diethyl 1-(2,4-dichlorophenyl)-5-methyl-4,5-dihydro-1H-pyrazole-3,5-dicarboxylate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1990

Report date:

1990

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 472 (Genetic Toxicology: Escherichia coli, Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

diethyl 1-(2,4-dichlorophenyl)-5-methyl-4,5-dihydro-1H-pyrazole-3,5-dicarboxylate

EC Number:

603-923-2

Cas Number:

135590-91-9

Molecular formula:

C16H18Cl2N2O4

IUPAC Name:

diethyl 1-(2,4-dichlorophenyl)-5-methyl-4,5-dihydro-1H-pyrazole-3,5-dicarboxylate

Method

Target gene:

His-operon, Trp-operon

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium, other: TA 100, TA 1535, TA 1537, TA 1538, TA 98

Species / strain 2

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254-induced rat liver S9-mix

Test concentrations with justification for top dose:

1. experiment: 0, 4, 20, 100, 500, 2500, 10000 µg/plate ± S9
2. experiment: 0, 4, 20, 100, 500, 2500, 5000 µg/plate ± S9

Vehicle / solvent:

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

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

9-aminoacridine

2-nitrofluorene

sodium azide

benzo(a)pyrene

other: N-Methyl-N-nitro-N-nitrosoguanidine (MNNG, -S9); 2.5 µg/plate for WP2uvra; 2-aminoanthracen (2-AA, +S9): 0.5 µg/plate for TA98, TA100 and TA1538, 1 µg/plate for TA1535 and TA1537, 10 µg/plate for WP2uvrA

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)


DURATION
- Exposure duration: 48 hours


NUMBER OF REPLICATIONS: tripliccates, 2 independent experiments


DETERMINATION OF CYTOTOXICITY
- Method: other: thinning of background lawn, reduction of colony count

Evaluation criteria:

Significant increase in the number of revertant colonies, dose-dependency of effect

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium, other: TA 100, TA 1535, TA 1537, TA 1538, TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

starting at 2500 µg/plate; visible precipitation at 2500 microgram/plate only in the experiments without S9 (only buffer)

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

Maximum number of revertants (means):

	Control		Test substance (µg/plate)
Strain	-S9	+S9	-S9	+S9
TA100	138	166	134 (5000)	161 (500)
TA1535	10	12	10 (100)	11 (4)
TA1537	7	9	8 (4)	10 (500)
TA1538	11	16	14 (4)	17 (2500)
TA98	20	26	22 (4)	29 (20
WP2uvrA	23	30	26 (100)	27 (4)

The second experiment was chosen for presentation, actually there are no significant differences between either experiment 1 or 2.

Conclusion:

Hoe 107892 was found to be non-mutagenic in the bacterial systems tested either with or without exogenous metabolic activation at the dose levels used.

Applicant's summary and conclusion

Conclusions:

Under the tested conditions, the test compound was not mutagenic in any of the five tested S. typhimurium strains (TA 98, TA 100, TA 1535, TA1537 and TA 1538) or in E. coli strain WP2 uvrA with and without metabolic activation up to 10000 µg/plate.