3-[(4-chloro-2-nitrophenyl)azo]-2-methylpyrazolo[5,1-b]quinazolin-9(1H)-one

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions (missing strain TA 102 to detect crosslinking agents, second independent trial is missing)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1981

Report date:

1981

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

no bacterial strains (E.coli WP2 or S.thyphimurium TA102) to detect cross-linking mutagens.

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

3-[(4-chloro-2-nitrophenyl)azo]-2-methylpyrazolo[5,1-b]quinazolin-9(1H)-one

EC Number:

277-823-9

EC Name:

3-[(4-chloro-2-nitrophenyl)azo]-2-methylpyrazolo[5,1-b]quinazolin-9(1H)-one

Cas Number:

74336-59-7

Molecular formula:

C17H11ClN6O3

IUPAC Name:

3-[(4-chloro-2-nitrophenyl)diazenyl]-2-methylpyrazolo[5,1-b]quinazolin-9(1H)-one

Details on test material:

- Name of test material (as cited in study report): Pigmentorange Kan 78/1775
- Test substance number: 80/404
- Physical state: solid, orange
- Analytical purity: > 98 %
- Lot/batch No.: Batch 8
- Storage condition of test material: +4°C

Method

Target gene:

his operon

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA 1535, TA 1537, TA 1538, TA 98, TA 100

Metabolic activation:

with and without

Metabolic activation system:

cofactor supplemented post-mitochondrial fraction (S9 mix), prepared from the livers of rats treated with Aroclor 1254

Test concentrations with justification for top dose:

4, 20, 100, 500 and 2500 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: with S-9 mix: 500 µg cyclophosphamide (dissolved in aqua dest.) for the strains TA 100 and TA 1535; 10 µg 2-aminoanthracene (dissolved in DMSO) for the strains TA 100, TA 98, TA 1538, TA 1537 and TA 1535.

Remarks:

with S-9 mix

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: without S-9 mix: 5 µg N-methyl-N-nitro-N-nitroso-guanidine (MNNG) (dissolved in DMSO) for TA 100, TA 98, TA 1535; 10 µg 4-nitro-o-phenylenediamine (dissolved in DMSO) for TA 1538; 100 µg 9-aminoacridine chloride monohydrate (dissolved in DMSO) for TA 1537

Remarks:

without S-9 mix

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation);

DURATION
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 4

DETERMINATION OF CYTOTOXICITY
- Method: relative total growth

OTHER:
- Solubility: Incomplete solubility of the test substance in DMSO from about 500 µg/plate onward.

Evaluation criteria:

In general, a substance to be characterized as positive in the Ames test has to fulfill the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results.

Results and discussion

Test results

Species / strain:

S. typhimurium, other: Salmonella typhimurium TA 1535, TA 1537, TA 1538, TA 98, TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: Incomplete solubility of the test substance in DMSO from about 500 µg/plate onward.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Standard plate test (4 - 2500 µg/plate)

Strain	Metabolic activation system	Mean revertants in Controls	Maximum revertant factor	dose dependency	Assessment
TA 98	no	22	1.1	no	negative
	yes	41	1.2	no	negative
TA 100	no	155	1.0	no	negative
	yes	135	1.0	no	negative
TA 1535	no	12	1.1	no	negative
	yes	17	1.4	no	negative
TA 1537	no	7	1.1	no	negative
	yes	7	1.4	no	negative
TA 1538	no	17	1.1	no	negative
	yes	24	1.3	no	negative

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative