4H-Pyrido[1,2-a]pyrimidin-4-one, 3-[2-[4-[(Z)-(2,4-difluorophenyl)(hydroxyimino)methyl]-1-piperidinyl]ethyl]-6,7,8,9-tetrahydro-2-methyl-

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:

2015-06-24 to 2015-07-24

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.4-C (Determination of the "Ready" Biodegradability - Carbon Dioxide Evolution Test)

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

ISO DIS 9439 (Ultimate Aerobic Biodegradability - Method by Analysis of Released Carbon Dioxide)

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: ISO 10634 (Water Quality - guidance for the preparation and treatment of poorly water-soluble organic compounds for the subsequent evaluation of their biodegradability in an aqueous medium) 1995

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

3-(2-{4-[(Z)-(2,4-DIFLUOROPHENYL)(HYDROXYIMINO)METHYL]PIPERIDIN-1-YL}ETHYL)-2-METHYL-6,7,8,9-TETRAHYDRO-4H-PYRIDO[1,2-A]PYRIMIDIN-4-ONE

EC Number:

603-689-1

Cas Number:

132961-05-8

Molecular formula:

C23H28F2N4O2

IUPAC Name:

3-(2-{4-[(Z)-(2,4-DIFLUOROPHENYL)(HYDROXYIMINO)METHYL]PIPERIDIN-1-YL}ETHYL)-2-METHYL-6,7,8,9-TETRAHYDRO-4H-PYRIDO[1,2-A]PYRIMIDIN-4-ONE

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

- Analytical purity: 100.0% (base titration)
- Lot/batch No.: I14LC5175
- Expiration date of the lot/batch: 2020-12-11 (retest date)
- Storage condition of test material: at room temperature
- solubility in water: 0.121 g/L
- Stability in water: not indicated
- Molecular weight: 430.5
- Molecular formula: C23H28F2N4O2

Study design

Oxygen conditions:

aerobic

Inoculum or test system:

activated sludge, domestic, non-adapted

Details on inoculum:

- Source: municipal sewage treatment plant receiving predominantly domestic sewage, 'Waterschap Aa en Maas', 's-Hertogenbosch, The Netherlands.
- Preparation of inoculum for exposure: The freshly obtained sludge was kept under continuous aeration until further treatment. Before use, the sludge was allowed to settle (44 minutes) and the supernatant liquid was used as inoculum at the amount of 10 mL/L of mineral medium.
- Concentration of sludge: The concentration of suspended solids was determined to be 4.5 g/L in the concentrated sludge.

Duration of test (contact time):

28 d

Initial test substance concentration

Initial test substance concentration 1

Initial conc.:

19 mg/L

Based on:

test mat.

Initial test substance concentration 2

Initial conc.:

12 mg/L

Based on:

other: TOC

Parameter followed for biodegradation estimation

Parameter followed for biodegradation estimation:

CO2 evolution

Details on study design:

TEST CONDITIONS
- Composition of medium: test water prepared according to test guidelines, analytical grade salts dissolved in tap-water purified by reverse osmosis (Milli-RO) and subsequently passed over activated carbon. Since T001624 was not sufficiently soluble to allow preparation of an aqueous solution at a concentration of 1 g/L, weighed amounts were added to the 2 L test bottles containing medium with microbial organisms and mineral components (test item bottle A: 37.74 mg; test item bottle B: 37.74 mg and toxicity control bottle: 37.03 mg). To this end, 10 mL of Milli-RO water was added to each weighing bottle containing the test item. After vigorous mixing, the resulting suspension was added quantitatively to the test medium. The test solution were continuously stirred during the test.
- Additional substrate: no
- Test temperature: 22 - 24°C
- pH: 7.6, measured at the start of the test (after addition of concentrated HCl), and on day 28 (7.6-7.9)
- pH adjusted: yes, using 37% HCl
- Aeration of dilution water: A mixture of oxygen (± 20%) and nitrogen (±80%) was passed through a bottle, containing 0.1 - 1 L 0.0125 M Ba(OH)2 solution to trap CO2. The synthetic air was sparged through the scrubbing solutions at a rate of ~1-2 bubbled per second ( ± 30-100 mL/min).
- Continuous darkness: yes

TEST SYSTEM
- Test flasks: 2 L glass brown coloured bottles
- Number of culture flasks/concentration: 2
- Method used to create aerobic conditions: A mixture of oxygen (~20%) and nitrogen (~80%) was passed through a bottle, containing 0.5 - 1 L 0.0125 M Ba(OH)2 solution to trap CO2. The synthetic air was sparged through the scrubbing solutions at a rate of ~1-2 bubbles per second ( ~30-100 mL/min).
- Details of trap for CO2 and volatile organics if used: 3 CO2-absorbers (bottles filled with 100 mL 0.0125 M Ba(OH)2) were connected in series to the exit air line of each bottle. The CO2 produced in each test bottle reacted with the barium hydroxide in the gas scrubbing bottle and precipitated out as barium carbonate. The amount of CO2 produced was determined by titrating the remaining Ba(OH)2 with 0,05 M standardized HCl.

CONTROL AND BLANK SYSTEM
- Inoculum blank: yes, two replicates with only inoculum
- Toxicity control: yes, one replicate with test item, reference substance, and inoculum
- Procedure control: yes, 1 replicate with reference item and inoculum

Reference substance

Reference substance:

acetic acid, sodium salt

Results and discussion

% Degradation

Parameter:

% degradation (CO2 evolution)

Value:

ca. 4

Sampling time:

28 d

Details on results:

No significant biodegradation of the test item occurred within 28 days of incubation (1% and 7%, based on ThCO2 in bottle A and B respectively). The toxicity controls indicated that the test item did not have an inhibitory effect on the microbial activity.

BOD5 / COD results

Results with reference substance:

The positive control item was biodegraded by at least 60% (62%) within 14 days, confirming suitability of the activated sludge.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Interpretation of results:

not readily biodegradable

Conclusions:

A 28-d ready biodegradability test (OECD 301B, modified sturm test) using unadapted activated sludge from a predominantly domestic waste water treatment plant indicated that JNJ-7941726-AAA (T001624) was not readily biodegradable under the conditions of the test (initial test concentration 19 mg/L, corresponding to 12 mg TOC/L). The results of the test can be considered reliable without restriction.