Discovery of novel double pyrazole Schiff base derivatives as anti-tobacco mosaic virus (TMV) agents

Synthesis of Ferrocenyl Chalcone-Containing Aminourea Schiff Bases and Their Detection on Tryptophan

In this paper, 1-phenyl-3-ferrocenylenone aminourea Schiff bases were synthesized by a novel method. A multifunctional molecular probe (Probe A) of 1-phenyl-3-ferrocenylenone, carbon-based solid acid, aminourea, and anhydrous ethanol was synthesized by adding them to a vessel at elevated temperatures and refluxing for the synthesis of a multifunctional molecular probe (Probe A) of 1-phenyl-3-ferrocenylenone aminourea Schiff base, and it was found that it recognizes tryptophan (Trp) in solution, and that the catalyst can be reused more than five times after recycling. This method is characterised by low cost, high efficiency, green environment and no waste acid. Fluorescence and UV spectra show that probe A specifically recognizes tryptophan (Trp) without interference by other amino acids or pH and time does not affect it within 45 min. The lowest limit of detection for Trp was 1.307 × 10- 4 mol/L for probe A. The binding ratios of probe A to Trp were measured to be 1:1 by Job's plotting method, respectively. The complexation constant of probe A with Trp was found to be 2.733 × 107 L/mol according to the Benesi-Hildebrand equation. The bonding mechanism was explored through IR spectroscopy and ¹H NMR titration.

Tagitinin A from Tithonia diversifolia provides resistance to tomato spotted wilt orthotospovirus by inducing systemic resistance

Tomato spotted wilt orthotospovirus (TSWV) causes devastating losses to agronomic and ornamental crops worldwide. Currently, there is no effective strategy to control this disease. Use of biotic inducers to enhance plant resistance to viruses maybe an effective approach. Our previous study indicated that Tagitinin A (Tag A) has a high curative and protective effect against TSWV. However, the underlying molecular mechanism of Tag A-mediated antiviral activity remains unknown. In this study, Tag A reduced the expression of the NSs, NSm genes was very low in untreated leaves following TSWV infection. In addition, the expression of all TSWV genes in the inoculated and systemic leaves was inhibited in the protective assay, and with an inhibition rate of more than 85% in systemic leaves. Tag A increased phenylalanine ammonia-lyase (PAL) activity in the curative and protective assays. The concentrations of jasmonic acid (JA) and jasmonic acid -isoleucine (JA-Ile) and the expression of its key gene NtCOI1 in Tag A-treated and systemic leaves of treated plants were significantly higher than those of the control plant. Furthermore, Tag A-induced resistance to TSWV could be eliminated by VIGS-mediated silencing of the NtCOI1 gene. These indicated that Tag A acts against TSWV by activating the JA defense signaling pathway.

Design, synthesis, anti-tobacco mosaic viral and molecule docking simulations of urea/thiourea derivatives of 2-(piperazine-1-yl)-pyrimidine and 1-(4-Fluoro/4-Chloro phenyl)-piperazine and 1-(4-Chloro phenyl)-piperazine - A study

The objectives of the present work are to design, syhthesize and introduce novel urea/thiourea derivatives of 2-(piperazine-1-yl)-pyrimidine and 1-(4-Fluoro/4-Chloro phenyl)-piperazine molecules as tobacco mosaic virus (TMV) inhibitors. A series of urea/thiourea derivatives containing pyrimidine and piperazine moieties were synthesized, characterized using Fourier-transform infrared (FTIR) mass spectra, nuclear magnetic resonance (NMR) spectroscopy, elemental analysis and evaluated their sustainability using biological experiments. The anti-viral bioassay of the title compounds showed an antiviral activity against TMV. The compounds synthesized, 9j, 6g and 3d, showed highly-potential curative, protective, and inhibitory activities against TMV at 500 mg/mL formulation. All these compounds were allowed to quantum-polarized-ligand (quantum mechanical and molecular mechanical (QM/MM)) docking experiments. The compounds 9j, 6g and 3d structurally exhibited identical higher affinity towards TMV-Helicase and TMV-Coat proteins. The docking interactions proposed had two stage inhibition of TMV virus by binding to coat protein and helicase for inhibition of RNA replication. The long-range molecular dynamics (150 ns) simulations has revealed more consistency by 9j, 6g and 3d. The present study outcomes good binding propensity for active-tunnel of TMV-Hel enzyme, by these thiourea, urea derivatives, 9j, 6g and 3d, to suggest that the designed and synthesized were ideal for proposing as selective novel inhibitors to target for TMV.

Synthesis of Anthranilic Diamide Derivatives Containing Moieties of Trifluoromethylpyridine and Hydrazone as Potential Anti-Viral Agents for Plants

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.

Proteomic and Phosphoproteomic Analysis in Tobacco Mosaic Virus-Infected Tobacco (Nicotiana tabacum)

Tobacco mosaic virus (TMV) is a common source of biological stress that significantly affects plant growth and development. It is also useful as a model in studies designed to clarify the mechanisms involved in plant viral disease. Plant responses to abiotic stress were recently reported to be regulated by complex mechanisms at the post-translational modification (PTM) level. Protein phosphorylation is one of the most widespread and major PTMs in organisms. Using immobilized metal ion affinity chromatography (IMAC) enrichment, high-pH C18 chromatography fraction, and high-accuracy mass spectrometry (MS), a set of proteins and phosphopeptides in both TMV-infected tobacco and control tobacco were identified. A total of 4905 proteins and 3998 phosphopeptides with 3063 phosphorylation sites were identified. These 3998 phosphopeptides were assigned to 1311 phosphoproteins, as some proteins carried multiple phosphorylation sites. Among them, 530 proteins and 337 phosphopeptides corresponding to 277 phosphoproteins differed between the two groups. There were 43 upregulated phosphoproteins, including phosphoglycerate kinase, pyruvate phosphate dikinase, protein phosphatase 2C, and serine/threonine protein kinase. To the best of our knowledge, this is the first phosphoproteomic analysis of leaves from a tobacco cultivar, K326. The results of this study advance our understanding of tobacco development and TMV action at the protein phosphorylation level.

Design, Synthesis and Biological Evaluation of Novel Pyrazole Sulfonamide Derivatives as Potential AHAS Inhibitors

Acetohydroxy acid synthase (AHAS; EC 2.2.1.6, also referred to as acetolactate synthase, ALS) has been considered as an attractive target for the design of herbicides. In this work, an optimized pyrazole sulfonamide base scaffold was designed and introduced to derive novel potential AHAS inhibitors by introducing a pyrazole ring in flucarbazone. The results of in vivo herbicidal activity evaluation indicates compound 3b has the most potent activity with rape root length inhibition values of 81% at 100 mg/L, and exhibited the best inhibitory ability against Arabidopsis thaliana AHAS. With molecular docking, compound 3b insert into Arabidopsis thaliana AHAS stably by an H-bond with Arg377 and cation-π interactions with Arg377, Trp574, Tyr579. This study suggests that compound 3b may serve as a potential AHAS inhibitor which can be used as a novel herbicides and provides valuable clues for the further design and optimization of AHAS inhibitors.