title: An approach of ionic liquids/lithium salts based microwave irradiation pretreatment followed by ultrasound-microwave synergistic extraction for two coumarins preparation from Cortex fraxini.
abstract: Ionic liquids/lithium salts solvent system was successfully introduced into the separation technique for the preparation of two coumarins (aesculin and aesculetin) from Cortex fraxini. Ionic liquids/lithium salts based microwave irradiation pretreatment followed by ultrasound-microwave synergy extraction (ILSMP-UMSE) procedure was developed and optimized for the sufficient extraction of these two analytes. Several variables which can potentially influence the extraction yields, including pretreatment time and temperature, [C4mim]Br concentration, LiAc content, ultrasound-microwave synergy extraction (UMSE) time, liquid-solid ratio, and UMSE power were optimized by Plackett-Burman design. Among seven variables, UMSE time, liquid-solid ratio, and UMSE power were the statistically significant variables and these three factors were further optimized by Box-Behnken design to predict optimal extraction conditions and find out operability ranges with maximum extraction yields. Under optimum operating conditions, ILSMP-UMSE showed higher extraction yields of two target compounds than those obtained by reference extraction solvents. Method validation studies also evidenced that ILSMP-UMSE is credible for the preparation of two coumarins from Cortex fraxini. This study is indicative of the proposed procedure that has huge application prospects for the preparation of natural products from plant materials.
authors.affiliation: Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, 150040 Harbin, China.
authors.forename: Zaizhi
authors.initials: Z
authors.lastname: Liu
authors.affiliation: School of Forestry, Northeast Forestry University, 150040 Harbin, China. Electronic address: ghuiyan@nefu.edu.cn.
authors.forename: Huiyan
authors.initials: H
authors.lastname: Gu
authors.affiliation: Key Laboratory of Forest Plant Ecology, Ministry of Education, Northeast Forestry University, 150040 Harbin, China. Electronic address: ylliunefu@163.com.
authors.forename: Lei
authors.initials: L
authors.lastname: Yang
mesh_terms: D031319:Aesculus; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D004929:Esculin / Q000302:isolation & purification*; D052578:Ionic Liquids; D018020:Lithium Compounds; D008872:Microwaves; D012997:Solvents; D000069453:Ultrasonic Waves; D014468:Umbelliferones / Q000302:isolation & purification*
chemical_list: D004365:Drugs, Chinese Herbal; D052578:Ionic Liquids; D018020:Lithium Compounds; D012997:Solvents; D014468:Umbelliferones; D004929:Esculin; C517354:horse chestnut seed; C007628:esculetin
keywords: Cortex fraxini; Coumarins; Ionic liquids; Lithium salts; Preparation