Synthesis and biological evaluation of stilbene‐based peptoid mimics against the phytopathogenic bacterium Xanthomonas citri pv. citri

Abstract

BACKGROUND: The emergence of drug-resistant phytopathogenic bacteria and the need for new types of biological diseasecontrol agents have accelerated efforts toward searching for alternative candidates with a low propensity for resistance development. In this study, a new series of stilbene-based peptoid mimics were synthesized, and their biological activities were evaluated against citrus pathogenic bacteria in vitro and in vivo. RESULTS: Antibacterial bioassay results showed that the dicationic peptoid mimics 9a and 9b displayed excellent bioactivity against Xanthomonas citri pv. citri, with the minimum inhibitory concentration values of 25 ∼M, which were superior to those of commercial copper biocides Delite (200 ∼M) and Kasumin Bordeaux (100 ∼M). In vivo bioassay further confirmed their control efficacy against plant bacterial diseases. In addition, the antibacterial mechanism of action elucidated their membranedisruption effects resulting in the leakage of the bacterial membranes, which was similar to that of antimicrobial peptides. Moreover, the inhibition effect on biofilm formation of peptoid mimics has also been demonstrated. CONCLUSION: Stilbene-based peptoid mimics synthesized in this study showed promising antibacterial activity with a potent membrane-disruptive mechanism. The results suggested that stilbene-based peptoid mimics have the potential as a candidate new type of bactericide for citrus disease protection.

Antibacterial Mechanism, Control Efficiency, and Nontarget Toxicity Evaluation of Actinomycin X2 against Xanthomonas citri Subsp. citri

“…Biofilm formation is essential for Xcc to adhere to citrus and survive in the early stages of infection, as well as for the release of virulence factor in the late period . It also plays a critical role in the development of resistance to pesticides . Therefore, this study investigated whether Act-X 2 affected the biofilm formation of Xcc.…”

“…10 It also plays a critical role in the development of resistance to pesticides. 33 Therefore, this study investigated whether Act-X 2 affected the biofilm formation of Xcc. As shown in Figure 1C, Act-X 2 was revealed as an excellent biofilm inhibitor, and its inhibitory activity was concentration-dependent.…”

Novel 1,3,4‐oxadiazole sulfonate/carboxylate flavonoid derivatives: synthesis and biological activity

“…At present, agricultural yield and quality are seriously threatened by many plant diseases. [1][2][3] The three plant pathogens Xanthomonas axonopodis pv. citri (Xac), 4 Xanthomonas oryzae pv.…”