LAUSR

BACKGROUND The intractable plant pathogens have overwhelmingly inflicted yield and quality losses on crops worldwide. The discovery and exploration of novel agrochemical alternatives based on chemical modification of bioactive natural products is a high-efficiency approach. Herein, two series of novel cinnamic acid derivatives incorporating diverse building blocks with alternative linking patterns were ingeniously designed and synthesized to identify their antiviral capacity and antibacterial activity. RESULTS Bioassay results demonstrated that most cinnamic acid derivatives had excellent antiviral competence toward tobacco mosaic virus (TMV) in vivo, especially compound A5 (EC50 = 287.7 μg/mL), which yielded a remarkably protective effect against TMV compared with commercial virucide RBV (EC50 = 622.0 μg/mL). Meanwhile, compound A17 had a remarkable protective efficiency of 84.3% at 200 μg/mL against Xac in plants. Given these outstanding results, engineered title compounds could be regarded as promising lead compounds for controlling plant virus and bacterial diseases. Preliminary mechanistic studies suggested that compound A5 could enhance host's defense responses by increasing defense enzyme activity and up-regulating defense genes, thereby resulting in suppressing phytopathogen invasion. CONCLUSION This research lays the foundation of cinnamic acid containing diverse building blocks with alternative linking patterns for practical application in pesticide exploration. This article is protected by copyright. All rights reserved.