Xanthylium, 9-(2-carboxyphenyl)-3,6-bis(diethylamino)-, hydrogen bis[3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-2-hydroxy-5-nitrobenzenesulfonato(3-)]chromate(3-), compd. with 3-[(2-ethylhexyl)oxy]-1-propanamine

Genetic toxicity: in vitro

Administrative data

Endpoint:

in vitro gene mutation study in bacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 Jun 2016 - 07 Jul 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

1997

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2008

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.5100 - Bacterial Reverse Mutation Test (August 1998)

Version / remarks:

1998

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

Xanthylium, 9-(2-carboxyphenyl)-3,6-bis(diethylamino)-, hydrogen bis[3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-2-hydroxy-5-nitrobenzenesulfonato(3-)]chromate(3-), compd. with 3-[(2-ethylhexyl)oxy]-1-propanamine

EC Number:

284-723-9

EC Name:

Xanthylium, 9-(2-carboxyphenyl)-3,6-bis(diethylamino)-, hydrogen bis[3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-2-hydroxy-5-nitrobenzenesulfonato(3-)]chromate(3-), compd. with 3-[(2-ethylhexyl)oxy]-1-propanamine

Cas Number:

84962-27-6

Molecular formula:

C32H20CrN10O14S2.1.5(C28H31N2O3).1.5(C11H25NO)

IUPAC Name:

Xanthylium, 9-(2-carboxyphenyl)-3,6-bis(diethylamino)-, hydrogen bis[3-[(4,5-dihydro-3-methyl-5-oxo-1-phenyl-1H-pyrazol-4-yl)azo]-2- hydroxy-5-nitrobenzenesulfonato(3-)]chromate(3-), compd. with 3-[(2-ethylhexyl)oxy]-1-propanamine

Specific details on test material used for the study:

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temperature

Method

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Metabolic activation:

with and without

Metabolic activation system:

Phenobarbital/ß-naphthoflavone induced rat liver S9 fraction and uninduced hamster liver S9 fraction

Test concentrations with justification for top dose:

1st Experiment
Strains: TA 1535, TA 100, TA 1537, TA 98 and E. coli WP2 uvrA
Doses: 0; 33; 100; 333; 1000; 2500 and 5000 μg/plate
Type of test: Standard plate test with and without S9 mix

2nd Experiment
Strains: TA 1535, TA 100, TA 1537, TA 98 and E. coli WP2 uvrA
Doses: 0; 10; 33; 100; 333; 1000 and 2500 μg/plate
Prival preincubation test with and without S9 mix

Vehicle / solvent:

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

Controls

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: see below

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar (plate incorporation); preincubation;

DURATION
- Exposure duration: 48 – 72 hours in the dark

NUMBER OF REPLICATIONS: 3 test plates per dose or per control

DETERMINATION OF CYTOTOXICITY
• decrease in the number of revertants (factor ≤ 0.6)
• clearing or diminution of the background lawn (= reduced his- or trp- background growth)

- POSITIVE CONTROLS
With rat liver S9 mix
• 2-aminoanthracene (2-AA)
- 2.5 μg/plate, dissolved in DMSO, strains: TA 1535, TA 100, TA 1537, TA 98
- 60 μg/plate, dissolved in DMSO, strain: Escherichia coli WP2 uvrA

With hamster liver S9 mix
• 2-aminoanthracene (2-AA)
-10 μg/plate, dissolved in DMSO, strains: TA 1535, TA 100, TA 1537, TA 98, Escherichia coli WP2 uvrA
• Congo red (CoR)
- 210 μg/plate, dissolved in DMSO, strain: TA 98

Without S9 mix
• N-methyl-N'-nitro-N-nitrosoguanidine (MNNG)
- 5 μg/plate, dissolved in DMSO, strains: TA 1535, TA 100
• 4-nitro-o-phenylenediamine (NOPD)
- 10 μg/plate, dissolved in DMSO, strain: TA 98
• 9-aminoacridine (AAC)
- 100 μg/plate, dissolved in DMSO, strain: TA 1537
• 4-nitroquinoline-N-oxide (4-NQO)
- 5 μg/plate, dissolved in DMSO, strain: E. coli WP2 uvrA

Evaluation criteria:

The test substance was considered positive in this assay if the following criteria were met:
• A dose-related and reproducible increase in the number of revertant colonies, i.e. at least doubling (bacteria strains with high spontaneous mutation rate, like TA 98, TA 100 and E.coli WP2 uvrA) or tripling (bacteria strains with low spontaneous mutation rate, like TA 1535 and TA 1537) of the spontaneous mutation rate in at least one tester strain either without S9 mix or after adding a metabolizing system.
A test substance was generally considered non-mutagenic in this test if:
• The number of revertants for all tester strains were within the historical negative control range under all experimental conditions in at least two experiments carried out independently of each other.

Results and discussion

Test results

Species / strain:

other: S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and E. coli WP2

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

no cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS
- Precipitation: Test substance precipitation was found from about 1000 μg/plate onward with and without S9 mix.

HISTORICAL CONTROL DATA (with ranges, means and standard deviation and confidence interval (e.g. 95%)
In this study with and without S9 mix, the number of revertant colonies in the negative controls was within the range of the historical negative control data for each tester strain. In addition, the positive control substances both with and without S9 mix induced a significant increase in the number of revertant colonies within or above the range of the historical positive control data or above.

ADDITIONAL INFORMATION ON CYTOTOXICITY:
A bacteriotoxic effect (decrease in the number of his+ or trp+ revertants) was observed in the standard plate test depending on the strain and test conditions from about 333 μg/plate onward. In the prival preincubation assay bacteriotoxicity (reduced his- or trp- background growth, decrease in the number of his+ or trp+ revertants) was observed depending on the strain and test conditions from about 1000 μg/plate onward.

Any other information on results incl. tables

STANDARD PLATE TEST

	Mean revertants per plate
Strain	TA 1535		TA 100		TA 1537		TA 98		WP2uvrA
Dose (µg/plate)	-S9	+S9	-S9	+S9	-S9	+S9	-S9	+S9	-S9	+S9
DMSO	15.7	11.0	106.3	110.0	10.0	12.0	24.7	28.0	27.0	24.0
33	11.7	15.0	127.0	112.3	8.3	10.3	22.3	30.0	19.7	31.0
100	14.3	13.0	94.0	112.0	8.3	8.7	25.3	30.0	24.7	27.3
333	12.7	10.3	95.7	103.0	6.7	9.3	23.0	24.7	17.3	22.7
1000	6.7	12.0	71.3	79.3	3.3	4.3	21.7	20.7	11.7	24.0
2500	9.3	7.7	33.7	40.7	4.3	2.0	5.0	4.7	10.0	17.7
5000	4.3	3.3	2.0	2.0	0.0	0.0	1.7	1.3	0.0	8.7
positive control	4606.0	311.0	4396.3	2296.7	922.3	217.7	980.0	1729.3	1082.3	204.0

PRIVAL PREINCUBATION TEST

	Mean revertants per plate
Strain	TA 1535		TA 100		TA 1537		TA 98		WP2uvrA
Dose (µg/plate)	-S9	+S9	-S9	+S9	-S9	+S9	-S9	+S9	-S9	+S9
DMSO	15.7	11.3	99.0	91.7	6.0	6.7	16.3	33.3	15.3	17.7
10	12.3	11.7	103.3	104.0	6.0	9.0	16.0	29.3	16.3	19.7
33	18.3	10.7	97.3	100.3	5.3	7.0	16.7	40.3	18.0	20.7
100	14.7	9.7	101.7	102.3	8.3	7.7	16.0	36.7	20.3	17.3
333	13.7	11.7	75.7	86.3	7.3	6.3	15.0	44.0	14.0	16.7
1000	9.3	9.0	57.7	85.7	3.0	9.3	14.3	28.3	10.0	14.7
2500	0.0	8.7	0.0	62.3	0.0	4.7	4.0	8.3	10.3	7.7
positive control	1470.0	453.7	1139.3	1328.7	2748.3	333.3	1069.3	1247.3	271.7	1181.3
positive control #2								466.7

Applicant's summary and conclusion

Conclusions:

Under the experimental conditions of this study, the test substance is not mutagenic in the Salmonella typhimurium/Escherichia coli reverse mutation assay in the absence and the presence of metabolic activation.

Executive summary:

The test substance was tested for its mutagenic potential based on the ability to induce point mutations in selected loci of several bacterial strains, i.e. Salmonella typhimurium and Escherichia coli, in a reverse mutation assay (Ames standard plate test and Prival preincubation test). Dose ranges were 33 μg - 5000 μg/plate in the standard plate test and 10 μg - 2500 μg/plate in the preincubation test, both with and without metabolic activation. Precipitation of the test substance was found from about 1000 μg/plate onward with and without S9 mix. A bacteriotoxic effect was observed depending on the strain and test conditions from about 333 μg/plate onward A relevant increase in the number of his+ or trp+ revertants (factor ≥ 2: TA 100, TA 98 and E.coli WP2 uvrA or factor ≥ 3: TA 1535 and TA 1537) was not observed in the standard plate test or in the prival preincubation test either without S9 mix or after the addition of a metabolizing system. Thus, under the experimental conditions of this study, the test substance is not mutagenic in the Salmonella typhimurium/Escherichia coli reverse mutation assay in the absence and the presence of metabolic activation.