1,5-dimethyl-1-vinylhex-4-enyl isobutyrate

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:

other: GLP and test guideline compliant study.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

1,5-dimethyl-1-vinylhex-4-enyl isobutyrate

EC Number:

201-108-2

EC Name:

1,5-dimethyl-1-vinylhex-4-enyl isobutyrate

Cas Number:

78-35-3

Molecular formula:

C14H24O2

IUPAC Name:

1,5-dimethyl-1-vinylhex-4-enyl isobutyrate

impurity 1

Reference substance name:

Unknown impurities

Molecular formula:

not applicable

IUPAC Name:

Unknown impurities

Test material form:

liquid

Details on test material:

Sponsor's Identification: Linalyl Isobutyrate
Description: Colourless liquid
Chemical name: 3,7-Dimethyl-1,6-octadien-3-yl 2-methyl propanoate
Storage conditions: Approximately 4 °C in the dark

Method

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Details on mammalian cell type (if applicable):

Not applicable

Additional strain / cell type characteristics:

not specified

Metabolic activation:

with and without

Metabolic activation system:

S9-fraction; S9 fraction prepared from liver homogenates of male Sprague-Dawley rats induced with three consecutive daily oral doses of phenobarbitone/β-naphthoflavone (80/100 mg/kg bw/day)

Test concentrations with justification for top dose:

Preliminary Toxicity Test:
- 0.15, 0.5, 1.5, 5, 15, 50, 150, 500, 1500 and 5000 µg/plate in TA100 strain, with and without S9 mix using the direct plate incorporation method

Mutation Test- Experiment 1 (Range-finding Test):
- 100, 333, 1000, 2500 and 5000 µg/plate in all tester strains, with and without S9 mix using the direct plate incorporation method

Mutation Test- Experiment 2 (Main Test):
- 100, 333, 1000, 2500 and 5000 µg/plate in all tester strains, with and without S9 mix using the direct plate incorporation method

Vehicle / solvent:

Vehicle(s)/solvent(s) used: Dimethyl sulfoxide (DMSO)
- Justification for choice of solvent/vehicle: The test material was immiscible in sterile distilled water at 50 mg/mL but was fully miscible in DMSO at the same concentration in solubility checks performed in-house. DMSO was therefore selected as the vehicle.
- Test substance preparation: The test material was accurately weighed and approximate half-log dilutions prepared in DMSO by mixing on a vortex mixer on the day of each experiment. Formulated concentrations were adjusted to allow for the stated water/impurity content (1.6 %) of the test material. Prior to use, the solvent was dried using molecular sieves (sodium alumino-silicate) i.e., 2 mm pellets with a nominal pore diameter of 4 x 10^-4 microns.

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: N-ethyl-N'-nitro-N-nitrosoguanidine: 3 µg/plate for TA100 and 5µg/plate for TA1535; 9-Aminoacridine: 80 µg/plate for TA1537; 4-Nitroquinoline-1-oxide: 0.2 µg/plate for TA98; Mitomycin C: 0.5 µg/plate for TA102

Remarks:

without S9-mix

Controls 2

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-Aminoanthracene: 1 µg/plate for TA100, 2 µg/plate for TA1535 and TA1537; Benzo(a)pyrene: 5 µg/plate for TA98; 1,8-dihydroxyanthraquinone: 10 µg/plate for TA102

Remarks:

with S9-mix

Details on test system and experimental conditions:

SOURCE OF TEST SYSTEM: Salmonella typhimurium strains were obtained from the University of California at Berkeley on culture discs on 4 August 1995 and were stored at -196°C in a Statebourne liquid nitrogen freezer, model SXR 34.

METHOD OF APPLICATION: In agar (plate incorporation)

DURATION
- Incubation period: Plates were incubated at 37 °C for approximately 48 h

NUMBER OF REPLICATIONS:
- Preliminary Toxicity Test: Single plate/dose for treatment and vehicle control
- Experiment 1 (Range-finding Test) and Experiment 2 (Main Test): 3 plates/dose for treatment, vehicle and positive controls

DETERMINATION OF CYTOTOXICITY
- Method: Toxicity was determined by growth of the bacterial background lawn.

OTHER:
- Revertant colonies were counted using a Domino colony counter.

Evaluation criteria:

The test material may be considered positive in this test system if the following criteria are met:
The test material should have induced a reproducible, dose-related and statistically (Dunnett's method of linear regression (5)) significant increase in the revertant count in at least one strain of bacteria.

Statistics:

no data

Results and discussion

Test results

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity, but tested up to precipitating concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Under the test conditions, Linalyl Isobutyrate is not considered as mutagenic in S. typhimurium TA 1535, TA 1537, TA 98 and TA 100 & TA 102 strains.