Methyl octanoate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across based on grouping of substances (category approach)

Adequacy of study:

weight of evidence

Study period:

28 Apr - 07 May 1992

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP guideline study with acceptable restrictions (incomplete strain selection, E. coli strain is missing)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

adopted in 1983

Deviations:

yes

Remarks:

(incomplete strain selection since E. coli strain is missing)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Methyl hexanoate

EC Number:

203-425-1

EC Name:

Methyl hexanoate

Cas Number:

106-70-7

IUPAC Name:

methyl hexanoate

Details on test material:

- Name of test material (as cited in study report): Methylhexanoat
- Substance type: Fatty acid methyl ester
- Physical state: liquid, colourless
- Analytical purity: >98%
- Impurities: Not given
- Lot/batch No.: 1291191
- Expiration date of the lot/batch: 24.06.1992
- Stability: approx. 3 years
- Storage condition of test material: Room temperature

Method

Target gene:

his operon

Species / strain

Species / strain 1

Species / strain / cell type:

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

Additional strain / cell type characteristics:

other: rfa-; uvrB- (R+ for TA 98)

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 1538

Additional strain / cell type characteristics:

other: rfa-; uvrB-; R+

Metabolic activation:

with and without

Metabolic activation system:

cofactor supplemented post-mitochondrial fraction (S9 mix) prepared from the livers of rats treated with Aroclor 1254.

Test concentrations with justification for top dose:

8, 40, 200, 1000 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: according to solubility properties tested before the start of the study

Controls

Untreated negative controls:

yes

Remarks:

untreated fresh cell suspension

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: 2 µg/plate sodium azide (TA100 and 1535, -S9), 80 µg/plate 9-aminoacridine (TA1537, -S9), 40 µg/plate 4-nitro-o-phenylendiamine (TA98 and 1538, -S9), 2.5 µg/plate 2-aminoanthracene (TA1535, 1537, +S9), 5 µg/plate 2-aminoanthracene (TA98, 100, 1538, +S9)

Details on test system and experimental conditions:

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

DURATION
- Exposure duration: 48 h
- Expression time (cells in growth medium): 48 h

NUMBER OF REPLICATIONS: triplicates in each of two independent experiments

DETERMINATION OF CYTOTOXICITY
- Method: Inspection of the bacterial background lawn wit a dissecting microscope


OTHER: The spontaneous mutation rates of each tester strain were within the characteristic spontaneous mutation rates

Evaluation criteria:

Revertant colonies were counted and the mean and standard deviation were calculated and compared to the controls. The tester strains were regulary tested for their genetic markers.
All cultures must demonstrate the characteristic mean number of spontaneous revertants in the vehicle controls.

Statistics:

Mean and standard deviation were calculated

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:

at 5000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1538

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

at 5000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

COMPARISON WITH HISTORICAL CONTROL DATA: Yes

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Mutagenicity on bacteria - experiment I

With or without S9-Mix	Test substance concentration (μg/plate)	Mean number of revertant colonies per plate (average of 3 plates)
		TA 1535	TA100	TA1537	TA1538	TA98
	Buffer	7	95	7	5	13
-	Solvent (DMSO)	9	101	7	7	12
-	8	8	90	7	9	10
-	40	8	98	10	9	14
-	200	9	92	7	6	19
-	1000	7	84	5	7	13
	5000	5	88	2	4	8
Positive controls - S9	Name	SA	SA	9AA	4ND	4ND
	Concentrations (μg/plate)	2	2	80	40	40
	Number of colonies/plate	626	769	918	1972	1532
+	Buffer	14	92	6	11	33
+	Solvent (DMSO)	10	96	11	16	37
+	8	13	99	10	18	36
+	40	11	108	5	19	34
	200	9	114	8	15	23
+	1000	6	99	6	17	25
+	5000	9	73	5	8	12
Positive controls + S9	Name	2AA	2AA	2AA	2AA	2AA
	Concentrations (μg/plate)	2.5	5	2.5	5	5
	Number of colonies/plate	221	1492	113	1465	1711

 

9AA = 9-Aminoacridine

2AA = 2-Aminoanthracene

SA = Sodium Acide

4ND = 4-Nitro-o-phenylendiamine

 

 

Table 2: Mutagenicity on bacteria - experiment II

With or without S9-Mix	Test substance concentration (μg/plate)	Mean number of revertant colonies per plate (average of 3 plates)
		TA 1535	TA100	TA1537	TA1538	TA98
	Buffer	10	112	14	11	19
-	Solvent (DMSO)	9	105	9	10	15
-	8	9	110	12	8	12
-	40	7	102	10	6	12
-	200	6	108	9	10	18
-	1000	9	101	7	8	16
	5000	8	81	6	11	10
Positive controls - S9	Name	SA	SA	9AA	4ND	4ND
	Concentrations (μg/plate)	2	2	80	40	40
	Number of colonies/plate	687	824	1016	1897	1418
+	Buffer	12	125	8	16	28
+	Solvent (DMSO)	7	109	7	18	27
+	8	8	113	7	14	27
+	40	11	117	9	14	25
	200	11	98	11	18	28
+	1000	8	105	9	14	30
+	5000	8	68	6	6	13
Positive controls + S9	Name	2AA	2AA	2AA	2AA	2AA
	Concentrations (μg/plate)	2.5	5	2.5	5	5
	Number of colonies/plate	218	1584	125	1415	1967

9AA = 9-Aminoacridine

2AA = 2-Aminoanthracene

SA = Sodium Acide

4ND = 4-Nitro-o-phenylendiamine

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative