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Toxicological information

Genetic toxicity: in vitro

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Administrative data

Endpoint:
in vitro gene mutation study in bacteria
Remarks:
Type of genotoxicity: gene mutation
Type of information:
migrated information: read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The analogue isobornyl acetate which shares the same functional groups with dextro alpha fenchyl acetate also has comparable values for the relevant molecular properties. Test method according to OECD 471. GLP study.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1988
Report date:
1988

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 471 (Bacterial Reverse Mutation Assay)
GLP compliance:
yes
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Chemical structure
Reference substance name:
Exo-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl acetate
EC Number:
204-727-6
EC Name:
Exo-1,7,7-trimethylbicyclo[2.2.1]hept-2-yl acetate
Cas Number:
125-12-2
Molecular formula:
C12H20O2
IUPAC Name:
(1S,2S,4S) 1,7,7-trimethylbicyclo[2.2.1]hept-2-yl acetate
Details on test material:
- Name of test material (as cited in study report): Isobornylacetat-Extra
- Molecular formula (if other than submission substance): C12H20O2
- Molecular weight (if other than submission substance): 196.286
- Smiles notation (if other than submission substance): CC(=O)O[C@H]1C[C@@H]2CC[C@@]1(C)C2(C)C
- InChl (if other than submission substance): 1/C12H20O2/c1-8(13)14-10-7-9-5-6-12(10,4)11(9,2)3/h9-10H,5-7H2,1-4H3
- Structural formula attached as image file (if other than submission substance): see Fig.
- Physical state: Liquid
- Lot/batch No.: 125.12.2
- Storage condition of test material: in a glass bottle, at room temperature

Method

Target gene:
Histidine-requiring gene
Species / strain
Species / strain / cell type:
S. typhimurium, other: TA 98, TA 100, TA 1535, TA 1537, TA 1538
Metabolic activation:
with and without
Metabolic activation system:
S9 from Sprague-Dawley rat livers induced with Aroclor 1254
Test concentrations with justification for top dose:
TEST 1:
With and without metabolic activation: 10, 50, 100, 250, 500 µg/plate
TEST 2:
With metabolic activation: 10, 50, 100, 250, 500 µg/plate (TA 1535, TA 98 and TA 100) and 10, 50, 100, 250, 400 µg/plate (TA 1537 and TA 1538)
Without metabolic activation: 10, 50, 100, 250, 500 µg/plate
Vehicle / solvent:
Vehicle(s)/solvent(s) used: DMSO
Controlsopen allclose all
Untreated negative controls:
yes
Negative solvent / vehicle controls:
yes
Remarks:
(DMSO)
Positive controls:
yes
Remarks:
(TA1535, TA100)
Positive control substance:
sodium azide
Remarks:
3 µg/plate
Positive controls:
yes
Remarks:
(TA1537)
Positive control substance:
9-aminoacridine
Remarks:
100 µg/plate
Positive controls:
yes
Remarks:
(TA1538, TA98, without metabolic activation)
Positive control substance:
2-nitrofluorene
Remarks:
0.5 µg/plate
Positive controls:
yes
Remarks:
(TA1538, TA98, with metabolic activation)
Positive control substance:
other: 2-aminofluorene
Remarks:
5 µg/plate
Details on test system and experimental conditions:
METHOD OF APPLICATION: in agar (plate incorporation)
0.1 mL of strain is added to 2 mL molten agar containing traces of histidine and biotin at 45 ºC. The test item is added in 0.1 mL solvent. Each concentration is tested in presence of 0.5 mL S-9 mix or 0.5 mL phosphate buffer. After rapid homogenization, the mixture is spread out on a petri plate containing minimum medium. Revertants are scored after 48 hours of incubation at 37 ºC.

DURATION
- Exposure duration: 48 h

NUMBER OF REPLICATIONS: 3 plates for each set of conditions

DETERMINATION OF CYTOTOXICITY
- Method: bacterial growth
Evaluation criteria:
Mutation rate: number of revertants in the treated plate/number of revertants in the respective control plate.

Results and discussion

Test results
Species / strain:
S. typhimurium, other: TA 98, TA 100, TA 1535, TA 1537, TA 1538
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
cytotoxicity
Remarks:
(TA 1537 and TA 1538 at 500 µg/plate)
Vehicle controls validity:
valid
Untreated negative controls validity:
valid
Positive controls validity:
valid
Additional information on results:
RANGE-FINDING/SCREENING STUDIES: To define the maximal concentration, four concentrations were tested in TA98 and TA100: 10, 100, 1000 and 5000 µg/plate. Bacteriostatic activity was measured by checking the background bacterial growth of survivors and a decrease in the revertant's number. A bacteriostatic effect was observed with and without metabolic activation at 1000 and 5000 µg/plate in both strains.
Remarks on result:
other: all strains/cell types tested
Remarks:
Migrated from field 'Test system'.

