2,4(1H,3H)-Pyrimidinedione, 1-[2-deoxy-3,5-bis-O-(4-methylbenzoyl)-.beta.-L-erythro-pentofuranosyl]-5-methyl-

Toxicity to aquatic algae and cyanobacteria

Administrative data

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

experimental study

Adequacy of study:

key study

Study period:

19. april 2004 - 3. june 2004

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method C.3 (Algal Inhibition test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

[(2S,3R,5S)-3-[(4-methylbenzoyl)oxy]-5-(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-2-yl]methyl 4-methylbenzoate

EC Number:

608-497-1

Cas Number:

3056-13-1

Molecular formula:

C26 H26 N2 O7

IUPAC Name:

[(2S,3R,5S)-3-[(4-methylbenzoyl)oxy]-5-(5-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl)tetrahydrofuran-2-yl]methyl 4-methylbenzoate

Sampling and analysis

Analytical monitoring:

yes

Test solutions

Vehicle:

no

Details on test solutions:

The test substance is of limited solubility in aqueous media. Therefore a water accomodated fraction (WAF) with a "loading rate" of 100 mg test substance per L nutrient medium (see Appendix 1) was generated by overnight stirring in the dark at ambient temperature and subsequent filtration of the medium (cellulose acetate, 0.2 μm, Sartorius).
This WAF was then used as the highest test substance concentration. Aliquots of this WAF were further diluted with sterile nutrient medium to obtain lower concentrations.
The preparations were made freshly before the start of the exposure.

Test organisms

Test organisms (species):

Raphidocelis subcapitata (previous names: Pseudokirchneriella subcapitata, Selenastrum capricornutum)

Study design

Test type:

static

Water media type:

freshwater

Limit test:

no

Total exposure duration:

72 h

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 0.01 mg/L

Nominal / measured:

nominal

Conc. based on:

other: WAF

Basis for effect:

growth rate

Remarks on result:

other: no inhibition up to the water solubility

Effect concentrations 2

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 0.01 mg/L

Nominal / measured:

nominal

Conc. based on:

other: WAF

Basis for effect:

growth rate

Remarks on result:

other: no inhibition up to the water solubility

Effect concentrations 3

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 0.01 mg/L

Nominal / measured:

nominal

Conc. based on:

other: WAF

Basis for effect:

biomass

Remarks on result:

other: no inhibition up to the water solubility

Effect concentrations 4

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

>= 0.01 mg/L

Nominal / measured:

nominal

Conc. based on:

other: WAF

Basis for effect:

biomass

Remarks on result:

other: no inhibition up to the water solubility

Details on results:

The actual test substance concentrations were below the limit of quantitation (0.01 mg/L) at the start of the incubation and 72 hours thereafter in all test substance cultures and in the blank without algae.

Any other information on results incl. tables

Growth inhibition

Compared to the negative controls, algal growth was marginally inhibited (by 17.8 % or 10.3 % based on the area under the growth curves or based on the average growth rates) at the highest tested concentration (WAF, corresponding to an actual starting concentration of < 0.01 mg/L). All other tested concentrations did either not influence algal growth or even slightly enhanced it.