2-methylhydroquinone

Toxicity to microorganisms

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

Test material information

Constituent 1

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 concentrations

Effect concentrations 1

Duration:

18 h

Dose descriptor:

other: MIC

Effect conc.:

25 mg/L

Remarks on result:

other: Bacillus subtilis

Effect concentrations 2

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