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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1992
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Remarks:
Strain TA100 used only.

Data source

Reference
Reference Type:
publication
Title:
Mutagenicity of Nitroxyl compounds: structure activity|relationships
Author:
Gallez, B., De Meester, C., Debuys, R.. Dejehet, F., Dumont, P.
Year:
1992
Bibliographic source:
Toxicol. Lett. 63, 35-45

Materials and methods

Test guideline
Qualifier:
equivalent or similar to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
Deviations:
yes
Remarks:
Strain TA100 used only.
Principles of method if other than guideline:
The test was carried out according to Maron and Ames (1983, Mutat. Res. 113, 173-215) using Salmonella typhimurium strain TA 100 with and without S9 mix.
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
2,2,6,6-tetramethylpiperidinooxy
EC Number:
219-888-8
EC Name:
2,2,6,6-tetramethylpiperidinooxy
Cas Number:
2564-83-2
Molecular formula:
C9H18NO
IUPAC Name:
2,2,6,6-tetramethylpiperidinooxy
Test material form:
solid
Details on test material:
obtained from Aldrich Company

Method

Species / strain
Species / strain / cell type:
S. typhimurium TA 100
Additional strain / cell type characteristics:
not specified
Metabolic activation:
with and without
Metabolic activation system:
S9 mix
Test concentrations with justification for top dose:
0.06, 0.6, 1.5, 3.0, 6.0, 15.0, and 30.0 μmol
Vehicle / solvent:
DMSO
Controls
True negative controls:
yes
Positive controls:
yes
Positive control substance:
sodium azide
other: 2-aminoanthracene when S9 mix was used
Details on test system and experimental conditions:
Aliquots of TEMPO (0.1 ml of a dilution in DMSO corresponding to 0.06, 0.6, 1.5, 3.0, 6.0, 15.0, and 30.0 μmol) were added into the top agar (plate incorporation assay), or into the top agar supplemented with S9 mix (500 μl corresponding to 50 μI of S9). The colonies grown on the minimal glucose-agar plates at 37°C were counted after 48h. Each assay was performed in duplicate with three plates for each concentration.
Statistics:
t-test

Results and discussion

Test results
Key result
Species / strain:
S. typhimurium TA 100
Metabolic activation:
without
Genotoxicity:
positive
Remarks:
180 to 210 revertants/plate, statistically significant
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
at 30 µmol/plate
Vehicle controls validity:
not specified
Untreated negative controls validity:
valid
Remarks:
140 (mean) revertants/plate
Positive controls validity:
valid
Remarks:
380 (mean) revertants/plate
Additional information on results:
A cytotoxic effect was observed at 30 μmol/plate. A weak but statistically significant (p<0.01) increase of the number of revertants (180 to 210 revertants/plate) was observed between 6 and 15 μmol/plate (assay repeated three times). Thus, a cytotoxic effect could mask partly the mutagenic activity at higher concentrations.

Applicant's summary and conclusion

Conclusions:
The test compound is positive for gene mutations in bacterial tester strain Salmonella typhimurium TA100.