2',3,5-Trifluoro-4''-(trans-4-propylcyclohexyl)-4-trifluoromethoxy-[1,1';4',1'']terphenyl

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:

2007-02-19 to 2007-06-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

adopted 21 July 1997

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

4-[3,5-difluoro-4-(trifluoromethoxy)phenyl]-3-fluoro-4'-[(1s,4r)-4-propylcyclohexyl]-1,1'-biphenyl

EC Number:

610-847-3

Cas Number:

524709-77-1

Molecular formula:

C28H26OF6

IUPAC Name:

4-[3,5-difluoro-4-(trifluoromethoxy)phenyl]-3-fluoro-4'-[(1s,4r)-4-propylcyclohexyl]-1,1'-biphenyl

Method

Target gene:

HIS operon (S. thyphimurium)
TRP operon (E. coli)

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535

Details on mammalian cell type (if applicable):

his G 46, uvrB, rfa

Additional strain / cell type characteristics:

other: mutations in the histidine operon

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1537

Details on mammalian cell type (if applicable):

his C 3076, uvrB, rfa

Additional strain / cell type characteristics:

other: mutations in the histidine operon

Species / strain 3

Species / strain / cell type:

S. typhimurium TA 98

Details on mammalian cell type (if applicable):

his D 3052, uvrB, rfa + R-factor

Additional strain / cell type characteristics:

other: mutations in the histidine operon

Species / strain 4

Species / strain / cell type:

S. typhimurium TA 100

Details on mammalian cell type (if applicable):

his G 46, uvrB, rfa + R-factor

Additional strain / cell type characteristics:

other: mutations in the histidine operon

Species / strain 5

Species / strain / cell type:

S. typhimurium TA 102

Details on mammalian cell type (if applicable):

his G 428, rfa + R-factor

Additional strain / cell type characteristics:

other: mutations in the histidine operon

Species / strain 6

Species / strain / cell type:

E. coli WP2

Details on mammalian cell type (if applicable):

uvrA pkM101

Additional strain / cell type characteristics:

other: mutations in the tryptophan operon

Metabolic activation:

with and without

Metabolic activation system:

liver S9 mix from Aroclor 1254-pretreated rats with standard co-factors

Test concentrations with justification for top dose:

The test material concentrations used were selected according to the EC and OECD guidelines for this test system and the requirements of the Labor Ministry of Japan:
1. Series: 2.81, 8.89, 28.1, 88.9, 281, 889 and 2810 μg per plate (S9 10 %)
2. Series: 2.81, 5.00, 8.89, 15.8 and 28.1 μg per plate (S9 30 %)

Vehicle / solvent:

acetone

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

9-aminoacridine

sodium azide

cumene hydroperoxide

other: daunomycin

Remarks:

without S9

Controls 2

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

other: 2-aminoanthracene

Remarks:

with S9

Details on test system and experimental conditions:

The assessment of test material-induced effects is dependent on the number of spontaneous revertants of each bacterial strain (solvent controls) and the increase in the number of revertants at the test material concentration which shows the highest number of colonies. The following criteria, based upon the historical controls of the laboratory and statistical considerations, are established:

-----------------------------------------------------------------------------------------
Mean Number of Colonies Maximal Mean Number of Colonies over the Actual
(Solvent Control) Solvent Control
(Test Material)
-----------------------------------------------------------------------------------------

<=10 <=9 >=30
<=30 <=19 >=40
<=80 <=29 >=80
<=200 <=49 >=120
<=500 <=79 >=200
Assessment: No increase Clear increase

-----------------------------------------------------------------------------------------

All further results, ranging between "no" and "clear", are assessed as "weak in-creases".

Interpretations:
A test material is defined as non-mutagenic in this assay if:

- "no" or "weak increases" occur in the first and second series of the main experiment. ("Weak increases" randomly occur due to experimental variation.)

A test material is defined as mutagenic in this assay if:

- a dose-related (over at least two test material concentrations) increase in the number of revertants is induced, the maximal effect is a "clear increase", and the effects are reproduced at similar concentration levels in the same test system;

- "clear increases" occur at least at one test material concentration, higher concentrations show strong precipitation or cytotoxicity, and the effects are reproduced at the same concentration level in the same test system.

In all further cases, a third test series with the bacterial strain in question should be performed.
If the criteria for a positive test result are not fulfilled in at least two out of the three series, the test material is defined as being non-mutagenic in this test system.

Rationale for test conditions:

according to Guideline

Evaluation criteria:

see Details on test systems and conditions

Statistics:

n.a.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

E. coli WP2 uvr A pKM 101

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

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