Design, Synthesis, Antibacterial Evaluation, and Induced Apoptotic Behaviors of Epimeric and Chiral 18β-Glycyrrhetinic Acid Ester Derivatives with an Isopropanolamine Bridge against Phytopathogens

• DOI: 10.1021/acs.jafc.9b06147
• Publication Date: 2019-11-08T20:24:26Z
• Authors: Meng Xiang; Xiang Zhou; Ting-Rong Luo; Pei-Yi Wang; Li-Wei Liu; Zhong Li; Zhi-Bing Wu; Song Yang
• Keywords: EC50; Mode of Action; Mechanism of Action

Because only a handful of agrochemicals can manage bacterial infections, the discovery and development innovative, inexpensive, high-efficiency antibacterial agents targeting these infections are challenging. Herein, series novel epimeric chiral 18β-glycyrrhetinic acid (GA) ester derivatives with various tertiary amine pendants were designed, synthesized, screened for pharmacological activity. Results showed that some title compounds conferred significantly enhanced activity toward phytopathogens Xanthomonas oryzae pv (A2, B1-B3, C1, EC50 values within 3.81-4.82 μg/mL) axonopodis citri (B1, = 3.18 μg/mL; B2, 2.76 μg/mL). These activities superior to those GA (EC50 > 400 μg/mL), thiodiazole copper, bismerthiazol. Pharmacophore studies revealed synergistic combination skeleton scaffolds contributed biological actions. In vivo experiments displayed their promising applications in controlling infections. Antibacterial mechanism could trigger apoptosis tested pathogens, evident by bacteria morphological changes observed scanning electron microscopy images. This outcome should motivate inducers against plant diseases mode action compared existing agricultural chemicals.