Fengli Chen,Kailin Mo,Qiang Zhang,Shimin Fei,Yuangang Zu,Lei Yang
In the present work, a simple and efficient method for steam distillation of paeonol and simultaneous extraction of paeoniflorin from the root bark of Paeonia suffruticosa Andr. (Cortex Moutan) was developed using an ionic liquid as the reaction medium and microwave irradiation. A series of 1-alkyl-3-methylimidazolium ionic liquids with different anions and alkyl chain lengths were evaluated for this method. The optimum conditions were 1.25 M 1-butyl-3-methylimidazolium bromine as the extraction solvent, 20 mL/g liquid–solid ratio, 25 min microwave irradiation time, 700 W microwave irradiation power, and 60–80 mesh particle size. Under these conditions, satisfactory yields of paeoniflorin (80.49 ± 2.58 mg/g) and paeonol (10.52 ± 0.36 mg/g) were obtained. The initial purity of paeonol was 84.95%, and this increased to >99% with simple recrystallization. The ionic liquid extraction solution, either with or without trace paeonol, was passed through HPD100B macroporous resin for enrichment and separation of paeoniflorin and recycling of the ionic liquid used. Recycling and reuse of the ionic liquid were achieved successfully, which could reduce ionic liquid requirements and the process cost. The method was validated using stability, recovery, and repeatability experiments. The proposed method is very promising for separation of natural compounds, especially for small molecules that can be isolated by steam distillation.
Chrysanthemum indicum var. aromaticum is a new variety in the family Compositae and is an aromatic plant resource with high economic value that was first discovered in Shennongjia, Hubei, China. In this work, an improved technique for collecting essential oil from leaves using solvent-less microwave irradiation-induced hydrodistillation and extraction in situ was developed. We extensively investigated a few of the variables that could impact essential oil yield using Pareto analysis and Box‒Behnken design response surface analysis. The highest yield of the essential oil under optimal circumstances was 7.22 ± 0.31 mL/kg DW. The results of GC‒MS analysis showed that C. indicum var. aromaticum leaf essential oil mainly contained terpenes, and the main abundant components were myrtene acetate (21.72%) and cis -sabinol (19.23%). And the first-order kinetic model demonstrated a better fit for the SLMHD. SLMHD (microwave irradiation power 540 W) for 30 min gives a higher yield of essential oil than conventional HD (heating power 450 W) for 180 min, i.e., the emission of CO 2 , the main greenhouse gas, is reduced from 1080 g for 180 min in conventional HD (heating power 450 W) to 216 g in SLMHD. It can be shown that for the same power consumption, SLMHD can indeed obtain more essential oil. The operator's working hours can be significantly reduced because of the quicker response time, which can help cut labor expenses. Taking all these points into account, further development of the approach could yield good economic benefits.
危险品化学品经营许可证（带存储）