Registration Dossier

Administrative data

Endpoint:
toxicity to microorganisms
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Scientifically acceptable publication

Data source

Reference
Reference Type:
publication
Title:
Biological effects of prenylated hydroquinones: structure-activity relationship studies in antimicrobial, brine shrimp, and fish lethality assays
Author:
De Rosa, S., De Giuli,o A. and Iodice, C.
Year:
1994
Bibliographic source:
Journal of Natural Products 57(12): 1711-1716, 1994

Materials and methods

Test guideline
Qualifier:
no guideline available
Principles of method if other than guideline:
A test guideline was not mentioned in the publication.
GLP compliance:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
2-methylhydroquinone
EC Number:
202-443-7
EC Name:
2-methylhydroquinone
Cas Number:
95-71-6
Molecular formula:
C7H8O2
IUPAC Name:
2-methylbenzene-1,4-diol
Constituent 2
Reference substance name:
Methylhydroquinone
IUPAC Name:
Methylhydroquinone
Details on test material:
- Origin of test material: Sigma-Aldrich s.r.l., Italy
- Purity: 100 %

Sampling and analysis

Analytical monitoring:
not specified

Test solutions

Vehicle:
not specified

Test organisms

Test organisms (species):
other: Bacillus subtilis and Micrococcus luteus
Details on inoculum:
- Strains: Bacillus subtilis DSM 347 and Micrococcus luteus DSM 348 (both Gram-positive bacteria)
- Origin of microorganisms: DSM, Germany

Study design

Test type:
other: diffusion tests on paper disks
Water media type:
not specified
Limit test:
no
Total exposure duration:
18 h

Test conditions

Test temperature:
35 - 37°C
Nominal and measured concentrations:
Two-fold serial dilutions were tested, starting from a 50 µg/mL solution.
Details on test conditions:
Preliminary results for antibacterial and antifungal activities were obtained by means of diffusion tests, using 100 mg of compound per paper disk (6 mm). The impregnated disks were applied on nutrient agar plates, seeded with overnight cultures of the test microorganisms. The inhibition zones were measured after 18 h incubation at 35-37° C. Quantitacive measurement on active compounds, selected by means of the diffusion test, were performed to determine the minimum inhibitory concentration (MIC). The end point in this assay was indicated by thr absence of detectable growth after 18 h of incubation.

Results and discussion

Effect concentrationsopen allclose all
Duration:
18 h
Dose descriptor:
other: MIC
Effect conc.:
25 mg/L
Remarks on result:
other: Bacillus subtilis
Duration:
18 h
Dose descriptor:
other: MIC
Effect conc.:
> 50 mg/L
Remarks on result:
other: Micrococcus luteus
Details on results:
MIC: minimum inhibitory concentration

Applicant's summary and conclusion