(R)-2,2,3-trimethylcyclopent-3-ene-1-acetaldehyde

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

Study period:

31st December 1999 to 3rd January 2000

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Study reported to have been conducted in accordance with OECD Guideline 471 and EU Method B13/14, however the information on all strains except TA100 was apparently deleted, therefore the test only has limited ability to detect mutations induced by base-pair substitution. However, the study was performed and reported to a good standard. Therefore it cannot be confirmed whether the test substance is mutagenic or not based on the results of the current study. No information on GLP status of the study provided.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

yes

Remarks:

(only TA100 used)

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

(only TA100 tested)

GLP compliance:

not specified

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

(R)-2,2,3-trimethylcyclopent-3-ene-1-acetaldehyde

EC Number:

224-815-8

EC Name:

(R)-2,2,3-trimethylcyclopent-3-ene-1-acetaldehyde

Cas Number:

4501-58-0

Molecular formula:

C10H16O

IUPAC Name:

(R)-2,2,3-trimethylcyclopent-3-ene-1-acetaldehyde

Details on test material:

- Name of test material (as cited in study report): Campholen aldehyde
- Storage condition of test material: cool and dry

Method

Target gene:

Histidine operon hisG46

Species / strain

Species / strain / cell type:

S. typhimurium TA 100

Details on mammalian cell type (if applicable):

- Type and identity of media: 1.5 % agar in Vogel-Bonner medium E with 2 % glucose
- Properly maintained: yes
- Periodically "cleansed" against high spontaneous background: yes

Metabolic activation:

with and without

Metabolic activation system:

S9

Test concentrations with justification for top dose:

15, 50, 150, 500, 1500 and 5000 µg per plate.

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene and sodium azide both administered at 0.7 µg/plate

Details on test system and experimental conditions:

METHOD OF APPLICATION: in medium; in agar (plate incorporation)

DURATION
- Exposure duration: 48 to 72h

NUMBER OF REPLICATIONS: Three per test concentration

Evaluation criteria:

Plates were counted for number of revertant colonies (his+ revertants) and examined for the existence of a normal background lawn and/or precipitates and microscopically for microcolony growth.

When there was any doubt about the nature of the colonies scored as revertants, and when positive mutagenic results are obtained, the genotype of the revertant colonies are spot-checked streaking on histidine free plates.

Results and discussion

Test results

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

slightly bacteriotoxic at 1500 µg/plate; background lawn was nearly absent at 5000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Induction of revertants in S. typhimurium by Campholen aldehyde in the absence of a metabolising system

Substance	Concentration (µg/plate)	S9	Number of revertants per plate TA100
			Counts	Mean	SD
Control	0	-	134
			162	154	16
			167
Solvent control	0	-	143
			151	157	15
			176
Campholen aldehyde	15	-	162
			142	157	11
			166
Campholen aldehyde	50	-	140
			141	136	7
			127
Campholen aldehyde	150	-	165
			144	152	10
			146
Campholen aldehyde	500	-	119
			129	134	16
			154
Campholen aldeyhde	1500	-	64
			112	82 T	22
			71
Campholen aldehyde	5000	-	0
			0	0 T	0
			0
NaN3	0.7	-	432
			446	434	10
			423

T - bacteriotoxic

Table 2: Induction of revertants inS. typhimuriumby Campholen aldehyde in the presence of a metabolising system

Substance	Concentration (µg/plate)	S9	Number of revertants per plate TA100
			Counts	Mean	SD
Control	0	+	149
			171	148	21
			123
Solvent control	0	+	163
			127	150	18
			161
Campholen aldehyde	15	+	141
			156	152	9
			158
Campholen aldehyde	50	+	159
			190	166	19
			148
Campholen aldehyde	150	+	170
			151	160	9
			160
Campholen aldehyde	500	+	124
			106	122	14
			137
Campholen aldehyde	1500	+	134
			119	126 T	7
			125
Campholen aldehyde	5000	+	0
			0	0 T	0
			0
2 -AA	0.7	+	1356
			1464	1330	122
			1170

T - bacteriotoxic

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative with and without metabolic activation in the S. typhimurium strain TA100

Under the conditions of the test, the test substance failed to induce a significant or dose-related increase in the mutation frequency of the strain TA100 in the absence and presence of metabolic activation. The estimation of the statistical significance of the difference between the mean number of revertants in the negative controls and the plates at each dose level, using a X2-test, did not reveal a significant effect at any of the test points.

Executive summary:

The mutagenicity of the substance Campholen aldehyde was studied with the mutant strain TA100 of Salmonella typhimurium. The investigations were carried using the standard plate incorporation assay with and without liver homogenates (S9) from Aroclor 1254 pretreated male rats as the metabolic activation system.

Campholen aldehyde was dissolved in DMSO and tested in concentrations of 15 to 5000 µg per plate in the presence and absence of S9. In the absence and presence of S9-mix, Campholen aldehyde was slightly bacteriotoxic towards the strain TA100 at 1500 µg/plate and at 5000 µg/plate background lawn was nearly absent and no revertants were found.

Sodium azide and 2 -aminoanthracene served as positive controls to confirm the reversion properties and the specificity of the bacterial strain as well as the efficacy of the metabolising system.

In the concentration range investigated, Campholen aldehyde did not induce any increase in the mutation frequency of the tester strain TA100 in the presence and absence of a metabolic activation system.

In conclusion, these results indicate that Campholen aldehyde, under the experimental conditions described, was not mutagenic to Salmonella typhimurium strain TA100 in the presence and absence of a metabolising system.