A mixture of: propan-2-one-O,O'(methoxyvinylsilandiyl)dioxime; propan-2-one-O-(dimethoxyvinylsilyl)oxime; propan-2-one-O,O',O''-(vinylsilantriyl)trioxime

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

October 11 - November 5, 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

According to OECD Guideline 471, with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

A mixture of: propan-2-one-O,O'(methoxyvinylsilandiyl)dioxime; propan-2-one-O-(dimethoxyvinylsilyl)oxime; propan-2-one-O,O',O''-(vinylsilantriyl)trioxime

EC Number:

458-680-3

EC Name:

A mixture of: propan-2-one-O,O'(methoxyvinylsilandiyl)dioxime; propan-2-one-O-(dimethoxyvinylsilyl)oxime; propan-2-one-O,O',O''-(vinylsilantriyl)trioxime

Cas Number:

797751-44-1

Molecular formula:

not applicable, multiconstituent substance

IUPAC Name:

3-ethenyl-3-methoxy-6-methyl-2,4-dioxa-5-aza-3-silahept-5-ene; 5-ethenyl-2,8-dimethyl-5-{[(propan-2-ylidene)amino]oxy}-4,6-dioxa-3,7-diaza-5-silanona-2,7-diene; 5-ethenyl-5-methoxy-2,8-dimethyl-4,6-dioxa-3,7-diaza-5-silanona-2,7-diene

Test material form:

liquid

Method

Target gene:

histidine-requiring gene

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium TA 1535

Species / strain 2

Species / strain / cell type:

S. typhimurium TA 98

Species / strain 3

Species / strain / cell type:

S. typhimurium TA 100

Species / strain 4

Species / strain / cell type:

S. typhimurium TA 102

Species / strain 5

Species / strain / cell type:

other: S. typhimurium TA 97a

Metabolic activation:

with and without

Metabolic activation system:

S9 liver microsomal fraction

Test concentrations with justification for top dose:

5000, 1667, 556, 185, and 62 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: the test substance hydrolyses rapidly in water

Controls

Controls 1

Negative solvent / vehicle controls:

yes

Remarks:

(DMSO)

Controls 2

Positive controls:

yes

Remarks:

(without activation)

Positive control substance:

other: 4-nitro-o-phenylene-diamine

Remarks:

TA97a: 4-nitro-o-phenylene-diamine- 10 µg

Controls 3

Positive controls:

yes

Remarks:

(with activation)

Positive control substance:

7,12-dimethylbenzanthracene

Remarks:

TA97a:7,12-dimethylbenz(a)anthracene-10 µg

Controls 4

Positive controls:

yes

Remarks:

(without activation)

Positive control substance:

2-nitrofluorene

Remarks:

TA98: 2-nitrofluorene - 2 µg

Controls 5

Positive controls:

yes

Remarks:

(without activation)

Positive control substance:

sodium azide

Remarks:

TA100: sodium azide-2 µg and TA1535: sodium azide- 1 µg

Controls 6

Positive controls:

yes

Remarks:

(with activation)

Positive control substance:

other: 2- aminoanthracene

Remarks:

TA98:2- aminoanthracene- 1 µg , TA1535: aminoanthracene- 2 µg and TA100: aminoanthracene- 2 µg

Controls 7

Positive controls:

yes

Remarks:

(with activation)

Positive control substance:

other: 1,8-Dihydroxy-anthraquinone

Remarks:

TA102: 1,8-Dihydroxy-anthraquinone - 50 µg

Controls 8

Positive controls:

yes

Remarks:

(without activation)

Positive control substance:

other: t-Butyl-hydroperoxide

Remarks:

TA102: t-Butyl-hydroperoxide-50 µg

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation). Bacteria, test substance (and microsomes) are in contact on the plate without preceding incubation in the liquid state. For each sample the following solutions were combined:
- 0.1 mL of the overnight culture of the bacteria,
- 0.5 mL of S9-mix (or phosphate buffered saline for samples without metabolic activation),
- 0.1 mL of the appropriate test- or reference substance solution and
- 2 mL of top agar.

