Quantitative two-dimensional HSQC experiment for high magnetic field NMR spectrometers

Koskela, Harri; Heikkilä, Outi; Kilpeläinen, Ilkka; Heikkinen, Sami

doi:10.1016/j.jmr.2009.09.021

Cited by 49 publications

(44 citation statements)

References 61 publications

(79 reference statements)

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“…For example the finite RF power available on the carbon channel in proton-carbon correlation experiments leads to non-uniform excitation of carbon resonances across the spectrum, although this is somewhat ameliorated by using adiabatic-pulse experiments [26]. If the experiment permits longer acquisition times, a range of quantitative 2D HSQC experiments [27,28] have been developed to mitigate this artifact.…”

Section: Discussionmentioning

confidence: 99%

Plant cell wall profiling by fast maximum likelihood reconstruction (FMLR) and region-of-interest (ROI) segmentation of solution-state 2D 1H–13C NMR spectra

Chylla

Acker

Kim

et al. 2013

Biotechnol Biofuels

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BackgroundInterest in the detailed lignin and polysaccharide composition of plant cell walls has surged within the past decade partly as a result of biotechnology research aimed at converting biomass to biofuels. High-resolution, solution-state 2D 1H–13C HSQC NMR spectroscopy has proven to be an effective tool for rapid and reproducible fingerprinting of the numerous polysaccharides and lignin components in unfractionated plant cell wall materials, and is therefore a powerful tool for cell wall profiling based on our ability to simultaneously identify and comparatively quantify numerous components within spectra generated in a relatively short time. However, assigning peaks in new spectra, integrating them to provide relative component distributions, and producing color-assigned spectra, are all current bottlenecks to the routine use of such NMR profiling methods.ResultsWe have assembled a high-throughput software platform for plant cell wall profiling that uses spectral deconvolution by Fast Maximum Likelihood Reconstruction (FMLR) to construct a mathematical model of the signals present in a set of related NMR spectra. Combined with a simple region of interest (ROI) table that maps spectral regions to NMR chemical shift assignments of chemical entities, the reconstructions can provide rapid and reproducible fingerprinting of numerous polysaccharide and lignin components in unfractionated cell wall material, including derivation of lignin monomer unit (S:G:H) ratios or the so-called SGH profile. Evidence is presented that ROI-based amplitudes derived from FMLR provide a robust feature set for subsequent multivariate analysis. The utility of this approach is demonstrated on a large transgenic study of Arabidopsis requiring concerted analysis of 91 ROIs (including both assigned and unassigned regions) in the lignin and polysaccharide regions of almost 100 related 2D 1H–13C HSQC spectra.ConclusionsWe show that when a suitable number of replicates are obtained per sample group, the correlated patterns of enriched and depleted cell wall components can be reliably and objectively detected even prior to multivariate analysis. The analysis methodology has been implemented in a publicly-available, cross-platform (Windows/Mac/Linux), web-enabled software application that enables researchers to view and publish detailed annotated spectra in addition to summary reports in simple spreadsheet data formats. The analysis methodology is not limited to studies of plant cell walls but is amenable to any NMR study where ROI segmentation techniques generate meaningful results.Please see Research Article: http://www.biotechnologyforbiofuels.com/content/6/1/46/.

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Section: Discussionmentioning

confidence: 99%

Plant cell wall profiling by fast maximum likelihood reconstruction (FMLR) and region-of-interest (ROI) segmentation of solution-state 2D 1H–13C NMR spectra

Chylla

Acker

Kim

et al. 2013

Biotechnol Biofuels

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“…A high analytical performance was demonstrated for the homo-nuclear INADEQUATE pulse sequence (Fig. Adapted from Koskela et al (2010). was essentially attributed to a much cleaner diagonal in the case of INADEQUATE. The high degree of precision reached by this technique Figure 3.10 NMR spectra from a human blood plasma sample: (A) 1 H NMR spectrum, (B) expansions of Q-OCCAHSQC spectrum.…”

Section: Applications For Metabolic Studiesmentioning

confidence: 99%

Fast and Ultrafast Quantitative 2D NMR

Giraudeau

Akoka

2013

Advances in Botanical Research

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“…The fundamental problem with the use of such two-dimensional approaches is that the biggest advantage of qNMR, its uniformity of response across analytes, is lost, and care must be taken to minimize these deviations and account for them in the uncertainty budget. Such bias can arise from factors including T 1 and T 2 relaxation during the pulse sequence, nonuniform magnetization transfer due to variation in 1 J CH (Koskela et al, 2005(Koskela et al, , 2010, and nonuniform excitation in the second dimension (Webb, 2008). Approaches such as time zero HSQC (HSQC 0 ) have been applied to reduce such biases (Hu et al, 2011).…”

Section: Quantification With a Two-dimensional Approachmentioning

confidence: 99%

Bias and Uncertainty in Non-Ideal qNMR Analysis

Gresley

Fardus²,

Warren³

2014

Critical Reviews in Analytical Chemistry

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We report a comprehensive analysis of the acquisition-related sources of uncertainty for internally and externally standardized qNMR experiments. The impacts of major instrument- and sample-related sources of biases and uncertainties are quantified where possible, and the validity of correction and calibration techniques are also discussed. The application of uncertainty budgets for qNMR is well established for simple, internally standardized systems, but the model is incomplete and does not allow for the additional biases and sources of uncertainty that arise from spectrum complexity and external standardization. This report considers the additional contributions to the uncertainty budget that need to be considered to ensure SI traceability of measurement across a wider range of analytes and NMR methodologies.

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Quantitative two-dimensional HSQC experiment for high magnetic field NMR spectrometers

Cited by 49 publications

References 61 publications

Plant cell wall profiling by fast maximum likelihood reconstruction (FMLR) and region-of-interest (ROI) segmentation of solution-state 2D 1H–13C NMR spectra

Plant cell wall profiling by fast maximum likelihood reconstruction (FMLR) and region-of-interest (ROI) segmentation of solution-state 2D 1H–13C NMR spectra

Fast and Ultrafast Quantitative 2D NMR

Bias and Uncertainty in Non-Ideal qNMR Analysis

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