Evidence for an arene oxide-NIH shift pathway in the transformation of naphthalene to 1-naphthol by Bacillus cereus

Abstract

Bacillus cereus ATCC 14579 transformed naphthalene predominately to 1-naphthol. Experiments with [¹⁴C]naphthalene showed that over a 24 h period, B. cereus oxidized 5.2% of the added naphthalene. 1-Naphthol accounted for approximately 80% of the total metabolites. B. cereus incubated with naphthalene under the presence of ¹⁸O₂ led to the isolation of 1-naphthol that contained 94% ¹⁸O. The metabolism of [1-²H]-and [2-²H]-naphthalene by B. cereus yielded 1-naphthol which retained 95% and 94% deuterium, respectively, as determined by mass spectral analysis. NMR spectroscopic analysis of the deuterated 1-naphthol formed from [1-²H]-naphthalene indicated an NIH shift mechanism in which 19% of the deuterium migrated from the C-1 to the C-2 position. The ¹⁸O₂ and NIH shift experiments implicate naphthalene-1,2-oxide as an intermediate in the formation of 1-naphthol from naphthalene by B. cereus.