title: A targeted strategy to analyze untargeted mass spectral data: Rapid chemical profiling of Scutellaria baicalensis using ultra-high performance liquid chromatography coupled with hybrid quadrupole orbitrap mass spectrometry and key ion filtering.
abstract: Structural identification of natural products by tandem mass spectrometry requires laborious spectral analysis. Herein, we report a targeted post-acquisition data processing strategy, key ion filtering (KIF), to analyze untargeted mass spectral data. This strategy includes four steps: (1) untargeted data acquisition by ultra-high performance liquid chromatography coupled with hybrid quadrupole orbitrap mass spectrometry (UHPLC/orbitrap-MS); (2) construction of a key ion database according to diagnostic MS/MS fragmentations and conservative substructures of natural compounds; (3) high-resolution key ion filtering of the acquired data to recognize substructures; and (4) structural identification of target compounds by analyzing their MS/MS spectra. The herbal medicine Huang-Qin (Scutellaria baicalensis Georgi) was used to illustrate this strategy. Its extract was separated within 20 min on a C18 column (1.8 μm, 2.1×150 mm) eluted with acetonitrile, methanol, and water containing 0.1% formic acid. The compounds were detected in the (-)-ESI mode, and their MS/MS spectra were recorded in the untargeted manner. Key ions were then filtered from the LC/MS data to recognize flavones, flavanones, O-/C-glycosides, and phenylethanoid glycosides. Finally, a total of 132 compounds were identified from Huang-Qin, and 59 of them were reported for the first time. This study provides an efficient data processing strategy to rapidly profile the chemical constituents of complicated herbal extracts.
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Qiao
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
authors.forename: Ru
authors.initials: R
authors.lastname: Li
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Song
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
authors.forename: Wen-juan
authors.initials: WJ
authors.lastname: Miao
authors.affiliation: Institute of Systems Biomedicine, School of Basic Medical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
authors.forename: Jia
authors.initials: J
authors.lastname: Liu
authors.affiliation: School of Chinese Medicine, Hong Kong Baptist University, Kowloon Tong, Hong Kong Special Administrative Region, China.
authors.forename: Hu-biao
authors.initials: HB
authors.lastname: Chen
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
authors.forename: De-an
authors.initials: DA
authors.lastname: Guo
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China. Electronic address: yemin@bjmu.edu.cn.
authors.forename: Min
authors.initials: M
authors.lastname: Ye
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods; D004365:Drugs, Chinese Herbal / Q000032:analysis*; D047309:Flavones / Q000032:analysis; D006027:Glycosides / Q000032:analysis; D031364:Scutellaria baicalensis / Q000737:chemistry*; D053719:Tandem Mass Spectrometry / Q000379:methods
chemical_list: D004365:Drugs, Chinese Herbal; D047309:Flavones; D006027:Glycosides
keywords: Flavanones; Flavones; Key ion filtering; Phenylethanoid glycosides; Quadrupole-orbitrap mass spectrometry; Scutellaria baicalensis Georgi