Design, synthesis and anti-PVY activity of planar chiral thiourea derivatives incorporated with [2.2]paracyclophane

Abstract

BACKGROUND: Potato virus Y (PVY) is a prominent representative of plant viruses. It can inflict severe damage upon Solanaceae plants, leading to global dissemination and substantial economic losses. To discover new antiviral agents, a class of planar chiral thiourea molecules through the key step of N-heterocyclic carbene-catalyzed nitrile formation reaction was synthesized with excellent optical purities for antiviral evaluations against plant virus PVY. RESULTS: The absolute configurations of the planar chiral compounds exhibited obvious distinctions in the anti-PVY activities. Notability, compound (S)-4u exhibited remarkable curative activities against PVY, with a half maximal effective concentration (EC50) of 349.3 μg mL−1, which was lower than that of the ningnanmycin (NNM) (EC50 = 400.8 μg mL−1). Additionally, The EC50 value for the protective effects of (S)-4u was 146.2 μg mL−1, which was superior to that of NNM (276.4 μg mL−1). Furthermore, the mechanism-of-action of enantiomers of planar chiral compound 4u was investigated through molecular docking, defensive enzyme activity tests and chlorophyll content tests. CONCLUSION: Biological mechanism studies have demonstrated that the configuration of planar chiral target compounds plays a crucial role in the molecular interaction with PVY-CP, enhancing the activity of defense enzymes and affecting chlorophyll content. The current study has provided significant insights into the roles played by planar chiralities in plant protection against viruses. This paves the way for the development of novel green pesticides bearing planar chiralities with excellent optical purities.