2-methylpropyl-(R)-2-hydroxypropanoate

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in mammalian cells

Remarks:

Type of genotoxicity: gene mutation

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Publication, results are based on the read-across partner 2-Methyl-1-propanol (isobutanol).

Data source

Reference

Reference Type:

publication

Title:

Evaluation of the genotoxic potential of some microbial volatile organic compounds (MVOC) with the comet assay, the micronucleus assay and the HPRT gene mutation assay

Author:

Kreja L

Year:

2002

Bibliographic source:

Mutation Research 513 (2002): 143-150

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 476 (In Vitro Mammalian Cell Gene Mutation Test)

Deviations:

yes

Remarks:

no positive control in the experiment with metabolic activation reported

GLP compliance:

no

Type of assay:

mammalian cell gene mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2-methylpropan-1-ol

EC Number:

201-148-0

EC Name:

2-methylpropan-1-ol

Cas Number:

78-83-1

Molecular formula:

C4H10O

IUPAC Name:

2-methylpropan-1-ol

Constituent 2

Reference substance name:

isobutanol

IUPAC Name:

isobutanol

Test material form:

not specified

Details on test material:

- Name of test material (as cited in study report): 2-Methyl-1-propanol

Method

Target gene:

HPRT

Species / strain

Species / strain / cell type:

Chinese hamster lung fibroblasts (V79)

Details on mammalian cell type (if applicable):

- Type and identity of media:
without metabolic activation: MEM Eagle medium with 10% fetal calf serum, 2mM L-glutamine, 100 IU/mL penicillin and streptomycin
with metabolic activation: above mentioned medium plus 3% S9-mix

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

only the highest non-toxic concentration tested is reported: 107 mM

Vehicle / solvent:

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

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

no

True negative controls:

no

Positive controls:

yes

Positive control substance:

methylmethanesulfonate

Remarks:

final concentration: 0.5 mM

Details on test system and experimental conditions:

METHOD OF APPLICATION:
in medium

DURATION
- Preincubation period: 24h
- Exposure duration: 2h
- Expression time (cells in growth medium): 7 days
- Selection time (if incubation with a selection agent): 7 days
- Fixation time (start of exposure up to fixation or harvest of cells): 14 days

SELECTION AGENT (mutation assays): 6-thioguanine (10 µg/mL)

DETERMINATION OF CYTOTOXICITY
- Method: cloning efficiency

Evaluation criteria:

The test compound was classified as a mutagen when it was able to enhance in a concentration-depended manner the spontaneous HPRT frequency by a factor of three or more.

Statistics:

N.A.

Results and discussion

Test results

Species / strain:

Chinese hamster lung fibroblasts (V79)

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

not applicable

Untreated negative controls validity:

valid

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: Mutant frequency for HPRT gene in V79 cells

Substance	Highest non toxic concentration tested (mM)	Mutant frequency (x 10^6)
		without S9		with S9
Negative Control	0	0 - 2.8		0 - 3.1
MMS (Positive control)	0.5	92		-
2-Methyl-1-propanol	107	0		1.3

Applicant's summary and conclusion

Conclusions:

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

In conclusion, in the described in vitro cell gene mutagenicity test under the experimental conditions reported, the test item 2-Methyl-1-propanol is considered to be non-mutagenic in the HPRT locus using V79 cells of the Chinese Hamster.

Executive summary:

In a mammalian cell HPRT gene mutation assay similar to OECD guideline 476, V79 cells cultured in vitro were exposed to 2-Methyl-1-propanol in medium. The highest non toxic concentration reported and tested was 107 mM in the presence and absence of mammalian metabolic activation. No increase in mutant frequency was observed after treatment with 2-Methyl-1-propanol in comparison to the untreated control. The positive control did induce the appropriate response. 2-Methyl-1-propanol (isobutanol) is used as read-across partner to isobutyl-R-lactate.