5-[(2,3-dihydro-6-methyl-2-oxo-1H-benzimidazol-5-yl)azo]barbituric acid

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1980

Report date:

1980

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Principles of method if other than guideline:

The tests were carried out in accordance with the method described by AMES et al.:
-AMES, B.N., F.D. LEE, and W.E. DURSTON (1973), An Improved Bacterial Test System for the Detection and Classification of Mutagens and Carcinogens. Proc. Natl. Acad. Sci. USA 70, 782-786.
-AMES, B.N., W.E. DURSTON, E. YAMASAKI, and F.D. LEE (1973), Carcinogens are Mutagens: A Simple Test System Combining Liver Homogenates for Activation and Bacteria for Detection. Proc. Natl. Acad. Sci. USA 70, 2281-2285.
-AMES, B.N., J. McCANN, and E. YAMASAKI (1975), Methods for Detecting Carcinogens and Mutagens with the Salmonella/ Mammalian-Microsome Mutagenicity Test. Mutation Res. 31, 347-364.

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

5-[(2,3-dihydro-6-methyl-2-oxo-1H-benzimidazol-5-yl)azo]barbituric acid

EC Number:

276-344-2

EC Name:

5-[(2,3-dihydro-6-methyl-2-oxo-1H-benzimidazol-5-yl)azo]barbituric acid

Cas Number:

72102-84-2

Molecular formula:

C12H10N6O4

IUPAC Name:

5-[(1E)-2-(6-methyl-2-oxo-2,3-dihydro-1H-1,3-benzodiazol-5-yl)diazen-1-yl]-1,3-diazinane-2,4,6-trione

Test material form:

solid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- lot/batch No.of test material: EN 25005

Method

Target gene:

histidine gene

Species / strain

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254 induced rat liver S9 mix

Test concentrations with justification for top dose:

Experiments were performed on strains TA 98, TA 100, TA 1535, TA 1537 with concentrations of 25, 75, 225, 675 and 2025 µg/0.1 mL
Additional experiments were performed on Strains TA 98 and TA 1538 with concentrations of 1000, 2000, 4000 and 8000 µg/0.1 mL

Vehicle / solvent:

DMSO

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

cyclophosphamide

Remarks:

Strain TA 1535 with metabolic activation

Controls 2

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

2-nitrofluorene

Remarks:

Strain TA 1538 without metabolic activation

Controls 3

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 9(5)aminoacridine hydrochloride monohydrate

Remarks:

Strain TA 1537 without metabolic activation

Controls 4

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: N-methyl-N'- nitro-N-nitrosoguanidine

Remarks:

Strain TA 1535 without metabolic activation

Controls 5

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

Strain TA 100 without metabolic activation

Controls 6

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: daunorubicin- HCl

Remarks:

Strain TA 98 without metabolic activation

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Incubation duration: about 48 hours
- Incubation temperature: 37°C in darkness

1 mL activation mixture contained: 0.3 mL S9 fraction of liver from rats induced with Aroclor 1254 and 0.7 mL of a solution of co-factors.

Evaluation criteria:

A test substance is generally considered to be nonmutagenic if the colony count in relation to the negative control is not doubled at any concentration.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

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

Metabolic activation:

with

Genotoxicity:

positive

Remarks:

Strain TA 98 (2025 µg/0.1 mL) and TA 1538 (8000 µg/0.1 mL)

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

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

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid