Benzamide, 4-methoxy-N-[2-nitro-4-(1,4,5,6-tetrahydro-4-methyl-6-oxo-3-pyridazinyl)phenyl]-

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:

2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted under GLP conditions according to OECD guideline.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

4-methoxy-N-[4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)-2-nitrophenyl]benzamide

EC Number:

616-053-3

Cas Number:

74149-73-8

Molecular formula:

C19 H18 N4 O5

IUPAC Name:

4-methoxy-N-[4-(4-methyl-6-oxo-1,4,5,6-tetrahydropyridazin-3-yl)-2-nitrophenyl]benzamide

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Nitropyridazinon synonymous to "Stufe A, UDCG 115"
- Physical state: solid
- Analytical purity: 99.0 %
- Purity test date: 02 August 2001
- Lot/batch No.: RH 1/1 - 1/23
- Expiration date of the lot/batch: August 2002
- Storage condition of test material: at room temperature, in the dark

Method

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 98

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 100

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

31.6 , 100.0, 316.2, 1000.0, 2500.0 and 5000.0 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: The solvent was compatible with the survival of the bacteria and the S9 activity.

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

other: 4-nitro-o-phenylene-diamine ; 2-aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation); preincubation

NUMBER OF REPLICATIONS: 3

Evaluation criteria:

A test item is considered as mutagenic if : - a dose-related increase in the number of revertant occurs and/or
- a reproducible biologically relevant positive response for at least one of the test points occurs
in at least one strain with or without metabolic activation.

A biologically relevant increase is described as follows : - if in strain TA 100 the numbers of reversions is at least twice as high
- if in strain TA 98 the number of reversions is at least three times higher
as compared to the spontaneous rate.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

not specified

Untreated negative controls validity:

not specified

Positive controls validity:

valid

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, it can be stated that during the described mutagenicity test and under the experimental conditions reported, the test item did not cause gene mutations by base pair changes or frameshifts in the genome of the tester strains used.

Executive summary:

In order to investigate the potential of Nitropyridazinon synonymous to "Stufe, UDCG 115" for its ability to induce gene mutations the plate incorporation test ( experiment I ) and the pre-incubation test ( experiment II ) were performed with Salmonella typhimurium strains TA 98 and TA 100.

The test item was tested in two independent experiments at several concentrations. Each assay was conducted with and without metabolic activation (S9 mix ). The concentrations, including the controls, were tested in triplicate. The following concentrations of the test item were prepared and used in the experiments : 31.6, 100.0, 316.2, 1000.0, 2500.00 and 5000.0 µg/plate

No toxic effects of the test item were observed in all tester strains in the experiment up to the highest investigated dose neither with nor without metabolic activation.

No substantial increases in the revertant colony numbers of any of the two tester strains were detected at any dose level of the test item neither with or without metabolic activation in both independently performed experiments.

As positive controls reference mutagens were tested in parallel to the test item. They showed a distinct increase of induced revertant colonies.

The reported data of this mutagenicity test show that the test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used.

Therefore, Nitropyridazinon synonymous to "Stufe, UDCG 115" is considered to be non-mutagenic in this bacterial reverse mutation assay.