Methyl 5-(dimethylamino)-2-methyl-5-oxopentanoate

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

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP-compliant guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

methyl (2R)-4-(dimethylcarbamoyl)-2-methylbutanoate; methyl (2S)-4-(dimethylcarbamoyl)-2-methylbutanoate

EC Number:

700-204-6

Cas Number:

1174627-68-9

Molecular formula:

C9H17NO3

IUPAC Name:

methyl (2R)-4-(dimethylcarbamoyl)-2-methylbutanoate; methyl (2S)-4-(dimethylcarbamoyl)-2-methylbutanoate

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): DV-SOLV 1059

Method

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:

Phenobarbital/Beta-Napthoflavone induced rat liver S9

Test concentrations with justification for top dose:

Experiments 1 & 2: 5, 15.81, 50, 158.1, 500, 1581 and 5000; µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO; water
- Justification for choice of solvent/vehicle: Solubility of test material and positive controls

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

Salmonella TA 100, TA 1535: without activation

Controls 2

Positive control substance:

9-aminoacridine

Remarks:

Salmonella TA 1537: without activation

Controls 3

Positive control substance:

other: 4-nitro-1,2-phenylene-diamine (NPD)

Remarks:

Salmonella TA 98: without activation

Controls 4

Positive control substance:

methylmethanesulfonate

Remarks:

E coli: without activation

Controls 5

Positive control substance:

other: 2-aminoanthracene

Remarks:

Salmonella all strains, E coli: with activation

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (experiment 1: plate incorporation); experiment 2: preincubation

DURATION - Preincubation period: 48 hours

Evaluation criteria:

Criteria for positive result:
- a dose-related increase in the number of revertants and/or
- a reproducible biologically relevant positive result for at least one of the dose groups in at least one strain with or without metabolic activation
An increase is considered biologically relevant if the number of reversions is twice that of controls for S. TA 100, or three times higher for other tested strains.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 5

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

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

There were no toxic effects. Plates incubated with the test item showed normal background growth up to 5000µg/plate with and without S9 mix in both experiments.
No substantial increase in revertant colony numbers of any of the 5 tester strains was observed following treatment withDV-SOLV 1059at any dose level, neither in the presence nor absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance.

Appropriate reference mutagens were used as positive controls and these showed a distinct increase of induced revertant colonies.

Results of Gene Mutation Assay: Experiment 1 (Plate incorporation):

Metabolic Activation	Test Group	Dose Level (µg/plate)		Revertant Colony Counts (Mean ±SD)
				TA 1535	TA 1537	TA 98	TA 100	WP2 uvrA
Without Activation	Untreated			7 ± 3	3 ± 1	21 ± 6	90 ± 23	31 ± 2
	DMSO			11 ± 5	6 ± 2	20 ± 6	90 ± 20	26 ± 4
	Distilled water			12 ± 2	6 ± 3	19 ± 1	86 ± 24	32 ± 6
	DV-SOLV 1059	5 µg		10 ± 1	4 ± 2	17 ± 6	93 ± 14	27 ± 6
		15.81 µg		7 ± 3	8 ± 4	28 ± 6	87 ± 8	30 ± 10
		50 µg		11 ± 2	5 ± 1	18 ± 1	104 ± 13	33 ± 10
		158.1 µg		10 ± 3	6 ± 2	15 ± 2	106 ± 9	35 ± 3
		500 µg		8 ± 1	8 ± 3	21 ± 7	99 ± 8	36 ± 3
		1581 µg		8 ± 1	7 ± 3	19 ± 5	93 ± 25	29 ± 4
		5000 µg		8 ± 3	6 ± 2	16 ± 5	101 ± 10	34 ± 4
	NaAZ	2 µg		635 ± 129			990 ± 56
	2AA	2 µg
	9AA	50 µg			287 ± 23
	NPD	4 µg				292 ± 03
	MMS	2 µL						651 ± 57
With Activation	Untreated			8 ± 3	5 ± 0	29 ± 5	88 ± 5	42 ± 6
	DMSO			8 ± 1	8 ± 1	20 ± 6	95 ± 6	37 ± 7
	Distilled water			11 ± 5	9 ± 1	19 ± 1	86 ± 7	44 ± 16
	DV-SOLV 1059	5 µg		10 ± 3	8 ± 2	26 ± 5	84 ± 7	37 ± 12
		15.81 µg		8 ± 6	6 ± 3	24 ± 2	86 ± 8	42 ± 3
		50 µg		11 ± 2	9 ± 1	24 ± 7	86 ± 5	32 ± 7
		158.1 µg		11 ± 2	5 ± 2	19 ± 3	78 ± 1	41 ± 5
		500 µg		12 ± 2	7 ± 2	26 ± 11	84 ± 5	44 ± 2
		1581 µg		8 ± 3	9 ± 2	26 ± 5	85 ± 11	41 ± 8
		5000 µg		9 ± 5	10 ± 2	27 ± 12	72 ± 15	38 ± 8
	2-AA	2 µg		223 ± 10	153 ± 19	1889 ± 157	1937 ± 107
	2-AA	50 µg						183 ± 5

