Fast and Accurate Quantitation of Glucans in Complex Mixtures by Optimized Heteronuclear NMR Spectroscopy

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• 作者：Marie B酶jstrup ; Bent O. Petersen ; Sophie R. Beeren ; Ole Hindsgaul ; Sebastian Meier
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：September 17, 2013
• 年：2013
• 卷：85
• 期：18
• 页码：8802-8808
• 全文大小：392K
• 年卷期：v.85,no.18(September 17, 2013)
• ISSN：1520-6882

文摘

Nuclear magnetic resonance (NMR) spectroscopy is a widely used technique for mixture analysis, but it has shortcomings in resolving carbohydrate mixtures due to the narrow chemical shift range of glycans in general and fragments of homopolymers in particular. Here, we suggest a protocol toward fast spectroscopic glycan mixture analysis. We show that a plethora of oligosaccharides comprising only 伪-glucopyranosyl residues can be resolved into distinct quantifiable signals with NMR experiments that are substantially faster than chromatographic runs. Conceptually, the approach fully exploits the narrow line widths of glycans (谓_1/2 < 3 Hz) in the ¹³C spectral dimension while disregarding superfluous spectral information in compound identification and quantitation. The acetal (H₁C₁) groups suffice to spectroscopically resolve 20 different starch fragments in optimized ¹H鈥?sup>13C NMR with a narrow ¹³C spectral width (3 ppm) that allows sampling the indirect ¹³C dimension at high resolution within 15 min. Rapid quantitations by high-resolution NMR data are achieved for glycans at concentrations as low as 10 渭g/mL. For validation, comparisons were made with quantitations obtained by more time-consuming chromatographic methods and yielded coefficients of determination (R²) above 0.99.