title: Improved extraction and identification by ultra performance liquid chromatography tandem mass spectrometry of phenolic compounds in burdock leaves.
abstract: The simultaneous ultrasonic and microwave assisted extraction (UMAE) technique was first employed to obtain phenolics. The effects of UMAE variables including extraction time, microwave power, and solvent to solid radio on the yield of phenolics were investigated. The optimized conditions were as follows: solvent to solid ratio was 20:1 (ml/g), extraction time was 30s, microwave power was 500W and two times of extraction. Moreover, the phenolic yield of UMAE was higher than that by maceration, indicating a significant reduction of extraction time and an improvement of efficiency. The phenomenon is related to the strong disruption of leaf tissue structure by microwave induced expansion and ultrasonic shaking, which had been observed with the scanning electron microscopy. The phenolic compositions of the extract was then identified by ultra performance liquid chromatography tandem mass spectrometry (UPLC-MS/MS), 10 compounds had been characterized, providing a more complete identification of phenolic compounds in burdock leaves than previously reported. The occurrence of benzoic acid and p-coumaric acid is reported for the first time. This study suggests that UMAE is a good alternative for the extraction of phenolics, with a great potential for industrial application. Also, UMAE provides a new sample preparation technique for characterization of the phenolic compounds from plants.
authors.affiliation: State Key Laboratory of Food Science and Technology, School of Food Science and Technology, Jiangnan University, Wuxi 214122, China.
authors.forename: Zaixiang
authors.initials: Z
authors.lastname: Lou
authors.forename: Hongxin
authors.initials: H
authors.lastname: Wang
authors.forename: Song
authors.initials: S
authors.lastname: Zhu
authors.forename: Ming
authors.initials: M
authors.lastname: Zhang
authors.forename: Yang
authors.initials: Y
authors.lastname: Gao
authors.forename: Chaoyang
authors.initials: C
authors.lastname: Ma
authors.forename: Zhouping
authors.initials: Z
authors.lastname: Wang
mesh_terms: D031170:Arctium / Q000737:chemistry*; D019817:Benzoic Acid / Q000032:analysis / Q000737:chemistry; D005591:Chemical Fractionation / Q000379:methods*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D003373:Coumaric Acids / Q000032:analysis / Q000737:chemistry; D008855:Microscopy, Electron, Scanning; D008872:Microwaves; D010636:Phenols / Q000032:analysis / Q000737:chemistry*; D018515:Plant Leaves / Q000737:chemistry; D011422:Propionates; D053719:Tandem Mass Spectrometry / Q000379:methods*; D014465:Ultrasonics
chemical_list: D003373:Coumaric Acids; D010636:Phenols; D011422:Propionates; D019817:Benzoic Acid; C495469:p-coumaric acid