Analysis and elimination of artifacts in indirect covariance NMR spectra via unsymmetrical processing

@article{Blinov2005AnalysisAE,
  title={Analysis and elimination of artifacts in indirect covariance NMR spectra via unsymmetrical processing},
  author={Kirill A. Blinov and Nicolay I. Larin and M. Kvasha and Arvin Moser and Antony J. Williams and Gary E. Martin},
  journal={Magnetic Resonance in Chemistry},
  year={2005},
  volume={43}
}
Indirect covariance NMR offers an alternative method of extracting spin–spin connectivity information via the conversion of an indirect‐detection heteronuclear shift‐correlation data matrix to a homonuclear data matrix. Using an IDR (inverted direct response)‐HSQC‐TOCSY spectrum as a starting point for the indirect covariance processing, a spectrum that can be described as a carbon–carbon COSY experiment is obtained. These data are analogous to the autocorrelated 13C–13C double quantum… 

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Results obtained from covariance‐processed GCOSY spectra are fully analyzed and compared to normally processed COSY and 80 ms TOCSY spectra and the origin of artifact responses is analyzed.

(13)C-(15)N correlation via unsymmetrical indirect covariance NMR: application to vinblastine.

The elimination of artifact responses with aromatic solvent-induced shifts (ASIS) is shown in addition to a method of forecasting potential artifact responses through the indirect covariance processing of the GHSQC spectrum used in the unsymmetrical indirect covariances processing.

Long‐range carbon–carbon connectivity via unsymmetrical indirect covariance processing of HSQC and HMBC NMR data

Using experimentally discrete HSQC and HMBC data sets, it is shown that unsymmetrical indirect covariance processing of the pair of NMR spectra affords a presentation containing long‐range carbon–carbon connectivity information.

Z-matrix formalism for quantitative noise assessment of covariance nuclear magnetic resonance spectra.

This work presents analytical relationships as well as simulated and experimental results characterizing the propagation of noise by unsymmetric covariance NMR processing, which concatenates two NMR spectra along a common dimension, resulting in a new spectrum showing spin correlations as cross peaks that are not directly measured in either of the two input spectra.

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