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Please be aware that this old REACH registration data factsheet is no longer maintained; it remains frozen as of 19th May 2023.

The new ECHA CHEM database has been released by ECHA, and it now contains all REACH registration data. There are more details on the transition of ECHA's published data to ECHA CHEM here.

Diss Factsheets

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:
9 - 11 May 2007
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: The study was conducted for internal use only and hence not conducted in GLP compliance. However, it was conducted by an experienced laboratory and was well described.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2007
Report date:
2007

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
The assay was performed according to the instruction manual for the Ames II (Xenometrix, Boulder/USA).
GLP compliance:
no
Type of assay:
bacterial reverse mutation assay

Test material

Constituent 1
Reference substance name:
Methscopolamine bromide
IUPAC Name:
Methscopolamine bromide
Test material form:
other: solid
Details on test material:
- Name of test material (as cited in study report): Methscopolamine bromide
- Physical state: solid

Method

Species / strain
Species / strain / cell type:
bacteria, other: S. typhimurium TA Mix (TA 7001, TA 7002, TA 7003, TA 7004, TA 7005 and TA 7006) and TA 98
Details on mammalian cell type (if applicable):
n/a
Additional strain / cell type characteristics:
not applicable
Metabolic activation:
with and without
Metabolic activation system:
microsomal liver enzymes from rats (Aroclor 1254-induced)
Test concentrations with justification for top dose:
1, 4, 20, 100, 500, 2500, 5000 μg/mL
Vehicle / solvent:
DMSO
Controls
Untreated negative controls:
no
Negative solvent / vehicle controls:
yes
True negative controls:
no
Positive controls:
yes
Positive control substance:
4-nitroquinoline-N-oxide
2-nitrofluorene
other: 2-aminoanthracene
Details on test system and experimental conditions:
The assay was performed according to the instruction manual for the Ames II (Xenometrix, Boulder/USA). Vehicle, test substance or positive control in a volume of 0.01 mL were incubated with 0.24 mL bacterial overnight culture (ca 107/mL)/exposure medium in 24-well plates for 90 min at 37°C and 250 rpm. With metabolic activation 0.2 mL strain mixture and 0.04 mL S9-mix (30%) were used.

After 90 min the exposed cultures were diluted with pH indicator medium lacking histidine and aliquoted into 48 wells of a 384-well plate (3 replicates) using an 8-channel pipettor. The plates were incubated for 48 hrs at 37°C. To confirm the sensitivity of the tester strains and the metabolic capacity of the S9 fractions, the diagnostic mutagens 2-nitrofluorene (2-NF), 4-nitroquinoline-N-oxide (4-NQO) and 2-aminoanthracene (2-AA) were used, respectively.
Evaluation criteria:
The pH indicator bromocresol purple turns the colour of the cultures from blue to yellow as the pH drops due to the accumulation of catabolites from the metabolic activity of revertant cells. The number of positive wells (yellow) out of a total of 48 wells is an indication of the frequency of reversion per replicate per dose and was compared to the number of spontaneous revertant wells of the solvent control. Each test point contains 48 wells of a 384-well plate. In each 48-well section, the wells were scored for the number of revertant wells (yellow) and the mean value of the triplicates was calculated.

Results and discussion

Test results
Species / strain:
bacteria, other: S. typhimurium TA Mix (TA 7001, TA 7002, TA 7003, TA 7004, TA 7005 and TA 7006) and TA 98
Metabolic activation:
with and without
Genotoxicity:
negative
Cytotoxicity / choice of top concentrations:
not determined
Vehicle controls validity:
valid
Untreated negative controls validity:
not examined
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

Solubility and Toxicity

Methscopolamine bromide showed neither precipitation nor bacteriotoxicity up to the highest tested concentration of 5000 μg/mL.

Mutagenicity

Methscopolamine bromide did not increase the number of positive wells in the different tester strains neither in presence nor absence of a metabolic activation system compared to the negative control (≤8/48 wells). The vehicle controls showed the expected responses and the positive controls (2-NF, 4-NQO and 2-AA, respectively) showed a clear mutagenic response demonstrating the validity of the

study.

Applicant's summary and conclusion

Conclusions:
Interpretation of results (migrated information):
negative

Methscopolamine bromide (chemical intermediate of BA 679 synthesis) caused neither base-pair substitution nor frameshift mutations in a series of S. typhimurium tester strains (TA Mix and TA 98) in the absence and presence of a metabolic activation system when tested up to recommended concentrations. Therefore, based on these results the test substance can be classified as "Ames II negative".