Eco-Friendly Cinnamic Acid Derivatives Containing Glycoside Scaffolds as Potential Antiviral Agents.

Natural products are a crucial source in the development of new eco-friendly antiviral agents to control plant viral diseases. In our previous studies, some ferulic acid derivatives with good antiviral activity were obtained as an immune activator. To continue the discovery of eco-friendly antiviral agents, different monosaccharides were introduced into cinnamic acid skeletons by an activity-based strategy to obtain a series of cinnamic acid derivatives containing glycoside scaffolds, and their antiviral activities against tobacco mosaic virus (TMV) and tomato spotted wilt virus (TSWV) were evaluated. Among them, compound 8d showed the greatest protective activities against TMV and TSWV, with the EC50 values of 128.5 and 236.8 µg mL-1, respectively, which were superior to those of ningnanmycin (238.5 and 315.7 µg mL-1, respectively). Moreover, compound 8d could significantly improve the defense enzyme activities of peroxidase, chitinase, and ß-1,3-glucanase. Proteomic and transcriptome analyses indicated that compound 8d regulated gene transcription and protein expression levels involved in the defense response to resist virus infection. The present study revealed that compound 8d is a potential lead candidate for the development of novel, eco-friendly, and natural-product-based antiviral agents.

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

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 EC50 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.

Novel Cyclized Derivatives of Ferulic Acid as Potential Antiviral Agents through Activation of Photosynthesis.

To further develop new antiviral agents, several novel cyclized derivatives of ferulic acid were designed and synthesized. Their antiviral activities were evaluated against the cucumber mosaic virus (CMV), pepper mild mottle virus (PMMoV), and tomato spotted wilt virus (TSWV). The results showed that some ferulic acid derivatives exhibited desirable antiviral activities. Particularly, compound 5e exhibited excellent protective activities against CMV, PMMoV, and TSWV, with EC50 values of 167.2, 102.5, and 145.8 µg mL-1, respectively, which were superior to those obtained for trans-ferulic acid (581.7, 611.2, and 615.4 µg mL-1), dufulin (312.6, 302.5, and 298.2 µg mL-1), and ningnanmycin (264.3, 282.5, and 276.5 µg mL-1). Thereafter, the protective mechanisms of 5e were evaluated through photosynthesis evaluation, transcriptome profiling, and proteomic analysis. The results indicated that 5e significantly activated the expression levels of photosynthesis-related regulatory genes and proteins in tobacco plants and promoted the accumulation of defense molecules to resist viral infection. Thus, the findings of this study indicated that novel cyclized ferulic acid derivatives are potential antiviral agents that act via regulating photosynthesis in the host.

Design, Synthesis, and Biological Activity of Novel Chalcone Derivatives Containing an 1,2,4-Oxadiazole Moiety.

To discover a lead compound for agricultural use, 34 novel chalcone derivatives containing an 1,2,4-oxadiazole moiety were designed and synthesized. Their nematocidal activities against Bursaphelenchus xylophilus, Aphelenchoides besseyi, and Ditylenchus dipsaci and their antiviral activities against tobacco mosaic virus (TMV), pepper mild mottle virus (PMMoV), and tomato spotted wilt virus (TSWV) were evaluated. Biological assay results indicate that compounds A13 and A14 showed good nematocidal activities against B. xylophilus, A. besseyi, and D. dipsaci, with LC50 values of 35.5, 44.7, and 30.2 µg/ml and 31.8, 47.4, and 36.5 µg/ml, respectively, which are better than tioxazafen, fosthiazate, and abamectin. Furthermore, compound A16 demonstrated excellent protective activity against TMV, PMMoV, and TSWV, with EC50 values of 210.4, 156.2, and 178.2 µg/ml, respectively, which are superior to ningnanmycin (242.6, 218.4, and 180.5 µg/ml).

Design, synthesis, antiviral activity, and mechanisms of novel ferulic acid derivatives containing amide moiety.

To explore the novel compounds with high antiviral activity, three series ferulic acid derivatives containing amide moiety were gradually designed and synthesized based on antiviral activity tracking. The bioassay results exhibited that some target compounds had notable antiviral activities against tomato spotted wilt virus (TSWV) and cucumber mosaic virus (CMV). Compounds Y1, Y2, Y8, Z1 and Z2 presented splendid curative, protective, and inactivating activities to TSWV and CMV at 500 µg/mL. Especially, these compounds displayed outstanding inactivating effects on TSWV with the EC50 values of 225.9, 126.1, 224.6, 216.1, and 147.3 µg/mL, which were superior to ningnanmycin (249.1 µg/mL) and ribavirin (315.7 µg/mL). Furthermore, the antiviral mechanisms of compound Y2 were investigated by conducting microscale thermophoresis experiment and molecular docking experiment. The results suggested that compound Y2 performed excellent binding affinity to TSWV coat protein (TSWV CP) with the binding constant of 2.14 µM, which due to two strong hydrogen bonds of compound Y2 to the key amino acids ARG94 of TSWV CP. Therefore, compound Y2 can be regarded as a leading structure for development of the potential antiviral agent.