Novel 1‐Indanone derivatives containing oxime and oxime ether moieties as immune activator to resist plant virus

Abstract Background Vegetable viruses are difficult to prevent and control in the field, causing massive economic losses of agricultural production in the world. A new natural product‐based antiviral agent would be an effective means to control viral diseases. As a class of natural products, 1‐indanones present various pharmacologically actives, while their application in agriculture remains to be found. Results A series of novel 1‐indanone derivatives were designed and synthesized and the antiviral activities were systematically evaluated. Bioassays showed that most compounds exhibited good protective activities against cucumber mosaic virus (CMV), tomato spotted wilt virus (TSWV), and pepper mild mottle virus (PMMoV). Notably, compound 27 exhibited the best protective effects against PMMoV with EC 50 values of 140.5 mg L −1 , superior to ninanmycin (245.6 mg L −1 ). Compound 27 induced immunity responses through multilayered regulation on mitogen‐activated protein kinase, plant hormone signal transduction and phenylpropanoid biosynthesis pathways. Conclusion These 1‐indanone derivatives especially compound 27 can be considered as potential immune activators to resist plant virus. © 2023 Society of Chemical Industry.