[3-methyl-5-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4-pentadienyl]triphenylphosphonium sulphate

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:

1998

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

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

May, 1983 / revised draft, March 1996

Deviations:

yes

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

May, 1983 / revised draft, March 1996

Deviations:

yes

Test guideline 3

Qualifier:

according to guideline

Guideline:

EU Method B.13/14 (Mutagenicity - Reverse Mutation Test Using Bacteria)

Version / remarks:

December 1992

Deviations:

yes

Principles of method if other than guideline:

According to the authors, there was the following deviation from the requirements of the above-mentioned principles:
- The stability of the test substance in the vehicle DMSO and in water has not been determined analytically.

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

[3-methyl-5-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4-pentadienyl]triphenylphosphonium sulphate

EC Number:

212-028-2

EC Name:

[3-methyl-5-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4-pentadienyl]triphenylphosphonium sulphate

Cas Number:

751-83-7

Molecular formula:

C33H38P.HO4S

IUPAC Name:

mono[3-methyl-5-(2,6,6-trimethyl-1-cyclohexen-1-yl)-2,4-pentadienyl]triphenylphosphonium hydrogensulphate

Details on test material:

- Name of test material (as cited in study report): C15-Salz kristallin (C15 salt, crystalline)
- Physical state: solid (white crystals)
- Analytical purity: 90 % (w/w) by GC
- Impurities (identity and concentrations): no data
- Lot/batch No.: 96/2-315 + 316; date of manufacture: 1996-12-09
- Storage condition of test material: refrigerator, N2 conditions
No further data

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 uvr A

Metabolic activation:

with and without

Metabolic activation system:

Aroclor-induced rat liver S-9

Test concentrations with justification for top dose:

0.3 - 5000 µg/plate (Standard Plate Test)
0.3 - 6 µg/plate (Preincubation Test)

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO
- Justification for choice of solvent/vehicle: Due to the limited solubility of the test substance in water, DMSO was selected as the vehicle, which had been demonstrated to be suitable in bacterial reverse mutation tests and for which historical control data are available.

Controls

Negative solvent / vehicle controls:

yes

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene, N-methyl-N'-nitro-N-nitrosoguanidine, 4-nitro-o-phenylenediamine, 9-aminoacridine, N-ethyl-N'-nitro-N-nitrosoguanidine

Remarks:

Positive control substance depending on tester strains and activation conditions

Details on test system and experimental conditions:

1) STANDARD PLATE TEST (SPT)

METHOD OF APPLICATION: in agar (plate incorporation)

DURATION
- Exposure duration: 48 - 72 h (at 37°C and in the dark)

NUMBER OF REPLICATIONS: 3 plates per dose and control

DETERMINATION OF CYTOTOXICITY
Toxicity was detected by a
- decrease in the number of revertants
- clearing or diminution of the background lawn (= reduced his or trp background growth)
- reduction in the titer


2) PREINCUBATION TEST (PIT)

METHOD OF APPLICATION: preincubation

DURATION
- Preincubation period: 20 minutes (at 37°C)
- Exposure duration: 48 - 72 h (at 37°C and in the dark)

NUMBER OF REPLICATIONS: 3 plates per dose and control

DETERMINATION OF CYTOTOXICITY
Toxicity was detected by a
- decrease in the number of revertants
- clearing or diminution of the background lawn (= reduced his or trp background growth)
- reduction in the titer

Evaluation criteria:

The test chemical is considered positive in this assay if the following criteria are met:
- A dose-related and reproducible increase in the number of revertant colonies, i.e. about doubling of the spontaneous mutation rate in at least one tester strain either without S-9 mix or after adding a metabolizing system.

A test substance is generally considered nonmutagenic in this test if:
- The number of revertants for all tester strains were within the historical negative control range under all experimental conditions in two 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:

>= 0.75 µg/plate

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:

>= 0.75 µg/plate

Vehicle controls validity:

valid

Positive controls validity:

valid

Additional information on results:

MUTAGENICITY
An increase in the number of his+ or trp + revertants was not observed in the standard plate test or in the preincubation test either without S-9 mix or after the addition of a metabolizing system.

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: No test substance precipitation was found.

ADDITIONAL INFORMATION ON CYTOTOXICITY:
A bacteriotoxic effect (reduced his- or trp- background growth, decrease in the number of his+ or trp+ revertants, reduction in the titer) was observed in the standard plate test depending on the strain and test conditions from about 3.0 µg - 12.5 µg/plate onward.
In the preincubation assay bacteriotoxicity was observed depending on the strain and test conditions from about 0.75 µg - 3 µg/plate onward.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative

According to the results of the present study, the test substance C15 -Salz kristallin is not mutagenic in the Salmonella typhimurium/Escherichia coli reverse mutation assay under the experimental conditions chosen here.