Xanthomonas citri subsp. citri (Xcc) causes citrus canker, affecting sweet orange-producing areas around the world. The current chemical treatment available for this disease is based on cupric compounds. For this reason, the objective of this study was to design antibacterial agents. In order to do this, we analyzed the anti-Xcc activity of 36 alkyl dihydroxybenzoates and we found 14 active compounds. Among them, three esters with the lowest minimum inhibitory concentration values were selected; compounds 4 (52 μM), 16 (80 μM) and 28 (88 μM). Our study demonstrated that alkyl dihydroxybenzoates cause a delay in the exponential phase. The permeability capacity of alkyl dihydroxybenzoates in a quarter of MIC was compared to nisin (positive control). Compound 28 was the most effective (93.8), compared to compound 16 (41.3) and compound 4 (13.9) by percentage values. Finally, all three compounds showed inhibition of FtsZ GTPase activity, and promoted changes in protofilaments, leading to depolymerization, which prevents bacterial cell division. In conclusion, heptyl dihydroxybenzoates (compounds 4, 16 and 28) are promising anti-Xcc agents which may serve as an alternative for the control of citrus canker.
柑橘溃疡病是由黄单胞菌亚种柑橘亚种(Xcc)引起的,影响全球甜橙产区。目前针对该疾病的化学治疗方法基于铜化合物。因此,本研究的目标是设计抗菌剂。为了实现这一目标,我们分析了36种烷基二羟基苯甲酸酯的抗Xcc活性,发现了14种活性化合物。其中,选择了三种具有最低最小抑制浓度值的酯类化合物;化合物4(52 μM)、16(80 μM)和28(88 μM)。我们的研究表明,烷基二羟基苯甲酸酯导致指数阶段的延迟。在四分之一MIC的渗透能力方面,烷基二羟基苯甲酸酯与尼星(阳性对照)进行了比较。化合物28的效果最好(93.8),相比化合物16(41.3)和化合物4(13.9)的百分比值。最后,所有三种化合物都显示了对FtsZ GTP酶活性的抑制,并促使原丝变化,导致解聚,从而阻止细菌细胞分裂。总之,庚基二羟基苯甲酸酯(化合物4、16和28)是有前途的抗Xcc剂,可能成为控制柑橘溃疡病的替代品。