| Popis: |
The reactions between nitrobiuret and the amino acids glycine and L-phenylalanine at pH 10, have been examined by mass spectrometry. Initially, the expected amino acyl biurets are formed, however these may re- act with a further nitrobiuret molecule yielding the amino acyl biuret N-carboxyanhydride. The anhydride then N-acylates a second amino acid molecule to afford a dipeptide derivative. The process is repeated and peptides up to glycine5, glycine5-biuret, phenyla- lanine4 and phenylalanine5-biuret have been detected. In addition the unstable N-carboxyanhydrides may also be converted to their respective ureides with loss of CO2. These reactions are of particular interest to the area of pre-biotic chemistry. |
