Preparation and Anti-Tobacco Mosaic Virus Activities of Crocetin Diesters

Myricetin derivatives containing the benzoxazinone moiety discovered as potential anti-tobacco mosaic virus agents

A series of myricetin derivatives containing benzoxazinone were designed and synthesized. The structures of all compounds were characterized by NMR and HRMS. The structure of Y4 had been confirmed by single-crystal X-ray diffraction analysis. The test results of EC50 values of tobacco mosaic virus (TMV) suggested that Y8 had the best curative and protective effects, with EC50 values of 236.8, 206.0 μg/mL, respectively, which were higher than that of ningnanmycin (372.4, 360.6 μg/mL). Microscale thermophoresis (MST) experiments demonstrated that Y8 possessed a strong binding affinity for tobacco mosaic virus coat protein (TMV-CP), with a dissociation constant (Kd) value of 0.045 μM, which was superior to the ningnanmycin (0.700 μM). The findings of molecular docking studies revealed that Y8 interacted with multiple amino acid residues of TMV-CP through the formation of non-covalent bonds, which had an effect on the self-assembly of TMV particles. The malondialdehyde (MDA) and superoxide dismutase assay (SOD) content assays also fully verified that Y8 could stimulate the plant immune system and enhance disease resistance by reducing MDA content and increasing SOD content. In summary, myricetin derivatives containing benzoxazinone could be considered to further research and development as novel antiviral agents.

Recent Achievements in Antiviral Agent Development for Plant Protection

Plant virus disease is the second most prevalent plant diseases and can cause extensive loss in global agricultural economy. Extensive work has been carried out on the development of novel antiplant virus agents for preventing and treating plant virus diseases. In this review, we summarize the achievements of the research and development of new antiviral agents in the recent five years and provide our own perspective on the future development in this highly active research field.

The Discovery of Novel Ferulic Acid Derivatives Incorporating Substituted Isopropanolamine Moieties as Potential Tobacco Mosaic Virus Helicase Inhibitors

Target-based drug design, a high-efficiency strategy used to guide the development of novel pesticide candidates, has attracted widespread attention. Herein, various natural-derived ferulic acid derivatives incorporating substituted isopropanolamine moieties were designed to target the tobacco mosaic virus (TMV) helicase. Bioassays demonstrating the optimized A₁₉, A₂₀, A₂₉, and A₃₁ displayed excellent in vivo antiviral curative abilities, affording corresponding EC₅₀ values of 251.1, 336.2, 347.1, and 385.5 μg/mL, which visibly surpassed those of commercial ribavirin (655.0 μg/mL). Moreover, configurational analysis shows that the R-forms of target compounds were more beneficial to aggrandize antiviral profiles. Mechanism studies indicate that R-A₁₉ had a strong affinity (K_d = 5.4 μM) to the TMV helicase and inhibited its ability to hydrolyze ATP (50.61% at 200 μM). Meanwhile, A₁₉ could down-regulate the expression of the TMV helicase gene in the host to attenuate viral replication. These results illustrate the excellent inhibitory activity of A₁₉ towards the TMV helicase. Additionally, docking simulations uncovered that R-A₁₉ formed more hydrogen bonds with the TMV helicase in the binding pocket. Recent studies have unambiguously manifested that these designed derivatives could be considered as promising potential helicase-based inhibitors for plant disease control.

Rapid screening of antioxidant from natural products by AAPH-Incubating HPLC-DAD-HR MS/MS method: A case study of Gardenia jasminoides fruit

A new AAPH-Incubating HPLC-DAD-HR MS/MS method was developed for the rapid and high-throughput screening of antioxidants directly in natural products and applied to Gardenia jasminoides fruit. This method was assumed that the peak areas of compounds with potential antioxidant activity in HPLC chromatograms would be significantly reduced or disappeared after incubating with the AAPH which can release ROO at physiological conditions (37 °C, pH 7.4). Additionally, the activity of antioxidants can be evaluated by comparing the peak reduction rates and the screened components can be further identified by HRMS/MS. Then, 17 potential natural antioxidants from the crude extract of GJF was screened. Among them, three major components including crocin I, crocin II and crocetin showed excellent ROO scavenging activity, which were further validated by the ORAC assay. In conclusion, our study provided a simple and effective strategy to rapidly screen antioxidants in natural products.

Discovery of Novel α-Aminophosphonates with Hydrazone as Potential Antiviral Agents Combined With Active Fragment and Molecular Docking

A series of novel α-aminophosphonate derivatives containing hydrazone were designed and synthesized based on active fragments. Bioassay results demonstrated that title compounds possessed good activities against tobacco mosaic virus. Among them, compounds 6a, 6g, 6i, and 6j were equivalent to the commercial antiviral agents like dufulin. On structure optimization-based molecular docking, compound 6k was synthesized and displayed excellent activity with values of 65.1% curative activity, 74.3% protective activity, and 94.3% inactivation activity, which were significantly superior to the commercial antiviral agents dufulin and ningnanmycin. Therefore, this study indicated that new lead compounds could be developed by adopting a joint strategy with active fragments and molecular docking.