Benzenepropanoic acid, .beta.,4-dimethoxy-, methyl ester

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: Guideline study conducted in accordance with GLP; low purity of the test substance (72.1 %)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1994

Report date:

1994

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

Test material information

Constituent 1

Reference substance name:

methyl 3-methoxy-3-(4-methoxyphenyl)propanoate

EC Number:

614-925-8

Cas Number:

69098-08-4

Molecular formula:

C12 H16 O4

IUPAC Name:

methyl 3-methoxy-3-(4-methoxyphenyl)propanoate

Details on test material:

- Name of test material (as cited in study report): 3-(4-Methoxyphenyl)-3-methoxypropionsaueremethylester, technical grade
- Substance No.: 93/98
- Batch No.: Ansatz 165
- Purity: 71.2 %.
- Date of manufacturing: 22 Apr 1993
- Physical state: solid, brown; after heating at about30 °C: liquid brown
- Storage condition of test material: REFRIGERATOR, EXCLUSION OF LIGHT AND AIR (UNDER NITROGEN), EXCLUSION OF MOISTURE

Method

Target gene:

Histidine operon

Species / strain

Species / strain / cell type:

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

Metabolic activation:

with and without

Metabolic activation system:

Aroclor induced rat liver S9-mix

Test concentrations with justification for top dose:

- 1st experiment: 20, 100, 500, 2500, 5000 µg/plate
- 2nd, 3rd, 4th and 5th experiment: 1000, 2000, 3000, 4000, 5000 µg/plate

Vehicle / solvent:

Vehicle used: DMSO

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: With S9-mix: 2.5 µg/plate 2-aminoanthracene for the strains TA 100, TA 98, TA 1537 and TA 1535; without S9-mix: 5 µg/plate N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) for the strains TA 100 and TA 1535, 10 µg/plate 4-nitro-o-phenylenediamine (NPD) for

Remarks:

all positive control substances dissolved in DMSO

Details on test system and experimental conditions:

METHOD OF APPLICATION:
- standard plate test

DURATION
- Preincubation period: no
- Exposure duration: 48 h

NUMBER OF REPLICATIONS: 3

USED STRAINS
1st experiment: strains TA 1535, TA 100, TA 1537, TA 98
2nd, 3rd, 4th and 5th experiments: strain TA1537

DETERMINATION OF CYTOTOXICITY
- decrease in number of his-revertants
- reduction of titer determination; titer only determined in the experiments with S-9 mix both without test substance (vehicle only) and after adding the two highest doses of test substance

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

Results and discussion

Test results

Test results 1

Species / strain:

other: S. typhimurium TA, 1535, TA 98, TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

>= 2500 µg/plate

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1537

Metabolic activation:

with and without

Genotoxicity:

ambiguous

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

>= 2500 µg/plate depending on the experiment

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Remarks on result:

other: strain/cell type: S. typhimurium TA, 1535, TA 98, TA 100

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Cytotoxicity: A weakly bacteriotoxic effect (slight decrease in the number of his + revertants and a reduced titer) was observed

depending on the strain and test conditions at doses >= 2500 µg/plate.

Mutagenicity:

Tests without S-9 mix:

The strains TA 1535, TA 100 and TA 98 showed no increase in the number of his+ revertants.

The strain TA 1537 showed occasionally some increased colony numbers in the 1st (factor 0.6 -1.5), 3rd (factor 0.5 -1.6),

4th (0.7 - 1.5) and 5th (factor 0.7 -1.4) experiment. The evaluation criteria indicated a positive reaction, when among other things a

doubling of the spontaneous mutation rate was observed. So the findings were stated as not relevant. A positive reaction was

observed in the 2nd experiment from 1000 - 5000 µg/plate (factor 1.8 - 4.4).

Tests with S-9 mix:

The strains TA 1535, TA 100 and TA 98 showed no increase in the number of his+ revertants.

The strain TA 1537 showed no increase in the number of his+ revertants in the 3rd and 4th experiments. Some not relevant, slightly

increased colony numbers were observed in the 1st experiment (factor 1.0 -1.9). A positive reaction was observed in the 2nd

experiment at 2000 - 4000 µg (factor 2.1 - 3.4) and in the 5th experiment at 3000 - 5000 µg/plate (factor 1.9 -3.1).

The positive controls showed the expected increase in his+ revertants/plate.

Results:

Dose µg/plate	metabolic activation	TA98			TA100			TA1535			TA1537
		Trial 1	Trial 2	Trial 3	Trial 1	Trial 2	Trial 3	Trial 1	Trial 2	Trial 3	Trial 1	Trial 2	Trial 3
0	+	44	34	47	144	107	114	13	11	17	10	10	13
20	+	51	37	53	112	121	128	13	20	15	10	11	11
100	+	43	46	43	125	138	136	15	16	15	17	7	10
500	+	37	41	37	132	127	127	20	14	14	19	10	20
2500	+	39	37	35	134	125	120	13	15	17	19	23	20
5000	+	25	19	25	117	118	132	20	23	15	19	16	16
2.5 µg 2-Aminoanthracene	+	670	586	676	970	970	930	111	88	96	82	92	114
0	-	38	29	39	114	115	89	16	19	23	13	12	14
20	-	21	21	26	107	113	122	20	20	20	6	8	8
100	-	43	28	30	100	148	121	27	20	21	6	10	9
500	-	29	32	23	118	113	116	23	26	21	20	10	9
2500	-	27	39	30	108	128	121	25	22	30	20	14	23
5000	-	42	36	31	117	71	80	29	33	26	18	19	19
5 µg MNNG	-				873	820	770	920	865	660
10 µg 4-Nitro-o-phenylendiamin	-	1054	1074	982
100 µg 9-Aminoacridiniumchloride monohydrate	-										602	804	843

Dose µg/plate	metabolic activation	TA1537			TA1537			TA1537			TA1537
		Trial 1	Trial 2	Trial 3	Trial 1	Trial 2	Trial 3	Trial 1	Trial 2	Trial 3	Trial 1	Trial 2	Trial 3
0	+	12	16	18	21	8	12	20	15	10	9	10	12
20	+	13	10	22	3	15	10	11	15	14	7	12	15
100	+	30	33	33	22	12	16	15	7	12	15	6	15
500	+	46	43	52	21	11	10	7	12	10	23	12	25
2500	+	47	51	60	13	12	10	12	10	15	29	20	15
5000	+	19B	25B	30B	2B	1B	B	24	12	18	29	28	38
2.5 µg 2-Aminoanthracene	+	87	87	104	78	89	92	105	110	100	95	101	112
0	-	10	10	12	12	6	14	11	12	15	10	8	12
20	-	22	17	20	18	6	9	14	14	10	11	8	16
100	-	21	36	48	17	15	15	14	4	13	8	10	11
500	-	49	55	37	15	16	20	9	19	10	10	8	5
2500	-	34	39	48	10	14	11	16	4	7	4	6	10
5000	-	33	42	33	6B	4B	B	26	18	14	8	16	18
100 µg 9-Aminoacridiniumchloride monohydrate	-	418	390	523	490	533	716	659	512	709	342	264	253

B: reduced backround