Abstract 5-Substituted benzylidene 3-acylthiotetronic acids are antifungal. A series of 3-acylthiotetronic acid derivatives with varying substitutions at the 5-position were designed, synthesized, and characterized, based on the binding pose of 3-acyl thiolactone with the protein C171Q KasA. Fungicidal activities of these compounds were screened against Valsa Mali, Curvularia lunata, Fusarium graminearum, and Fusarium oxysporum f. sp. lycopersici. Most target compounds exhibited excellent fungicidal activities against target fungi at the concentration of 50 μg·mL−1. Compounds 11c and 11i displayed the highest activity with a broad spectrum. The median effective concentration (EC50) values of 11c and 11i were 1.9–10.7 and 3.1–7.8 μg·mL−1, respectively, against the tested fungi, while the EC50 values of the fungicides azoxystrobin, carbendazim, and fluopyram were respectively 0.30, 4.22, and > 50 μg·mL−1 against V. Mali; 6.7, 41.7, and 0.18 μg·mL−1 against C. lunata; 22.4, 0.42, and 0.43 μg·mL−1 against F. graminearum; and 4.3, 0.12, and > 50 μg·mL−1 against F. oxysporum f. sp. lycopersici. The structures and activities of the target compounds against C. lunata were analyzed to obtain a statistically significant comparative molecular field analysis (CoMFA) model with high prediction abilities (q2 = 0.9816, r2 = 0.8060), and its reliability was verified. The different substituents on the benzylidene at the 5-position had significant effects on the activity, while the introduction of a halogen atom at the benzene ring of benzylidene was able to improve the activity against the tested fungi.

中文翻译：

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硫乳霉素衍生物的合成、表征和抗真菌评价

摘要 5-取代的亚苄基 3-酰基硫代丁二烯酸具有抗真菌作用。基于 3-酰基硫内酯与蛋白质 C171Q KasA 的结合位姿，设计、合成和表征了一系列在 5 位具有不同取代的 3-酰基硫代四酮酸衍生物。筛选了这些化合物对 Valsa Mali、Curvularia lunata、Fusarium graminearum 和 Fusarium oxysporum f 的杀真菌活性。sp. 番茄酱。大多数目标化合物在50 μg·mL-1的浓度下对目标真菌表现出优异的杀菌活性。化合物 11c 和 11i 在广谱范围内表现出最高的活性。11c 和 11i 对受试真菌的中位有效浓度 (EC50) 值分别为 1.9-10.7 和 3.1-7.8 μg·mL-1，而杀菌剂嘧菌酯、多菌灵、和氟吡菌酰胺分别为 0.30、4.22 和 > 50 μg·mL-1 对 V. Mali；6.7、41.7 和 0.18 μg·mL-1 对抗 C. lunata；22.4、0.42 和 0.43 μg·mL-1 对抗禾谷镰刀菌；和 4.3、0.12 和 > 50 μg·mL-1 对抗尖孢镰刀菌 f. sp. 番茄酱。对目标化合物的结构和活性进行了分析，得到了具有高预测能力（q2=0.9816，r2=0.8060）的统计显着的比较分子场分析（CoMFA）模型，并验证了其可靠性。苯亚甲基上5位不同取代基对活性有显着影响，而在苯亚甲基苯环上引入卤原子能提高对受试真菌的活性。18 μg·mL-1 对抗 C. lunata；22.4、0.42 和 0.43 μg·mL-1 对抗禾谷镰刀菌；和 4.3、0.12 和 > 50 μg·mL-1 对抗 F. oxysporum f. sp. 番茄酱。对目标化合物的结构和活性进行了分析，得到了具有高预测能力（q2=0.9816，r2=0.8060）的统计显着的比较分子场分析（CoMFA）模型，并验证了其可靠性。苯亚甲基上5位不同取代基对活性有显着影响，而在苯亚甲基苯环上引入卤原子能提高对受试真菌的活性。18 μg·mL-1 对抗 C. lunata；22.4、0.42 和 0.43 μg·mL-1 对抗禾谷镰刀菌；和 4.3、0.12 和 > 50 μg·mL-1 对抗尖孢镰刀菌 f. sp. 番茄酱。对目标化合物的结构和活性进行了分析，得到了具有高预测能力（q2=0.9816，r2=0.8060）的统计显着的比较分子场分析（CoMFA）模型，并验证了其可靠性。苯亚甲基上5位不同取代基对活性有显着影响，而在苯亚甲基苯环上引入卤原子能提高对受试真菌的活性。对目标化合物的结构和活性进行了分析，得到了具有高预测能力（q2=0.9816，r2=0.8060）的统计显着的比较分子场分析（CoMFA）模型，并验证了其可靠性。苯亚甲基上5位不同取代基对活性有显着影响，而在苯亚甲基苯环上引入卤原子能提高对受试真菌的活性。对目标化合物的结构和活性进行了分析，得到了具有高预测能力（q2=0.9816，r2=0.8060）的统计显着的比较分子场分析（CoMFA）模型，并验证了其可靠性。苯亚甲基上5位不同取代基对活性有显着影响，而在苯亚甲基苯环上引入卤原子能提高对受试真菌的活性。