Terpenoids from of Euphorbia helioscopia L. with anti-Zika virus activity

Four new diterpenoids (helioscopinas A-D, 1, 2, 8, 9), two new triterpenoids (helioscopinas E-F, 12, 13), and nine known compounds were isolated from the methanol extract of the whole plant of Euphorbia helioscopia L. The structures of all new compounds were elucidated based on spectroscopic and HRESIMS analyses, and their absolute configurations were determined by ECD calculations. Experimental evaluation using polymerase chain reaction (qRT-PCR), western blotting (WB), and immunofluorescence assays demonstrated that compound 3 exhibits potent anti-Zika virus activity (EC₅₀ = 12.01 ± 1.15 μM), surpassing ribavirin (23.75 ± 0.9 μM) with lower cytotoxicity. Molecular docking studies further revealed that compound 3 stably binds to the Zika E protein.