p,p'-(2-pyridylmethylene)bisphenol

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:

2002-12-12 to 2002-12-20

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: The study was conducted under GLP conditions in accordance with the official OECD guideline No 471 (1997) and is regarded as reliable with restrictions as only two strains (TA 98 and TA 100) were tested

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2003

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

(July 1997)

Deviations:

yes

Remarks:

Only the strains TA 98 and TA 100 were tested

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: Commission Directive 2000/32/EC, L1362000, Annexe 4D (May 2000)

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

1

Reference substance name:

p,p'-(2-pyridylmethylene)bisphenol

EC Number:

210-039-7

EC Name:

p,p'-(2-pyridylmethylene)bisphenol

Cas Number:

603-41-8

Molecular formula:

C18H15NO2

IUPAC Name:

4-[(4-hydroxyphenyl)(pyridin-2-yl)methyl]phenol

Test material form:

solid

Method

Target gene:

strain: TA 98; genotype: his D 3052; rfa, uvrB; R-factor; type of mutation: frame shift mutationstrain: TA 100; genotype: his G 46; rfa, uvrB; R-factor; base pair substitution

Species / strain

Species / strain / cell type:

other: S. typhimurium TA 98 and TA 100

Additional strain / cell type characteristics:

nitroreductase deficient

Metabolic activation:

with and without

Metabolic activation system:

S9

Test concentrations with justification for top dose:

33, 100, 333, 1000, 2500 and 5000 µg/plate

Vehicle / solvent:

- Vehicle(s)/solvent(s) used: DMSO- Justification for choice of solvent/vehicle: The solvent was chosen because of its solubility properties and its relative nontoxicity for the bacteria.

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

yes

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

other: 4-Nitro-o-phenylenediamine; 2-aminoanthracene

Details on test system and experimental conditions:

METHOD OF APPLICATION: in agar; Experiment I: plate incorporation and Experiment II: pre-incubationDURATION- Exposure duration: 48 hrsNUMBER OF REPLICATIONS: 3

Evaluation criteria:

A test item is considered as a mutagen if a biologically relevant increase in the number of revertants exceeding the threshold of twice the colony count of the corresponding solvent control is observed.A dose dependent increase is considered biologically relevant if the threshold is exceeded at more than one concentration.An increase exceeding the threshold at only one concentration is judged as biologically relevant if reproduced in an independent second experiment.A dose dependent increase in the number of revertant colonies below the threshold is regarded as an indication of a mutagenic potential if reproduced in an independent second experiment. However, whenever the colony counts remain within the historical range of negative and solvent controls such an increase is not considered biologically relevant.

Statistics:

not regarded as neccessary according to the OECD guidelines.

Results and discussion

Test results

Species / strain:

S. typhimurium, other: TA 98 and TA 100

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Vehicle controls validity:

valid

Untreated negative controls validity:

valid

Positive controls validity:

valid

Additional information on results:

TEST-SPECIFIC CONFOUNDING FACTORS- Precipitation: in the following concentrations: Experiment I: TA 98 and TA 100 5000 µg/plate with and without S9 mix; Experiment II: TA 98 and TA 100 5000 µg/plate without S9 mix; TA 98 2500 and 5000 µg/plate with S9 mix- Other effects: Slight toxic effects, evident as a reduction in the number of revertants, were observed in strain TA 98 at 2500 and 5000 µg/plate with metabolic activation and in strain TA 100 at 5000 µg/plate without metabolic activation in experiment II. No visible reduction of the background growth was observed up to the highest concentration with and without S9 mix.

Remarks on result:

other: all strains/cell types tested

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

No substantial increase in revertant colony numbers of any of the two tester strains was observed following treatment with Oxypicoline RF at any dose level, neither in the presence nor absence of metabolic activation (S9 mix). There was also no tendency of higher mutation rates with increasing concentrations in the range below the generally acknowledged border of biological relevance.

In experiment I, the number of colonies did not quite reach the lower limit of our historical control data in strain TA 100 (with S9 mix) in the solvent control. Since this deviation is rather small, this effect is judged to be based upon biological fluctuations and has no detrimental impact on the outcome of the study.

The historical range of positive controls was exceeded in strains TA 100 (Exp. I) without metabolic activation. This effect indicates the sensivity of the strains rather than compromising the assay.

Appropriate reference mutagens were used as positive controls. They showed a distinct increase in induced revertant colonies.

Experiment I: Plate Incorporation Test

Concentration µg/plate	Revertants/plate		Revertants/plate
	Mean of three plates	Standard deviation	Mean of three plates	Standard deviation
TA 98	Without S9 mix		With S9 mix
Negative Control	23	3.2	39	2.5
Solvent Control	27	4.5	34	1.0
Positive Control	144	17.3	613	25.5
33	25	5.7	34	3.5
100	30	5.7	31	4.0
333	27	2.5	40	7.0
1000	31	5.5	44	2.5
2500	29	4.5	44	4.5
5000	27	3.1	27	2.5
TA 100
Negative Control	93	11.2	108	12.0
Solvent Control	101	6.7	81	4.4
Positive Control	1084	84.5	718	46.3
33	90	11.6	96	9.2
100	99	9.7	116	22.7
333	90	5.5	85	6.4
1000	79	7.5	110	6.1
2500	69	5.5	70	6.2
5000	60	2.5	40	2.3

Experiment II: Pre-Incubation Test

Concentration µg/plate	Revertants/plate		Revertants/plate
	Mean of three plates	Standard deviation	Mean of three plates	Standard deviation
TA 98	Without S9 mix		With S9 mix
Negative Control	27	6.9	27	3.8
Solvent Control	21	3.8	25	2.6
Positive Control	404	36.5	508	45.6
33	23	5.3	27	3.8
100	23	3.5	28	7.5
333	25	3.6	27	5.7
1000	21	9.3	29	4.0
2500	14	3.2	9	1.7
5000	12	0.6	5	1.0
TA 100
Negative Control	111	12.1	144	17.6
Solvent Control	93	8.7	118	9.1
Positive Control	874	50.2	590	96.9
33	101	5.3	111	8.7
100	94	13.9	102	17.2
333	80	5.3	133	7.0
1000	56	48.8	101	6.0
2500	51	12.0	73	9.8
5000	35	2.0	67	8.5

 

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):negativeIn conclusion, it can be stated that during the described mutagenicity test and under the experimental conditions reported, the test item did not induce gene mutations by base pair changes or frameshifts in the genome of the strains used.Therefore, Oxypicoline RF is considered to be non-mutagenic in this Salmonella typhimurium reverse mutation assay.