Linalyl propionate

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:

29/10/2003 - 28/11/2003

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:

2004

Report date:

2004

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:

Linalyl propionate

EC Number:

205-627-5

EC Name:

Linalyl propionate

Cas Number:

144-39-8

Molecular formula:

C13H22O2

IUPAC Name:

3,7-dimethylocta-1,6-dien-3-yl propanoate

impurity 1

Reference substance name:

Unknown impurities

Molecular formula:

not applicable

IUPAC Name:

Unknown impurities

Test material form:

liquid

Details on test material:

Internal RCC-CCR Test Item number: S 4135 1 1
Batch Number: 9000519514
Aggregate State at room temperature: Liquid
Colour: Colorless to pale yellow
Purity: 97.1%
Stability in solvent: Not indicated by sponsor
Storage: Room Temperature
Expiration date: June 16, 2004

Method

Target gene:

Reversion to histidine dependence

Species / strain

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

Phenobarbital / beta-naphthoflavone induced male Wistar rat liver S9 fraction

Test concentrations with justification for top dose:

In the pre-experiment the concentration range of the test item was 3 - 5000 µg/plate. The pre-experiment is reported as experiment I since only minor toxic effects were observed and 5000 µg/plate were chosen as maximal concentration.

The following concentrations were tested:

-Experiments I and II: 33; 100; 333; 1000; 2500; and 5000 ug/plate
-Experiment II a: 10; 33; 100; 333; 666; 1000; 2500; and 5000 ug/plate

Vehicle / solvent:

Ethanol ( Purity >99%). The solvent was chosen because of its solubility properties and its relative non toxicity to the bacteria.

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Remarks:

ethanol

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

methylmethanesulfonate

other: 2-aminoanthracene, 4-NOPD

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium; in agar (plate incorporation); preincubation; in suspension; as impregnation on paper disk

DURATION
- Preincubation period: 60 minutes
- Exposure duration: 48 hours

NUMBER OF REPLICATIONS: 3

DETERMINATION OF CYTOTOXICITY
- Method: colny numbers, assessment of background lawn

Evaluation criteria:

This assay was considered acceptable if it meets the following criteria:

-Regular background growth in the negative and solvent control
-the spontaneous reversion rates in the negative and solvent control are in the range of historical data
-the positive control substances should product a significant increase in mutant colony frequencies

Statistics:

A statistical analysis of the data is not required

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

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:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 4

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 5

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

In the first experiment, the plates incubated with the test item showed normal background growth up to 5000 ug/plate with and without S9 in all strains used. In the second experiment bacterial background growth was reduced in strain TA 1535 at 5000 ug/plate without metabolic activation, in strains TA 1537, TA 98, and TA 100 at 2500-5000 ug/plate with and without metabolic activation and in strain TA 102 at 1000-5000 ug/plate with and without metabolic activation. In the repeat experiment IIa - the background growth of strain TA 102 was reduced at 1000-5000 ug/plate.

No substantial increase in the revertant colony numbers of any of the five tester strains was observed following treatment with Linalyl Propionate at any concentration level, neither in the presence nor absence of metabolic activation ( S9 mix). There was also no tendency of higher mutation rtes with increasing concentrations in the range below the generally acknowledged border of biological relevance.

Appropriate reference mutagens were used as positive controls. They showed a distinct increase in induced revertant colonies. The upper limit of the historical control range was exceeded in strain TA 1535 in the second experiment without metabolic activations and in strain TA 1537 with metabolic activation in both experiments as well as strain TA 102 in the first experiment with metabolic activation. This effect is considered to emphasise the sensitivity of the assay rather than compromising the study.

Any other information on results incl. tables

No further information available

Applicant's summary and conclusion

Conclusions:

There is no evidence of mutagenicity was seen under the conditions of this study.

Executive summary:

The potential of linalyl propionate to induce reverse mutation was investigated in an Ames test using Salmonella typhimurium strains TA98, TA100, TA1535, TA1537 and TA 102 in the absence and presence of an exogenous metabolic activation system (phenobarbital / β-naphthoflavone-induced male Wistar rat liver S9 fraction). In an initial (plate incorporation) assay, triplicate cultures of bacterial strains were exposed to the test material (dissolved in ethanol) at concentrations of between 0 and 5000 µg/plate. Exposure to the test material did not result in any significant increase in the numbers of revertant colonies.  Results were confirmed in an independently repeated pre-incubation assay. The sensitivity of the assay was demonstrated by the induction of significant increases in numbers of revertant colonies by appropriate positive control compounds. No evidence of mutagenicity was seen under the conditions of this assay.