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

Abstract

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 (Kd = 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.

Identification of natural Rutaecarpine as a potent tobacco mosaic virus (TMV) helicase candidate for managing intractable plant viral diseases

“…Authoritatively, the principal component analysis (PCA) was mainly engaged to identify the movements and transformations of pure proteins or complex molecules through dynamics trajectory data 37–39 . Helicase‐Rutaecarpine or helicase‐Acyclovir system PCA [principal component one (PC1) was Gyrate, while principal component two (PC2) was RMSD] were calculated using the gmx covar module.…”

“…The expression and purification of TMV helicase were successfully performed in the recombinant plasmid (pPIC9K‐HIS‐TMV‐Hel) Escherichia coli bacterial solution. Specific experimental procedures can be seen in Supporting Information Methods S1 and S2 26 …”

“…After that, the supernatant (10 μL) was absorbed into a new sample tube, and 100 μL of phosphorus fixing reagent (ATPase assay reagent kits) was added (40 °C, 10 min). The absorbance of the sample was then measured at 660 nm and the corresponding inhibition value was calculated by referring to the ATPase assay instructions 26,30 …”

“…Then, the pretreated samples were fixed in potassium bromide (KBr) discs and placed into a Nicolet iS50 instrument and scanned at 500–4000 cm (32 scans). The overall operating procedure refers to our previous approach 26,30,31 …”

“…[22][23][24] These meticulous studies have made it possible to evaluate and screen potential inhibitors of TMV helicase that could impede TMV at the replication stage, interfere with its protein expression and subsequent assembly, and ultimately impair the proliferation and spread of plant viruses. In previous studies, using a naturally occurring alkaloid and ferulic acid skeleton as the matrix, we identified nucleoside analogs 25 and ferulic acid derivatives 26 with anti-TMV activity and potential helicase inhibitory activity through chemical synthesis and structural modification.…”