2-isobutyl-4-methyltetrahydro-2H-pyran-4-yl acetate

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:

2017

Report date:

2017

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:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)

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:

2-isobutyl-4-methyltetrahydro-2H-pyran-4-yl acetate

EC Number:

942-380-9

Cas Number:

131796-64-0

Molecular formula:

C12H22O3

IUPAC Name:

2-isobutyl-4-methyltetrahydro-2H-pyran-4-yl acetate

Test material form:

liquid

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: ZH 291 A1 Fr.2-4
- Date of production of the lot/batch: 2016-08

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature

Method

Species / strain

Species / strain / cell type:

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

Remarks:

uvrA

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

S9-mix

Test concentrations with justification for top dose:

0, 33, 100, 333, 1000, 2600, and 5200 μg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: Due to the insolubility of the test substance in water, DMSO was used as vehicle, which had been demonstrated to be suitable in bacterial reverse mutation tests and for which historical control data are available.

Controls

Controls 1

Untreated negative controls:

yes

Remarks:

Sterility control

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Remarks:

with S9-mix

Positive control substance:

other: 2-aminoanthracene

Remarks:

2.5 μg/plate, TA 1535, TA 100, TA 1537, TA 98. 60 μg/plate, Escherichia coli WP2 uvrA

Controls 2

Untreated negative controls:

yes

Remarks:

Sterility control

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Remarks:

without S9-mix

Positive control substance:

other: N-methyl-N'-nitro-N-nitrosoguanidine

Remarks:

5 μg/plate, TA 1535, TA 100

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Remarks:

without S9-mix

Positive control substance:

other: 4-nitro-o-phenylenediamine

Remarks:

10 μg/plate, TA 98

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Remarks:

without S9-mix

Positive control substance:

9-aminoacridine

Remarks:

100 μg/plate, TA 1537

Controls 5

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

yes

Positive controls:

yes

Remarks:

without S9-mix

Positive control substance:

4-nitroquinoline-N-oxide

Remarks:

5 μg/plate, E. coli WP2 uvrA

Details on test system and experimental conditions:

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

DURATION
- Preincubation period: 20 min
- Exposure duration: 48 - 72 h

NUMBER OF REPLICATIONS: 3 per dose or per control

DETERMINATION OF CYTOTOXICITY
- Method:
decrease in the number of revertants (factor ≤ 0.6)
clearing or diminution of the background lawn (= reduced his- or trp- background growth)

Evaluation criteria:

Acceptance criteria:
Generally, the experiment was considered valid if the following criteria were met:
• The number of revertant colonies in the negative controls was within the range of the historical negative control data for each tester strain.
• The sterility controls revealed no indication of bacterial contamination.
• The positive control substances both with and without S9 mix induced a distinct increase in the number of revertant colonies within the range of the historical positive control data or above.
• Fresh bacterial culture containing approximately 10 to the power of 9 cells per mL were used.

Assessment criteria:
The test substance was considered positive in this assay if the following criteria were met:
• A dose-related and reproducible increase in the number of revertant colonies, i.e. at least doubling (bacteria strains with high spontaneous mutation rate, like TA 98, TA 100 and E.coli WP2 uvrA) or tripling (bacteria strains with low spontaneous mutation rate, like TA 1535 and TA 1537) of the spontaneous mutation rate in at least one tester strain either without S9 mix or after adding a metabolizing system.
A test substance was generally considered non-mutagenic in this test if:
• The number of revertants for all tester strains were within the range of the historical negative control data under all experimental conditions in at least two experiments carried out independently of each other.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

> 100 µg/plate with S9-mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

> 333 µg/plat with S9-mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Key result

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

> 1000 µg/plate with S9-mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Key result

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

> 1000 µg/plate, with S9-mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 5

Key result

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

> 1000 µg/plate with and without S9-mix

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Any other information on results incl. tables

Experiment 1 (SPT)
Dose (µg/plate)	Mean number of revertant colonies/3 replicate plates with different strains of Salmonella typhimurium and Escherichia coli
	TA1535	TA1537	TA98	TA100	WP2 uvrA
	Results with S9
DMSO	14.3	8.0	31.0	117.3	19.7
33	11.7	10.3	34.0	123.3	17.3
100	8.0	8.3	30.3	124.0	18.0
333	8.7	8.3	28.0	107.0	17.7
1000	6.7	7.3	32.0	112.7	17.3
2600	2.3	5.3	22.0	91.0	22.0
5200	0.0	1.7	9.7	0.0	18.7
positive control	141.0	164.7	1543.7	2151.7	97.0
	Results without S9
DMSO	13.3	6.3	25.7	97.7	20.3
33	15.0	7.7	22.0	107.3	21.0
100	12.3	5.3	22.0	117.0	24.3
333	9.7	6.3	22.7	107.0	19.3
1000	11.7	6.3	19.7	108.0	21.7
2600	6.0	5.3	8.7	92.3	17.7
5200	3.3	0.0	0.0	0.0	24.0
positive control	3923.0	1032.0	714.0	3595.7	1391.3
Experiment 2 (PIT)
Dose (µg/plate)	Mean number of revertant colonies/3 replicate plates with different strains of Salmonella typhimurium and Escherichia coli
	TA1535	TA1537	TA98	TA100	WP2 uvrA
	Results with S9
DMSO	9.7	6.7	24.7	89.7	28.7
33	8.7	8.3	25.7	83.3	21.3
100	9.3	7.0	20.3	97.3	22.7
333	8.0	8.0	28.0	100.0	26.3
1000	8.7	3.0	27.7	83.0	20.0
2600	2.3	2.7	6.7	28.3	24.0
5200	0.0	0.0	0.0	0.0	18.3
positive control	241.0	160.3	2192.7	2388.3	94.3
	Results without S9
DMSO	8.3	7.0	18.3	89.0	20.3
10	12.3	9.3	25.3	91.0	26.0
33	10.0	8.3	20.0	96.7	23.3
100	8.0	8.7	18.7	102.3	25.0
333	5.0	6.0	13.3	79.7	22.3
1000	5.3	4.7	12.3	87.3	19.7
2600	7.7	3.7	14.7	68.7	17.3
positive control	3376.0	1214.0	555.3	2661.0	467.0