Methanone, (2-chloro-5-iodophenyl)(4-fluorophenyl)-

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:

02 Aug 2007 - 06 Dec 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

OECD Guideline 471

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

not specified

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

(2-chloro-5-iodophenyl)(4-fluorophenyl)methanone

EC Number:

619-596-4

Cas Number:

915095-86-2

Molecular formula:

C13 H7 Cl F I O

IUPAC Name:

(2-chloro-5-iodophenyl)(4-fluorophenyl)methanone

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Specific details on test material used for the study:

BI 10773 Fluorid was a white powder.Purity was stated as 100 %. It was received on
25 July 2007 and was stored at room temperature in the dark with desiccant.

Method

Target gene:

Four strains of Salmonella typhimurium bacteria (TA98, TA100, TA1535 and TA1537) and
one strain of Escherichia coli bacteria (WP2 uvrA pKM101) were used in this study. All
strains were bought from Sigma Aldrich Chemical Co., Inc., St. Louis, Missouri USA.

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

Experiment 1: concentrations of BI 10773 Fluorid at 5, 16, 50, 160, 500, 1600 and 5000 μg/plate
Experiment 2 : The maximum test concentration of 5000 μg/plate was retained for all
strains. Narrowed concentration intervals were employed covering the range
80-5000 μg/plate,

Experiment 3: treatments of strains TA98, TA1535 and TA1537, TA100 and E. coli WP2 uvr A were performed in the
absence of S-9 using pre-incubation methodology. The maximum test concentration was reduced to 625 μg/plate based on toxicity observed in Experiment 2. Narrowed
concentrations intervals were employed covering the range 300-625 μg/plate.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO

Controls

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene (AAN), 2-nitrofluorene, sodium azide, 9-aminoacridine, methyl methanesulfonate

Details on test system and experimental conditions:

The test system was suitably labelled to clearly identify the study number, bacterial strain,
test article concentration (where appropriate), positive and vehicle controls, absence or
presence of S-9 mix.

Rationale for test conditions:

The assay was to be considered valid if the following criteria were met:
1. The vehicle control counts fell within the laboratory’s historical control ranges as defined
in Appendix 1.
2. The positive control chemicals induced increases in revertant numbers of ≥2-fold (in
strains TA98, TA100 and WP2 uvrA pKM101) or ≥3-fold (in strains TA1535 and The assay was to be considered valid if the following criteria were met:
1. The vehicle control counts fell within the laboratory’s historical control ranges as defined
in Appendix 1.
2. The positive control chemicals induced increases in revertant numbers of ≥2-fold (in
strains TA98, TA100 and WP2 uvrA pKM101) or ≥3-fold (in strains TA1535 and The assay was to be considered valid if the following criteria were met:
1. The vehicle control counts fell within the laboratory’s historical control ranges as defined
in Appendix 1.
2. The positive control chemicals induced increases in revertant numbers of ≥2-fold (in
strains TA98, TA100 and WP2 uvrA pKM101) or ≥3-fold (in strains TA1535 and TA1537) the concurrent vehicle control confirming discrimination between different strains, and an active S-9 preparation
3. At least five analysable concentrations of the test article are available.

Evaluation criteria:

For valid data, the test article was considered to be mutagenic if:
1. A concentration related increase in revertant numbers was ≥2-fold (in strains TA98,
TA100 or, WP2 uvrA pKM101) or ≥3-fold (in strains TA1535 or TA1537) the concurrent
vehicle control values
2. Any observed response is reproducible.
The test article was considered positive in this assay if both of the above criteria were met.
The test article was considered negative in this assay if neither of the above criteria were met.
Results which only partially satisfied the above criteria were dealt with on a case-by-case
basis. Biological relevance was taken into account, for example consistency of response
within and between concentrations and (where applicable) between experiments.

Statistics:

Individual plate counts were recorded separately and the mean and standard deviation of the
plate counts for each treatment were determined. Control counts were compared with the
laboratory’s historical control ranges (Appendix 1). Data were considered
acceptable if the vehicle control counts fell within the calculated historical control ranges and
the positive control plate counts were comparable with the historical control ranges.
The presence or otherwise of a concentration response was checked by non-statistical
analysis, up to limiting levels (for example toxicity, precipitation or 5000 μg/plate).
However, adequate interpretation of biological relevance was of critical importance.

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

Remarks:

Precipitate was observed beginning at 500 or at 1500 microgram per plate

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

Precipitate was observed beginning at 1500 or at 5000 microgram per plate

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

Remarks:

Precipitate was observed beginning at 500 or at 1500 microgram per plate

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Remarks:

Precipitate was observed beginning at 1500 or at 5000 microgram per plate

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

All criteria for a valid study were met. IN00078280 did not cause a positive mutagenic response

with any of the tester strains in either the presence or absence of S9 activation.

Under the conditions of this study, IN00078280 was concluded to be negative in the Bacterial

Reverse Mutation Assay when tested up to maximum recommended concentrations.

Applicant's summary and conclusion

Conclusions:

It was concluded that IN 00078280/ BI 10773 Fluorid did not induce mutation in four histidine-requiring strains of
Salmonella typhimurium (TA98, TA100, TA1535 and TA1537) and one tryptophan-
requiring strain of Escherichia coli (WP2 uvrA pKM101) when tested under the conditions of this
study using the plate incorporation and pre-incubation methodologies. These conditions
included treatments at concentrations up cytotoxic concentrations and/or to 5000 μg/plate
(the maximum recommended concentration according to current regulatory guidelines), and
testing in the absence and in the presence of a rat liver metabolic activation system (S-9).

Executive summary:

The test article, IN 00078280, was tested in the IN 00078280: Bacterial Reverse Mutation Assay

using Salmonella typhimurium tester strains TA98, TA100, TA1535 and TA1537 and

Escherichia coli tester strain WP2 uvrA in the presence and absence of Aroclor-induced rat liver

S9. The assay was performed in two phases, using the plate incorporation method. The first

phase, the initial toxicity-mutation assay, was used to establish the dose-range for the

confirmatory mutagenicity assay and to provide a preliminary mutagenicity evaluation. The

second phase, the confirmatory mutagenicity assay, was used to evaluate and confirm the

mutagenic potential of the test article.

Dimethyl sulfoxide (DMSO) was selected as the solvent of choice based on the solubility of the

test article and compatibility with the target cells. The test article formed a soluble and clear

solution in dimethyl sulfoxide (DMSO) at approximately 500 mg/mL, the highest concentration

tested.

In the initial toxicity-mutation assay, the maximum dose tested was 5000 µg per plate; this dose

was achieved using a concentration of 100 mg/mL and a 50 uL plating aliquot. The dose levels

tested were 1.5, 5.0, 15, 50, 150, 500, 1500 and 5000 ug per plate, In the initial

toxicity-mutation assay, no positive mutagenic response was observed. Precipitate was

observed beginning at 1500 or at 5000 ug per plate. No appreciable toxicity was observed.

Based on the findings of the initial toxicity-mnutation assay, the maximum dose plated in the

confirmatory mutagenicity assay was 5000 µg per plate.

In the confirmatory mutagenicity assay, no positive mutagenic response was observed. The

dose levels tested were 50, 150, 500, 1500 and 5000 ug per plate. Precipitate was observed

beginning at 500 or 1500 ug per plate. No background lawn toxicity was observed.

Under the conditions of this study, test article IN 00078280 was concluded to be negative in the

IN 00078280: Bacterial Reverse Mutation Assay.