Backbone amide protection

Quibell, M., Owen, D., Packman, L. C., and Johnson, T. (1994) Suppression of piperidine-mediated side product formation for Asp(OBut)-containing peptides by the use of N-(2-hydroxy-4-methoxybenzyl)(Hmb) backbone amide protection. J. Chem. Soc. Chem. Commun. 20, 2343—2344. 

M. Quibell, L.C. Packman, T. Johnson, Solid-phase assembly of backbone amide-protected peptide segments an efficient and reliable strategy for the synthesis of small proteins, J. Am. Chem. Soc., Perkin Trans. 1 1996, 1, 1227. 

All of the other protected peptide segments required for the synthesis were also prepared on trityl-based solid supports of the type 25 (except that the C-terminal amino acid of the segment in question was incorporated rather than j3-Ala). In each case, following chain elongation, the peptide-resins were acetylated so that backbone amide protection was in the form of AcHmb groups. Cleavage of the protected peptides occurred in high yield on treatment of the peptide-resins with 0.75% TEA in DCM. 

Peptoid methodology, a method of Fmoc-based SPPS for the synthesis of difficult sequences free of aspartimide and related products. This approach utilizes the well-established concept of backbone amide protection with benzyl-type... 

Figure 9.3 Backbone amide protection maps of hoio- (a) and apo- (b) myoglobin obtained with top-down HX-MS (fragment ions produced with ECD). Adapted with permission from 122] 2009 American Chemical Society...

The N-(2-hydroxy-4-methoxybenzyl) (Hmb) backbone amide-protecting group... 

FiguraT. HPLC profiles of total crude products from the assembly of decapeptide IV. (a) Standard assembly without backbone amide protection, (b) Introduction of (Hmb)Ala, no aggregation during remaining assembly. Conditions Aquapore RP-300 Cs (250 x 4.6 mm) 10-50% B in A linear gradient over 25 min, 1.5 ml/min, 215 nm UV detection, where solvent A = 0.1% aq. TFA and solvent B = 90% acetonitrile/10% solvent A. (Reproduced from ref. 60 with permission from The Royal Society of Chemistry.)...

Quibell M, Packman LC, Johnson T (1995) Synthesis of the 3-repeat region of human tau-2 by the solid-phase assembly of backbone amide-protected segments. J Am Chem Soc 117 11656-11668... 

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