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1814301 
Technical Report 
Mechanisms and Effects of Plant Activation of Chemicals in the Environment 
Plewa, MJ 
1992 
NTIS/02987064 
GRA and I 
English 
Plants can activate promutagens into stable mutagens and these genotoxic agents may be hazardous to the environment and to the public health. Using m-phenylenediamine (m-PDA) as a archetype compound we developed a working model for plant-activation. (1) The aromatic amine is transported into the plant cell, (2) intracellular peroxidase oxidizes the molecule (3) the metabolite is conjugated to a macromolecule, (4) the amine-conjugate is secreted into the extracellular medium, (5) the conjugate or a deconjugated plant-activated metabolite is absorbed by the Salmonella tester strains, (6) the plant-activated N-hydroxylated product is acetylated and deacetylated by the bacterial acetylCoA: N-hydroxyarylamine 0-acetyltransferase, and (7) the deacetylation results in a highly reactive nitrenium ion that can react with or adduct to DNA. The relative potency of six plant-activated aromatic amines is 2-aminofluorene and gt; benzidine and gt; m-phenylenediamine and gt; 4aminobiphenyl and gt; 2,4-diaminotoluene. 2-Naphthylarmine was not plant-activated. From a structure-function perspective, there appears to be some correlation between free diamino functional groups. These structure-function relationships are expressed by the relative plant-activation potency of m-PDA and 2,4-diaminotoluene, and benzidine and 4aminobiphenyl. The plant-activated products are stable, and are associated with a macromolecule ( and gt;300 kDa). The plant-activated product is further metabolized by cells with high acetyl-CoA: N-hydroxyarylamine 0-acetyltransferase activity.The possibility exists that these plant-activated products maybe formed into non-toxic proximal mutagens in intact plants that can be metabolized back into potent frameshift mutagens in organisms that consume the plants. 
Environments; *Mutagens; Activation; Amines; Cells; Chains; Correlation; Food; Food chains; Functions; Health; Ions; Metabolites; Models; Peroxidases; Phenylenediamines; Potency; Public health; Salmonella; Structures; Plants(Botany); *Metabolic activation