title: Orthogonal analytical methods for botanical standardization: determination of green tea catechins by qNMR and LC-MS/MS.
abstract: The development of analytical methods for parallel characterization of multiple phytoconstituents is essential to advance the quality control of herbal products. While chemical standardization is commonly carried out by targeted analysis using gas or liquid chromatography-based methods, more universal approaches based on quantitative (1)H NMR (qHNMR) measurements are being used increasingly in the multi-targeted assessment of these complex mixtures. The present study describes the development of a 1D qHNMR-based method for simultaneous identification and quantification of green tea constituents. This approach utilizes computer-assisted (1)H iterative Full Spin Analysis (HiFSA) and enables rapid profiling of seven catechins in commercial green tea extracts. The qHNMR results were cross-validated against quantitative profiles obtained with an orthogonal LC-MS/MS method. The relative strengths and weaknesses of both approaches are discussed, with special emphasis on the role of identical reference standards in qualitative and quantitative analyses.
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, United States of America.
authors.forename: José G
authors.initials: JG
authors.lastname: Napolitano
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, United States of America.
authors.forename: Tanja
authors.initials: T
authors.lastname: Gödecke
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, United States of America.
authors.forename: David C
authors.initials: DC
authors.lastname: Lankin
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, United States of America.
authors.forename: Birgit U
authors.initials: BU
authors.lastname: Jaki
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, United States of America.
authors.forename: James B
authors.initials: JB
authors.lastname: McAlpine
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, United States of America.
authors.forename: Shao-Nong
authors.initials: SN
authors.lastname: Chen
authors.affiliation: Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago, Chicago, IL 60612, United States of America. Electronic address: gfp@uic.edu.
authors.forename: Guido F
authors.initials: GF
authors.lastname: Pauli
mesh_terms: D002392:Catechin / Q000737:chemistry*; D002853:Chromatography, Liquid / Q000379:methods*; D019906:Nuclear Magnetic Resonance, Biomolecular / Q000379:methods*; D011786:Quality Control; D012015:Reference Standards; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013662:Tea / Q000737:chemistry
chemical_list: D013662:Tea; D002392:Catechin
keywords: (1)H NMR fingerprints; Green tea catechins; HiFSA; LC–MS/MS; qHNMR; qNMR