Chemical and Environmental Engineering Department, University of the Basque Country UPV/EHU, Plaza Europa, 1, 20018 Donostia-San Sebastián, Spain.
Laboratory Materials, Molecules and Application, Preparatory Institute for Scientific and Technical Studies, 2070 Marsa, Tunisia.
Molecules. 2019 Sep 29;24(19):3532. doi: 10.3390/molecules24193532.
In this study, L. essential oil (CEO) and L. essential oil (MEO) was steam-distillated under reduced pressure. We henceforth obtained three fractions for each essential oil: CF, CF, CF, MF, MF, and MF. Then, these fractions were characterized using the gas chromatography-mass spectrometry (GC-MS) technique. The results indicated that some fractions were rich in oxygenated compounds (i.e., CF, CF, MF and MF) with concentrations ranging from 79.21% to 98.56%. Therefore, the influence of the chemical composition of the essential oils on their antifungal activity was studied. For this purpose, three food spoilage fungi were isolated, identified, and inoculated in vitro, in order to measure the antifungal activity of CEO, MEO, and their fractions. The results showed that stronger fungi growth inhibitions (FGI) (above 95%) were found in fractions with higher percentages of oxygenated compounds, especially with (-)-carvone and terpin-4-ol as the major components. Firstly, this work reveals that the free-terpenes hydrocarbons fractions obtained from MEO present higher antifungal activity than the raw essential oil against two families of fungi. Then, it suggests that the isolation of (-)-carvone (97.15 ± 5.97%) from CEO via vacuum distillation can be employed successfully to improve antifungal activity by killing fungi (FGI = 100%). This study highlights that separation under reduced pressure is a simple green method to obtain fractions or to isolate compounds with higher biological activity useful for pharmaceutical products or natural additives in formulations.
在这项研究中，我们在减压下对薰衣草精油（CEO）和薰衣草精油（MEO）进行了水蒸气蒸馏。由此，我们从每种精油中获得了三个馏分：CF、CF 和 CF、MF、MF 和 MF。然后，我们使用气相色谱-质谱联用技术（GC-MS）对这些馏分进行了表征。结果表明，一些馏分富含含氧化合物（即 CF、CF、MF 和 MF），浓度范围为 79.21%至 98.56%。因此，我们研究了精油的化学成分对其抗真菌活性的影响。为此，我们分离、鉴定并体外接种了三种食品腐败真菌，以测量 CEO、MEO 及其馏分的抗真菌活性。结果表明，在含氧化合物百分比较高的馏分中发现了更强的真菌生长抑制（FGI）（超过 95%），特别是以（-）-香芹酮和萜品-4-醇为主要成分的馏分。首先，这项工作揭示了从 MEO 获得的游离萜烯碳氢化合物馏分比原始精油对两种真菌家族具有更高的抗真菌活性。然后，它表明通过减压蒸馏从 CEO 中分离（-）-香芹酮（97.15±5.97%）可以成功用于通过杀死真菌来提高抗真菌活性（FGI=100%）。本研究强调，减压下的分离是一种获得具有更高生物活性的馏分或分离化合物的简单绿色方法，这些馏分或化合物可用于制药产品或制剂中的天然添加剂。
