Trifluoromethylpyridine piperazine derivatives: synthesis and anti-plant virus activity.

BACKGROUND: The cucumber mosaic virus (CMV) is well-known for its expansive host range and distribution, resulting in a detrimental effect on agricultural production, thus making it imperative to implement measures for its control. RESULTS: Novel compounds S1-S28 were synthesized by connecting trifluoromethyl pyridine, amide and piperazine scaffolds. Bioassays indicated that most of the synthesized compounds exhibited good curative effects against CMV, with half maximal effective concentration (EC50 ) values of compounds S1, S2, S7, S8, S10, S11, S15, and S28 being 119.6, 168.9, 197.6, 169.1, 97.9, 73.9, 224.4, and 125.2 µg mL-1 , respectively, which were lower than the EC50 of ningnanmycin (314.7 µg mL-1 ). Compounds S5 and S8 exhibited protective activities with EC50 of 170.8 and 95.0 µg mL-1 , respectively, which were lower than ningnanmycin at 171.4 µg mL-1 . The inactivation activities of S6 and S8 at 500 µg mL-1 were remarkably high at 66.1% and 78.3%, respectively, surpassing that of ningnanmycin (63.5%). Additionally, their EC50 values were more favorable at 22.2 and 18.1 µg mL-1 , respectively, than ningnanmycin (38.4 µg mL-1 ). And molecular docking and molecular dynamics simulation showed compound S8 had better binding with CMV-coat protein, providing a possible explanation for the anti-CMV activity of compound S8. CONCLUSIONS: Compound S8 showed a strong binding affinity to CMV-coat protein and impacted the self-assemble of CMV particles. Compound S8 could be a potential lead compound for discovering a new anti-plant virus candidate. © 2023 Society of Chemical Industry.

Design, Synthesis, and Bioactivity of Spiro Derivatives Containing a Pyridine Moiety.

We designed and synthesized a series of pyridine spiro derivatives and evaluated their insecticidal and antiviral activities. Some compounds exhibited good insecticidal and antiviral activities. Notably, the E series of compounds displayed good insecticidal activity against Tetranychus urticae. Compounds E20 (EC50 = 63.68 mg/L) and F4 (EC50 = 47.81 mg/L) exhibited inactivation activities against the tobacco mosaic virus (TMV), which were similar to that of Ningnanmycin (EC50 = 58.01 mg/L). Molecular docking showed that compounds E20 and F4 exhibited satisfactory affinities for the TMV coat protein (TMV-CP), with binding energies (-6.7 and -6.4 kcal/mol, respectively) slightly lower than that of Ningnanmycin (-6.3 kcal/mol). Further, molecular dynamics analysis revealed that compounds E20 and F4 exhibited better binding stability values than Ningnanmycin. Microscale thermophoresis showed that compounds E20 (Kd = 0.053 ± 0.016 µM) and F4 (Kd = 0.045 ± 0.022 µM) bound more strongly to TMV-CP than Ningnanmycin (Kd = 0.10 ± 0.029 µM). The results of transmission electron microscopy showed that these two compounds hindered the self-assembly and growth of TMV. In summary, we showed that these pyridine spiro derivatives could be used as a basis for the research and development of novel pesticides.

Novel trifluoromethylpyridine piperazine derivatives as potential plant activators.

Plant virus diseases seriously affect crop yield, especially tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV). The development of plant immune activators has been an important direction in the innovation of new pesticides. Therefore, we designed and synthesized a series of trifluoromethyl pyridine piperazine derivatives (A1-A27), and explored the action mechanism of active compound. The antiviral activity test showed that compounds A1, A2, A3, A9, A10, A16, A17 and A21 possessed higher activities than commercialized ningnanmycin. Particularly, the in vivo antiviral activity indicated that compound A16 showed the most potent protective activity toward TMV (EC50 = 18.4 µg/mL) and CMV (EC50 = 347.8 µg/mL), compared to ningnanmycin (50.2 µg /mL for TMV, 359.6 µg/mL for CMV). The activities of defense enzyme, label -free proteomic and qRT-PCR analysis showed that compound A16 could enhance the defensive enzyme activities of superoxide dismutase (SOD),polyphenol oxidase (PPO) and phenylalanine ammonialyase (PAL), and activate the phenylpropanoid biosynthesis pathway to strenthen the antiviral activities of tobacco. This study provides reliable support for the development of new antiviral pesticides and potential antiviral mechanism.

Spiro Derivatives in the Discovery of New Pesticides: A Research Review.

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.

Design, synthesis, and bioactivity of ferulic acid derivatives containing an ß-amino alcohol.

