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A General Method for Detecting Nitrosamide Formation in the In Vitro Metabolism of Nitrosamines by Cytochrome P450s
Published on: September 25, 2017
Relationship between mutagenicity and reactivity or biodegradability for nitroaromatic compounds.
Toshinari Maeda1, Ryosuke Nakamura, Kiwao Kadokami
1Department of Biological Functions and Engineering, Graduate School of Life Science and Systems Engineering, Kyushu Institute of Technology, 2-4 Hibikino, Wakamatsu-ku, Kitakyushu 808-0196, Japan.
Environmental Toxicology and Chemistry
|August 24, 2007
Summary
Nitroaromatic compounds like 2,4,6-trinitrotoluene (TNT) show high mutagenicity, linked to their reactivity and biodegradability. This study explores the mechanisms behind their mutagenic activity in bacteria.
Area of Science:
- Environmental Chemistry
- Microbiology
- Toxicology
Background:
- Nitroaromatic compounds, including 2,4,6-trinitrotoluene (TNT), are known for their mutagenicity.
- The precise mechanisms underlying the mutagenic activity of these compounds remain largely unelucidated.
Purpose of the Study:
- To investigate the relationship between mutagenicity, chemical reactivity, and bacterial biodegradation of various nitroaromatic compounds.
- To elucidate the mutagenic mechanisms of nitroaromatics.
Main Methods:
- Assessing mutagenicity using the umu test with luminescent bacteria (Salmonella typhimurium strain TA1535/pTL210).
- Measuring single-electron reduction potentials of nitroaromatic compounds.
- Evaluating biodegradation capabilities of Pseudomonas sp. strain TM15 on nitroaromatics.
- Analyzing the biotransformation products, specifically the reduction of nitro groups to amino groups.
Main Results:
- Aromatic compounds with three nitro groups, excluding 2,4,6-trinitrophenol (TNP), exhibited high mutagenicity.
- Trinitro-aromatics (except TNP) demonstrated higher reducibility compared to other tested compounds.
- Pseudomonas sp. strain TM15 efficiently biodegraded TNT, 1,3,5-trinitrobenzene (TNB), 2,4,6-trinitroaniline (TNA), and tetryl, reducing nitro groups to amino groups.
- 2,4-dinitrotoluene (24DNT), 2,6-dinitrotoluene (26DNT), and TNP were less biodegradable.
Conclusions:
- Mutagenicity of nitroaromatics correlates significantly with their chemical reactivity and biodegradability.
- The findings provide insights into the mechanisms of mutagenic expression of nitroaromatic compounds in biological systems.
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