Design, synthesis and anti-bacterial evaluation of novel 1,3,4-thiadiazole derivatives bearing a semicarbazone moiety

• Published in: Phosphorus, sulfur, and silicon and the related elements Vol. 193; no. 7; pp. 443 - 450
• Main Authors: Wan, Jinlin, Gan, Yiyuan, Hu, Weinan, Meng, Jiao, Tian, Kun, Li, Xiaoqin, Wu, Shouqun, Xu, Yang, Ouyang, Guiping, Wang, Zhenchao
• Format: Journal Article
• Language: English
• Published: ABINGDON Taylor & Francis 03.07.2018; Taylor & Francis Ltd
• Subjects: 1,3,4-thiadiazole; antibacterial activities; Bacteria; Chemistry; Chemistry, Inorganic & Nuclear; Chemistry, Organic; Derivatives; Hydrazines; indole; Methylene; NMR; Nuclear magnetic resonance; Physical Sciences; Science & Technology; semicarbazone; Thiadiazoles; WILT; indole; BIOLOGICAL EVALUATION; SULFONE DERIVATIVES; RESISTANCE; 1,3,4-thiadiazole; semicarbazone; antibacterial activities; BACTERIAL LEAF-BLIGHT
• ISSN: 1042-6507; 1563-5325
• DOI: 10.1080/10426507.2018.1436546

Novel 1,3,4-thiadiazole derivatives bearing a semicarbazone moiety were prepared and evaluated for their anti-bacterial activities against Xanthomonas oryzae pv. oryzae (Xoo) and Xanthomonas axonopodis pv. citri (Xac) by performing a turbidimetre test. The products were structurally characterised by IR, 1 H NMR, 13 C NMR, 19 F NMR and HRMS. Anti-bacterial testing showed that most of the evaluated compounds (6a-6s) exhibited excellent activity (≥74.19%) against Xoo at a concentration of 200 µg/mL, with 50% effective concentration (EC 50 ) values ranging from 12.21 to 67.20 µg/mL, which were superior to the commercial antibacterial agent bismerthiazol (92.23 µg/mL). Among them, compound 2-((2-chloro-1H-indol-3-yl)methylene)-N-(5-((2-chlorobenzyl)thio)-1,3,4-thiadiazol-2-yl)hydrazine-1-carboxamide (6b) demonstrated good inhibitory activity against Xac (89.46% at 200 µg/mL) and Xoo (EC 50 = 18.28 µg/mL); compound 2-((2-chloro-1H-indol-3-yl)methylene)-N-(5-((4-methoxybenzyl)thio)-1,3,4-thiadiazol-2-yl)hydrazine-1-carboxamide (6g) displayed excellent activity against Xoo with EC 50 value of 12.21 µg/mL.