Inhibition of in vitro biosynthesis of N-acetylneuraminic acid by N-acyl- and N-alkyl-2-amino-2-deoxyhexoses.

The biosynthesis of N-acetylneuraminic acid is markedly inhibited by 2-deoxy-2-propionamido-D-glucose (GlcNProp) and to a much lesser extent by 2-deoxy-2-propionamido-D-mannose (ManNProp), but not by 2-deoxy-2-propionamido-D-galactose and N-methylated derivatives of 2-amino-2-deoxy-D-glucose. 2-Deoxy-2-trimethylamino-D-glucose is a weak inhibitor of 2-acetamido-2-deoxy-D-mannose metabolism. When incubated in a cell-free system from rat liver, GlcNProp gives the 6-phosphate, which is converted into N-propionylneuraminic acid. Evidence is presented which shows that it is the metabolites GlcNProp-6-P and ManNProp-6-P which are the competitive inhibitors, and not GlcNProp itself.