1H-1,2,4-Triazole-1-carboxamide, 4-amino-N-(1,1-dimethylethyl)-4,5-dihydro-3-(1-methylethyl)-5-oxo-

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:

12 May 1995 to 22 May 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Only 4 s. typhimur. strains used with no E coli strain (as per the requirements of current guidance)

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 471 (Bacterial Reverse Mutation Assay)

Version / remarks:

(1983)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EU Method B.14 (Salmonella typhimurium, reverse mutation test) (1992)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OTS 798.5265 (The Salmonella typhimurium Bacterial Reverse Mutation Test)

Version / remarks:

(1984)

GLP compliance:

yes

Type of assay:

bacterial reverse mutation assay

Test material

Test material information

Constituent 1

Reference substance name:

4-amino-N-tert-butyl-5-oxo-3-(propan-2-yl)-4,5-dihydro-1H-1,2,4-triazole-1-carboxamide

EC Number:

603-373-3

Cas Number:

129909-90-6

Molecular formula:

C10H19N5O2

IUPAC Name:

4-amino-N-tert-butyl-5-oxo-3-(propan-2-yl)-4,5-dihydro-1H-1,2,4-triazole-1-carboxamide

Constituent 2

Reference substance name:

MKH 3586

IUPAC Name:

MKH 3586

Details on test material:

- Name of test material (as cited in study report): MKH 3586
- Physical state: powder
- Analytical purity: 98.4%
- Purity test date: 30 Nov 1994
- Lot/batch No.: 17004/93
- Expiration date of the lot/batch: 29 May 1995

Method

Species / strain

Species / strain / cell type:

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

Additional strain / cell type characteristics:

not applicable

Metabolic activation:

with and without

Metabolic activation system:

Aroclor 1254

Test concentrations with justification for top dose:

Plate incorporation and preincubation +/-S9: 16, 50, 158, 500, 1581, 5000 ug/plate

Controls

Controls 1

Untreated negative controls:

no

Negative solvent / vehicle controls:

yes

Remarks:

DMSO

True negative controls:

no

Positive controls:

yes

Positive control substance:

sodium azide

Remarks:

10 ug/plate (TA 1535) -S9

Controls 2

Positive controls:

yes

Positive control substance:

other: Nitrofurantoin

Remarks:

0.2 ug/plate (TA100) -S9

Controls 3

Positive controls:

yes

Positive control substance:

other: 4-nitro-1,2-phenylene diamine

Remarks:

10 ug/plate (TA1537, TA98) -S9

Controls 4

Positive controls:

yes

Positive control substance:

other: 2-aminoanthracene

Remarks:

3 ug/plate (all strains) +S9

Results and discussion

Test results

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:

no cytotoxicity nor precipitates, but tested up to recommended limit concentrations

Vehicle controls validity:

valid

Untreated negative controls validity:

not applicable

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

INITIAL TOXICITY-MUTATION ASSAY:

Six doses of the test material ranging from 16 to 5000 ug/plate ±S9 were evaluated in the plate incorporation test. No precipitation or toxicity was observed up to the limit dose, 5000 ug/plate.

 

CONFIRMATORY MUTAGENICITY ASSAY:

Again no precipitation or cytotoxic effects were observed in any of the strains tested.

 

Table 7.6.1 -1: Bacterial mutation assay, summary of results– Initial (plate incorporation) test

Dose (ug/plate)	0	16	50	158	500	1581	5000	Positive control
REVERTANTS/PLATE
TA1535 –S9	12 ± 3	14 ± 2	11 ± 3	13 ± 3	10 ± 2	8 ± 3	13 ± 3	782 ± 20
TA1535 +S9	10 ± 1	11 ± 3	12 ± 3	12 ± 3	12 ± 4	12 ± 3	14 ± 3	166 ± 6
TA100 –S9	129 ± 8	95 ± 8	100 ± 13	109 ± 9	97 ± 17	102 ± 5	100 ± 12	264 ± 14
TA100 +S9	103 ± 4	107 ±10	115 ± 14	115 ± 3	109 ± 13	106 ± 7	113 ± 8	1661 ± 126
TA1537 –S9	9 ± 2	10 ± 2	9 ± 3	9 ± 3	8 ± 3	9 ± 2	9 ± 3	119 ± 6
TA1537 +S9	11 ± 2	12 ± 2	8 ± 2	12 ± 3	9 ± 3	8 ± 3	7 ± 1	304 ± 47
TA98 –S9	25 ± 7	22 ± 2	26 ± 3	23 ± 5	20 ± 8	20 ± 5	19 ± 4	176 ± 29
TA98 +S9	26 ± 4	29 ± 5	36 ± 5	28 ± 8	34 ± 4	28 ± 6	28 ± 1	1646 ± 102

 

Table 7.6.1 -2: Bacterial mutation assay, summary of results– Initial (pre-incubation) test

Dose (ug/plate)	0	16	50	158	500	1581	5000	Positive control
REVERTANTS/PLATE
TA1535 –S9	11 ± 1	14 3	14 ± 4	13 ± 1	12 ± 3	14 ± 3	12 ± 2	717 ± 12
TA1535 +S9	12 ± 3	13 ± 3	15 ± 4	12± 4	14 ± 3	11 ± 3	12 ± 4	218 ± 19
TA100 –S9	126 ± 17	116 ± 8	116 ± 19	114 ± 13	122 ± 3	114 ± 14	89 ± 9	356 ± 17
TA100 +S9	124 ± 3	124 ± 11	113 ± 7	107 ± 17	117 ± 15	118 ± 9	121 ± 13	1562 ± 68
TA1537 –S9	11 ± 1	11 ± 2	12 ± 1	9 ± 3	12± 3	101 ± 4	7 ± 2	124 ± 8
TA1537 +S9	11 ± 2	11 ± 3	9 ± 1	9 ± 2	11 ± 2	10 ± 2	13 ± 1	227 ± 31
TA98 –S9	25 ± 5	23 ± 4	22 ± 3	20 ±4	21 ± 8	26 ±8	26 ± 3	166 ± 24
TA98 +S9	27 ± 3	33 ± 3	32 ± 3	30 ± 6	32 ± 5	30 ± 6	31 ± 4	1216 ± 50

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information):
negative with metabolic activation
negative without metabolic activation

Based on the results from this study, MKH 3586 was not mutagenic in the bacterial strains tested, either in the presence or absence of metabolic activation when tested up 5000 ug/plate (the maximum dose in accordance with regulatory guidelines).

Executive summary:

In a reverse gene mutation assay in bacteria,Salmonella typhimuriumstrains TA98, TA100, TA1535, and TA1537 were exposed to MKH 3586 formulated in DMSO. The assay was performed in two phases, using the plate incorporation snd the pre-incubation method.

 

In an initial test, the plate incorporation method was used with dose levels of 16 to 5000 ug/plate in the presence and absence of S9 activation was assessed. No precipitation, cytotoxicity or increase in revertants were observed in any strain tested. The same effects were observed in the pre-incubation, confirmatory test where the same dose range was tested.

 

Based on the results from this study, MKH 3586 was not mutagenic in the bacterial strains tested, either in the presence or absence of metabolic activation when tested up 5000 ug/plate (the maximum dose in accordance with regulatory guidelines).