Nitrosation and nitrosylation of haemoproteins and related compounds. Part 4. Pentaco-ordinate nitrosylprotohaem as the pigment of cooked cured meat. Direct evidence from e.s.r. spectroscopy

Abstract

The pigment of cured meat, nitrosylprotohaem, was obtained by synthesis and by extractionn from nitrosylhaemoglobin and from cured meats. The e.s.r. spectrum of nitrosylprotohaem was observed in two types of solvent; those which do, and those which do not, provide an effective nitrogenous sixth ligand : spectra characteristic of hexa- and penta-co-ordination are observed, respectively. Similar e.s.r. spectra were detected in the direct examination of a variety of cured meats, and are interpreted in terms of pigment structure.