title: Head-to-Head Comparison of Ultra-High-Performance Liquid Chromatography with Diode Array Detection versus Quantitative Nuclear Magnetic Resonance for the Quantitative Analysis of the Silymarin Complex in Silybum marianum Fruit Extracts.
abstract: Quantitative nuclear magnetic resonance (qNMR) spectroscopy is known as an excellent alternative to chromatography-based mixture analysis. NMR spectroscopy is a non-destructive method, needs only limited sample preparation, and can be readily automated. A head-to-head comparison of qNMR to an ultra-high-performance liquid chromatography with diode array detection (uHPLC-DAD)-based quantitative analysis of six flavonolignan congeners (silychristin, silydianin, silybin A, silybin B, isosilybin A, and isosilybin B) of the Silybum marianum silymarin complex is presented. Both assays showed similar performance characteristics (linear range, accuracy, precision, and limits of quantitation) with analysis times below 30 min/sample. The assays were applied to industrial S. marianum extracts (AC samples) and to extracts locally prepared from S. marianum fruits (PL samples). An assay comparison by Bland-Altman plots (relative method bias AC samples, -0.1%; 2SD range, ±5.1%; relative method bias PL samples, -0.3%; 2SD range, ±7.8%) and Passing-Bablok regression analysis (slope and intercept for AC and PL samples not significantly different from 1.00 and 0.00, respectively; Spearman's coefficient of rank correlation, >0.99) did show that qNMR and uHPLC-DAD can be used interchangeably to quantitate flavonolignans in the silymarin complex.
authors.affiliation: Institute of Pharmacy, Department of Pharmacognosy, Centrum of Chemistry and Biomedicine (CCB), University of Innsbruck , Innrain 80/82, 6020 Innsbruck, Austria.
authors.forename: Antigoni
authors.initials: A
authors.lastname: Cheilari
authors.affiliation: Institute of Pharmacy, Department of Pharmacognosy, Centrum of Chemistry and Biomedicine (CCB), University of Innsbruck , Innrain 80/82, 6020 Innsbruck, Austria.
authors.forename: Sonja
authors.initials: S
authors.lastname: Sturm
authors.affiliation: Bionorica Research GmbH , Mitterweg 24, 6020 Innsbruck, Austria.
authors.forename: Daniel
authors.initials: D
authors.lastname: Intelmann
authors.affiliation: Institute of Pharmacy, Department of Pharmacognosy, Centrum of Chemistry and Biomedicine (CCB), University of Innsbruck , Innrain 80/82, 6020 Innsbruck, Austria.
authors.forename: Christoph
authors.initials: C
authors.lastname: Seger
authors.affiliation: Institute of Pharmacy, Department of Pharmacognosy, Centrum of Chemistry and Biomedicine (CCB), University of Innsbruck , Innrain 80/82, 6020 Innsbruck, Austria.
authors.forename: Hermann
authors.initials: H
authors.lastname: Stuppner
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000379:methods*; D020944:Silybum marianum / Q000737:chemistry*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry*; D012838:Silymarin / Q000737:chemistry*
chemical_list: D010936:Plant Extracts; D012838:Silymarin
keywords: Asteraceae; Silybum marianum; flavonolignans; qNMR; quantitation; silymarin; uHPLC−DAD