(3S,6S,7R,8R)-8-Benzyl-3-{[(3-hydroxy-4-methoxypyridin-2-yl)carbonyl]amino}-6-methyl-4,9-dioxo-1,5-dioxonan-7-yl 2-methylpropanoate

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 202 (Daphnia sp. Acute Immobilisation Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(3S,6S,7R,8R)-8-benzyl-3-(3-hydroxy-4-methoxypyridine-2-amido)-6-methyl-4,9-dioxo-1,5-dioxonan-7-yl 2-methylpropanoate

Cas Number:

167173-85-5

Molecular formula:

C26H30N2O9

IUPAC Name:

(3S,6S,7R,8R)-8-benzyl-3-(3-hydroxy-4-methoxypyridine-2-amido)-6-methyl-4,9-dioxo-1,5-dioxonan-7-yl 2-methylpropanoate

Specific details on test material used for the study:

Substance name: X642188
Lot#: SYN-FS08353-048
Purity: 99%

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

yes

Test organisms

Test organisms (species):

Daphnia magna

Study design

Test type:

flow-through

Water media type:

freshwater

Limit test:

no

Total exposure duration:

48 h

Test conditions

Hardness:

156 mg CaCO3/L

Test temperature:

20.5 to 21.0°C

pH:

6.9 to 7.1

Dissolved oxygen:

6.9 to 8.4 mg/L (81 to 99% saturation)

Conductivity:

470 μS/cm

Nominal and measured concentrations:

Nominal: 0 (control), 0 (vehicle control), 0.049, 0.11, 0.23, 0.52, 1.1, and 2.5 μg/L
Measured:

Results and discussion

Effect concentrations

Effect concentrations 1

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.79 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: Immobility

Effect concentrations 2

Duration:

24 h

Dose descriptor:

EC50

Effect conc.:

> 1.3 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: Immobility

Remarks on result:

other: Highest dose tested

Effect concentrations 3

Duration:

48 h

Dose descriptor:

NOEC

Effect conc.:

0.33 µg/L

Nominal / measured:

meas. (arithm. mean)

Conc. based on:

test mat.

Basis for effect:

other: Immobility

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

48-h EC50 (Daphnia magna): 0.79 µg/L (Immobility)

Executive summary:

The test substance was tested for acute toxicity to Daphnia magna at 48-h of exposure under flow-through conditions. The test was conducted according to OECD guideline 402.

Nominal concentrations used were 0 (control), 0 (vehicle control), 0.049, 0.11, 0.23, 0.52, 1.1, and 2.5 μg/L, corresponding to mean measured concentrations of <MQL (control), <MQL (vehicle control), 0.034, 0.068, 0.14, 0.33, 0.62, and 1.3 μg/L, respectively.

After 48 hours of exposure, immobility was 5% in the control and vehicle control, and 5, 0, 10, 0, 25, and 95% in 0.034, 0.068, 0.14, 0.33, 0.62, and 1.3 μg/L treatments, respectively. Daphnids not found were noted in the vehicle control, 0.14, and 1.3 μg/L test treatments at 24 hours, and in the vehicle control, 0.14, and 1.3 μg/L test treatments at 48 hours. Daphnids noted as not found at termination were considered dead and counted as immobile. No other sublethal effects were noted during the definitive test. There was a statistically significant increase in the immobility in the 0.62 and 1.3 μg/L test treatments compared to the pooled controls (Williams’ test, p ≤ 0.05). The 48-hour NOEC was 0.33 μg/L, based on the mean measured concentrations and the lack of statistically significant effects at this, and all lower test substance concentrations. The estimated 24-hour EC50 value was >1.3 μg/L, the highest concentration tested. The slope of the 24-hour concentration-response line was not calculated. The estimated 48-hour EC50 value was 0.79 μg/L, with 95% confidence limits of 0.66 and 0.95 μg/L. The slope of the 48-hour concentration-response line was 7.6.