Diisooctyl 2,2'-[(dioctylstannylene)bis(thio)]diacetate

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:

Not reported

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1978

Report date:

1978

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

GLP compliance:

no

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Diisooctyl 2,2'-[(dioctylstannylene)bis(thio)]diacetate

EC Number:

247-666-0

EC Name:

Diisooctyl 2,2'-[(dioctylstannylene)bis(thio)]diacetate

Cas Number:

26401-97-8

Molecular formula:

C36-H72-O4-S2-Sn

IUPAC Name:

6-methylheptyl 14-methyl-4,4-dioctyl-7-oxo-8-oxa-3,5-dithia-4-stannapentadecan-1-oate

Constituent 2

Reference substance name:

Mono-n-octyltin-tri-thioglycol-acid isooctyl ester

IUPAC Name:

Mono-n-octyltin-tri-thioglycol-acid isooctyl ester

Test material form:

liquid

Details on test material:

- Appearance: colourless liquid

Method

Target gene:

S. typhimurium: Histidine locus

Species / strain

Species / strain 1

Species / strain / cell type:

S. typhimurium, other: TA 98, TA 100, TA 1535, TA 1537, TA 1538

Species / strain 2

Species / strain / cell type:

Saccharomyces cerevisiae

Remarks:

Strain D4

Metabolic activation:

with and without

Metabolic activation system:

S9 mix

Test concentrations with justification for top dose:

5.000, 1.000, 0.100, 0.010, 0.001 µL/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: deionised water or DMSO
- Methylnitrosoguanidine: Water
- 2-Nitrofluorene: DMO
- Quinacrine mustard: Water
- 2-Anthramine: DMSO
- 2-Acetylaminofluorene: DMSO
- 8-Aminoquinoline: DMSO

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

water/ DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

2-nitrofluorene

other: Methylnitrosoguanidine, Quinacrine mustard, 2-Anthramine, 2-Acetylaminofluorene, 8-Aminoquinoline

Details on test system and experimental conditions:

- Approximately 10^8 cells from an overnight culture of each indicator strain were added to separate test tubes containing 2.0 mL of molten agar supplemented with biotin and a trace of histidine. For non-activation tests, at least four dose levels of the test material were added to the contents of the appropriate tubes and poured over the surfaces of selective agar plates. In activation tests, a minimum of four different concentrations of the test material were added to the appropriate tubes with cells. Just prior to pouring, an aliquot of reaction mixture (0.5 mL containing the 9,000 x g liver homogenate) was added to each of the activation overlay tubes, which were then mixed, and the contents poured over the surface of a minimal agar plate and allowed to solidify.

- The plates were incubated for 48 hours at 37 °C, and scored for the number of colonies growing on each plate.

- Positive and solvent controls using both directly active positive chemicals and those that require metabolic activation were run with each assay.

- The numbers of colonies on each plate were counted and recorded on printed forms. These raw data were analysed in a computer program and reported on a printout.

Evaluation criteria:

Evaluation Criteria for Ames Assay:
Because the procedures used to evaluate the mutagenicity of the test chemical are semi-quantitative, the criteria used to determine positive effects are inherently subjective and are based primarily on a historical data base. Most data sets are evaluated using the following criteria:
- Strains TA1535, TA1537, and TA1538
If the solvent control value is within the normal range, a chemical that produces a positive dose response over three concentrations with the lowest increase equal to twice the solvent control value is considered to be mutagenic.
- Strains TA98, TA100, and D4
If the solvent control value is within the normal range, a chemical that produces a positive dose response over three concentrations with the highest increase equal to twice the solvent control value for TA100 and two to three times the solvent control value for strains TA98 and D4 is considered to be mutagenic. For these strains, the dose response increase should start at approximately the solvent control value.
- Pattern
Because TA1535 and TA100 were both derived from the same parental strain (G-46) and because TA1538 and TA98 were both derived from the same parental strain (D3052), there is a built-in redundancy in the microbial assay. In general the two strains of a set respond to the same mutagen and such a pattern is sought. It is also anticipated that if a given strain, e.g. TA1537, responds to a mutagen in non-activation tests it will generally do so in activation tests. (The converse of this relationship is not expected.) While similar response patterns are not required for all mutagens, they can be used to enhance the reliability of an evaluation decision.
- Reproducibility
If a chemical produces a response in a single test that cannot be reproduced in one or more additional runs, the initial positive test data loses significance.

