Hexasodium 7,7'-(carbonyldiimino)bis[4-hydroxy-3-[[2-sulphonato-4-[(4-sulphonatophenyl)azo]phenyl]azo]naphthalene-2-sulphonate]

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)

Rationale for reliability incl. deficiencies:

other: Study performed under GLP, well reported with many details on the results acceptable for the assessment of the endpoint. Include also the Prival and Mitchell procedure for mutagenicity.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

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:

Hexasodium 7,7'-(carbonyldiimino)bis[4-hydroxy-3-[[2-sulphonato-4-[(4-sulphonatophenyl)azo]phenyl]azo]naphthalene-2-sulphonate]

EC Number:

220-027-3

EC Name:

Hexasodium 7,7'-(carbonyldiimino)bis[4-hydroxy-3-[[2-sulphonato-4-[(4-sulphonatophenyl)azo]phenyl]azo]naphthalene-2-sulphonate]

Cas Number:

2610-10-8

Molecular formula:

C45H32N10O21S6.6Na

IUPAC Name:

hexasodium 7,7'-(carbonyldiimino)bis[4-hydroxy-3-[[2-sulphonato-4-[(4-sulphonatophenyl)azo]phenyl]azo]naphthalene-2-sulpho

Test material form:

solid: particulate/powder

Method

Species / strain

Species / strain / cell type:

S. typhimurium, other: TA 98, TA 100, TA 102, TA 1535, TA 1537

Details on mammalian cell type (if applicable):

TA 1535 and TA 100 bear the base-pair substitution, his G 46, and TA 100 additionally contains the plasmid pKM 101. This R factor, asso contained in TA 98 and TA 102, codes for an ampicillin resistance and should raise the sensitivity of the strains. TA 102 carries the ochre mutation his G 428 ora the multicopy plasmid pAQ1, which codes in addition for tetracycline resistance. TA 1537 and TA 98 bear frameshift markers. TA 1537 exhibits the +1 mutant, his C 3076, while TA 98 bears the +2 type, his D 3052.Furthermore, the strains have other properties, which should increase their sensitivity. They are all Jeep rough, i.e. partiy deficient in lipopolysaccharide side chains in their celi walis, enabling larger molecules to penetrate the bacterial celi wall and pro-duce mutations. With the exception of TA 102, ali strains have reduced capability to repair DNA-damage which increases the likelihood that such damage results in mutations.

Additional strain / cell type characteristics:

other: see details above

Metabolic activation:

with and without

Metabolic activation system:

Aroclor-induced rat liver S-9 mix

Test concentrations with justification for top dose:

16, 50, 160, 500, 1600 and 5000.0 µg/plate

Vehicle / solvent:

Levaceli Rot E10B was dissolved in deionized water and formed red solutions. Ganga red and mitomycin C were dissolved in deionized water. The other positive controls were dissolved in DMSO.The solvent used was chosen out of the following solvents, in the order given: water, DMSO, methanol, ethanol, acetone, ethylene glycol dimethylether (EGDE), and DMF according to information given by the internai sponsor. The order of these solvents is based on their bacteriotoxic effects in preincubation experiments.

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: 4-nitro-1,2-phenylendiamine (4-NPDA)

Remarks:

TA98 and TA1537 without S9 mix

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: nitrofurantoin

Remarks:

TA100 without S9 mix

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

cumene hydroperoxide

Remarks:

TA102 without S9 mix

Controls 4

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA1535 without S9 mix

Controls 5

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene (2-AA)

Remarks:

all strains with S9 mix

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation)NUMBER OF REPLICATIONS: The assay was performed in two independent experiments. The first under Ames test conditions and the second under the Prival and Mitchell procedure both with and without liver microsomal activation.

Evaluation criteria:

The following criteria determined the acceptance of an assay:a) The negative controls had to be within the expected range, as defined by pub-lished data (e.g. Maron and Ames, 1983) andl or the laboratories' own historical data (see Chapter 8).b) The positive controls had to show sufficient effects, as defined by the laboratories' experience (see Chapter 8).c) Titer determinations had to demonstrate sufficient bacterial density in the suspension.

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA98, TA100, TA102, TA 1535 and TA 1537

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

not specified

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Applicant's summary and conclusion

Conclusions:

Interpretation of results: :negative
Under the experimental conditions reported, the test article did not induce point mutations by base pair changes or frameshifts in the genome of the strains used. Therefore, the test article is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.

Executive summary:

The study followed OECD guideline 471 and the principles of GLP. In the presence and absence of rat liver S-9 microsomal activation system and at doses of up to 5000 μg/plate, S. typhimurium strains TA 98, TA 100, TA102, TA 1535 and TA 1537 did not show an increased number of revertant colonies. Therefore, no evidence of a mutagenic potential was associated with the test substance.