Bergmann degradation

An extensive review of the chemistry of aliphatic and aromatic azides is given by Boyer and Canter [167] and Gray [168]. Organic azides are subject to various reactions such as the Bergmann degradation and the synthesis of peptides, the well known Curtius rearrangement, the Darapsky synthesis of a-aminoacids [169], for synthesis of triazoles [170], tetrazoles ( Schmidt reaction ) [169] and [171] etc. These reactions lie beyond the scope of the present book. 

Other references related to the Bergmann degradation are cited in the literature. ... 

Bergmann Azlactone Peptide Synthesis Bergmann Degradation Bergmann-Zervas Carbobenzoxy Method Bergs (see Bucherer-Bergs Reaction)... 

The degradation is based upon a reaction first described by Bergmann and Miekeley and further developed by Abderhalden and Brockmann in which phenylisocyanate reacts with the a-amino group of the terminal amino acid of a peptide chain, yielding a phenylcarbamyl derivative. This can be cyclisized... 

Oxidation of SeC 144 derivatives also generates AAla derivatives. Hoffmann degradation of u,p-diaminopropanoic acid, 145 Bergmann s re action11461 of condensation of amides with pyruvic acid, N-hydroxylation followed by dehydration, 147 and N-chlorination/dehydro-chlorination 122-124 have also been used for the synthesis of AAla derivatives. 

A further degradation of methyl a-n-glucoside by the action of barium hypobromite was observed by Bergmann and Wolff. From 12 g. of the glycoside, 4.6 g. of glyoxylic acid benzylphenylhydrazone was obtained. The experimental conditions differed from those used in the preparation of menthol a-D-glucuronide in that about twice as much bromine was used. 

Weygand and Bergmann investigated the oxidation of certain derivatives (known as Amadori products) of l-amino-l-deoxy-n-fructose. The oxidation of 1-deoxy-l-p-toluidino-n-fructose in 2 V ammonium hydroxide at 50° in the presence of a platinum-on-carbon catalyst led to the degradation of the compound to n-arabinonic acid, presumably according to the following sequence. 

J.N. Esposito, G. Economy, W.A. Byers, J.B. Esposito, F.W. Pement, R.J. Jacko, C.A. Bergmann, The addition of zinc to primary reactor coolant for enhanced PWSCC resistance, in Proceedings of the 5th International Symposium on Environmental Degradation of Materials in Nuclear Power Systems— Water Reactors, vol. 1, American Nuclear Society, Pittsburgh, 1992, pp. 495-503. 

Decisive progress in stepwise degradation was brought about by Pehr Edman (Plate 15) in 1950 [11], who found that phenylisothiocyanate, the sulfur analog of Bergmann s reagent, reacts with the N-terminal amino group at pH 9 even at room temperature, and that the thioureido compound hereby formed is readily split by weak acids, e.g. trifluoroacetic acid, to yield a 2-anilinothiazolin-5-one. 

Lee TV, Fan Y, Wang S, Srivastava M, Broemer M, Meier P, Bergmann A. Drosophila lAPl [-mediated ubiquitylation controls activation of the initiator caspase DRONC independent of protein degradation. PLoS Genet. 2011 7(9) el002261. doi 10.1371/ joumal.pgen. 1002261. 

The new N-terminal residue can then be removed as a phenylhydantoin in a second cycle of phenylcarbamoylation and cyclization. This method of stepwise degradation, while discovered several decades earlier (Bergmann et al. 1927), reached practicality only in 1950 when Edman modified the reagent and applied chromatographic procedures for identification of the cyclic products. The improved reagent, phenylisothiocyanate, smoothly converts the peptide to the phenylthiocarbamoyl derivative which is cyclized and cleaved by the action of hydrochloric acid (dissolved in an organic solvent such as dioxane) ... 

Bergmann has employed the azides of acylated amino acids for the stepwise degradation of peptides, as illustrated by the conversion of hippurylalanine to hippuramide and acetaldehyde. Hippurylalanine is converted through its ester and hydrazide to its azide, which is heated with benzyl alcohol to give 1-hippuramido-l-carbobenzoxyaminoethmie. This upon hydrogenation is cleaved to hippuramide mid acetaldehyde. ... 

Bergmann, M. Synthesis and Degradation of Proteins in The Laboratory and in Metabolism . Science 1934, 79, 439-445. 

B.J. Cook, R.P. Clay, C.W. Bergmann, P. Albersheim, A.G. Darvill. Fungal polygalacturonases exhibit different substrate degradation patterns and differ in their susceptibility to polygalacturonase inhibitor proteins. Mol Plant Microbe Int, 1999,12, 703 711... 

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