Marine natural products have attracted more and more attention in drug research and development due to their unique structure, diverse biological activities, and novel mode of action. Using antiviral alkaloid aldisine as the lead compound and drawing on the hydrogen bond effect widely used in drug design, derivatives containing oxime and hydrazone moieties were designed and synthesized by introducing functional groups with hydrogen-bond receptors or donors into molecules. The configuration of derivatives was systematically studied through nuclear Overhauser effect (NOE) spectroscopy and single crystal analysis. The antiviral activity test result showed that most derivatives had antiviral activity against tobacco mosaic virus (TMV), and some compounds had better activity than the commercial antiviral drug ribavirin, especially compounds 2 and 24, which had comparable activity to the most effective commercial antiviral drug ningnanmycin. Preliminary mode of action studies showed that compound 2 could affect the assembly of rod-shaped TMVs by promoting the aggregation and fragmentation of TMV coat proteins. Molecular docking experiments demonstrated that the introduction of oxime and hydrazone moieties could indeed increase the hydrogen bond between molecules and target proteins. In addition, we conducted fungicidal and larvicidal activities study of these derivatives. Most of these derivatives had good larvicidal activities against Mythimna separata and Plutella xylostella and showed broad-spectrum fungicidal activities.
Keywords: aldisine; antiviral activity, larvicidal activity, fungicidal activity; hydrazone; marine natural products; oxime.