2-Pyridinecarboxamide, 4-(4-amino-3-fluorophenoxy)-N-methyl-

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:

other information

Study period:

July 2007

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

4-(4-amino-3-fluorophenoxy)-N-methylpyridine-2-carboxamide

EC Number:

692-721-8

Cas Number:

757251-39-1

Molecular formula:

C13 H12 F N3 O2

IUPAC Name:

4-(4-amino-3-fluorophenoxy)-N-methylpyridine-2-carboxamide

Method

Target gene:

Histidine gene locus

Species / strain

Species / strain / cell type:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254 induced male rat liver S9 mix

Test concentrations with justification for top dose:

0, 16, 50, 158, 500, 1581, 5000 µg/plate (first test, +/-S9 mix, all strains)
0, 300, 600, 1200, 2400, 3600, 4800 µg/plate (repeat test, +S9 mix, TA 98 and TA 100 only)

Vehicle / solvent:

DMSO

Controls

Untreated negative controls:

yes

Negative solvent / vehicle controls:

no

Remarks:

No solvent control was used since sufficient evidence was available in the literature and from testing laboratory experience, indicating that the solvents used had no influence on the spontaneous mutant counts of the used strains.

True negative controls:

no

Positive controls:

yes

Positive control substance:

other: sodium azide (only TA 1535), nitrofurantoin (only TA 100), 4-nitro-1,2-phenylene diamine (TA 1537 and TA 98), mitomycin C (only TA 102), 2-aminoanthracene (all strains).

Remarks:

The positive controls sodium azide, nitrofurantoin, 4-nitro-1,2-phenylene diamine and mitomycin C were only used without S9 mix; the positive control 2-aminoanthracene was only used with S9 mix.

Details on test system and experimental conditions:

METHOD: each concentration including the controls was tested in triplicate.

Evaluation criteria:

A reproducible and dose-related increase in mutant counts of at least one strain is considered to be a positive result. For TA 1535, TA 100 and TA 98 this increase should be about twice that of negative controls, whereas for TA 1537 at least a threefold increase should be reached. For TA 102 an increase of about 100 mutants should be reached. Otherwise, the result is evaluated as negative. However, these criteria may be overruled by good scientific judgment. In case of questionable results, investigations should continue, possibly with modifications, until a final evaluation is possible.

Statistics:

not specified

Results and discussion

Test results

Test results 1

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with

Genotoxicity:

positive

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

weak, strain-specific bacteriotoxic effect at 3600 µg/plate and above

Vehicle controls validity:

not examined

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 2

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

weak, strain-specific bacteriotoxic effect at 3600 µg/plate and above

Vehicle controls validity:

not examined

Untreated negative controls validity:

valid

Positive controls validity:

valid

Test results 3

Species / strain:

S. typhimurium TA 1535, TA 1537, TA 98, TA 100 and TA 102

Metabolic activation:

with and without

Genotoxicity:

negative

Cytotoxicity / choice of top concentrations:

cytotoxicity

Remarks:

weak, strain-specific bacteriotoxic effect at 3600 µg/plate and above

Vehicle controls validity:

not examined

Untreated negative controls validity:

valid

Positive controls validity:

valid

Remarks on result:

other: strain/cell type: TA 98, TA 100

Remarks:

Migrated from field 'Test system'.

Any other information on results incl. tables

Table 1: Summary of results from the Salmonella mutagenicity assay (first test) with AFP-Picolinmethylamid (mean values of revertants per plate)

Dose (µg per plate)	Without metabolic activation
	TA 1535	TA 100	TA 1537	TA 98	TA 102
0	14	148	7	15	273
16	13	145	7	18	243
50	15	143	6	14	258
158	10	139	7	18	268
500	16	130	7	16	265
1581	16	167	9	16	235
5000	14	155	7	18	193
Positive control	871*	357*	92*	180*	628*
Dose ( µg per plate )	With metabolic activation (liver S9 mix)
	TA 1535	TA 100	TA 1537	TA 98	TA 102
0	13	211	8	28	326
16	12	219	10	29	321
50	15	265*	7	47	275
158	17	344*	7	44	307
500	23	457*	10	58*	330
1581	20	517*	7	89*	307
5000	15	493*	9	97*	254
Positive control	259*	2178*	276*	947*	568*

* = mutagenic effect

 

Table 2: Summary of results from the Salmonella mutagenicity assay (repeat test with strains TA 98 and TA 100 and metabolic activation) with AFP-Picolinmethylamid (mean values of revertants per plate)

 

Dose (µg per plate)	With metabolic activation (liver S9 mix)
	TA 1535	TA 100	TA 1537	TA 98	TA 102
0	-	149	-	29	-
300	-	358*	-	56*	-
600	-	322*	-	63*	-
1200	-	335*	-	72*	-
2400	-	744*	-	97*	-
3600	-	761*	-	98*	-
4800	-	707*	-	98*	-
Positive control	-	1966*	-	1490*	-

 

* = mutagenic effect

Doses up to and including 2400 µg per plate did not cause any bacteriotoxic effects. Total bacteria counts remained unchanged and no inhibition of growth was observed. At higher doses, the substance had only a weak, strain-specific bacteriotoxic effect. Due to the weakness of this effect this range could nevertheless be used for assessment purposes.

Evidence of mutagenic activity of AFP-Picolinmethylamid was seen. On Salmonella typhimurium TA 100 and TA 98, a biologically relevant increase was found in the mutant count compared to the corresponding negative control. Positive response was found only with S9 mix. The lowest effective dose was 50 µg per plate for TA 100 and 300 µg per plate for TA 98. The Salmonella/microsome test thus showed AFP-Picolinmethylamid to have a mutagenic effect.

The positive controls sodium azide, nitrofurantoin, 4-nitro-1,2-phenylene diamine, mitomycin C and 2-aminoanthracene had a marked mutagenic effect, as was seen by a biologically relevant increase in mutant colonies compared to the corresponding negative controls.

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
positive with metabolic activation

Executive summary:

The mutagenic potential of AFP-Picolinmethylamid was evaluated in a Salmonella/microsome test with the S. typhimurium strains TA 98, TA 100, TA 102, TA 1535 and TA 1537 in the presence and absence of S9 mix according to OECD TG 471. Doses up to and including 2400 µg per plate did not cause any bacteriotoxic effects. Total bacteria counts remained unchanged and no inhibition of growth was observed. At higher doses, the substance had only a weak, strain-specific bacteriotoxic effect. Due to the weakness of this effect this range could nevertheless be used for assessment purposes. Evidence of mutagenic activity of AFP-Picolinmethylamid was seen. On Salmonella typhimurium TA 100 and TA 98, a biologically relevant increase was found in the mutant count compared to the corresponding negative control. Positive response was found only with S9 mix. The lowest effective dose was 50 µg per plate for TA 100 and 300 µg per plate for TA 98. The Salmonella/microsome test thus showed AFP-Picolinmethylamid to have a mutagenic effect.