2-(1,3-dihydro-3-oxo-2H-indol-2-ylidene)-1,2-dihydro-3H-indol-3-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

Study period:

Jan/Feb 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2-(1,3-dihydro-3-oxo-2H-indol-2-ylidene)-1,2-dihydro-3H-indol-3-one

EC Number:

207-586-9

EC Name:

2-(1,3-dihydro-3-oxo-2H-indol-2-ylidene)-1,2-dihydro-3H-indol-3-one

Cas Number:

482-89-3

Molecular formula:

C16H10N2O2

IUPAC Name:

2-(1,3-dihydro-3-oxo-2H-indol-2-ylidene)-1,2-dihydro-3H-indol-3-one

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Indigo
- Test substance number: 98/388-1
- Substance type: active substance
- Physical state: solid
- Analytical purity: 98%

Method

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:

other: histidine dependent

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Additional strain / cell type characteristics:

other: tryptophan dependent

Metabolic activation:

with and without

Metabolic activation system:

rat liver homogenate

Test concentrations with justification for top dose:

0; 20; 100; 500; 2500; 5000 µg/plate

Vehicle / solvent:

DMSO

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

all strains with S9

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

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

Remarks:

TA1535, TA100 w/o S9

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 4-nitro-o-phenylendiamine

Remarks:

TA98 w/o S9

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

TA1537 w/o S9

Controls 5

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

E. coli WP2 uvrA w/o S9

Details on test system and experimental conditions:

METHOD OF APPLICATION:
1. Plate incorporation
- Incubation: 37°C 48 to 72 hours
2. Preincubation
- Preincubation: 37°C for 20 minutes
- Incubation: 37°C 48 to 72 hours

- Triplicate plating


DETERMINATION OF CYTOTOXICITY
- decrease in number of revertants
- clearing or diminuation of background lawn
- reduction of titer

Evaluation criteria:

Positive: dose-related and reproducible increase in number of revertant colonies
- doubling of spontaneous mutation rate in at least one tester strains either with or without S9

Negative: number of revertants are within historical negative control range in two independent experiments

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:

cytotoxicity

Remarks:

occasionally from 2500 µg/plate onwards

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

occasionally from 2500 µg/plate onwards

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: from 100 µg/plate onwards

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

Indigo did not lead to an increase of the number of revertant colonies with or without S9 in the standard plate and preincubation test

Executive summary:

The substance Indigo was tested for its mutagenic potential based on the ability to induce point mutations in selected loci of several bacterial strains, i.e. Salmonella typhimurium and Escherichia coli, in a reverse mutation assay.

Strains: TA 1535, TA 100, TA 1537, TA 98, E.coli WP2 uvrA

Dose range: 20 to 5000 µg/plate Standard plate and preincubation

Test conditions: Standard plate and preincubatio test with and without metabolic activation

Solubility: Precipitation of TS from about 100 µg/plate onwards

Toxicity: A slight decrease in the number of revertants was occasionally observed depending on the strain and test conditions from about 2500 µg/plate onwards

Mutagenicity: negative in all strains

Conclusion: According to the present study, the test substance Indigo is not mutagenic in the Salmonella typhimurium/ Escherichia coli reverse mutation assay under the experimental conditions chosen.