Abstract：
In the protracted \"arms race\" between host and plant pathogenic bacteria, host organisms have evolved powerful weapons known as host defense peptides (HDPs). However, natural HDPs are not suitable for large-scale applications; therefore, researchers have chosen to develop bespoke small-molecule functional mimics. Phenothiazine derivatives were developed as functional HDPs mimics, owing to their broad biological activity and high lipophilicity. The phenothiazine analogues designed in this study exhibited excellent in vitro bioactivity against the three Gram-negative bacteria Xanthomonas oryzae pv oryzae, Xanthomonas axonopodis pv citri, and Pseudomonas syringae pv actinidiae, with optimal EC50 values of 0.80, 0.31, and 1.91 μg/mL, respectively. Preliminary evidence suggests that compound C2 may act on bacterial cell membranes and interact with bacterial Deoxyribonucleic acid in the groove binding mode. In vivo trials showed that compound C2 was highly effective against rice leaf blight (51.97-56.69%), with activity superior to those of bismerthiazol (40.7-43.4%) and thiodiazole copper (30.2-37.1%). Our study provides strong evidence to support the development of phenothiazine derivatives into pesticide candidates.
摘要：
在宿主和植物病原菌之间旷日持久的“军备竞赛”中，宿主生物已经进化出称为宿主防御肽（HDP）的强大武器。然而,天然HDP不适合大规模应用；因此，研究人员选择开发定制的小分子功能模拟物。苯噻嗪衍生物被开发为功能性HDP模拟物，由于其广泛的生物活性和高亲脂性。本研究中设计的吩噻嗪类似物对三种革兰氏阴性菌黄单胞菌具有优异的体外生物活性。黄单胞菌轴突pv柑橘，和丁香假单胞菌，最佳EC50值为0.80、0.31和1.91μg/mL，分别。初步证据表明，化合物C2可能作用于细菌细胞膜，并以沟结合模式与细菌脱氧核糖核酸相互作用。体内试验表明，化合物C2对水稻白叶枯病有很高的效果（51.97-56.69％），活性优于双甲噻唑（40.7-43.4％）和噻二唑铜（30.2-37.1％）。我们的研究提供了有力的证据来支持将吩噻嗪衍生物开发为农药候选物。