DURATION
- Exposure duration: 48 h

NUMBER OF REPLICATIONS: triplicates (an independent repetition of the experiment was performed)

DETERMINATION OF CYTOTOXICITY
Method: the citotoxicity was rated as follows:
A reduced bacterial background lawn (mottled instead of homogeneous).
Microcolonies of bacteria instead of a homogeneous background lawn.
No background lawn.
Clearly reduced numbers of revertant colonies.

Evaluation criteria:

The criteria for a positive result are:
A reproducible increase of the number of revertants to more than the following threshold values for at least one of the concentrations:
- For the strains with a low spontaneous revertant rate i.e. TA98 and TA1535: The 2.5 fold of the amount of the spontaneous revertants.
- For the strains with a high spontaneous revertant rate i.e. TA97a, TA100 and TA102: The 1.67 fold of the amount of the spontaneous revertants.
These threshold values were derived from the variations in the control samples of the Ames test.

Results and discussion

Test results

Key result

Species / strain:

other: TA97a, TA98, TA100, TA102, and TA1535

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: No precipitation of the test substance was seen in any on the concentrations groups

RANGE-FINDING/SCREENING STUDIES:
Preliminary experiment was performed: different concentrations of test substance solutions were mixed with phosphate buffer, bacteria (TA100) and top-agar, as described in 3.5 and spread over a plate with minimal agar. The plates were incubated at 37 °C for 2 days and the growth of the bacterial background and the density of revertant colonies was determined.

COMPARISON WITH HISTORICAL CONTROL DATA:
The numbers of spontaneous revertans were comparable with the historic control data for the negative controls.

Any other information on results incl. tables

Individual numbers of revertants per plates

 

StrainTA97a: experiment no.1

concentr. µg/plate	revertants without metabolisation			revertants with metabolisation
5000	96	109	124	147	160	114
1667	114	103	103	117	121	135
556	111	100	91	129	128	122
185	90	98	85	134	122	133
62	98	90	75	131	145	120
solvent	41	94	66	98	82	78
solvent	70	64	70	133	102	110
positive	219	194	200	517	482	460

 

StrainTA97a: experiment no.2

concentr. µg/plate	revertants without metabolisation			revertants with metabolisation
5000	137	130	120	125	134	142
1667	108	111	113	131	163	131
556	104	130	128	130	108	180
185	131	142	130	157	180	128
62	119	130	102	104	163	143
solvent	123	142	131	148	151	168
solvent	133	175	123	125	119	145
positive	465	675	569	645	526	601

 

solvent:     DMSO

positive:    without metabolisation: 4-Nitro-o-phenylene-diamine, 10 µg / plate

                  with metabolisation: 7,12-Dimethylbenz[a]anthracene, 10 µg / plate

StrainTA98: experiment no.1

concentr. µg/plate	revertants without metabolisation			revertants with metabolisation
5000	7	8	6	4	13	5
1667	14	10	11	11	6	11
556	7	17	11	8	8	7
185	9	2	4	14	11	4
62	7	3	10	6	6	15
solvent	11	10	10	9	12	12
solvent	6	8	9	14	6	12
positive	155	131	110	216	227	209

 

StrainTA98: experiment no.2

concentr. µg/plate	revertants without metabolisation			revertants with metabolisation
5000	10	0	11	17	13	13
1667	10	8	6	14	10	12
556	12	7	5	9	18	9
185	14	12	14	10	13	15
62	12	12	4	9	10	8
solvent	13	10	8	10	13	14
solvent	11	5	4	12	11	16
positive	343	450	306	338	273	329

 

solvent:     DMSO

positive:    without metabolisation: 2-Nitrofluorene, 2 µg / plate

                  with metabolisation: 2-Amino-anthracene, 1 µg / plate

 

