2D-NMR data

Borgias B A, Gochin M, KenA/ood D J and James T L 1990 Relaxation matrix analysis of 2D NMR data Prog. NMR Spectrosc. 22 83-100... 

It can be concluded that MD is a very powerful tool to refine structures of proteins and polypeptides in solution, based on 2D NMR data. This combination of techniques emerges as an important means to determine the 3 D structure of macromolecules up to a molecular weight of 20,000 in solution or in micelles or membrane fragments. 

Using 1,1- and INADEQUATE 2D NMR Data in Structure Elucidation Protocols... 

TABLE 4 The impact of various of 2D NMR data on the number of structures generated and generation times for retrorsine (22) using the Structure Elucidator CASE program46... 

The epimerization likely occurs through an enamine retro-aAAol reaction after formation of the initial cyclized product (92) (Scheme 6.16) [47]. First, a ring opening of 92 forms the enamine-aldehyde (93a). Rotation about the C-C a-bond in 93a provides intermediate 93b in which enamine addition to the aldehyde to reclose the ring would give 93c. After protonation of the enolate, 91 would result with an overall epimerization of the spirocyclic carbon. In addition to the 2D NMR data, we also planned a complement of experiments to support the epimerization assignment. 

This ladybird is protected by hyperaspine (23) (Fig. 4), the structure of which was deduced from its ID and 2D NMR data. These spectra disclosed the presence in the molecule of a 3-oxaquinolizidine skeleton substituted by a 2-pyrro-lecarboxylate moiety, by a secondary methyl group, and by a n-pentyl side chain. The ds-fused ring conformation and the relative configuration of 23 were based on IR and 2D NMR methods [37]. 

Processing of ID NMR Data HELP Routine Processing of 2D NMR Data HELP Routine... 

The comprehensive ID and 2D NMR data obtained from various modern NMR... 

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