Miner dismantling
The Bergmann degradation is a name reaction in organic chemistry, which for the first time in 1934 by the Jewish chemist Max Bergmann was presented (from 1886 to 1944) and named after him. This reaction has general application in protein and peptide sequencing . In addition, it was used to break down the penicillin core.
Overview reaction
In this reaction, a peptide 1 with azide at the C -terminal end is split into a shortened peptide 2 with an amide at the C -terminal end and an aldehyde 3 . In general, this method thus removes the C -termial amino acid residue as the next lowest aldehyde in the homologous series and thus leaves the remainder of the peptide in the form of an amide.
Reaction mechanism
It is assumed that a thermal rearrangement ( Curtius degradation ) of the terminal azide 1 initially takes place in this reaction . The elemental nitrogen split off in the process escapes as a gas . The hydroxyl group of the added benzyl alcohol then forms a bond with the isocyanate group 2 formed. Toluene is split off from the newly formed compound 3 by hydrogenolysis . Then a rearrangement of the carbamic acid group 4 takes place, in which both carbon dioxide and the shortened peptide 5 , at the C-terminal end of which the remaining amide is located, are split off. In an acidic environment , the remaining imine 6 initially forms a primary amine 7 with the addition of water . The ammonium is split off from this and an aldehyde 8 remains.
Individual evidence
- ↑ a b c Bergmann degradation . In: Comprehensive Organic Name Reactions and Reagents . Wiley, 2010, ISBN 978-0-470-63885-9 , pp. 349-352 , doi : 10.1002 / 9780470638859.conrr076 .