Department of Materials and Life Sciences, Faculty of Science and Technology, Sophia University, 7-1 Kioicho, Chiyoda-ku, Tokyo 102-8554, Japan.
Ebisu Kagaku Co. Ltd., 1-10-6 Kajicho, Chiyoda-ku, Tokyo 101-0044, Japan.
Molecules. 2021 Jul 14;26(14):4271. doi: 10.3390/molecules26144271.
The essential oils of hinoki () leaves have anti-bacterial, anti-fungal, and relaxation properties that are likely associated with the major components such as sabinene, α-terpinyl acetate, limonene, elemol, myrcene, and hibaene. The present study describes the use of a cellulose-dissolving ionic liquid (IL) [Cmim][(MeO)(H)PO] and low-toxicity solvents called betaine-based deep eutectic solvents (DESs) for the efficient extraction of hinoki essential oils. As a control method, organic solvent extraction was performed using either hexane, ethyl acetate (EtOAc), or acetone at 30 °C for 1 h. Both the experimental and control methods were conducted under the same conditions, which relied on partial dissolution of the leaves using the IL and DESs before partitioning the hinoki oils into the organic solvent for analysis. Quantitative analysis was performed using gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode. The results indicated that extraction using the [Cmim][(MeO)(H)PO]/acetone bilayer system improved the yields of limonene and hibaene, 1.5- and 1.9-fold, respectively, when compared with the control method. In addition, extraction using betaine/l-lactic acid (molar ratio 1:1) gave the greatest yields for both limonene and hibaene, 1.3-fold and 1.5-fold greater, respectively, than when using an organic solvent. These results demonstrate the effective extraction of essential oils from plant leaves under conditions milder than those needed for the conventional method. The less toxic and environmentally begin DESs for the extraction are also applicable to the food and cosmetic industries.
柏木叶精油具有抗菌、抗真菌和放松的特性，这可能与主要成分如蒎烯、α-松油醇乙酸酯、柠檬烯、柏木醇、月桂烯和扁柏烯有关。本研究描述了使用纤维素溶解的离子液体（IL）[Cmim][（MeO）（H）PO]和低毒性溶剂，如甜菜碱基深共晶溶剂（DESs），从柏木叶中高效提取精油。作为对照方法，在 30°C 下使用正己烷、乙酸乙酯（EtOAc）或丙酮进行有机溶剂提取 1 小时。IL 和 DESs 部分溶解叶片后，实验和对照方法都在相同条件下进行，将柏木叶油分配到有机溶剂中进行分析。使用气相色谱-质谱联用（GC-MS）在选择离子监测（SIM）模式下进行定量分析。结果表明，与对照方法相比，使用[Cmim][（MeO）（H）PO]/丙酮双层体系提取可分别提高柠檬烯和扁柏烯的收率 1.5 倍和 1.9 倍。此外，使用甜菜碱/ L-乳酸（摩尔比 1:1）提取时，柠檬烯和扁柏烯的产率最高，分别比使用有机溶剂时提高 1.3 倍和 1.5 倍。这些结果表明，在比传统方法所需条件更温和的条件下，从植物叶片中有效提取了精油。用于提取的毒性较小且环境友好的 DESs 也适用于食品和化妆品行业。
