3-methoxyestra-2,5(10)-dien-17β-ol

Toxicity to microorganisms

Administrative data

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Jul 1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: According to DIN guideline under GLP

Cross-reference

Cross-reference 1

Reason / purpose for cross-reference:

reference to same study

Cross-reference 2

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

DIN 38412-8 (Pseudomonas Zellvermehrungshemmtest)

Deviations:

no

Principles of method if other than guideline:

Not relevant

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

3-methoxyestra-2,5(10)-dien-17β-ol

EC Number:

214-130-2

EC Name:

3-methoxyestra-2,5(10)-dien-17β-ol

Cas Number:

1091-93-6

Molecular formula:

C19H28O2

IUPAC Name:

(1S,3aS,3bR,9bS,11aS)-7-methoxy-11a-methyl-1H,2H,3H,3aH,3bH,4H,5H,6H,9H,9bH,10H,11H,11aH-cyclopenta[a]phenanthren-1-ol

Details on test material:

- Name of test material (as cited in study report): Dihydro-Estradiol-Methylether
- Analytical purity: 89.8%
- Lot/batch No.: 21400234-35

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Test organisms

Test organisms (species):

Pseudomonas putida

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

16 h

Results and discussion

Effect concentrations

Duration:

16 h

Dose descriptor:

EC50

Effect conc.:

> 1.5 mg/L

Nominal / measured:

meas. (initial)

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Any other information on results incl. tables

Table 1: Turbidity (expressed as TE/F) and growth inhibition as a function of the concentration

Concentration	TE/F ± standard deviation	Growth inhibition
	[mean value (16 hours)]	(%)
Control	535 ± 6	0
1: 160 diluted	549 ± 15	-3
1 : 80 diluted	593 ± 2	-11
1 : 40 diluted	597 ± 5	-12
1 : 20 diluted	572 ± 1	-7
1 : 10 diluted	538 ± 1	-1

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

Dihydro-Estradiol-Methylether in a diluted solution (1 :160 to 1:10) had no inhibitory effect on the growth of
Pseudomonas putida.

Executive summary:

The test substance was incubated in an aqueous solution including nutrients with a bacterial population of Pseudomonas putida for a test duration of approximately 16 ± 1 hours. The nutrient solution was made up of mainly nitrate, phosphates, carbohydrates, so me trace elements and vitamins. Since the test substance has a low solubility in water, a suspension with a nominal concentration of 1000 mg/l was prepared, treated in an ultrasonic bath for 2 hours, stirred for another 22 hours and filtered subsequently. The stock solution obtained by this procedure was diluted 1:10, 1 :20, 1 :40, 1 :80 and 1 :160 to obtain the test solutions. Additionally, one control without the test substance was used. All test solutions including the control were incubated in triplicate. Furtherrnare, for each test concentration one test vessel was incubated without addition of the inoculum in order to analyse the inherent turbidity of the test compound. The concentration of the stock solution was estimated by a TOC-analysis and subsequent calculation based on the structural formula. It was estimated with approximately 15 mg/L. As a parameter for the growth of the bacterial population, the turbidity of the test and control solu'tions was analysed photometrically at a wave-Iength of 436 nm.

The measurements showed that there was no growth inhibition of the bacterial population. However, there was a slight growth increase in comparison with the control group. The test substance in a diluted solution (1 :160 to 1:10) had no inhibitory effect on the growth of Pseudomonas putida. The increase of growth is not considered to be relevant with regard to the purpose of this study and probably represents the biological variation attributable to the test method. Following the results of a range-finding study it can be stated that no inhibitory effects are to be expected from Dihydro-Estradiol-Methylether up to its solubility limit.