AUTHOR=Li Pei , Chen Cong , Zhu Rongxi , Yang Guixia , Xu Min , Wan Guanghua , Wang Xiang 

TITLE=Novel botanical active component derivatives containing carboxamide and 1,3,4-Thiadiazole thioether moieties: Design, synthesis, and inhibitory activity

JOURNAL=Frontiers in Chemistry

VOLUME=10

YEAR=2022

URL=https://www.frontiersin.org/journals/chemistry/articles/10.3389/fchem.2022.1036909

DOI=10.3389/fchem.2022.1036909

ISSN=2296-2646

ABSTRACT=<p>In this study, using the botanical active components of carvacrol, thymol, guaiacol, and sesamol as the lead structures, 19 novel botanical active component derivatives containing carboxamide and 1,3,4-thiadiazole thioether moieties (<bold>5a</bold>−<bold>5s</bold>) were synthesized and structurally characterized by <sup>1</sup>H NMR, <sup>13</sup>C NMR, and HRMS. The antibacterial bioassay results <italic>in vitro</italic> showed that compound 2-(2-methoxyphenoxy)-N-(5-(methylthio)-1,3,4-thiadiazol-2-yl)acetamide (<bold>5k</bold>) revealed excellent inhibitory activities against Xanthomonas axonopodis pv. citri (Xac) and Xanthomonas oryzae pv. oryzicolaby (Xoc), with the median effective concentration (EC<sub>50</sub>) values of 22 and 15 μg/ml, respectively, which were even better than those of thiodiazole copper and bismerthiazol. Meanwhile, all the target compounds revealed lower <italic>in vitro</italic> inhibitory effects on Mucor bainieri (M. bainieri), Mucor fragilis (M. fragilis), and Trichoderma atroviride (T. atroviride), than carbendazim.</p>