4-Piperidinone, 2,6-diethyl-2,3,6-trimethyl-1-(1-phenylethoxy)-

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test performed according to OECD- and EEC- Guidelines under GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Details on test material:

ldentity: TKA 40270 (CGPS 345)

Method

Target gene:

The Salmonella typhimurium histidine (his) and the E. coli tryptophan (trp) reversion system measures his * his and trp * trp reversions,
respectively. The 5. typhimurium and Escherichia coli strains are constructed to differentiate between base pair (TA 1535, TA 100, and WP2 uvrA)
and frameshift (TA 1537, TA 98) mutations.

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Additional strain / cell type characteristics:

not specified

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

Phenobarbital/beta-Naphthoflavone induced rat liver S9

Test concentrations with justification for top dose:

33; 100; 333; 1000; 2500; and 5000 µg/plate

Vehicle / solvent:

DMSO

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

sodium azide

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: 4-nitro-o-phenylene-diamine, 4-NOPD

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Details on test system and experimental conditions:

The test item was assessed for its potential to induce gene mutations in the plate incorporation test (experiment 1) and the
pre-incubation test (experiment II) using Salmonella typhimurium strains TA 1535, TA 1537, TA 98, and TA 100, and the Escherichia cdi strain
WP2 uvrA.
The assay was performed in two independent experiments both with and without liver microsomal activation. Each concentration and the controls were tested in triplicate. The test item was tested at the following concentrations:
33; 100; 333; 1000; 2500; and 5000 µg/plate
The plates incubated with the test item showed normal background growth up to 5000 µg/plate with and without S9 mix in both experiments.

Evaluation criteria:

A test item is considered as a mutagen for biologically relevant increase in the number of revertants exceeding the threshold of twice (strains TA 98, TA 100, and WP2 uvrA) or thwice (strains TA 1535 and TA 1537) the colony count of the corresponding solvent control is observed (3).
A dose dependent increase is considered biologically relevant if the threshold is exceeded at more than one concentration (2).
An increase exceeding the threshold at only one concentration is judged as biologically relevant if reproduced in an independent second
experiment.
A dose dependent increase in the number of revertant colonies below the threshold is regarded as an indication of a mutagenic potential if
reproduced in an independent second experiment. However, whenever the colony counts remain within the historical range of negative and solvent
controls such an increase is not considered biologicaily relevant.

Statistics:

No statistical evaluation of the data was required.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

The plates incubated with the test item showed normal back­ground growth up to 5000 µg/plate with and without metabolic activation in both
independent experiments.
Moderate toxic effects, evident as a reduction in the number of revertants, occurred only in strain TA 98 at 5000 µg/plate in the presence of
metabolic activation.
No substantial and reproducible increase in revertant colony numbers of any of the five tester strains was observed following treatment with
CGPS 345 at any dose level, neithe in the presence nor absence of metabolic activation (S9 mix). There was also no tendency of higher mutation
rates with increasing concentrations in the range below the generally acknowledged border of biological relevance.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

In conclusion, the test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used under the experimental conditions reported.