Synthesis of E -stilbene azomethines as potent antimicrobial and antioxidant agents
作者:Ahsan IQBAL、Zulfiqar Ali KHAN、Sohail Anjum SHAHZAD、Muhammad USMAN、Shakeel Ahmad KHAN、Abdul H. FAUQ、Ayesha BARI、Muhammad Aamir SAJID
DOI:10.3906/kim-1801-104
日期:——
A series of new extensively conjugated $E$-stilbene azomethines (5a-5h) were synthesized and screened for their antioxidant and antimicrobial activity. The compounds were tested against bacterial (Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Bacillus subtilis) and fungal strains (Aspergillus niger, A. flavus, and Trichoderma harzianum) using the agar well diffusion method. Among the tested compounds, $N$'-(4-nitrobenzylidene)-2-(($E)$-styryl)benzohydrazide (5g) was found to possess potent antimicrobial activity higher than some drugs with significant activity reported in the literature, e.g., cefradine and terbinafine hydrochloride. Additionally, compounds 5a-5h were also evaluated for antioxidant potential using DPPH free radical scavenging and ferric thiocyanate (FTC) assays. Among these, $N$'-(4-hydroxybenzylidene)-2-(($E)$-styryl)benzohydrazide (5e) exhibited significant antioxidant potential by both assays. Compound 5e demonstrated higher DPPH free radical scavenging activity (IC$_50} = 22 \pm 0.19 \mu$ g/m) than the standard, butylated hydroxytoluene (BHT; IC$_50} =28 \pm 0.10 \mu$ g/mL). A similar trend was observed for compound 5e in FTC assay, which exhibited 86 $\pm$ 0.19% inhibition, whereas the BHT control showed 81 $\pm$ 0.21% inhibition of linoleic acid peroxidase. The structure elucidation of the synthesized compounds was carried out by UV-Vis, FT-IR, $^1}$H NMR, $^13}$C NMR, and elemental analysis and mass spectrometry. These results suggest possible use of these compounds for the rational design of new antimicrobial and antioxidant agents.
研究人员合成了一系列新的广泛共轭的 E$-stilbene 氮杂环丁烷(5a-5h),并对其抗氧化和抗菌活性进行了筛选。采用琼脂井扩散法测试了这些化合物对细菌(大肠杆菌、金黄色葡萄球菌、肺炎克雷伯氏菌和枯草芽孢杆菌)和真菌菌株(黑曲霉、黄曲霉和哈茨毛霉)的抗菌活性。在测试的化合物中,发现 $N$'-(4-硝基亚苄基)-2-(($E)$-苯乙烯基)苯甲酰肼(5g)具有强效抗菌活性,高于文献中报道的一些具有显著活性的药物,如头孢拉定和盐酸特比萘芬。此外,还使用 DPPH 自由基清除法和硫氰酸铁(FTC)法评估了化合物 5a-5h 的抗氧化潜力。其中,$N$'-(4-羟基苯亚甲基)-2-(($E)$苯乙烯基)苯甲酰肼(5e)在这两种检测方法中都表现出了显著的抗氧化潜力。化合物 5e 的 DPPH 自由基清除活性(IC$_50} = 22 \pm 0.19 \mu$ g/m)高于标准物质丁基羟基甲苯(BHT;IC$_50} = 28 \pm 0.10 \mu$ g/mL)。化合物 5e 在四氯化碳检测中也表现出类似的趋势,它对亚油酸过氧化物酶的抑制率为 86 \pm$ 0.19%,而 BHT 对照组的抑制率为 81 \pm$ 0.21%。通过紫外可见光、傅立叶变换红外光谱、^1}$H NMR、^13}$C NMR、元素分析和质谱分析,对合成的化合物进行了结构鉴定。这些结果表明,这些化合物可用于合理设计新型抗菌剂和抗氧化剂。