4-[2-(2-amino-4,7-dihydro-4-oxo-3H-pyrrolo[2,3-d]pyrimidin-5-yl)ethyl]benzoic acid

Biodegradation in water: screening tests

Administrative data

Endpoint:

biodegradation in water: ready biodegradability

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 October to 4 November 1998

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1999

Report date:

1999

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 301 B (Ready Biodegradability: CO2 Evolution Test)

Version / remarks:

yes (Temperature range was 16 -25oC rather than 20 -24oC. Initial IC in medium was not meas ured. A single inoculum blank vessel was used rather than two.)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4-[2-(2-amino-4,7-dihydro-4-oxo-3H-pyrrolo[2,3-d]pyrimidin-5-yl)ethyl]benzoic acid

EC Number:

429-790-9

EC Name:

4-[2-(2-amino-4,7-dihydro-4-oxo-3H-pyrrolo[2,3-d]pyrimidin-5-yl)ethyl]benzoic acid

Cas Number:

137281-39-1

Molecular formula:

Hill formula: C15 H14 N4 O3 CAS formula: C15 H14 N4 O3

IUPAC Name:

4-(2-{2-amino-4-oxo-3H,4H,7H-pyrrolo[2,3-d]pyrimidin-5-yl}ethyl)benzoic acid

Test material form:

solid: particulate/powder

Details on test material:

- Compound 202723
- Storage condition of test material: In the dark at ambient temperature

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source of inoculum/activated sludge: Activated sludge from municipal sewage works in the UK
- Preparation of inoculum for exposure: blending, aqueous layer used for inoculation

- Pretreatment:
- Concentration of sludge: 10 mL aqueous layer/L
- Water filtered: yes/no: yes (Milli Q water)

Duration of test (contact time):

29 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

17 mg/L

Based on:

act. ingr.

Initial test substance concentration 2

Initial conc.:

33 mg/L

Based on:

act. ingr.

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium:
85 mg/L KH2PO4
217.5 mg/L K2HPO4
334 mg/L Na2HPO4.2H2O
5 mg/L NH4Cl
36.4 mg/L CaCl2.2H2O
22.5 mg/L MgSO4.7H2O
0.25 FeCL3.6H2O

- Test temperature:16 to 25°C
- pH:
- pH adjusted: no
- CEC (meq/100 g):
- Aeration of dilution water: yes

TEST SYSTEM
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: purge with CO2-free air
- Details of trap for CO2 and volatile organics if used: 3 traps in series for each bioreactor each conta ining 100 mL of 0.0125 M BaOH.

SAMPLING
- Sampling frequency: Days 2, 4, 6, 8, 10, 15, 20, 25, and 29
- Sampling method: Remove trap closest to bioreactor and move remaining traps up one position and add a fresh trap furthest away from bioreactor

CONTROL AND BLANK SYSTEM
- Inoculum blank: 10 mL/L inoculum + medium (no test substance)
- Toxicity control: 10 mL/L inoculum + 20 mg C/L (34.3 mg/L) as sodium benzoate + 20 mg C/L (33 mg/L) as compound 202723
- Other: Reference: 10 mL/L inoculum + 20 mg C/L (34.3 mg/L) as sodium benzoate

Reference substance

Reference substance:

benzoic acid, sodium salt

Results and discussion

Preliminary study:

Not applicable

Test performance:

No unusual observations noted during test, which impact results obtained.

% Degradation

Remarks on result:

other: See table 1 below

Details on results:

See table 1 below

BOD5 / COD results

Results with reference substance:

See table 2 below

Any other information on results incl. tables

Table 1 - Biodegradation of compound 202723

Timepoint (Days)	MeanCumulative %Biodegradation
	10mgOC.l-1*1	20mgOC.l-1*2
	0	0
2	5.90	1.43
4	8.31	1.43
6	11.33	3.00
8	15.56	3.38
10	15.56	3.38
15	20.09	3.61
20	20.09	3.61
25	20.69	3.61
29	21.16	3.61

*1 equivalent to 17 mg/L of compound 202723

*2 equivalent to 33mg/L of compound 202723

Table 2 - Biodegradation of reference material, Sodium Benzoate and toxicity Control

Timepoint (Days)	MeanCumulative %Biodegradation
	SodiumBenzoate	ToxicityControl
To	0	0
2	47.22	43.33
4	91.00	84.57
6	120.58	115.35
8	131.49	128.05
10	131.49	130.74
15	142.40	144.19
20	142.40	148.22
25	144.94	152.55
29	144.94	157.78

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Remarks:

The total evolved CO2 from the inoculum blank was less than 40 mg/L. The cumulative % degradation in the two replicates at each concentration did not differ by more than 20%. Compound 2 02723 did not inhibit the biodegradation of the reference compound.

Interpretation of results:

other: not readily biodegradable

Conclusions:

Since the study validity criteria were fulfilled it was possible to conclude that the substance is not readily biodegradable

Executive summary:

Ready biodegradability testing of compound 202723 has been carried out with reference to the Modified Sturm Test which is described in OECD Guideline 301 Part B 1992.

The mean cumulative percentage biodegradation values of compound 202723 after the 29 day test period were 21.16% and 3.61% for the 10mg organic carbon / L (17 mg compound 202723/L) and 20 mg organic carbon/L (33mg compound 202723/L) respectively. A toxicity control showed that compound 202723 was not inhibitory to the bacteria in activeate sludge at the concentration of 33mg/l in accordance with the definitions detailed in the OECD guideline 301B, it is determined that compound 202723 is not readily biodegradable

Theoretical CO2              3.67 mg CO2/mg C in compound 202723

CO2 analysis                     Titration method

Temperature range              16 to 25 oC

Results

Biodegradation                     10 mg OC/L 21.16% after 29 days

                                           20 mg OC/L 3.61% after 29 days

Validation of Results

Biodegration of sodium benzoate              131.9% after 10 days

144.94% after 29 days

13.37 mg/L after 29 days (CO2 evolved from blank bioreactor)