3-ethoxy-4,6-difluoro-7-(pentyloxy)dibenzo[b,d]furan

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

November 06, 2013 - March 03, 2014

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

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:

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

1

Reference substance name:

3-ethoxy-4,6-difluoro-7-(pentyloxy)dibenzo[b,d]furan

EC Number:

942-871-8

Cas Number:

1799569-89-3

Molecular formula:

C19H20F2O3

IUPAC Name:

3-ethoxy-4,6-difluoro-7-(pentyloxy)dibenzo[b,d]furan

Specific details on test material used for the study:

Name of test material: Art. 201386
Synonym: B-2O-O5
Chemical name: 3-Ethoxy-4,6-difluoro-7-pentyloxy-dibenzofuran
Batch No.: EF13003186
Purity (GC): 99.02 %
Appearance: white solid
Supplier: Merck KGaA, Darmstadt
Released until: October 31, 2014

Method

Target gene:

HIS Operon, TRP Operon

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Metabolic activation:

with and without

Metabolic activation system:

liver S9 mix obtained from rats pretreated with Aroclor 1254

Test concentrations with justification for top dose:

1st series: 5.00, 15.8, 50.0, 158, 500, 1580, 5000 µg/plate
2 nd series: 5.00, 15.8, 50.0, 88.9, 158, 281 µg/plate

Vehicle / solvent:

Acetone

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: Without S9: Sodium azide 9-Aminoacridine Daunomycin 4-Nitroquinoline-N-oxide with S9: 2-Aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium; in agar plate incorporation
- Cell density at seeding (if applicable): approx. 1 e9

DURATION
- Exposure duration: 2-3 days

SELECTION AGENT (mutation assays): histidine

STAIN (for cytogenetic assays):

NUMBER OF REPLICATIONS: neg. controls: 6, test item: 3, pos control: 3

DETERMINATION OF CYTOTOXICITY
reduction of background lawn

OTHER EXAMINATIONS:
Precipitation

- OTHER:

Rationale for test conditions:

According to guideline

Evaluation criteria:

According to guideline

Statistics:

Standard statistical methods have been applied for data processing.

Results and discussion

Test results

Key result

Species / strain:

other: all strains / all conditions

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Precipitation of the test material on the agar plates occurred at concentrations ≥ 158 µg/plate.

Any other information on results incl. tables

Objective

The present study was conducted to investigate the test material for mutagenic potential in a bac-terial reverse gene mutation assay.

Study Design

The investigations for the mutagenic potential of Art. 201386 were performed using Salmonella typhimurium tester strains TA 98, TA 100, TA 1535 and TA 1537, and Escherichia coli WP2 uvrA. The plate incorporation test with and without addition of liver S9 mix from Aroclor 1254-pretreated rats was used. Two independent experimental series were performed. In the two series with S9 mix, 10 % S9 in the S9 mix were used in the 1st and 30 % in the 2nd series, respectively.

This study was performed according to GLP and the methods applied are fully compliant with OECD TG 471.

Results

Art. 201386 was dissolved in acetone and tested at concentrations ranging from 5.00 to 5000 µg/plate. Precipitation of the test material on the agar plates occurred at concentrations ≥ 158 µg/plate. Toxicity to the bacteria was not observed.

Daunomycin, sodium azide, 9-aminoacridine and 4-nitroquinolin-N-oxide served as strain specif-ic positive control test materials in the absence of S9 mix. 2-Aminoanthracene was used for test-ing the bacteria and the activity of the S9 mix. Each treatment with the test materials used as positive controls led to a clear increase in revertant colonies, thus, showing the expected reversion properties of all strains and good metabolic activity of the S9 mix used.

Following Art. 201386 treatments of all the tester strains in the absence and presence of S9 mix, no relevant increases in revertant numbers were observed.

Conclusion

With and without addition of S9 mix as the external metabolizing system, Art. 201386 was not mutagenic under the experimental conditions described.

Applicant's summary and conclusion

Conclusions:

With and without addition of S9 mix as the external metabolizing system, Art. 201386 was not mutagenic under the experimental conditions described.

Executive summary:

With and without addition of S9 mix as the external metabolizing system, Art. 201386 was not mutagenic under the experimental conditions described.