Tetrahydro-4-methylene-2-(2-methyl-1-propenyl)-2H-pyran

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 and guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2008

Report date:

2008

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

yes (incl. QA statement)

Remarks:

testing lab.

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Tetrahydro-4-methylene-2-(2-methyl-1-propenyl)-2H-pyran

EC Number:

262-475-2

EC Name:

Tetrahydro-4-methylene-2-(2-methyl-1-propenyl)-2H-pyran

Cas Number:

60857-05-8

Molecular formula:

C10H16O

IUPAC Name:

4-methylidene-2-(2-methylprop-1-en-1-yl)oxane

Method

Target gene:

Histidine or tryptophan gene

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:

Aroclor-induced rat liver S9 mix

Test concentrations with justification for top dose:

20 μg - 5000 μg/plate (standard plate test)
50 μg - 2000 μg/plate (preincubation test)

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: with metabolic activation: 2-aminoanthracene; without metabolic activation: N-methyl-N'-nitro-N-nitrosoguanidine, 4-nitro-o-phenylendiamine, 9-aminoacridine and 4-nitroquinoline-N-oxide

Details on test system and experimental conditions:

METHOD OF APPLICATION: plate incorporation; preincubation

DURATION
- Preincubation period: 20 minutes

DETERMINATION OF CYTOTOXICITY
- Method: decrease in the number of revertants, clearing or diminution of the background lawn, reduction in the titer

Evaluation criteria:

Acceptance criteria
• 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.
• The titer of viable bacteria was >= 10^8/mL.

Assessment criteria
The test chemical is considered positive if:
• A dose-related and reproducible increase in the number of revertant colonies, i.e. about doubling of the spontaneous mutation rate in at least one tester strain either without S9 mix or after adding a metabolizing system.
A test substance is generally considered non-mutagenic in this test if:
• The number of revertants for all tester strains were within the historical negative control range under all experimental conditions in at least two experiments carried out independently of each other.

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

from about 400 μg/plate onward.

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

from about 400 μg/plate onward.

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: No test substance precipitation was found with and without S9 mix.

ADDITIONAL INFORMATION ON CYTOTOXICITY:
A bacteriotoxic effect was observed in the standard plate test depending on the strain and test conditions from about 500 μg/plate onward. In the preincubation assay bacteriotoxicity was observed depending on the strain and test conditions from about 400 μg/plate onward.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.