The present study investigates the chemical composition, antioxidant and antimicrobial bioactivities of essential oil and hexane extract from Citrus limon leaves. The isolation of essential oil was carried out using the Clevenger apparatus. The percentage yield of essential oil and hexane extract from Citrus limon leaves was 0.59 and 0.50 %, respectively. 2,2-Diphenyl-1-picrylhydrazyl (DPPH) scavenging assay highlighted that Citrus limon leaves essential oil (CLEO) and hexane extract exhibited the significant antioxidant potential of 69.64 and 67.55 %, respectively, compared to the BHT standard. Similarly, a significant inhibition in linoleic acid peroxidation was recorded in both CLEO (81.93 %) and hexane extract (50.34 %). Characterization of chemical constituents in CLEO and extract was executed using GC/MS, where Limonene was detected as a major compound in CLEO (60.52 %) and hexane extract (73.62 %). The haemolytic activity ranged from 2.46 to 5.75 % revealing negligible cytotoxicity of CLEO and hexane extract. In silico studies agree with the in vitro antimicrobial studies, where vinimalol, taraxasterol, and moretenol present in CLEO showed strong interactions/inhibition against dihydroorotase and DNA gyrase from E. coli, and the tyrosyl-tRNA synthetase and DNA gyrase from S. aureus. Based on the current data, it may be concluded that both CLEO and hexane extract possessed significant bioactivities, such as antimicrobial and antioxidant activity, with minimal cytotoxicity.

中文翻译：

---

柠檬叶己烷提取物和精油的化学表征、抗氧化、抗菌、细胞毒性和计算机研究

本研究调查了柠檬叶精油和己烷提取物的化学成分、抗氧化和抗菌生物活性。使用 Clevenger 装置进行精油的分离。来自柑橘叶的精油和己烷提取物的百分比产率分别为 0.59 和 0.50%。2,2-二苯基-1-苦基肼 (DPPH) 清除试验强调柑橘柠檬与 BHT 标准相比，叶精油 (CLEO) 和己烷提取物分别表现出 69.64% 和 67.55% 的显着抗氧化潜力。类似地，在 CLEO (81.93 %) 和己烷提取物 (50.34 %) 中记录到对亚油酸过氧化的显着抑制。使用 GC/MS 对 CLEO 和提取物中的化学成分进行表征，其中柠檬烯被检测为 CLEO (60.52%) 和己烷提取物 (73.62%) 中的主要化合物。溶血活性范围为 2.46 至 5.75%，表明 CLEO 和己烷提取物的细胞毒性可忽略不计。计算机研究与体外研究一致抗菌研究，其中 CLEO 中存在的 vinimalol、蒲公英甾醇和 moretenol 显示出对来自大肠杆菌的二氢乳清酶和 DNA 促旋酶以及来自金黄色葡萄球菌的酪氨酰-tRNA 合成酶和 DNA 促旋酶的强烈相互作用/抑制。根据目前的数据，可以得出结论，CLEO 和己烷提取物都具有显着的生物活性，例如抗菌和抗氧化活性，且细胞毒性最小。