HPLC鈥揘MR Revisited: Using Time-Slice High-Performance Liquid Chromatography鈥揝olid-Phase Extraction鈥揘uclear Magnetic Resonance with Database-Assisted Dereplication

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• 作者：Kenneth T. Johansen ; Sileshi G. Wubshet ; Nils T. Nyberg
• 刊名：Analytical Chemistry
• 出版年：2013
• 出版时间：March 19, 2013
• 年：2013
• 卷：85
• 期：6
• 页码：3183-3189
• 全文大小：362K
• 年卷期：v.85,no.6(March 19, 2013)
• ISSN：1520-6882

文摘

Time-based trapping of chromatographically separated compounds onto solid-phase extraction (SPE) cartridges and subsequent elution to NMR tubes was done to emulate the function of HPLC鈥揘MR for dereplication purposes. Sufficient mass sensitivity was obtained by use of a state-of-the-art HPLC鈥揝PE鈥揘MR system with a cryogenically cooled probe head, designed for 1.7 mm NMR tubes. The resulting ¹H NMR spectra (600 MHz) were evaluated against a database of previously acquired and prepared spectra. The in-house-developed matching algorithm, based on partitioning of the spectra and allowing for changes in the chemical shifts, is described. Two mixtures of natural products were used to test the approach: an extract of Carthamus oxyacantha (wild safflower), containing an array of spiro compounds, and an extract of the endophytic fungus Penicillum namyslowski, containing griseofulvin and analogues. The database matching of the resulting spectra positively identified expected compounds, while the number of false positives was few and easily recognized.