Abstract

The use of a mixed-salt substrate (sodium chloride-choline bromide-1-ethyl-1-methyl-pyrrolidinium bromide; molar ratio: 1:1:1) has been proposed for hydrodistillation of essential oils. Tree peony ‘Taiping Hong’ (Paeoniaceae), a cultivated essential oil-bearing plant, was investigated. After using the salt substrate, distillation time decreased from 140 to 40 min, essential oil yield increased from 0.48 % to 0.69 % and the pseudo-first-order rate constant increased from 0.0233 to 0.123 min^-1. Potential mechanisms are (1) osmosis effect and hydrogen-bond interactions, which improve cell wall rupture; (2) the increase in polarity of aqueous distillation media, which prevents emulsification. The essential oil composition was influenced by an increase in oxygenated compound content (32.9 % to 49.0 %) and a decrease in hydrocarbon content (65.3 % to 49.6 %). Furan linalool oxide (cis and trans), linalool and α-terpineol contents increased by 400 %, 250 % and 200 %, respectively. (E,E)-α-farnesene, α-muurolene and octadecane contents decreased by 50 %, 46 % and 38 %, respectively. Possible mechanisms are: (1) improved cell rupture, which significantly facilitates extraction of oxygenated compounds; (2) hydrogen bonding with oxygenated compounds, which enhances their transfer from the inside of cells to bulk solution; (3) salting-out effect, which decreases dissolution of oxygenated compounds and improves their distillation. The essential oil obtained was mainly composed of phloroglucinol trimethyl ether (21.9 %), nerol (10.2%), tricosane (9.1 %), nonadecane (9.0 %), α-muurolene (5.0 %) and furan linalool oxides (3.0 %). Target prediction analysis indicated that it has potential applications in aromatherapy. In conclusion, the use of the mixed-salt substrate combined with hydrodistillation can result in efficient isolation of essential oils.

摘要

已经提出使用混合盐底物（氯化钠-胆碱溴化物-1-乙基-1-甲基-吡咯烷溴化物；摩尔比：1∶1∶1）用于精油的加氢蒸馏。对牡丹栽培的“太平香”（ing药）进行了研究。使用盐底物后，蒸馏时间从140分钟减少至40分钟，精油产率从0.48％增加至0.69％，拟一级反应速率常数从0.0233增加至0.123 min ^-1。可能的机制是（1）渗透作用和氢键相互作用，从而改善细胞壁破裂；（2）增加水蒸馏介质的极性，阻止乳化。精油组成受氧化化合物含量的增加（32.9％至49.0％）和烃含量的减少（65.3％至49.6％）的影响。呋喃芳樟醇氧化物（顺式和反式），芳樟醇和α-松油醇含量分别增加了400％，250％和200％。（E，E）-α-法呢烯，α-茂烯和十八烷的含量分别降低了50％，46％和38％。可能的机制是：（1）细胞破裂的改善，大大促进了含氧化合物的提取；（2）与含氧化合物形成氢键，从而增强它们从细胞内部转移到本体溶液中的能力；（3）盐析作用，可减少含氧化合物的溶解并改善其蒸馏。所获得的精油主要由间苯三酚三甲醚（21.9％），神经醇（10.2％），三二十烷（9.1％），十八烷（9.0％），α-茂烯（5.0％）和呋喃芳樟醇氧化物（3.0％）组成。目标预测分析表明，它在芳香疗法中具有潜在的应用。结论，