Abstract
It was investigated that N-oxide derivatives of nicotinic acid and its amide showed no vitamin activity on the growth of Lactobacillus arabinosus 17-5 and Staphylococcus aureus 209-P which require nicotinic acid or its amide as essential vitamins. Nicotinic acid or nicotinamide-N-oxide was not antimetabolite of nicotinic acid or its amide for these microorganisms. These N-oxides did not be reduced to nicotinic acid or its amide by L. arabinosus, Staph. aureus, Escherichia coli or bakers'yeast.
