2,9-dichloro-5,12-dihydroquino[2,3-b]acridine-7,14-dione

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:

From 15 DEC 2004 to 10 JAN 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD 471)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

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)

Remarks:

in accordance to German Chemikaliengesetz and Directive 88/320/EEC

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

5,12-dihydroquino[2,3-b]acridine-7,14-dione

EC Number:

213-879-2

EC Name:

5,12-dihydroquino[2,3-b]acridine-7,14-dione

Cas Number:

1047-16-1

Molecular formula:

C20H12N2O2

IUPAC Name:

5,12-dihydroquino[2,3-b]acridine-7,14-dione

Test material form:

solid: nanoform

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:

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:

induced rat liver S9 (phenobarbital/ß-naphtoflavone used for induction)

Test concentrations with justification for top dose:

Experiment I (plate incorporation): 3, 10, 33, 100, 333, 1000, 2500, and 5000 µg/plate
Experiment II (preincubation test): 33, 100, 333, 1000, 2500, and 5000 µg/plate

Vehicle / solvent:

- Vehicle used: DMSO

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: sodium azide (TA 1535, TA 100), 4-nitro-o-phenylene-diamine (TA1537, TA 98), methyl methan sulfonate (WP2uvrA)

Remarks:

without metabolic activation

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene (all strains)

Remarks:

with metabolic activation

Details on test system and experimental conditions:

METHOD OF APPLICATION:
Experiment I: plate incorporation
Experiment II: preincubation

DURATION
- Preincubation period: only Experiment II: 60 minutes at 37 °C
- Exposure duration: 48 hours


NUMBER OF REPLICATIONS: 3 plates per strain and dose level, including controls

Evaluation criteria:

test item considerer as a mutagen, if:
- number of revertants exceeding a threshold of twice (TA 98, TA 100 and WP2uvrA) or
- number of revertants exceeding a threshold of thrice (TA 1535, TA 1537)
the colony count of the corresponding solvent control

- a dose dependent increase is considered relevant if the threshold is exceeded more than once

- increase in threshold at only one concentration is judged relevant if reproduced in a second independent experiment

-dose dependent increase below the threshold is regarded as indication of a mutagenic potential if reproduced in a second independent experiment, whenever the colony counts remain within the historical range of negative and solvent controls such an increase is not considered relevant

Results and discussion

Test results

Species / strain:

other: S. typhimurium TA 1535, TA 98, TA 100 and TA 1537, E. coli WP2uvrA

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

minor effect in plate incorporation assay at 5000 µg/plate in TA1537 (reduction in the number of revertants to ~50% of control plates)

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: visible in Experiment II without S9 at a concentration of 5000 µg/plate and with S9-Mix at concentrations of 1000 µg/plate and above

COMPARISON WITH HISTORICAL CONTROL DATA:
- historical range of positive controls was exceeded with metabolic activation in strains TA 98 and TA 1537 (Experiment I) and in strain TA 100 (Experiment/ and II), this effect indicates the sensitivity of the strains rather than compromising the assay
- Strain WP2uvrA (ExperimentI) with metabolic activation historical control range of negative and solvent controls was slightly exceeded
- Strain WP2uvrA and TA 1535 (ExperimentII) with and without metabolic activation historical control range of negative and solvent controls was slightly exceeded
- Strain TA 1535 and TA 98 (ExperimentII) with metabolic activation historical control range of negative and solvent controls was slightly exceeded

ADDITIONAL INFORMATION ON CYTOTOXICITY:
- TA 1537: plate incorporation assay without metabolic activation minor effect at 5000 µg/plate

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

The test item showed no mutagenic activity in both experiments (plate incorporation assay, preincubation assay) each with and without metabolic activation.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation

The test item did not exert mutagenic activity in the reverse bacterial mutation assay (plate incorporation assay and preincubation assay) with and without metabolic activation.

Executive summary:

Mutagenic activity of the test item was investigated in Salmonella typhimurium strains TA 1535, TA 1537, TA98, TA100 and Escherichia coli strain WP2uvrA with (induced rat liver S9 mix) and without metabolic activation at concentrations of 3, 10, 33, 100, 333, 1000, 2500, and 5000 µg/plate using the plate incorporation assay. Additionally, a preincubation assay with or without metabolic activation was performed using the concentrations 33, 100, 333, 1000, 2500, and 5000 µg/plate.

The test item did not reveal any mutagenic activity under the conditions tested. The appropriate reference mutagenes showed distinct positive mutagenic effects.