StrainTA100:  experiment no.1

concentr. µg/plate	revertants without metabolisation			revertants with metabolisation
5000	85	53	47	88	79	88
1667	91	76	108	85	85	79
556	81	96	78	107	73	73
185	81	81	70	91	96	96
62	90	102	73	99	96	102
solvent	73	59	88	102	101	122
solvent	66	82	102	113	108	73
positive	410	399	375	1096	1321	1081

 

strainTA100: experiment no.2

concentr. µg/plate	revertants without metabolisation			revertants with metabolisation
5000	55	62	55	98	104	84
1667	101	93	101	102	104	127
556	78	91	69	91	130	105
185	69	44	34	88	96	96
62	84	90	67	90	108	99
solvent	87	59	69	84	91	81
solvent	87	84	67	94	84	76
positive	181	149	160	469	393	375

 

solvent:     DMSO

positive:    without metabolisation: Sodium azide, 2 µg / plate

                  with metabolisation: 2 -Amino-anthracene, 2 µg / plate

 

StrainTA102: experiment no.1

concentr. µg/plate	revertants without metabolisation			revertants with metabolisation
5000	148	149	168	140	230	230
1667	166	194	170	233	250	215
556	157	151	140	267	224	239
185	166	146	152	239	213	248
62	172	200	195	247	274	247
solvent	169	162	157	251	250	265
solvent	169	206	187	248	239	241
positive	629	742	634	629	588	576

 

StrainTA102: experiment no.2

concentr. µg/plate	revertants without metabolisation			revertants with metabolisation
5000	194	198	198	264	253	248
1667	215	213	181	251	232	250
556	198	183	169	270	273	227
185	194	209	187	268	253	265
62	181	218	206	248	245	224
solvent	183	206	183	242	267	224
solvent	157	183	148	238	247	248
positive	975	902	686	477	442	533

 

solvent:     DMSO

positive:    without metabolisation: t-Butyl-hydroperoxide, 50 µg / plate

                  with metabolisation: 1,8-Dihydroxy-anthraquinone, 50 µg / plate

 

StrainTA1535: experiment no.1

concentr. µg/plate	revertants without metabolisation			revertants with metabolisation
5000	8	3	6	14	8	4
1667	4	7	8	14	3	6
556	7	7	5	7	6	5
185	8	5	8	8	10	7
62	7	16	8	10	7	4
solvent	6	10	6	12	5	8
solvent	8	4	8	10	15	10
positive	256	229	207	181	127	175

StrainTA1535: experiment no.2

concentr. µg/plate	revertants without metabolisation			revertants with metabolisation
5000	6	12	13	11	9	10
1667	13	8	9	8	14	9
556	10	15	12	8	8	11
185	14	7	15	10	10	15
62	12	11	9	12	8	12
solvent	14	18	12	18	12	11
solvent	14	18	11	10	12	13
positive	253	244	274	154	154	184

 

solvent:     DMSO

positive:    without metabolisation: Sodium azide, 1 µg / plate

                  with metabolisation: 2-Amino-anthracene, 2 µg / plate

Applicant's summary and conclusion

Conclusions:

According to the results obtained in this study, the test substance is non-mutagenic in the Ames test with the strains TA97a, TA98, TA100, TA102 and TA1535 with and without an external metabolising system up to 5000 µg/plate.

Executive summary:

The Bacterial Reverse mutation Assay (Ames test) for the test substance was performed with five histidine dependents strains of Salmonella typhimurium TA97a, TA98, TA100, TA102 and TA1535. Plate Incorporation Method was carried out at the concentrations of 5000, 1667, 556, 185, and 62 µg/plate in the presence and absence of metabolic activation. No precipitation of the test substance and no signs of cytotoxicity were noted at any dose level. In none of the concentrations tested and with none of the strains used an significant increase of the mutation frequency to more than the threshold values (250 % of the controls for strains TA98 and TA1535 and 167 % of the controls for strains TA97a, TA100 and TA102) was obtained. Metabolic activation did not change these results.

According to the obtained results, the test substance is non-mutagenic in the Ames test with and without an external metabolizing system up to 5000 µg/plate.