N-Méthylations de l'aniline par Mycobacterium tuberculosis

Abstract

N-methylations of aniline by Mycobacterium tuberculosis 1. 1. Following reports by Sloane et al. 1–5 on the enzymatic hydroxymethylation of the aromatic nucleus by Mycobacterium tuberculosis ATCC 607 or guinea-pig liver microsomes, the possible donors of the “C-1” moiety were investigated. 2. 2. Incubation of aniline with whole cells of M. tuberculosis ATCC 607 in the presence of [ 14C]formate resulted in a very low incorporation of activity, compared with that form [ Me- 14C]methionine, into the aromatic amine fraction isolated. 3. 3. Methionine was therefore considered as the most likely C-1 donor, and the products arising from incubation of aniline with M. tuberculosis in the presence of [ Me- 14C]methionine were examined. No evidence was found for the formation of p-aminobenzyl alcohol; the major radioactive product proved to be N-methylaniline. This compound, together with a small proportion of N-dimethylaniline, was also isolated from similar experiments with cell-free extracts. The formation of N-dimethylaniline was confirmed by incubation of N-methylaniline itself. 4. 4. Subsequently, [ 14C]aniline was incubated with whole cells of M. tuberculosis, according to the method of Sloane and Untch 1. Radioactivity was not completely lost from derivatives prepared from carrier p-aminobenzyl alcohol, but control experiments, without cells and with autoclaved cells, gave identical results. It is concluded that, in this case, enzymic formation of p-aminobenzyl alcohol does not occur.