abstract Bioassay-guided fractionation of an ethanolic extract of Zoanthus spp. collected in Taiwan has resulted in the isolation of one new ecdysone, zoanthone A ( 1 ), along with thirteen known compounds ( 2 – 14 ). The structures of these compounds were determined by spectroscopic methods, especially 2D NMR analyses. The in vitro antiviral activities of all isolated ecdysones ( 1 – 14 ) against dengue virus type 2 (DENV-2) were evaluated using DENV infectious system. New compound ( 1 ) exhibited potent antiviral activity (EC 50  = 19.61 ± 2.46 μM) with a selectivity index (CC 50 /EC 50 ) value of 36.7. The structure–activity relationships of isolated ecdysones against DENV-2 were concluded. Molecular docking information of 3 and NS5 polymerase was performed either.