The essential oils (EOs) of Origanum floribundum Munby, an aromatic and medicinal plant endemic in Algeria, were extracted by different hydrodistillation times (30 min, 1, 2 and 3 h) and analyzed by GC and GC-MS. The chromatographic analysis showed that thymol (32.7-45.0%), p-cymene (16.8-23.1%) and γ-terpinene (21.6-28.7%) were the most prominent components of the oils. The antioxidant ability was measured using the reductive potential, thiobarbituric acid reactive substances (TBARS) assay and the inhibition of free radicals DPPH● and ABTS●+. Antibacterial activity was assessed by the disc diffusion method against three bacteria (Escherichia coli, Staphylococcus aureus and Bacillus subtilis) and one fungus (Candida albicans). Minimal inhibitory concentrations (MICs) were determined using a microdilution method. Thymol is one of the compounds of EOs, which are widely reported as very biologically active. Although the oil isolated for 30 min was the less-thymol rich, it was the most active with all the antioxidant tests. In the most cases, the antimicrobial activity showed the best results with oils isolated for 30 min and 3 h (MIC = 0.25-1.75 μL/mL). These results suggest that it might be possible to isolate the EO from this plant for a minimum distillation time to obtain oil that can give maximum biological activities.

中文翻译：

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蒸馏时间对牛至精油成分及其抗氧化和抗菌活性的影响

Origanum floribundum Munby 是阿尔及利亚特有的芳香药用植物，通过不同的水蒸馏时间（30 分钟、1、2 和 3 小时）提取精油 (EO)，并通过 GC 和 GC-MS 进行分析。色谱分析表明百里酚 (32.7-45.0%)、对伞花烃 (16.8-23.1%) 和 γ-萜品烯 (21.6-28.7%) 是这些油中最突出的成分。使用还原电位、硫代巴比妥酸反应物质（TBARS）测定和自由基DPPH●和ABTS●+的抑制来测量抗氧化能力。通过圆盘扩散法对三种细菌（大肠杆菌、金黄色葡萄球菌和枯草芽孢杆菌）和一种真菌（白色念珠菌）的抗菌活性进行评估。使用微量稀释方法确定最小抑制浓度 (MIC)。百里酚是 EO 的一种化合物，被广泛报道为具有非常高的生物活性。尽管分离 30 分钟的油中百里酚含量较低，但在所有抗氧化测试中它的活性最高。在大多数情况下，将油分离 30 分钟和 3 小时（MIC = 0.25-1.75 μL/mL）的抗微生物活性显示出最佳结果。这些结果表明，有可能在最短的蒸馏时间内从该植物中分离 EO，以获得可提供最大生物活性的油。