ADEQUATE, a New Set of Experiments to Determine the Constitution of Small Molecules at Natural Abundance

Reif, Bernd; Köck, Matthias; Kerssebaum, Rainer; Kang, Heonjoong; Fenical, William; Griesinger, Christian

doi:10.1006/jmra.1996.0038

Cited by 168 publications

(150 citation statements)

References 9 publications

(14 reference statements)

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“…In contrast, there have been a number of studies reported using variants of the 1,1-ADEQUATE experiment first reported by Griesinger and coworkers. 10,11 A summary of the variants of the ADEQUATE experiment, including 1,1-, n,1-, 1,n-and m,n-ADEQUATE…”

Section: Abstract: Nmr; Hsqc; Hmbc; Covariance Processing; Long-rangementioning

confidence: 99%

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

Blinov¹,

Larin²,

Williams³

et al. 2006

Magn. Reson. Chem.

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It was recently demonstrated that an IDR- (Inverted Direct Response) HSQC-TOCSY data set could be decomposed into a negatively phased direct response spectrum and a positively phased relayed response spectrum that could then be subjected to unsymmetrical indirect covariance processing for the removal of artifacts due to response overlap in the proton NMR spectrum of the molecule. 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. The method is demonstrated using strychnine as a model compound. The resulting data are largely free of artifacts although artifacts can arise due to proton response overlap, as previously reported.

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Section: Abstract: Nmr; Hsqc; Hmbc; Covariance Processing; Long-rangementioning

confidence: 99%

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

Blinov¹,

Larin²,

Williams³

et al. 2006

Magn. Reson. Chem.

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“…Hence, the structure elucidation of highly hydrogendeficient molecules might be a problem since the carbon network of such molecules cannot be completely followed by information only from 2,3 J CH connectivities. For structure elucidation of such compounds, several approaches have been reported such as D-HMBC 3 which detects small n J CH (n > 3) and 1 H detecting 2D n, n-ADEQUATE 4 which detects 1 H magnetization transferred from n J CC ! n J CH .…”

Section: Introductionmentioning

confidence: 99%

Application of 1D BIRD or X-filtered DEPT long-range CC relay for detection of proton and carbon via four bonds and measuring long-range13C13C coupling constants

Fukushi¹,

Kawabata²

2006

Magn. Reson. Chem.

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We propose the 13C-detecting 1D DEPT long-range C-C relay to detect super long-range H-C connectivity via four bonds (1H-13C-X-X-13C, X represents 12C or heteronuclear). It is derived from the DEPT C-C relay which detects the H-C correlations via two bonds (1H-13C-13C) by setting the delays for J(CC) in the C-C relay sequence to the (LR)J(CC). This sequence gives correlation signals split by small (LR)J(CC), which seriously suffers from residual center signal. The unwanted signal is due to long-range C-H couplings ((LR)J(CH)). The expected relayed magnetization transfer 1J(CH) --> (LR)J(CC) occurs in the 1H-13C-X-(X)-13C isotopomer, whereas the unwanted signal of (LR)J(CH) comes from 1H-12C-(X)-13C isotopomers, whose population is 100 times larger than that of the 1H-13C-X-(X)-13C isotopomer. The large dispersive line of this unwanted center signal would be a fatal problem in the case of detecting small (LR)J(CC) couplings. This central signal could be removed by an insertion of BIRD pulse or X-filter. DEPT spectrum editing solved a signal overlapping problem and enabled accurate determination of particular (LR)J(CC) values. We demonstrate here the examples of structure determination using connectivity between 1H and 13C via four bonds, and the application of long-range C-C coupling constants to discrimination of stereochemical assignments.

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“…[34] We found, however, the experiment to be far less sensitive than the approach described above due to the lower inherent sensitivity of carbon detection and the fact that contrary to working in natural abundance passive couplings become an issue. One could also think of an ADEQUATE [35] experiment in natural abundance but even though this was not attempted it is very likely that the low concentration available is prohibitive in that case.…”

mentioning

confidence: 96%

Assignment of phycocyanobilin in HMPT using triple resonance experiments

Röben

Schmieder

2011

Magnetic Reson in Chemistry

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A complete assignment of all resonances of a small organic molecule is a prerequisite for a structure determination using NMR spectroscopy. This is conventionally obtained using a well-established strategy based on COSY, HMQC and HMBC spectra. In case of phycocyanobilin (PCB) in HMPT this strategy was unsuccessful due to the symmetry of the molecule and extreme signal overlap. Since (13)C and (15)N labeled material was available, an alternative strategy for resonance assignment was used. Triple resonance experiments derived from experiments conventionally performed for proteins are sensitive and easy to analyze. Their application led to a complete and unambiguous assignment using three types of experiments.

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ADEQUATE, a New Set of Experiments to Determine the Constitution of Small Molecules at Natural Abundance

Cited by 168 publications

References 9 publications

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

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

Application of 1D BIRD or X-filtered DEPT long-range CC relay for detection of proton and carbon via four bonds and measuring long-range13C13C coupling constants

Assignment of phycocyanobilin in HMPT using triple resonance experiments

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