 

Key to Positive Controls
NaAZ 2-AA 9AA NPD MMS	sodium azide 2-aminoanthracene 9-aminoacridine 4-nitro-1,2-phenylene-diamine methyl methane sulfonate

 

Results of Gene Mutation Assay: Experiment 2 (Pre-incubation):

Metabolic Activation	Test Group	Dose Level (µg/plate)		Revertant Colony Counts (Mean ±SD)
				TA 1535	TA 1537	TA 98	TA 100	WP2 uvrA
Without Activation	Untreated			14 ± 5	9 ± 2	19 ± 5	98 ± 3	40 ± 4
	DMSO			10 ± 4	8 ± 3	22 ± 2	100 ± 11	30 ± 0
	Distilled water			16 ± 4	6 ± 2	19 ± 1	105 ± 2	38 ± 5
	DV-SOLV 1059	5 µg		16 ± 1	6 ± 1	16 ± 6	107 ± 8	37 ± 9
		15.81 µg		16 ± 1	5 ± 1	20 ± 4	103 ± 6	38 ± 9
		50 µg		14 ± 3	5 ± 1	16 ± 4	102 ± 10	39 ± 7
		158.1 µg		17 ± 1	9 ± 5	12 ± 6	98 ± 2	46 ± 4
		500 µg		15 ± 4	6 ± 3	13 ± 1	101 ± 16	36 ± 4
		1581 µg		11 ± 1	6 ± 3	13 ± 1	96 ± 21	33 ± 6
		5000 µg		13 ± 4	4 ± 3	14 ± 3	92 ± 5	28 ± 5
	NaAZ	2 µg		801 ± 39			1087 ± 133
	2AA	2 µg
	9AA	50 µg			220 ± 30
	NPD	4 µg				230 ± 35
	MMS	2 µL						803 ± 21
With Activation	Untreated			18 ± 6	2 ± 0	30 ± 3	115 ± 20	43 ± 8
	DMSO			16 ± 4	9 ± 1	27 ± 6	102 ± 3	43 ± 8
	Distilled water			14 ± 3	16 ± 6	26 ± 4	113 ± 7	49 ± 4
	DV-SOLV 1059	5 µg		17 ± 2	8 ± 4	19 ± 6	112 ± 6	58 ± 9
		15.81 µg		16 ± 4	12 ± 5	25 ± 3	105 ± 4	49 ± 3
		50 µg		13 ± 1	9 ± 3	24 ± 3	100 ± 9	54 ± 3
		158.1 µg		14 ± 1	11 ± 3	16 ± 2	98 ± 1	53 ± 10
		500 µg		16 ± 2	10 ± 5	18 ± 3	84 ± 6	63 ± 2
		1581 µg		17 ± 1	7 ± 2	22 ± 4	91 ± 5	58 ± 2
		5000 µg		15 ± 4	8 ± 3	24 ± 3	85 ± 12	47 ± 5
	2-AA	2 µg		156 ± 13	148 ± 7	1677 ± 198	1887 ± 201
	2-AA	50 µg						188 ± 16

 

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

The test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used.
Therefore, DV-SOLV 1059 is considered to be non-mutagenic in this Salmonella typhimurium and Escherichia coli reverse mutation assay.

Executive summary:

This study was performed to investigate the potential of DV-SOLV 1059 to induce gene mutations in the plate incorporation test (experiment I) and the pre-incubation test (experiment II) using Salmonella typhimurium strains TA 1535, TA 1537, TA 98, and TA 100, and Escherichia coli strain WP2 uvrA.

The assay was performed in two independent experiments both with and without liver microsomal activation. Each concentration, including the controls, was tested in triplicate. The test item was tested at the following concentrations of the active ingredient:

Pre-Experiment/Experiment I/Experiment II: 5, 15.81, 50, 158.1, 500, 1581 and 5000 µg/plate

The plates incubated with the test item showed normal background growth up to 5000 µg/plate with and without metabolic activation in both independent experiments.

No toxic effects, evident as a reduction in the number of revertants (below the induction factor of 0.5), occurred in the test groups with or without metabolic activation.

No substantial increase in revertant colony numbers of any of the five tester strains was observed following treatment with DV-SOLV 1059 at any dose level, either in the presence or absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance.

Appropriate reference mutagens were used as positive controls and showed a distinct increase of induced revertant colonies.

In conclusion, in the mutagenicity test described and under the experimental conditions reported, the test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used.

Therefore, DV-SOLV 1059 is considered to be non-mutagenic in this Salmonella typhimurium and Escherichia coli reverse mutation assay.