Different substituted phenylhydrazone groups were linked to the quinoxaline scaffold to provide 26 compounds (6a–6z). Their structures were confirmed by ¹H and ¹³C NMR, MS, elemental analysis, and X-ray single-crystal diffraction. The antifungal activities of these compounds against Rhizoctonia solani were evaluated in vitro. Compound 6p is the most promising one among all the tested compounds with an EC₅₀ of 0.16 μg·mL^–1, more potent than the coassayed positive control fungicide carbendazim (EC₅₀: 1.42 μg·mL^–1). In addition, these compounds were subjected to antioxidant assay by employing diphenylpicrylhydrazyl (DPPH) and mice microsome lipid peroxidation (LPO) methods. Most of these compounds are potent antioxidants. The strongest compounds are 6e (EC₅₀: 7.60 μg·mL^–1, DPPH) and 6a (EC₅₀: 0.96 μg·mL^–1, LPO), comparative to or more potent than the positive control Trolox [EC₅₀: 5.90 μg·mL^–1 (DPPH) and 18.23 μg·mL^–1 (LPO)]. The structure and activity relationships were also discussed.

中文翻译：

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（E）-6-（（2-苯基肼基甲基）甲基）喹喔啉衍生物的设计，合成，抗真菌和抗氧化活性

将不同的取代苯基hydr基团连接到喹喔啉骨架上，以提供26种化合物（6a - 6z）。它们的结构通过¹ H和¹³ C NMR，MS，元素分析和X射线单晶衍射确定。在体外评价了这些化合物对茄枯萎病的抑菌活性。化合物6p是所有测试化合物中最有前途的化合物，EC ₅₀为0.16μg ·mL ^–1，比共同测定的阳性对照杀菌剂多菌灵（EC ₅₀：1.42μg ·mL ^–1）。此外，这些化合物通过使用二苯基吡啶甲基肼基（DPPH）和小鼠微粒体脂质过氧化（LPO）方法进行了抗氧化剂测定。这些化合物大多数是有效的抗氧化剂。最强的化合物是6e（EC ₅₀：7.60μg·mL ^–1，DPPH）和6a（EC ₅₀：0.96μg·mL ^–1，LPO），与阳性对照Trolox相比或更有效[EC ₅₀：5.90μg ·mL ^–1（DPPH）和18.23μg·mL ^–1（LPO）]。还讨论了结构和活动关系。