INITIAL HYDROGENATION AND EXTENSIVE REDUCTION OF SUBSTITUTED 2,4-DINITROPHENOLS

Rhodococcus erythropolis HL 24-1 isolated as a 2,4-dinitrophenol-degra ding organism can utilize 2-chloro-4,6-dinitrophenol as the sole nitro gen, carbon, and energy source under aerobic conditions. This compound is metabolized with liberation of stoichiometric amounts of chloride and nitrite. Under anaerobic conditions, 2,4-dinitrophenol was transie ntly accumulated in the culture fluid, indicating a reductive eliminat ion of chloride. During aerobic bioconversion of 2-amino-4,6-dinitroph enol by R. erythropolis HL 24-1, a reductive elimination of nitrite le ading to 2-amino-6-nitrophenol was observed, Elimination of chloride o r nitrite by the initial formation of a hydride Meisenheimer complex i s discussed. A methyl group in the ortho position of the 2,4-dinitroph enol gives rise to an extensive reduction of the aromatic ring under a erobic conditions. Thus, 2-methyl-4,6-dinitrophenol was shown to be co nverted to the two diastereomers of 4,6-dinitro-2-methylhexanoate as d ead-end metabolites which were identified by spectroscopic methods.