Sodium hydrogen N-(1-oxododecyl)-L-glutamate

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

Study period:

1994/03/23 - 1994/05/31

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Remarks:

Only four bacterial strains were tested. But these were two strains each with base pair substitution and frameshift mutation and thus did not influence the quality and validity of the study. Also a read-across study with an analogous substance was scientifically justified, because it was conducted from the disodium salt to the monosodium salt of the test substance.

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)

Deviations:

yes

Remarks:

Only four bacterial strains were tested. But these were two strains each with base pair substitution and frameshift mutation and thus did not influence the quality and validity of the study.

Principles of method if other than guideline:

Only four bacterial strains were tested. But these were two strains each with base pair substitution and frameshift mutation and thus did not influence the quality and validity of the study

GLP compliance:

yes

Remarks:

Only four bacterial strains were tested. But these were two strains each with base pair substitution and frameshift mutation and thus did not influence the quality and validity of the study.

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

L-Glutamic acid, N-coco acyl derivs., monosodium salts

EC Number:

269-087-2

EC Name:

L-Glutamic acid, N-coco acyl derivs., monosodium salts

Cas Number:

68187-32-6

IUPAC Name:

68187-32-6

Method

Target gene:

Histidine

Species / strain

Species / strain / cell type:

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

Remarks:

Only 4 bacterials strains were tested but there were 2 strains each with base pair substitution and frameshift mutation and this did not influence the quality and validity of the study

Additional strain / cell type characteristics:

not specified

Remarks:

Only 4 bacterials strains were tested but there were 2 strains each with base pair substitution and frameshift mutation and this did not influence the quality and validity of the study

Metabolic activation:

with and without

Metabolic activation system:

S9 mix (Aroclor 1254 induced)

Test concentrations with justification for top dose:

0, 4, 20, 100, 500, 2500 and 5000 µg/plate (all doses were tested in triplicates)

Vehicle / solvent:

bi-distilled water

Controls

Controls 1

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

other: 2- aminoanthracene

Remarks:

TA 98, TA 100, TA 1535, TA 1537 with S9

Controls 2

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

9-aminoacridine

Remarks:

TA 1537 without S9

Controls 3

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

not specified

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

TA 100, TA 1535 without S9

Details on test system and experimental conditions:

Test group

Top agar was prepared for the Salmonella strains by mixing 100 mL agar (0.6 % agar, 0.5 % NaCI) with 10 mL of a 0.5 mM histidine-biotin solution.
The following ingredients were added (in order) to 2 mL of molten top agar at approx. 45 °C:

0.1mL of an overnight nutrient broth culture of the bacterial tester strain
0.1 mL test compound solution
0.5 mL S-9 Mix (if required) or buffer

After mixing, the liquid was poured into a petridish with minimal agar (1.5 % agar, Vogel-Bonner E medium with 2 % glucose). After incubation for approximatly 48 hours at approx. 37 °C in the dark, colonies (his* revertants) were counted.
Two independent experiments were performed.

Positive controls

Positive control plates were included for each strain. The following substances were used as positive controls.
a) without metabolic activation:
Sodium-azide: TA 100, TA 1535 9-Aminoacridine: TA 1537 2-Nitrofluorene: TA 98
b) with metabolic activation:
2-Aminoanthracene: TA 98, TA 100, TA 1535, TA 1537

Negative controls

a) solvent controls (0 microgram/plate)
b) untreated controls

Evaluation criteria:

A test article is classified mutagenic if either of the following conditions under a) and b) is achieved:

a) a test article produces at least a 2-fold increase in the mean number of revertants per plate of at least one of the tester strains over the mean number of revertants per plate of the appropriate vehicle control at complete bacterial background lawn

b) a test article induces a dose-related increase in the mean number of revertants per plate of at least one of the tester strains over the mean number of revertants per plate of the appropriate vehicle control in at least two to three concentrations of the test article at complete bacterial background lawn.
The test results must be reproducible.

Results and discussion

Test results

Species / strain:

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

Remarks:

Only 4 bacterials strains were tested but there were 2 strains each with base pair substitution and frameshift mutation and this did not influence the quality and validity of the study

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

.TEST-SPECIFIC CONFOUNDING FACTORS
- Water solubility: test substance did not precipitate on the plates up to the highest investigated dosis
- Precipitation: no

RANGE-FINDING/SCREENING STUDIES: The substance proved to be toxic for the bacterial strain TA 100 in the absence of a metabolizing system at a dose of 5000µg/plate only in the cytotoxic experiment. Therefore 5000 µg/plate was chosen as the highest dose in the experiment.

Remarks on result:

other: All strains/cells were tested. Only four bacterial strains were tested. But these were two strains each with base pair substitution and frameshift mutation and thus did not influence the quality and validity of the study.

Any other information on results incl. tables

Only four bacterial strains were tested. But these were two strains each with base pair substitution and frameshift mutation and thus did not influence the quality and validity of the study.

Applicant's summary and conclusion

Conclusions:

Based on the results of the read across study, the substance can be considered as not mutagenic in S. typhimurium with and without matabolic activation

Executive summary:

The test substance was investigated for its mutagenicity in accordance with OECD guideline 471 in test strains TA 98, TA 100, TA 102, TA 1537 and TA 1538 in two independant experiments. None of the test strains showed an increased mutation rate at any test concentration. The respective positive controls were valid. The test substance is considered to be non mutagenic in this test system.