Heteronuclear single-quantum correlation HSQC

Conformations of mycothiol bimane (MSmB) were studied by H and 13C NMR using rotational nuclear Overhauser effect spectroscopy (ROESY) and heteronuclear single quantum correlation (HSQC) methods with expansions of the anomeric region <2003JOC3380>. NMR characterization of iV-acetyl-L-(Y)-cysteinyl monobimane and peracetylated MSmB was also published (Section 12.10.15.4) <2002JA3492>. 

No general studies have been carried out for these compounds, but there are several reports in which the stereochemistry of the final product has been elucidated by NOESY, correlation spectroscopy (COSY), or heteronuclear single quantum correlation (HSQC) experiments. For example, intensive NOESY experiments were used to establish the exact nature of each of the three cycloadducts 151a-c generated by the cycloaddition of a substituted nitrone to dimethyl (Z)-diethylenedicarboxylate <2000EJ03633>. 

Furthermore, the allohimachalane (see Section 13.11.9.1) <1999T14623> as well as boletunones A and B, highly functionalized sesquiterpenes from the fruit body of the mushroom Boletus calopus <20040L823>, have been characterized by 2D-NMR (heteronuclear single quantum correlation (HSQC), HMBC, and 111-COSY). The structure of a drimen-ll,12-acetonide, isolated from Maya s herb, was deduced by means of 111 and 13C NMR, distortionless enhancement by polarization transfer (DEPT), COSY, NOESY, HSQC, and HMBC analyses <2005MRC339>. 

Introducing a heteronuclear dimension reduces the signal overlap by using the additional chemical shift dispersion of the heteronuclei and facilitates assignment of biomolecules. The Heteronuclear Single Quantum Correlation (HSQC) experiment yields a spectmm that correlates the chemical shift of a spin with that of a covalently bound or spin (55). In a HSQC spectrum, every peak represents the correlation of an amide bond, which shows correlations... 

A simple way of illustrating multidimensional NMR is through reference to hetero-nuclear correlation spectroscopy, in which two or more separate frequency dimensions are correlated with one another. For example, a particularly valuable 2D experiment is heteronuclear single quantum correlation (HSQC) spectroscopy, in which the resultant spectrum has two frequency axes, corresponding to and frequency dimensions, and one intensity axis. Analogous HSQC... 

In the heteronuclear experiment category, the experiments of interest are the heteronuclear multiple quantum correlation (HMQC) experiment, the heteronuclear single quantum correlation (HSQC) experiment, and the heteronuclear multiple bond correlation (HMBC, including the gradient-selected version gHMBC) experiment. Both the HMQC and HSQC produce similar results, but each has its own unique advantages and disadvantages. 

There are two basic types of such techniques, heteronuclear single quantum correlation (HSQC) (see Fig. 9.7) and heteronuclear multiple quantum correlation... 

NMR ( N-HSQC) Observation of change in two-dimensional H- or N-heteronuclear single quantum correlation (HSQC) backbone chemical shift spectra upon ligand binding described as A5( h/ N) = [L]/([L]+Kd) FKBP [9]... 

Figure 2 Heteronuclear single quantum correlation (HSQC) pulse sequences with optional decoupling of the 5-spin (a) standard sequence (b) modified for the /-spin-multiplicity determination.

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