Abstract The chemical composition of essential oils (EOs) isolated by hydrodistillation (HD) and simultaneous distillation extraction (SDE) from Aloe debrana roots were determined for the first time by GC/MS analysis. The EOs displayed variations in their chemical constituents together with their concentrations. A total of 14 compounds representing 99.1 % of the EO composition isolated by HD were identified with thymohydroquinone dimethyl ether (47.1 %) as a major constituent. Moreover, thirty-three compounds were identified from SDE extracted EO, which represent 88.8 % of the EO constituents with thymohydroquinone dimethyl ether (39.6 %), thymol (7.7 %), humulene epoxide II (5.8 %), dibutyl phthalate (5.0 %) and carvacrol (4.2 %) as major components. Furthermore, the EOs were assessed for their antioxidant activity using DPPH• and H2O2 scavenging assays; and antibacterial activity against S. aureus and E. coli bacteria. Both the EOs demonstrated appreciable activity against these bacterial strains. The EO of A. debrana roots obtained by SDE demonstrated promising antibacterial activity (8.96±1.20 and 13.29±1.06 mm) against Gram-positive S. aureus bacterium at 0.5 and 1.0 mg/mL concentrations, respectively. This EO also showed promising antioxidant activity with IC50 values of 48.65±1.32 ìg/mL in DPPH; and 51.97±2.14 ìg/mL in H2O2. Overall results suggest that EOs of A. debrana may be useful in foods, pharmaceuticals, and other industries. However, SDE was found to be an efficient method of EO extraction to identify several compounds from its roots when compared with HD. Moreover, the method was better in terms of EO extraction yield, antioxidant and antibacterial activities.

中文翻译：

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芦荟根部精油的化学成分和生物活性

摘要 GC/MS 分析首次确定了从芦荟根部通过水蒸馏(HD) 和同时蒸馏萃取(SDE) 分离的精油(EOs) 的化学成分。EO 显示出其化学成分及其浓度的变化。共有 14 种化合物，占由 HD 分离的 EO 组合物的 99.1%，经鉴定，其中以百里氢醌二甲醚 (47.1%) 作为主要成分。此外，从 SDE 提取的 EO 中鉴定出 33 种化合物，占 EO 成分的 88.8%，其中包括百里香氢醌二甲醚 (39.6%)、百里酚 (7.7%)、环氧化葎草烯 II (5.8%)、邻苯二甲酸二丁酯 (5.0%)和香芹酚 (4.2%) 作为主要成分。此外，使用 DPPH• 和 H2O2 清除试验评估了 EO 的抗氧化活性；以及对金黄色葡萄球菌和大肠杆菌的抗菌活性。两种 EO 均显示出对这些细菌菌株的显着活性。通过 SDE 获得的 A. debrana 根的 EO 在浓度分别为 0.5 和 1.0 mg/mL 时显示出对革兰氏阳性金黄色葡萄球菌的有希望的抗菌活性（8.96±1.20 和 13.29±1.06 mm）。该 EO 还显示出有希望的抗氧化活性，在 DPPH 中的 IC50 值为 48.65±1.32 µg/mL；和 51.97±2.14 µg/mL 在 H2O2 中。总体结果表明，A. debrana 的 EO 可用于食品、制药和其他行业。然而，与 HD 相比，SDE 被发现是一种有效的 EO 提取方法，可以从其根部识别出几种化合物。而且，