Nonanamide, N,N-dimethyl-

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:

21 November 2016 to 08 May 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

OECD guideline for testing of chemicals No. 471, “Bacterial Reverse Mutation Test”, adopted on 21st July 1997.

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

1

Reference substance name:

N,N-dimethylnonanamide

EC Number:

612-975-5

Cas Number:

6225-08-7

Molecular formula:

C11H23NO

IUPAC Name:

N,N-dimethylnonanamide

Details on test material:

- Name of test material (as cited in study report): N,N-Dimethylnonanamide
- Synonyme: Genagen PA

Method

Target gene:

Histidine and tryptophan locus

Species / strain

Species / strain / cell type:

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

Details on mammalian cell type (if applicable):

not applicable

Additional strain / cell type characteristics:

other: Genetic Characterization of Tester Strains, histidine & tryotophan requirement

Metabolic activation:

with and without

Metabolic activation system:

1 mL of S9 homogenate was mixed with 9 mL of co-factor solution.

Test concentrations with justification for top dose:

0.01, 0.03, 0.10, 0.31 and 1 µL /plate , based on the results of solubility, precipitation and initial cytotoxicity test

Vehicle / solvent:

Vehicle(s)used: DMSO
Justification for choice of vehicle: The test item at the given concentration of 50 µL/mL was miscible in dimethyl sulphoxide

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

4-nitroquinoline-N-oxide

9-aminoacridine

2-nitrofluorene

sodium azide

other: 2-aminoantracene

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation); preincubation;


DURATION
- Preincubation period: 30 minutes
- Exposure duration: 48 to 72 hours

NUMBER OF REPLICATIONS: triplicates


- OTHER: cytotoxicity by lawn evaluation and mutagenicity by evauatimg revertant colonies

Rationale for test conditions:

not applicable

Evaluation criteria:

The test will be judged positive if the increase in mean revertants at the peak of the dose response is equal to or greater than 2 times the mean vehicle control value in Salmonella typhimurium strains TA98, TA100 and Escherichia coli WP2 uvrA (pKM101) or equal to or greater than 3 times the mean vehicle control value in tester strains TA1535 and TA1537In the two independent trials conducted, the test item concentrations tested resulted in no appreciable increase in the number of revertant colonies over the vehicle control.

Statistics:

not applicable

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

E. coli WP2 uvr A pKM 101

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS

- Water solubility: insoluble
- Precipitation:no precipitation upto tested concentration


HISTORICAL CONTROL DATA (with ranges, means and standard deviation) : Attached as Annexure 1 in study report (Page no. 32 of 35)

Applicant's summary and conclusion

Conclusions:

The mutagenicity of Genagen PA/ N, N-Dimethylnonanamide was investigated according to the Guideline OECD 471 (Ames Test). No mutagenic acitivity was found.

Executive summary:

The test item, Genagen PA/ N, N-Dimethylnonanamide was evaluated for mutagenicity in Bacterial Reverse Mutation Test as per the OECD guideline for testing of chemicals No. 471, “Bacterial Reverse Mutation Test”, adopted on 21^stJuly 1997.

The tester strains used in the mutation assay were Salmonella typhimurium TA98, TA100, TA1535, and TA1537 and Escherichia coli WP2 uvrA (pKM101).

The test concentrations tested in the mutation assay were selected based on the results of solubility, precipitation and initial cytotoxicity test. The two independent trials (trial 1 and 2) were conducted by plate incorporation method in the presence and absence of metabolic activation system. In mutation assay the test item was tested at the concentrations of0.01, 0.03, 0.10, 0.31 and 1 µL /plate. Vehicle control (dimethyl sulphoxide) and appropriate positive controls (2-nitrofluorene, sodium azide and 9-Aminoacridine, 4-nitroquinoline 1-oxide for trials “without metabolic activation” and 2-Aminoanthracene for trials “with metabolic activation”) were tested simultaneously.

On the basis of test item solubility and precipitation tests, the initial cytotoxicity test was performed at 1, 2, 3, 4, and 5 µL/plate. Initial cytotoxicity test was performed with TA100 both in the presence and absence of metabolic activation system.

The tester strain, TA100 treated with test item, Genagen PA/ N, N-Dimethylnonanamide at the concentration of 3, 4 and 5 µL /plate both in the presence and absence of metabolic activation revealed extremely reduced lawn (grade1+) when compared to vehicle control. Similarly, TA100 treated with test item at 2 and 1 µL/plate showed moderately reduced lawn (grade 3+) and slightly reduced lawn (grade 2+) respectively when compared to vehicle control. On the basis of cytotoxicity results 1 µL /plate was considered as the highest test concentration for mutation assay.

The results of mutation assay performed in two independent experiment (Trial 1 and 2) clearly revealed that there was no appreciable increase in the mean revertant colonies compared to those of the vehicle control, in both the trials, in the presence and absence of metabolic activation, at any of the tested concentrations.