Aminodinitrotoluene 4-amino-2,6-dinitrotoluene

Trinitrotoluene is reduced by the aquatic plant Myriophyllum spicatum to aminodinitrotoluenes (Pavlostathis et al. 1998), and in axenic root cultures of Catharanthus roseus the initial metabolites 2-amino-4,6-dinitrotoluene and 4-amino-2,6-dintrotoluene are conjugated probably with C6-units (Bhadra et al. 1999). There are then several important unresolved issues including the phytotoxicity of these metabolitres before phytoremediation can be exploited. 

Note +, produced not produced ND, no data T, toluene NT, nitrotoluene DNT, dinitrotoluene 2A4NT, 2-amino-4-nitrotoluene ADNT, aminodinitrotoluene. 

Both aminodinitrotoluene isomers are products of the first reduction step in cell suspensions of Desulfovibrio (39). However, most publications on TNT reduction indicate that the nitro group para to the methyl group is reduced first, with 4-amino-2,6-dinitrotolu-ene being the main reduction product (23, 32, 37). Only Naumova et al. (33) observed the reduction of TNT mainly to 2-amino-4,6-dinitrotoluene by 2i Pseudomonas strain. Figure 6 illustrates the pathway of complete TNT reduction and summarizes the characteristics of the sequential reduction steps. 

Since ligninolytic activity was required for extensive mineralization of TNT, the accumulation of substrates of the ligninolytic enzymes originating from aminodinitrotoluenes was expected under non-ligninolytic conditions. Nitrogen-sufficient (12 mM ammonium tartrate) agitated cultures were incubated with 4-amino-2,6-dini-trotoluene for 48 h, and a transformation product was extracted, purified by preparative thin layer chromatography and analyzed by mass spectroscopy. By comparison with chemically synthesized reference compounds it was identified as 4-formamido-2,6-dinitrotoluene. 

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