Direct 13C NMR Detection in HPLC Hyphenation Mode: Analysis of Ganoderma lucidum Terpenoids

详细信息    查看全文

• 作者：Sileshi G. Wubshet ; Kenneth T. Johansen ; Nils T. Nyberg ; Jerzy W. Jaroszewski
• 刊名：Journal of Natural Products
• 出版年：2012
• 出版时间：May 25, 2012
• 年：2012
• 卷：75
• 期：5
• 页码：876-882
• 全文大小：388K
• 年卷期：v.75,no.5(May 25, 2012)
• ISSN：1520-6025

文摘

Solid phase extraction (SPE) was introduced as a crucial step in the HPLC-SPE-NMR technique to enable online analyte enrichment from which proton-detected NMR experiments on submicrogram amounts from complex mixtures were possible. However, the significance of direct-detected ¹³C NMR experiments is indubitable in simplifying structural elucidations. In the current study, we demonstrated direct ¹³C NMR detection of triterpenoids from a Ganoderma lucidum extract in hyphenation mode. The combined advantage of a cryogenically cooled probe, miniaturization, and multiple trapping enabled the first reported application of HPLC-SPE-NMR analysis using direct-detected ¹³C NMR spectra. HPLC column loading, accumulative SPE trappings, and the effect of different elution solvents were evaluated and optimized. A column loading of approximately 600 渭g of a prefractionated triterpenoid mixture, six trappings, and an acquisition time of 13 h resulted in spectra with adequate signal-to-noise ratios to detect all C-13 signals.