A series of novel anthranilic diamide derivatives (5a–5ab) containing moieties of trifluoromethylpyridine and hydrazone was designed and synthesized. The synthesized compounds were evaluated in vivo for their activities against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV). Most of the synthesized compounds displayed good to excellent antiviral activities. The compounds 5i, 5k, 5s, 5w, 5x, and 5z had the curative activity over 65% against TMV at the concentration of 500 μg/mL, which were significantly higher than those of ningnanmycin (55.0%) and ribavirin (37.9%). Notably, the curative activity of compound 5i was up to 79.5%, with the EC50 value of 75.9 μg/mL, whereas the EC50 value of ningnanmycin was 362.4 μg/mL. The pot experiments also further demonstrated the significantly curative effect of 5i. Meanwhile, compounds 5h, 5p and 5x displayed more protective activities on TMV than that of ningnanmycin. Moreover, compounds 5a, 5e, 5f, and 5i showed inactivation activity similar to ningnanmycin at 500 μg/mL, and the EC50 value of 5e (41.5 μg/mL) was lower than ningnanmycin (50.0 μg/mL). The findings of transmission electron microscopic (TEM) indicated that the synthesized compounds exhibited strong and significant binding affinity to TMV coat protein (CP) and could obstruct the self-assembly and increment of TMV particles. Microscale thermophoresis (MST) studies on TMV-CP and CMV CP revealed that some of the active compounds, particularly 5i, exhibited a strong binding capability to TMV-CP or CMV-CP. This study revealed that anthranilic diamide derivatives containing moieties of trifluoromethylpyridine and hydrazone could be used as novel antiviral agents for controlling the plant viruses.

A series of trifluoromethyl pyridine derivatives containing 1,3,4-oxadiazole moiety was designed, synthesized and bio-assayed for their insecticidal activity. The result of bio-assays indicated the synthesized compounds exhibited good insecticidal activity against Mythimna separata and Plutella xylostella, most of the title compounds show 100% insecticidal activity at 500 mg L À1 and >80% activity at 250 mg L À1 against the two pests. Compounds E18 and E27 showed LC 50 values of 38.5 and 30.8 mg L À1 against Mythimna separata, respectively, which were close to that of avermectin (29.6 mg L À1 ); compounds E5, E6, E9, E10, E15, E25, E26, and E27 showed 100% activity at 250 mg L À1, which were better than chlorpyrifos (87%). CoMFA and CoMSIA models with good predictability were proposed, which revealed the electron-withdrawing groups with an appropriate bulk at 2-and 4-positions of benzene ring could enhance insecticidal activity.

BACKGROUND: Devastating plant virus diseases leading to bad harvests and lower quality of crops have made feeding the beyond seven billion population a huge challenge. Nevertheless, growing resistance and cross resistance of crop protection agents have made this challenge harder. Therefore, an efficient crop protection agent with novel structure and mode of action showing higher efficiency and eco-friendly is urgently needed. RESULTS: The coat protein (CP) of a virus is a potential target for the discovery of new antiviral agents. Antiviral molecules can inhibit infection by obstructing the assembly of virus particles. A series of novel phthalamide-like thiourea derivatives containing trifluoromethylpyridine was designed and synthesized. Most of the compounds exhibited good antiviral activity against tobacco mosaic virus (TMV). Compound 7b showed notable curative, protective and inactivation activities against TMV. Its inactivation half-maximal effective concentration (EC 50 ) value (20.5 ∼g mL −1 ) was better even than commercial ningnanmycin (23.2 ∼g mL −1 ). Compound 7b also had stronger TMV-CP binding ability than ningnanmycin and destroyed the external shape of TMV particles and hindered the self-assembly of TMV-CP and TMV-RNA.CONCLUSION: These phthalamide-like thiourea derivatives especially compound 7b containing trifluoromethylpyridine are potential lead compounds and inhibitors of TMV particle self-assembly.

