Preparation of a Crystalline A1-(2-Nitro-4-trimethylammoniophenyl) Derivative of Bovine Insulin

Abstract
The reaction of bovine insulin with the hydrophilic reagent 1-fluoro-2-nitro-4-trimethylammoniobenzene iodide at pH 8.2 was reexamined. From the mixture of products a crystalline derivative substituted at the GlyAl terminus was isolated. It was characterized by amino acid analysis, end group analysis, cellulose acetate electrophoresis and sulphitolysis. The derivative has a biological activity (mouse convulsion assay) of 60% relative to insulin.