Any other information on results incl. tables

TEST 1:

Strain

Dose µg/plate

Without metabolic activation

With metabolic activation

Revertants/plate (mean value)

Mutation rate

Revertants/plate (mean value)

Mutation rate

TA1535

-

16

-

-

-

0

12

0.7

12

-

10

16

1.3

9

0.7

50

17

1.4

11

0.9

100

18

1.4

9

0.8

250

8

0.7

11

0.9

500

12

1.0

10

0.9

NaN3 3

929

79.6

-

-

TA1537

-

8

-

-

-

0

8

1.0

11

-

10

8

1.0

10

1.0

50

8

0.9

8

0.8

100

10

1.2

7

0.6

250

8

1.0

5

0.5

500

*

*

5

0.5

9AA 100

2383

286.0

-

-

TA1538

-

17

-

-

-

0

12

0.7

17

-

10

13

1.1

19

1.1

50

15

1.3

24

1.4

100

12

1.0

18

1.1

250

13

1.1

18

1.0

500

3*

0.3*

8

0.4

2NF 0.5 / 2AF 5

425

36.4

2006

115.8

TA98

-

14

-

-

-

0

14

1.0

19

-

10

10

0.7

18

1.0

50

15

1.1

17

0.9

100

16

1.2

17

0.9

250

17

1.2

21

1.1

500

11

0.8

18

1.0

2NF 0.5 / 2AF 5

231

16.9

2072

111.0

TA100

-

122

-

-

-

0

105

0.9

95

-

10

103

1.0

107

1.1

50

99

0.9

104

1.1

100

92

0.9

105

1.1

250

88

0.8

88

0.9

500

80

0.8

84

0.9

NaN3 3

973

0.9

-

-

*: Inhibition of bacterial growth

TEST 2:

Strain

Dose µg/plate

Without metabolic activation

With metabolic activation

Revertants/plate (mean value)

Mutation rate

Revertants/plate (mean value)

Mutation rate

TA1535

-

19

-

-

-

0

24

1.3

14

-

10

20

0.8

17

1.2

50

19

0.8

14

1.0

100

15

0.6

15

1.1

250

18

0.8

14

1.0

500

12

0.5

10

0.7

NaN3 3

852

35.5

-

-

TA1537

-

12

-

-

-

0

11

0.9

10

-

10

10

0.9

9

1.0

50

7

0.6

8

0.6

100

9

0.8

6

0.7

250

7

0.6

7

0.7

500

5

0.4

7

0.7

9AA 100

2238

197.5

-

-

TA1538

-

12

-

-

-

0

12

1.1

20

-

10

11

0.9

19

1.0

50

15

1.2

25

1.2

100

11

0.9

23

1.2

250

18

1.4

21

1.1

400

11

0.9

16

0.8

2NF 0.5 / 2AF 5

476

36.5

1501

75.1

TA98

-

24

-

-

-

0

22

0.9

25

-

10

20

0.9

30

1.2

50

14

0.6

35

1.4

100

14

0.6

23

0.9

250

10

0.4

26

1.0

400

11

0.5

19

0.7

2NF 0.5 / 2AF 5

184

8.4

1541

51.7

TA100

-

98

-

-

-

0

91

0.9

79

-

10

89

1.1

87

1.1

50

81

1.0

87

1.1

100

80

1.0

71

0.9

250

65

0.6

55

0.7

500

55

0.7

43

0.6

NaN3 3

1038

12.7

-

-

The data matrix is included in the reporting format attached.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative (with and without metabolic activation)

Based on the read-across approach from experimental data on analogue isobornyl acetate, dextro alpha fenchyl acetate was determined to be not mutagenic with or without metabolic activation in any of the tested strains.
Executive summary:

An in-vitro bacterial reverse mutation assay (Ames test) was performed with the analogue substance isobornyl acetate in accordance with OECD 471. Based on preliminary results, Salmonella typhimurium strains TA1535, TA1537, TA1538, TA98 and TA100 were exposed up to 500 µg/plate test item in DMSO with and without metabolic activation (triplicates), in two separate tests. The positive controls attested the sensitivity of the used strains and the efficiency of metabolic activation. No mutagenic effect occurred with and without metabolic activation in any of the five strains. Based on these results, the read-across approach was applied and dextro alpha fenchyl acetate was determined to be not mutagenic in the Ames test.