Results and discussion

Test results

Test results 1

Key result

Species / strain:

S. typhimurium, other: TA1535, TA1537, TA1538, TA98, TA100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Test results 2

Key result

Species / strain:

Saccharomyces cerevisiae

Remarks:

D

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not examined

Positive controls validity:

valid

Additional information on results:

TOXICITY TEST RESULTS
The test material was tested over a series of concentrations such that there was either quantitative or qualitative evidence of some chemically-induced physiological effects at the high dose level. The low dose in all cases was below a concentration that demonstrated any toxic effect. The dose range employed for the evaluation of this compound was from 0.001 to 5 µL/ plate.

WITHOUT METABOLIC ACTIVATION
The results of the tests conducted on the test material in the absence of a metabolic system were all negative.

WITH METABOLIC ACTIVATION
The results of the tests conducted on the test material in the presence of the rat liver activation system were all negative.

CONCLUSIONS
The test material did not demonstrate mutagenic activity in any of the assays conducted in this evaluation and was considered as not mutagenic under these test conditions.

Any other information on results incl. tables

Table 1: Summary of Experiment

± S9 Mix	Concentration (µL/plate)	Revertants/plate
		TA1535	TA1537	TA1538	TA98	TA100	D4
-	Solvent 0.001 0.010 0.100 1.000 5.000	31 50 25 38 31 30	6 4 6 9 9 7	20 11 21 21 16 17	42 21 31 38 52 33	201 211 194 204 204 319	42 51 32 50 40 40
+	Solvent 0.001 0.010 0.100 1.000 5.000	35 38 31 14 16 23	14 18 21 14 12 7	25 17 30 25 35 21	51 45 42 40 49 43	226 224 237 243 254 272	44 46 47 38 45 42
Positive Controls
-	Name	MNNG	QM	NF	NF	MNNG	MNNG
	Concentration (µg/plate)	10	10	100	100	10	10
	Revertants/plate	935	448	834	939	>1000	925
+	Name	ANTH	AMQ	AAF	AAF	ANTH	DMNA
	Concentration (µg/plate)	100	100	100	100	100	100(µM)
	Revertants/plate	402	208	451	791	>1000	68

MNNG = Methylnitrosoguanidine

QM = Quinacrine mustard

ANTH = 2-Anthramine

NF = 2-Nitrofluorene

AAF = 2-Acetylaminofluorene

AMQ = 8-Aminoquinoline

Applicant's summary and conclusion

Conclusions:

Under the conditions of the study, the test material did not demonstrate mutagenic activity in any of the assays conducted in this evaluation and was considered as not mutagenic with or without metabolic activation.

Executive summary:

The genetic toxicity of the test material was investigated in a bacterial reverse mutation assay, broadly similar to OECD 471.

The test material was tested at 5.000, 1.000, 0.100, 0.010, 0.001 µL/plate both with and without metabolic activation, in the form of S9-mix. The following bacterial strains were used: Salmonella typhimurium tester strains TA98, TA100, TA1535, TA1537 and TA1538, and Saccharomyces cerevisiae strain D4. The overlay method of application was used.

The plates were incubated for 48 hours at 37°C, and scored for the number of colonies growing on each plate. Positive and solvent controls using both directly active positive chemicals and those that require metabolic activation were run with each assay. The numbers of colonies on each plate were counted and recorded.

The test material was tested over a series of concentrations such that there was either quantitative or qualitative evidence of some chemically-induced physiological effects at the high dose level. The low dose in all cases was below a concentration that demonstrated any toxic effect. The results of the tests conducted on the test material in the absence of a metabolic system were all negative. The results of the tests conducted on the test material in the presence of the rat liver activation system were all negative.

Under the conditions of the study, the test material did not demonstrate mutagenic activity in any of the assays conducted in this evaluation and was considered as not mutagenic with or without metabolic activation.