The current global population has reached 7.6 billion, and the per capita agricultural acreage is declining continuously, imposing a big challenge to establish fully sustainable food production systems to provide sufficient food for the growing population (Carvalho, 2017;Godfray et al., 2010;Tilman et al., 2011). However, this challenge is made more difficult by many issues, including climate change, soil environment change, resistant pests, pathogens, and weeds (Fritsche, 2018;

A series of novel α-ketoamide derivatives bearing a vanillin skeleton were designed and synthesized. Bioactivity tests on virus and bacteria were performed. The results indicated that some compounds exhibited excellent antitobacco mosaic virus (TMV) activities, such as compound 34 exhibited an inactivation activity of 90.1% and curative activity of 51.8% and compound 28 exhibited a curative activity of 54.8% at 500 μg mL −1 , which is equivalent to that of the commercial ningnanmycin (inactivation of 91.9% and curative of 51.9%). Moreover, the in vitro antibacterial activity test illustrated that compounds 2, 22, and 33 showed much higher activities than commercial thiodiazole copper, which could be used as lead compounds or potential candidates. The findings of transmission electron microscopy and molecular docking indicated that the synthesized compounds exhibited strong and significant binding affinity to the TMV coat protein and could obstruct the self-assembly and increment of TMV particles. This study revealed that α-ketoamide derivatives bearing a vanillin skeleton could be used as a novel potential pesticide for controlling the plant diseases.

Novel acylurea derivatives 7a–7ab were designed and synthesized by linking the active substructures trifluoromethylpyridine and anthranilic diamide via an acylurea bridge. Most of the title compounds exhibited good activity against tobacco mosaic virus (TMV), particularly compound 7x (EC50 of 211.8 μg/mL), which showed much higher curative activity than ningnanmycin (EC50 of 389.8 μg/mL), and compound 7ab, which showed excellent inactivation activity (EC50 of 36.1 μg/mL), similar to ningnanmycin (EC50 of 23.2 μg/mL). The preliminary mechanism of these derivatives was investigated. Autodocking analysis revealed that compounds 7x and 7ab had good affinity for TMV coat protein (TMV CP), with low binding energies (−7.86 and −8.59 kcal/mol) comparable to ningnanmycin (−8.75 kcal/mol). Molecular dynamics simulation showed that compound 7x had a stable system structure with a better binding free energy (−32.94 kcal/mol) than ningnanmycin (−25.62 kcal/mol). Microscale thermophoresis showed that compound 7x bound more strongly to TMV CP (K d of 19.8 ± 7.3 μM) than ningnanmycin (K d of 21.2 ± 7.3 μM). Transmission electron microscopy and self-assembly experiments demonstrated that compounds 7x and 7ab significantly obstructed the self-assembly of TMV RNA and TMV CP. This new acylurea derivative has excellent antiviral activity by targeting TMV CP and inhibiting TMV self-assembly and can be considered a candidate for antiviral applications.

Spiro compounds are biologically active organic compounds with unique structures, found in a wide variety of natural products and drugs. They do not readily lead to drug resistance due to their unique mechanisms of action and have, therefore, attracted considerable attention regarding pesticide development. Analyzing structure−activity relationships (SARs) and summarizing the characteristics of spiro compounds with high activity are crucial steps in the design and development of new pesticides. This review mainly summarizes spiro compounds with insecticidal, bactericidal, fungicidal, herbicidal, antiviral, and plant growth regulating functions to provide insight for the creation of new spiro compound pesticides.

Thirty-eight novel ferulic amide 1-aminocyclohexane carboxylic acid (Ac6c) derivatives D1−D19 and E1−E19 were designed and synthesized, and their antibacterial, antifungal, and insecticidal activities were tested. Most of the synthesized compounds displayed excellent activity againstXanthomonas oryzae pv. oryzae (Xoo), with EC 50 values ranging from 11.6 to 83.1 μg/ mL better than that of commercial bismerthiazol (BMT, EC 50 = 84.3 μg/mL), as well as much better performance compared to that of thiediazole copper (TDC, EC 50 = 137.8 μg/mL). D6 (EC 50 = 17.3 μg/mL), D19 (EC 50 = 29.4 μg/mL), E3 (EC 50 = 29.7 μg/ mL), E9 (EC 50 = 27.0 μg/mL), E10 (EC 50 = 18.6 μg/mL), and E18 (EC 50 = 20.8 μg/mL) showed much higher activity on Xanthomonas oryzae pv. oryzicola compared with BMT (EC 50 = 80.1 μg/mL) and TDC (EC 50 = 124.7 μg/mL). In relation to controlling the fungus, Rhizoctonia solani, E1, E10, and E13 had much lower EC 50 values of 0.005, 0.140, and 0.159 μg/mL compared to hymexazol at 74.8 μg/mL. Further in vivo experiments demonstrated that E6 and E12 controlled rice bacterial leaf blight disease better than BMT and TDC did. Scanning electron microscopy (SEM) studies revealed that E12 induced the Xoo cell membrane collapse. Moreover, D13 (73.7%), E5 (80.6%), and E10 (73.4%) also showed moderate activity against Plutella xylostella. These results indicated that the synthesized ferulic amide Ac6c derivatives showed promise as candidates for treating crop diseases.