Methyl 5-deoxy-2,3-O-isopropylidene-β-D-ribofuranoside

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:

01 March 2013 to 26 September 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Fully GLP compliant and in accordance with current test guidelines

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 201 (Alga, Growth Inhibition Test)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Methylfuranoside

IUPAC Name:

Methylfuranoside

Constituent 2

Reference substance name:

Methyl 5-deoxy-2,3-O-isopropylidene-β-D-ribofuranoside

EC Number:

245-485-1

EC Name:

Methyl 5-deoxy-2,3-O-isopropylidene-β-D-ribofuranoside

Cas Number:

23202-81-5

Molecular formula:

C9H16O4

IUPAC Name:

methyl 5-deoxy-2,3-O-isopropylidene-beta-D-ribofuranoside

Test material form:

other: Pale yellow liquid

Details on test material:

Name: Methylfuranoside
CAS number: 23202-81-5
Batch number: 201111082008
Quantity received: 1.5 kg
Purity: 99.7%
Expiry date: November 2013
Date of receipt: 20 February 2013
Storage details: stored in a sealed container, at room temperature (15 to 30°C) in the dark

Sampling and analysis

Analytical monitoring:

yes

Details on sampling:

At approximately 24-hour intervals after the start of the incubation period, pre determined volumes of test media were removed from each incubated test vessel, and transferred to individually identified cell counting vials. The contents of each vial were diluted to a 10 mL final volume with an electrolyte solution. The cell density of the vial contents was then determined using a particle counter (Z2 Coulter Counter®).

Test solutions

Vehicle:

yes

Details on test solutions:

Based on the results of the range-finding test which is not fully reported, the definitive test was conducted at a single nominal test substance concentration of 125 mg/L. This test design constitutes a ‘Limit Test’ to determine that, at the maximum concentration defined by the test guideline of 100 mg/L no inhibition of growth was observed. A concentration of 125 mg/L was used to ensure measured concentrations were as close to 100 mg/L as possible.
At the start of the test, the 125 mg/L test concentration was prepared by dissolving ca 125 mg of test substance in 1000 mL with EC medium. A control treatment was also prepared using EC medium only.

Test organisms

Test organisms (species):

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

Details on test organisms:

TEST ORGANISM
- Common name: Pseudokirchneriella subcapitata
- Strain:Strain 278/4
- Source (laboratory, culture collection): originally obtained from the Culture Collection of Algae and Protozoa (CCAP)
- Age of inoculum (at test initiation): a starting alga cell density of 1 x 10^4 cells/mL
- Method of cultivation: To prepare the alga culture medium, stock solutions containing the various nutrients were prepared with reverse osmosis (RO) water. Aliquots of each of the stock solutions were then added to RO water. The alga culture medium was autoclaved. Once cooled, an aliquot of a stock solution of NaHCO3 was added to the alga culture medium through a sterile filter (0.2 µm filter pore size).

ACCLIMATION
- Acclimation period: Not applicable

Study design

Test type:

static

Water media type:

not specified

Total exposure duration:

72 h

Test conditions

Hardness:

Not applicable

Test temperature:

Temperature range: 22.5 - 22.8°C

pH:

Control: 0-hour (with algal cells) - 7.95, 0-hour (without algal cells) - 8.00, 72-hour (with algal cells) - 10.35, 10.48, 10.07, 10.20, 9.97 and 10.14, 72-hour (without algal cells) - 8.43
125 mg/L: 0-hour (with algal cells) - 7.90, 0-hour (without algal cells) - 8.00, 72-hour (with algal cells) - 10.22, 10.26, 10.40, 10.44, 10.26 and 10.08, 72-hour (without algal cells) - 8.25

Dissolved oxygen:

Not applicable

Salinity:

Not applicable

Nominal and measured concentrations:

Nominal concentration: 125 mg/L
0-hours (new): 122 mg/L (98% nominal)
72-hours with algae (old): 123 mg/L (98% nominal)
72-hours without algae (new): 117 mg/L (94% nominal)

Details on test conditions:

TEST SYSTEM
- Test vessel: sterile autoclaved glass 250 mL Erlenmeyer (conical) flasks
- Material, size, headspace, fill volume: 100 mL of the appropriate control or test media
- Aeration: Not applicable
- Type of flow-through (e.g. peristaltic or proportional diluter): Not applicable
- Renewal rate of test solution (frequency/flow rate): Not applicable
- Initial cells density: 1 x 10^4 cells/mL
- Control end cells density: 1 x 10^4 cells/mL
- No. of vessels per concentration (replicates): Six
- No. of vessels per control (replicates): Six

GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Sterile test conditions: yes
- Adjustment of pH: Not applicable
- Photoperiod: Constant light conditions
- Light intensity and quality: conditions of constant light (4440 to 8880 Lux), using cooled white fluorescent tube lights, emitting white light across the visible portion of the spectrum (400 - 700 nm)

TEST CONCENTRATIONS
- Test concentrations: Based on the results of the range-finding test which is not fully reported, the definitive test was conducted at a single nominal test substance concentration of 125 mg/L. This test design constitutes a ‘Limit Test’ to determine that, at the maximum concentration defined by the test guideline of 100 mg/L no inhibition of growth was observed. A concentration of 125 mg/L was used to ensure measured concentrations were as close to 100 mg/L as possible.

Results and discussion

Effect concentrations

Effect concentrations 1

Duration:

72 h

Dose descriptor:

NOEC

Effect conc.:

125 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Effect concentrations 2

Duration:

72 h

Dose descriptor:

EC50

Effect conc.:

> 125 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Details on results:

Chemical results
Chemistry analysis of the 125 mg/L test concentration at 0 and 72 hours showed concentrations of Methylfuranoside to be 122 and 123 mg/L, respectively. Nominal concentrations were achieved on preparation and were maintained for the duration of the test therefore the results will be reported as nominal concentrations.
The limit of detection (LOD) for Methylfuranoside in EC medium using this method was 0.035 µg/L.

Growth test
There was no significant growth inhibition relative to the control treatment during the definitive test, therefore the 72-hour EyC50 and the 0 - 72-hour EbC50 and ErC50 values were estimated.
Based on nominal concentrations, the 72-hour EyC50 and the 0-72 hour EbC50 and ErC50 values were estimated to be greater than125 mg/L.
The corresponding NOEC values for yield, biomass and specific growth rate after 72 hours were all equal to 125 mg/L.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

The effects of Methylfuranoside on the growth of the unicellular green alga, Pseudokirchneriella subcapitata, were determined during a 72-hour growth inhibition toxicity test conducted in accordance with OECD Chemicals Testing Guideline No. 201 Alga, Growth Inhibition Test (adopted 23 March 2006) (Annex 5 corrected 28 July 2011).
All validity criteria were met therefore the test was considered valid.
Based on nominal concentrations, the 72-hour EyC50 and the 0-72 hour EbC50 and ErC50 values were estimated to be greater than 125 mg/L.
The corresponding NOEC values for yield, biomass and specific growth rate after 72 hours were all equal to 125 mg/L.
It is concluded that Methylfuranoside was considered non toxic to Pseudokirchneriella subcapitata at nominal concentrations less than 125 mg/L under the conditions of this test.

Executive summary:

The objective of the study was to determine the effects of Methylfuranoside on the growth of the green alga, Pseudokirchneriella subcapitata, during a 72-hour growth inhibition toxicity test. The test was conducted in accordance with OECD Chemicals Testing Guideline No. 201: Alga, Growth Inhibition Test (adopted 23 March 2006) (Annex 5 corrected 28 July 2011).

The definitive test was conducted as a limit test at a single nominal concentration of 125 mg/L. The concentration used was based on the results of a range-finding test, which is not fully reported. A control group was also included.

Test vessels (250 mL conical flasks) were prepared containing 100 mL of the appropriate test or control medium. Each test vessel was inoculated with 1 x 10⁴ alga cells/mL and incubated at 21 - 24°C (under 4440-8880 Lux light intensity) for 72 hours with cell counts at 24-hour intervals.

Chemistry analysis of the 125 mg/L test concentration at 0 and 72 hours showed concentrations of Methylfuranoside to be 122 and 123 mg/L, respectively. Nominal concentrations were achieved on preparation and were maintained for the duration of the test therefore the results will be reported as nominal concentrations

Methylfuranoside did not inhibit the growth of Pseudokirchneriella subcapitata under the conditions of the test and therefore no formal statistical analysis was conducted to determine the EC_x values. An estimate EC_10, EC₂₀ and EC₅₀ values was given by inspection of the data.

Based on nominal concentrations, the 72-hour E_yC₅₀ and the 0-72 hour E_bC₅₀ and E_rC₅₀ values were estimated to be greater than 125 mg/L.

The corresponding NOEC values for yield, biomass and specific growth rate after 72 hours were all equal to 125 mg/L.

All validity criteria were met therefore the test was considered valid.

It is concluded that Methylfuranoside was considered non toxic to Pseudokirchneriella subcapitata at nominal concentrations less than 125 mg/L under the conditions of this test.