2,2'-dithiodi(benzoic acid)

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:

1 (reliable without restriction)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 472 (Genetic Toxicology: Escherichia coli, Reverse Mutation Assay)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

2,2'-dithiodi(benzoic acid)

EC Number:

204-352-8

EC Name:

2,2'-dithiodi(benzoic acid)

Cas Number:

119-80-2

Molecular formula:

C14H10O4S2

IUPAC Name:

2-[(2-carboxyphenyl)disulfanyl]benzoic acid

Test material form:

other: Solid

Details on test material:

The test material had a purity of 75.7%

Method

Species / strain

Species / strain 1

Species / strain / cell type:

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

Species / strain 2

Species / strain / cell type:

E. coli WP2

Species / strain 3

Species / strain / cell type:

E. coli WP2 uvr A

Metabolic activation:

with and without

Metabolic activation system:

Liver S9 from phenobarbital/beta-naphthaflavone induced male rats

Test concentrations with justification for top dose:

5000, 2500, 1000, 500, 200, 100 ug/plate

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

N-ethyl-N-nitro-N-nitrosoguanidine

mitomycin C

other: Acridine mutagen, 2-aminoanthracene & Daunomycin HCl

Details on test system and experimental conditions:

Incubation period: 3 days
Incubation temperature: 37 degrees C
Revertant colonies were counted using an automated elctronic colony counter (AMS 40-10 Image Analyser fitted with appropriate software)

Evaluation criteria:

Test was considered valid when: (a) concurrent solvent control data are acceptable (b) positive control data show unequivocal positive response (c) at least the lowest test compound dose shows no evidence of toxicity and at least 3 test doses show no significant toxicity (i.e. significnat loss of background growth and/or reductions in colony numbers)
-Positive response achieved when: (a) statistically significant dose-related increase in mean number of revertant colonies is obtained and/or (b) twofold or greater increase in the mean number of revertant colonies (over that observed for the concurrent solvent control plastes) which is statistically significant in observed at at least one dose level. For a positive response in an individual experiment to be considered indicative of an unequivocal positive i.e. mutagenic results fot that strain S9 combination then the observed effect msut be consistently reproducible.
-Negative response acjieved when: (a) no statistically significant dose-related increase in the mean number of revertant colonies per plate observed for the test compound and (b) in the absence of any such dose response, no increase in colony numbers is observed (at any test dose) which exceeds 2x the concurrent solvent control

Statistics:

An assessment of statistical significance was carried out using a one-tailed Student's t-test. The corresponding probabiltiy for each dose level was derived by computer using the appropriate degrees of freedom. Values of p,0.01 are treated as significant, with values 0.01,p,0.05 being indicative of a possible effect.

Results and discussion

Test results

Test results 1

Species / strain:

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

Metabolic activation:

with and without

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

other: Slight effects

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

Slight effects were observed in E. coli WP2P uvrA +S9 however they did not exceed 1.8x background in either of 2 experiments.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'. Remarks: Positive in TA98 with and without metabolic activation. Also in TA1537 with metabolic activation

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
positive

DTBA gave a positive response in S. typhimurium strain TA98 in both the presence and absence of S9 and in strain TA1537 in the presence of S9. Slight effects were also observed in E. coli strain W2P2 uvrA in the presence of S9.