Formamide, N-[(2-bromo-5-hydroxy-4-methoxyphenyl)methyl]-N-[2-(4-hydroxyphenyl)ethyl]-

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:

2005-10-19 to 2005-11-21

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Remarks:

Non-GLP study performed according to the OECD Guideline 471 (Bacterial Reverse Mutation Assay) with the following deviations: only three strains are tested. However, an expert statement is added in the field "any other remarks" to justify the fact that no further testing is necessary.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

1) only 3 strains were used: 2) no repeat experiment and 3) limited information provided on the test substance (i.e. purity was lacking) and materials and methods.

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

N-[(2-bromo-5-hydroxy-4-methoxyphenyl)methyl]-N-[2-(4-hydroxyphenyl)ethyl]formamide

Cas Number:

122584-18-3

Molecular formula:

C17H18BrNO4

IUPAC Name:

N-[(2-bromo-5-hydroxy-4-methoxyphenyl)methyl]-N-[2-(4-hydroxyphenyl)ethyl]formamide

Test material form:

solid: particulate/powder

Details on test material:

- Name of test material (as cited in study report): JNJ-28645409-AAA (T002078)
- Physical state: solid (powder)
- Appearance: White, brown grey powder

Specific details on test material used for the study:

- Name of test material (as cited in study report): T2078 (N-[(2-bromo-5-hydroxy-4-methoxyphenyl)methyl]-N-[2-(4-hydroxy-phenyl)ethyl]formamide)
- Physical state: pale gray powder
- Lot/batch No.: 00464170
- Storage condition of test material: room temperature in the dark
- Other: received on 2005-08-31

Method

Target gene:

histidine locus

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA 98, TA 100, and TA 102

Details on mammalian cell type (if applicable):

not applicable

Metabolic activation:

with and without

Metabolic activation system:

rat liver homogenate metabolising system (10% liver S9 in standard co-factors)

Test concentrations with justification for top dose:

0, 0.5, 1.5, 5, 15, 50, 150, 500, 1500, 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: dimethyl sulphoxide
- Justification for choice of solvent/vehicle: no data

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

Without S9: 0.2 μg/plate for TA98

Controls 2

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

N-ethyl-N-nitro-N-nitrosoguanidine

Remarks:

Without S9: 3 μg/plate for TA100

Controls 3

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

mitomycin C

Remarks:

Without S9: 0.5 μg/plate for TA102

Controls 4

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

benzo(a)pyrene

Remarks:

With S9: 5 μg/plate for TA98

Controls 5

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

With S9: 1 μg/plate for TA100

Controls 6

Untreated negative controls:

yes

Remarks:

untreated

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 1, 8-Dihydroxyanthraquinone

Remarks:

With S9: 10 μg/plate for TA102

Details on test system and experimental conditions:

METHOD OF APPLICATION: -in agar (plate incorporation)

Measured aliquots (0.1 ml) of one of the bacterial cultures were dispensed into sets of test tubes followed by 2.0 ml of molten, trace histidine supplemented, top agar, 0.1 ml of the test material formulation, vehicle or positive control and either 0.5 ml of S9-mix of phosphate buffer. The contents of each test tube were mixed and equally distributed onto the surface of Vogel-Bonner Minimal agar plates (one tube per plate). This procedure was repeated, in triplicate, for each bacterial strain and for each concentration of the test material both with and without S9-mix.

DURATION
- Exposure duration: 3 days

SELECTION AGENT: histidine

NUMBER OF REPLICATIONS: triplicate

DETERMINATION OF CYTOTOXICITY
- Method: reduction in the growth of the bacterial background lawn

Evaluation criteria:

no data

Statistics:

no data

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA100, TA102, and TA98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS:
No test substance precipitate was observed on the plates at any of the doses tested in either the presence or absence of metabolic activation.

RANGE-FINDING/SCREENING STUDIES: no data

COMPARISON WITH HISTORICAL CONTROL DATA: The vehicle control plates gave counts of revertants colonies wihtin the normal range. All of the positive controls chemicals used in the test induced marked increases in the frequency of revertant colonies, both with and without metabolic activation. Thus, the sensitivity of the assay and the efficacity of the S9-mix were validated. Results for the negative controls (spontaneous mutation rates) were considered to be acceptable.

ADDITIONAL INFORMATION ON CYTOTOXICITY:
- The test substance caused a visible reduction in the growth of the bacterial background lawn of strains TA100 and TA98 (with and without S9) at 5000 µg/plate. No reduction in bacterial background lawn growth was noted to TA102, however, a substantial reduction in the frequency of revertant colonies was noted both with and without S9 mix at the same concentration. Therefore, the test substance was tested up to the maximum recommended dose level of 5000 µg/plate.

Remarks on result:

other: all strains tested

Applicant's summary and conclusion

Conclusions:

Interpretation of results:
negative with and without metabolic activation

The test substance was evaluated for mutagenic potential in the Ames test using S. typhimurium strains TA98, TA100 and TA102 in the absence and presence of metabolic activation. The test substance was considered to be non-mutagenic under the conditions of this test up to the limit concentration of 5000 µg/plate.