Design, Synthesis, and Bioactivity Evaluation of Novel Isoxazole-Amide Derivatives Containing an Acylhydrazone Moiety as New Active Antiviral Agents

Abstract

As a continuation of our efforts to discover and develop “me-better” active molecules, in this study, a series of novel isoxazole-amide derivatives containing an acylhydrazone moiety were synthesized and evaluated for their antiviral activities against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV). Antiviral bioassays indicated that some of the target compounds exhibited better in vivo antiviral activities against TMV and CMV than those of Ningnanmycin (NNM). Especially, the compound 7t exhibited the best curative, protection, and inactivation activities against TMV and CMV which were superior to those of NNM. Meanwhile, our present work also revealed that compound 7t could enhance the defense-related enzyme activity and increase the chlorophyll content in tobacco leaves to induce resistance and enhance plant tolerance to TMV infection.

Recent Achievements in Antiviral Agent Development for Plant Protection

“…In 2019, Yang et al 83 designed and synthesized a series of novel isoxazole-amide derivatives containing an acylhydrazone moiety and evaluated them for antiviral activities against TMV and CMV. The compound 54 exhibited the best curative, protection, and inactivation activities among these compounds against TMV and CMV and were also superior to those of ningnanmycin.…”

Synthesis and Bioactivity Evaluation of Novel Thiochroman-4-One Derivatives Incorporating Carboxamide and 1, 3, 4-Thiadiazole Thioether Moieties

“…In our previous study, we disclosed a series of novel thiochroman-4-one derivatives (Figure 1) which showed moderate to good antibacterial and antifungal activities [11][12][13][14]. e carboxamide moiety, an important functional group in pesticide chemistry, had attracted more and more attention to the researchers due to its broad spectrum of pesticidal bioactivities, for example, antibacterial [15,16], antifungal [17,18], antiviral [19][20][21], insecticidal [22,23], and herbicidal [24] properties. Over the past few decades, many new pesticides containing carboxamide moiety, such as fluxapyroxad, penflufen, and isoflucypram, had been developed.…”

Novel botanical active component derivatives containing carboxamide and 1,3,4-Thiadiazole thioether moieties: Design, synthesis, and inhibitory activity

“…However, the inhibitory effects on plant pathogenic bacteria diseases of carvacrol, thymol, guaiacol, sesamol and their derivative had not been reported yet. Meanwhile, the carboxamide and 1,3,4-thiadiazole thioether moieties had extensive pesticide biological activities, including antibacterial, antifungal, antiviral, and insecticidal activity ( Dalgaard, et al, 1994 ; Wu et al, 2016 ; Yang et al, 2018 ; Chen, et al, 2019 ; Yang et al, 2019 ; Tang et al, 2020 ; Chen et al, 2021 ). In our previous work, a series of novel thiochromanone derivatives containing carboxamide and 1,3,4-thiadiazole thioether moieties ( Figure 2 ) were prepared and demonstrated to have suitable antibacterial and antifungal activity ( Yu et al, 2020 ).…”