1,3-Cyclopentanedione, 2-[(2E)-2-(3,4-dihydro-6-methoxy-1(2H)-naphthalenylidene)ethyl]-2-ethyl-

Toxicity to microorganisms

Administrative data

Endpoint:

toxicity to microorganisms

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Dec 1995

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:

1997

Report date:

1997

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-Methoxy-18-methyl-8,14-seco-1,3,5(10),9(11)-estratetraene-14,17-dione

EC Number:

613-005-3

Cas Number:

62298-52-6

Molecular formula:

C20H24O3

IUPAC Name:

3-Methoxy-18-methyl-8,14-seco-1,3,5(10),9(11)-estratetraene-14,17-dione

Details on test material:

- Name of test material (as cited in study report): 17-Keto-Ethyl-Seco-Verbindung
- Analytical purity: 98.8 %
- Lot/batch No.: 10037206

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:

yes

Total exposure duration:

28 d

Results and discussion

Effect concentrations

Duration:

16 h

Dose descriptor:

EC50

Effect conc.:

> 7 mg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

growth inhibition

Any other information on results incl. tables

Table 1: Mean values of turbidity (expressed as TE/F) and growth inhibition of Pseudomonas putida as a function of the concentration (n=3) of ZK 46073

Dilution of ZK 46073	TE/F [mean value (16 hours)]	Growth inhibition (%)
Control	174	0
1 :32 diluted	174	0
1 :16 diluted	165	5
1 :8 diluted	166	5
1 :4 diluted	165	5
1 :2 diluted	160	8
Saturated	194	-12

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

A saturated solution of ZK 46073 (approximately 7 mg/L) had no inhibitory effect on the growth
of Pseudomonas putida.

Executive summary:

The purpose of this study was to determine the growth inhibition of Pseudomonas putida under exposure to 17 -Keto-Ethyl-Seco-Verbindung (ZK 46073). The test was conducted in agreement with the DIN standard 38412, L8, "Wachstumshemmtest mit dem Bakterium Pseudomonas putida".

The test substance was incubated in an aqueous solution including nutrients with a bacterial population of Pseudomonas putida for a test duration of appraximately 16 hours. 200 mg ZK 46073 were suspended in 1000 ml demineralized water under constant strirring for 24 hours. For the test solutions the suspension was filtered. This solution was used as the highest test concentration and was further diluted 1 :2, 1 :4, 1 :8, 1 :16 and 1 :32. Additionally, one control without the test substance was used. All test solutions including the control were incubated in triplicate. Furthermore, 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 saturated, filtered stock solution was estimated by a TOC-analysis and subsequent calculation based on the molecular formula with 7 mg/L. As a parameter for the growth of the bacterial population, the turbidity of the test and control solutions was analysed photometrically at a wave-length of 436 nm.

There was a slight growth increase at the highest test concentration in comparison with the control group. All other dilutions showed approximately the same growth as the control.