BACKGROUND: Plant diseases caused by viruses and bacteria cause huge economic losses due to the lack of effective control agents. New potential pesticides can be discovered through biomimetic synthesis and structural modification of natural products. A series of ferulic acid derivatives containing an ß-amino alcohol were designed and synthesized, and their biological activities were evaluated. RESULT: Bioassays results showed that the EC50 values of compound D24 against Xanthomonas oryzae pv. oryzae (Xoo) was 14.5 µg/mL, which was better than that of bismerthiazol (BT, EC50 = 16.2 µg/mL) and thiodiazole copper (TC, EC50 = 44.5 µg/mL). The in vivo curative and protective activities of compound D24 against Xoo were 50.5% and 50.1%, respectively. The inactivation activities of compounds D2, D3 and D4 against tobacco mosaic virus (TMV) at 500 µg/mL were 89.1, 93.7 and 89.5%, respectively, superior to ningnanmycin (93.2%) and ribavirin (73.5%). In particular, the EC50 value of compound D3 was 38.1 µg/mL, and its molecular docking results showed that compound D3 had a strong affinity for TMV-CP with a binding energy of - 7.54 kcal/mol, which was superior to that of ningnanmycin (- 6.88 kcal /mol). CONCLUSIONS: The preliminary mechanism research results indicated that compound D3 may disrupt the three-dimensional structure of the TMV coat protein, making TMV particles unable to self-assemble, which may provide potential lead compounds for the discovery of novel plant antiviral agents.

1,3,4-Oxadiazole Contained Sesquiterpene Derivatives: Synthesis and Microbiocidal Activity for Plant Disease.

A series of 1,3,4-oxadiazole contained sesquiterpene derivatives were synthesized, and the activity of the target compounds against Xanthomonas oryzae pv. oryzae (Xoo), Xanthomonas axonopodis pv. citri (Xac), and tobacco mosaic virus (TMV) were evaluated. The biological activity results showed that the EC50 values of compounds H4, H8, H11, H12, H14, H16, and H19 for Xac inhibitory activity were 33.3, 42.7, 56.1, 74.5, 37.8, 43.8, and 38.4 µg/ml, respectively. Compounds H4, H8, H15, H19, H22, and H23 had inhibitory effects on Xoo, with EC50 values of 51.0, 43.3, 43.4, 50.5, 74.6, and 51.4 µg/ml, respectively. In particular, the curative and protective activities of compound H8 against Xoo in vivo were 51.9 and 49.3%, respectively. In addition, the EC50 values of the inactivation activity of compounds H4, H5, H9, H10, and H16 against TMV were 69.6, 58.9, 69.4, 43.9, and 60.5 µg/ml, respectively. The results of molecular docking indicated that compound H10 exhibited a strong affinity for TMV-coat protein, with a binding energy of -8.88 kcal/mol. It may inhibit the self-assembly and replication of TMV particles and have an anti-TMV effect, which supports its potential usefulness as an antiviral agent.

Hydrazone modification of non-food natural product sclareolide as potential agents for plant disease.

Plant diseases and their drug resistance pose a serious threat to agricultural production. One way to solve this problem is to discover new and efficient botanical pesticides. Herein, a series of novel hydrazide-hydrazone-containing sesquiterpenoid derivatives were synthesized by simply modifying the structure of the non-food natural product sclareolide. The biological activity results illustrated that compared to ningnanmycin (39.2 µg/mL), compound Z28 had the highest antiviral activity against tobacco mosaic virus (TMV), and the concentration for 50% of maximal effect (EC50) of its inactivation activity was 38.7 µg/mL, followed by compound Z14 (40.6 µg/mL). Transmission electron microscopy (TEM) demonstrated that TMVs treated with compounds Z14 and Z28 were broken into rods of different lengths, and their external morphology was fragmented or even severely fragmented. Autodocking and molecular dynamics (MD) simulations indicated that compound Z28 had a strong affinity for tobacco mosaic virus coat protein (TMV-CP), with a higher binding energy of -8.25 kcal/mol compared to ningnanmycin (-6.79 kcal/mol). The preliminary mechanism revealed that compound Z28 can achieve an antiviral effect by targeting TMV-CP, rendering TMV unable to self-assemble and replicate, and might be a candidate for a novel plant antiviral agent. Furthermore, the curative and protective activities of compound Z22 (EC50 = 16.1 µg/mL) against rice bacterial blight were 51.3% and 50.8%, respectively. Its control effect was better than that of bismerthiazol (BT) and thiadiazole copper (TC), compound Z22 that can be optimized as an active molecule.