Bioactive components from medicinal plants are said to be responsible for the antioxidant and antimicrobial effects of plant extracts. It was the main purpose of this paper to evaluate the total phenolic content (TPC), total flavonoid content (TFC), and antioxidant and antimicrobial activities of leaf extracts of Euclea schimperi. Strong evidence was found when a positive correlation was found between TPC or TFC and antioxidant power. To put it differently, TPC of the E. schimperi leaf extracts varied between 748.78 ± 3.11 mgGAE/100 g of dry extract (methanol) and 40.45 ± 0.66 mgGAE/100 g of dry extract (chloroform) while TFC varied from 3.306 ± 0.142 mgQE/100 g of dry extract (methanol) to 0.334 ± 0.002 mgQE/100 g dry extract (chloroform). Similarly, all extracts exhibited significant amount of antioxidant and antimicrobial activities. Ferric reducing power was ranged between 312.145 ± 1.542 mgAAE/100 g extract (methanol) and 48.177 ± 0.286 mgAAE/100 g (chloroform). DPPH radical scavenging activity (%) lied between 83.4% (methanol) and 58.5% (chloroform). The voltammetric analysis of the crude extract gave three different sharp peaks at the oxidation potential side. Finally, the reducing agent capacity of the extracts was further confirmed by synthesizing silver nanoparticles from AgNO3 solution and the plant crude extracts. Crude extracts of E. schimperi leaves showed various degree of antimicrobial activity towards different standard strains with mean zone of inhibition ranging from 0 to 20.67 mm. Both solvent leaf extracts of E. schimperi exhibited MIC ranging from 62.5 to 125 mg/mL towards most bacterial species. Euclea schimperi leaf extracts were found to contain high amount of total phenolic and small amount of flavonoid compounds which play a major role in controlling oxidation. In general, therefore, the results prove the effectiveness of the plant for its excellent antioxidant and antimicrobial activities. Accordingly, the positive values of the plant in traditional medicines have been confirmed.

中文翻译：

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杜仲叶提取物的抗氧化和抗菌活性研究

药用植物的生物活性成分据称负责植物提取物的抗氧化和抗菌作用。本文的主要目的是评估小叶桉的叶提取物的总酚含量（TPC），总黄酮含量（TFC）以及抗氧化和抗菌活性。当TPC或TFC与抗氧化能力之间呈正相关时，发现了有力的证据。换句话来说，香叶大肠杆菌提取物的TPC在748.78±3.11 mgGAE / 100 g干提取物（甲醇）和40.45±0.66 mgGAE / 100 g干提取物（氯仿）之间变化，而TFC在3.306±0.142 mgQE之间变化/ 100 g干提取物（甲醇）至0.334±0.002 mgQE / 100 g干提取物（氯仿）。同样，所有提取物均表现出大量的抗氧化剂和抗菌活性。铁还原能力介于312.145±1.542 mgAAE / 100 g提取物（甲醇）和48.177±0.286 mgAAE / 100 g（氯仿）之间。DPPH自由基清除活性（％）介于83.4％（甲醇）和58.5％（氯仿）之间。粗提物的伏安分析在氧化电位侧给出了三个不同的尖峰。最后，通过从AgNO3溶液和植物粗提物中合成银纳米颗粒，进一步确定了提物的还原剂容量。E. schimperi叶片的粗提物对不同标准菌株表现出不同程度的抗菌活性，平均抑制区范围为0至20.67 mm。两种大肠埃希菌的溶剂叶提取物对大多数细菌的MIC均在62.5至125 mg / mL之间。发现小叶Euclea schimperi叶提取物含有大量的总酚类和少量的类黄酮化合物，它们在控制氧化中起主要作用。因此，总的来说，结果证明该植物具有出色的抗氧化和抗菌活性。因此，已经确认了该植物在传统药物中的正值。