3-methyl-2-butenal

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

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions. Restriction: only 2 strains of S. typhimurium used.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1991

Report date:

1991

Materials and methods

Principles of method if other than guideline:

Reverse mutation according to Ames, B. N. et al., Proc. Nat. Acad. Sci. USA, 70, 2281-2285 (1973). Modification described by Rannug et al., Chem. Biol. Interaction, 12, 151-263 (1976) and Lutz et al., Mut. Res., 93, 305-315 (1982)

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

3-methyl-2-butenal

EC Number:

203-527-6

EC Name:

3-methyl-2-butenal

Cas Number:

107-86-8

Molecular formula:

C5H8O

IUPAC Name:

3-methyl-2-butenal

Details on test material:

- Name of test material (as cited in study report): 3-Methyl-2-butenal, CAS: 107-86-8
- Analytical purity: 98%
- Lot/batch No.: B 2240/12.04.88
- Storage condition of test material: room temperature

Method

Target gene:

Salmonella/Mammalian-Microsomes

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 98

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 100

Metabolic activation:

with and without

Metabolic activation system:

liver S9 Aroclor 1254-induced

Test concentrations with justification for top dose:

20, 100, 500, 2000, 2500, 3000, 4000, 5000, 6000 ug/plate

Vehicle / solvent:

water

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: with S-9: 2-aminoanthracene (2-AA) (DMSO) for TA 100 and TA 98; without S-9: N-methyl-N*-nitro-N-nitrosoguanidine (MNNG) (DMSO) for the strain TA 100 4-nitro-o-phenylendiamine (NPD) (DMSO) for the strain TA 98

Evaluation criteria:

In general, a substance to be characterized as positive in the Ames test has to fulfill the following requirements:
- doubling of the spontaneous mutation rate (control)
- dose-response relationship
- reproducibility of the results

Statistics:

none

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 98

Metabolic activation:

with and without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

other: 1000-3000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 100

Metabolic activation:

with and without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

other: 1000-3000 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

Results without S9-mix: TA 100 was weakly positive (2.1-2.5-fold) in the 1st experiment at 2500-5000 ug/plate and more positive in subsequent experiments from 100-500 ug/plate (factor 1.7-4.6) with a maximum at 1000-3000 ug/plate (factor 6.0-8.1). TA 98 showed a slight increase (factor 2.1) at 2500 µg/plate which was not concentration dependent.
Results with S9-mix: With TA 100 increased revertant numbers were seen at very high concentrations in the first experiment (1.6-fold at 5000 ug/plate) and in the second experiment (2.5-fold at 2000 ug/plate). In the third experiment mutagenicity was seen at lower concentrations (2.4-2.7-fold at 100-500 ug/plate). TA 98 showed no increased number of revertants. Cytotoxicity was observed only in the 2nd and 3rd experiment using TA 100 from 1000-3000 ug/plate.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

TA 100

Dose (mg/plate)	S9-mix	mean	SD	S9-mix	mean	SD
negative ctrl	- S9	106	8	+S9	124	8
20		98	9		108	14
100		100	7		96	12
500		123	14		90	16
2500		219	28		122	28
5000		265	44		199	60
positive ctrl (2-AA)		n.d.	n.d.		851	497
positive ctrl (MNNG)		670	3		n.d.	n.d.
positive ctrl (CA)		265	17		n.d.	n.d.
positive ctrl (MVK)		261	19		n.d.	n.d.

TA 98

Dose (mg/plate)	S9-mix	mean	SD	S9-mix	mean	SD
negative ctrl	- S9	40	3	+S9	37	6
20		37	7		32	2
100		33	3		39	5
500		34	3		34	6
2500		84	8		31	2
5000		49	9		29	2
positive ctrl (NPD)		581	104		n.d.	n.d.
positive ctrl (2-AA)		n.d.	n.d.		2113	110

Test 2:

TA 100

Dose (mg/plate)	S9-mix	mean	SD	S9-mix	mean	SD
negative ctrl	- S9	126	7	+S9	139	12
2000		1013	26		349	59
3000		865	22		-	-
4000		300	8		-	-
5000		-	-		0	0
6000		0	0		0	0
positive ctrl (2-AA)		n.d.	n.d.		2313	244
positive ctrl (MNNG)		2927	64		n.d.	n.d.
positive ctrl (CA)		1317	51		n.d.	n.d.
positive ctrl (MVK)		544	31		n.d.	n.d.

TA 98

Dose (mg/plate)	S9-mix	mean	SD	S9-mix	mean	SD
negative ctrl	- S9	125	11	+S9	115	17
100		208	14		279	60
500		579	37		309	38
1000		743	91		76	45
2000		331	20		37	9
3000		234	78		28	5
positive ctrl (2-AA)		n.d.	n.d.		1643	199
positive ctrl (MNNG)		1527	119		n.d.	n.d.
positive ctrl (CA)		779	31		n.d.	n.d.
positive ctrl (MVK)		489	34		n.d.	n.d.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
positive

Positive results of the study are ambiguous since the
effects were not coherent between the three experiments and the dose-relationship was not clear.