HMBC VGSE

FIGURE 5.33 The HMQC spectrum for VGSE. Assignments are given as an aid. 

as there are obvious correlations to the valine C-2 proton (V2) and the valine C-3 proton (V3). In addition, there are correlations to the glycine methylene group (G2) and to the glycine amide proton (G NH). 

These two correlations (and generally, ones like them) are extremely important in the process of sequencing the amino acids. Until now, all of the correlations have been intra-residue, but the HMBC allows generally for inter-residue correlations. Develop a line of reasoning to sequence the remaining two amino acids (serine and glutamic acid). Note that the carbonyl carbons for glycine and serine overlap in the carbon spectrum. 

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