Neodecanoyl chloride

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Remarks:

Type of genotoxicity: chromosome aberration

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1998

Report date:

1998

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:

Neodecanoyl chloride

EC Number:

254-875-0

EC Name:

Neodecanoyl chloride

Cas Number:

40292-82-8

Molecular formula:

C10H19ClO

IUPAC Name:

2,2-dimethyloctanoyl chloride

Details on test material:

The purity of the test material was 98.6%.

Method

Target gene:

S. typhimurium: his-
E. coli: trp-

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 uvr A

Metabolic activation:

with and without

Metabolic activation system:

liver S-9 mix from Aroclor 1254 induced rats

Test concentrations with justification for top dose:

20 - 5000 micrograms/plate (standard plate); 31.25 - 500 micrograms/plate (preincubation)

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: see below

Details on test system and experimental conditions:

S-9 was prepared from at least 5 male Sprague-Dawley rats (200 - 300 g) that received an i.p. injection of 500 mg Aroclor 1254 (as a 20% solution in corn oil) five days before liver collection. S-9 was stored at -70 to -80 degrees C. S-9 mix was prepared freshly prior to each experiment. One volume of S-9 was mixed with 9 volumes of a cofactor mix containing 8 mM MgCl2, 33 mM KCl, 5 mM glucose-6-phsophate, 4 mM NADP and 15 mM sodium phosphate buffer (pH 7.4).
The Salmonella strains (TA98, TA100, TA1535, and TA1537) and E. coli WP2uvrA were checked periodically for deep rough character (rfa), UV sensitivity (uvrB), and ampicillin resistance (R factor plasmid). Deep-frozen bacterial cultures were thawed, and 0.1 ml of the bacterial suspension was inoculated in nutrient broth and incubated in a shaking water bath at 37 degrees C for about 10-12 hours (to an approximate density of > = 10E9 bacteria/ml). The cultures were then placed in ice water to prevent further growth.
For the standard plate test, test solution (0.1 ml), bacterial suspension (0.1 ml), and phosphate buffer or S-9 mix (0.5 ml) were added to tubes containing 2 ml soft agar. For the preincubation test, the test solution, bacterial suspension and S-9 mix were incubated at 37 degrees C for 20 minutes before being added to the soft agar. After mixing, the samples for either test were poured onto minimal glucose agar plates. Cells were incubated at 37 degrees C for 48-72 hours in the dark, and the number of colonies was counted. All tests were performed in triplicate.
The concentrations tested varied according to experiment (standard incubation experiment 1 (with and without S-9 mix): 0, 20, 100, 500, 2500 and 5000 micrograms/plate in all strains; standard incubation experiment 2 (with and without S-9 mix): 0, 20, 100, 500, 1000 and 1500 micrograms/plate in all strains; preincubation experiment (with and without S-9): 0, 31.25, 62.5, 125, 250 and 500 micrograms/plate in all strains. Precipitation of the test material was recorded (if present).
A solvent control (DMSO) and the positive controls N-methyl-N'-nitro-N-nitroso-guanidine (5 micrograms/plate for strains TA100 and TA1535), 4-nitro-o-phenylenediamine (10 micrograms/plate, strain TA98), 9-aminoacridine (100 micrograms/plate for strain TA1537), and 2-aminoanthracene (2.5 micrograms/plate for all strains with S-9) were tested in each experiment. For E. coli, N-ethyl-N'-nitro-N-nitroso-guanidine (10 micrograms/plate, without S-9 mix) and 2-aminoanthracene (60 micrograms/plate with S-9) were tested in each experiment. The positive control chemicals were dissolved in DMSO.
Toxicity was detected by a decrease in the number of revertants, a clearing or diminution of the background lawn or a reduction in the titer.

Evaluation criteria:

The experiment was considered valid if the number of colonies in the negative controls was within the normal range of the historical data for the strain, sterility controls had no evidence of contamination, the positive controls induced a significant increase in the number of revertants and the tier of viable bacteria was > = 10E9/ml.
A substance was considered mutagenic if it caused a doubling in the spontaneous mutation rate, in at least one strain, and the effect was dose-dependent and reproducible. A test substance was considered non-mutagenic if the number of revertants for all tester strains was within the historical negative control range under all experimental conditions in 2 experiments carried out independently of each other.

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:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

> = 500 micrograms/plate (standard plate); >= 250 micrograms/plate (preincubation)

Vehicle controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

E. coli WP2 uvr A

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

1500 micrograms/plate (standard plate); 500 micrograms/plate (preincubation)

Vehicle controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

A bacteriotoxic effect was observed at about 500 micrograms/plate in the standard plate test and about 250 micrograms/plate in the plate incubation test. The test material did not precipitate. All positive controls induced at least a 2-fold increase in mutants.

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S. typhimurium

Standard plate test: There was no mutagenic effect of test material in the presence or absence of S-9. In the absence of S-9, the average number of mutants in controls in strains TA98, TA100, TA1535 and TA1537 were 28 and 29 (2 experiments), 147 and 150 (2 experiments), 21 and 22 (2 experiments) and 12 (both experiments). The average number of mutants in treated strains TA98, TA100, TA1535 and TA1537 ranged from 24-29 (2 experiments), 106-149 (2 experiments), 11-21 (2 experiments), and 6-15 (2 experiments). In the presence of S-9, the average number of mutants in controls in strains TA98, TA100, TA1535 and TA1537 were 41 and 42 (2 experiments), 133 and 156 ( 2 experiments), 21 (both experiments) and 12 and 13 (2 experiments). The average number of mutants in treated strains TA98, TA100, TA1535 and TA1537 with S-9 ranged from 30-39 (2 experiments), 135-176 (2 experiments), 1-20 (2 experiments), and 7-10 (2 experiments). 
Preincubation test: There was no mutagenic effect of test material in the presence or absence of S-9. In the absence of S-9, the average number of mutants in controls in strains TA98, TA100, TA1535 and TA1537 were 34, 159, 19, and 11. The average number of mutants in treated strains TA98, TA100, TA1535 and TA1537 ranged from 26-33, 27-165, 15-24, and 10-11. In the presence of S-9, the average number of mutants in controls in strains TA98, TA100, TA1535 and TA1537 were 44, 160, 20 and 12. The average number of mutants in treated strains TA98, TA100, TA1535 and TA1537 with S-9 ranged from 26-41, 137-162, 19-21 and 8-11.

E. coli

Standard plate test: There was no mutagenic effect of test material in the presence or absence of S-9. In the absence of S-9, the average numbers of mutants in controls in the 2 experiments were 32 and 39. The average number of mutants in treated cells in the 2 experiments ranged from 12-40. In the presence of S-9, the average numbers of mutants in controls in the 2 experiments were 38 and 45. The average number of mutants in treated cells (both experiments) ranged from 9-37. 
Preincubation test:  There was no mutagenic effect of test material in the presence or absence of S-9. In the absence of S-9, the average number of mutants in the control was 33. The average number of mutants in treated cells ranged from 15-32. In the presence of S-9, the average number of mutants in the control was 41. The average number of mutants in treated cells ranged from 11-33.