3-(diethylamino)-7-imino-7H-[1]benzopyrano[3',2':3,4]pyrido[1,2-a]benzimidazole-6-carbonitrile

Toxicity to aquatic algae and cyanobacteria

Link to relevant study record(s)

Reference

Endpoint:

toxicity to aquatic algae and cyanobacteria

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

Experimental rsults of read across chemicals

Justification for type of information:

Data for the target chemical is summarized based on the structurally similar read across chemicals.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: Refer below principle

Principles of method if other than guideline:

WoE report is prepared based on short term toxicity to aquatic algae study.

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (IUPAC name): 3-(diethylamino)-7-imino-7H-chromeno[3',2':3,4]pyrido[1,2-a]benzimidazole-6-carbonitrile
- Common name: Solvent Red 197
- Molecular formula:C23H19N5O
- Molecular weight: 381.437 g/mol
- Smiles : c12cc3c4nc5ccccc5n4c(=N)c(C#N)c3oc1cc(N(CC)CC)cc2
- InChI : 1S/C23H19N5O/c1-3-27(4-2)15-10-9-14-11-16-21(29-20(14)12-15)17(13-24)22(25)28-19-8-6-5-7-18(19)26-23(16)28/h5-12,25H,3-4H2,1-2H3
- Substance Type: Organic

Analytical monitoring:

no

Vehicle:

yes

Details on test solutions:

1. The stock solution 100 mg/l was prepared by dissolving white powder in acetone. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture.

2. The stock solution (100 mg/L) was prepared by dissolving pinkish red powder in OECD growth medium. The stock solution was kept in ultrasonic bath for 20min Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture.

Test organisms (species):

Desmodesmus subspicatus (previous name: Scenedesmus subspicatus)

Details on test organisms:

TEST ORGANISM
- Common name:
- Strain: 86.81 SAG
- Source (laboratory, culture collection): Institute of botany of the ASCR
- Initial biomass concentration: 5x10(3) cells /ml
- Method of cultivation: No data available

ACCLIMATION - No data available
- Acclimation period:
- Culturing media and conditions (same as test or not):
- Any deformed or abnormal cells observed:

Test type:

static

Water media type:

freshwater

Total exposure duration:

72 h

Remarks on exposure duration:

±1 hour

Test temperature:

23±2°C

pH:

1 study:
Test at highest concentration: 7.9 (Change to 7.4 during tests)
Control: 8.1 (changed to 7.7 during test)
Control + acetone: 8.1 change to 7.7

2. WIthout adjustment
The sample at concentration 40 mg/l: pH=8 changed to 7.9 during the test
Control: pH= 8.1 changed to pH= 7.5 during the test

Nominal and measured concentrations:

1. 0, 0, 6, 12, 24, 50 and 100 mg/l
2. 0, 2.5, 5, 10, 20 and 40 mg/L

Details on test conditions:

1. TEST SYSTEM
- Test vessel: 50 ml Glass vessel
- Type (delete if not applicable): closed (with air permeable stopper)
- Sample volume: 15 ml
- Initial cells density: 5x10(3) cells/ml
- No. of vessels per concentration (replicates): 3

GROWTH MEDIUM
- Standard medium used: yes

OTHER TEST CONDITIONS
- Adjustment of pH: No
- Photoperiod: Continuous
- Light intensity and quality: 6000-8000 lx

EFFECT PARAMETERS MEASURED (with observation intervals if applicable) :
- Determination of cell concentrations: microscope with counting chamber Cyrus I or electronic particle counter.
- Other: ErC50 was calculated using non-linear regression by the software Prism 4.0

Reference substance (positive control):

yes

Remarks:

Potassium dichromate (K2Cr2O7)

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

17.5 mg/L

Nominal / measured:

nominal

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: In ist study: 95 % CI was 14.2 - 21.6 mg/l

Duration:

72 h

Dose descriptor:

other: ErC50

Effect conc.:

13.4 mg/L

Nominal / measured:

meas. (not specified)

Conc. based on:

test mat.

Basis for effect:

growth rate

Remarks on result:

other: In 2nd study: 95 % CI was 11.9 - 15.2 mg/l

Results with reference substance (positive control):

Results with reference substance valid
1. - EC50: 0.69 mg/L
2. - EC50: 0.75 mg/L

Reported statistics and error estimates:

ErC50 was calculated using non-linear regression by the software Prism 4.0

Validity criteria fulfilled:

yes

Conclusions:

1. Based on the growth rate inhibition of Desmodesmus subspicatus, by the test chemical after the exposure for 72 hrs, the ErC50 value was determine to be 17.5 mg/l.
2. The median effective concentration (EC50) for the test substance, in Desmodesmus subspicatus was determined to be 13.4 mg/L on the basis of effects on growth rate in a 72 hour study.

Executive summary:

Short term toxicity of 3-(diethylamino)-7-imino-7H-chromeno[3',2':3,4]pyrido[1,2-a]benzimidazole-6-carbonitrile (52372 -39 -1) on the growth and other biological activity of aquatic algae is predicted on the basis of it structurally and functionally similar read across chemicals. The studies are as mentioned below:

 

Toxicity study was performed to determine the toxic effect of the structurally and functionally similar read across chemicals on the growth of aquatic algae and cyanobacteria. Aim of this study was to assess the short term toxicity of test chemical to aquatic algae and cyanobacteria. Study was performed according to the OECD Guideline 201 (Alga, Growth Inhibition Test) in a static system for the total exposure period of 72 hrs. The stock solution 100 mg/l was prepared by dissolving white powder in acetone. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture and performed at various nominal concentrations 0, 0, 6, 12, 24 and 100 mg/L. Effects on growth rate were observed for 72 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. The median effective concentration (EC50) for the test substance, in Desmodesmus subspicatus was determined to be 17.5 mg/L on the basis of effects on growth rate in a 72 hour study. Based on the ErC50 value, it can be concluded that the substance is likely to be hazardous to aquatic algae and can be consider to be classified as aquatic chronic 3 as per the CLP classification criteria.

 

 

Similarly short term toxicity study was performed to determine the toxic effect of the structurally and functionally similar read across chemicals. Aim of this study was to assess the short term toxicity of test chemical to aquatic algae and cyanobacteria. Study was performed according to the OECD Guideline 201 (Alga, Growth Inhibition Test) in a static system for the total exposure period of 72 hrs. The stock solution (100 mg/L) was prepared by dissolving pinkish red powder in OECD growth medium. The stock solution was kept in ultrasonic bath for 20min Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture and performed at various nominal concentrations 0, 2.5, 5, 10, 20 and 40 mg/L. Effects on growth rate were observed for 72 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. The median effective concentration (EC50) for the test substance, in Desmodesmus subspicatus was determined to be 13.4 mg/L on the basis of effects on growth rate in a 72 hour study. Based on the EC50 value, it can be concluded that the substance is likely to be hazardous to aquatic algae and cyanobacteria and can be consider to be classified as aquatic chronic 3 as per the CLP classification criteria.

 

Thus based on the overall studies for the structurally and functionally similar read across chemical for 3-(diethylamino)-7-imino-7H-chromeno[3',2':3,4]pyrido[1,2-a]benzimidazole-6-carbonitrile (52372 -39 -1), it can be concluded that the test chemical was toxic and can be consider to be classified as aquatic chronic 3 as per the CLP classification criteria.

 

Description of key information

1. Based on the growth rate inhibition of Desmodesmus subspicatus, by the test chemical after the exposure for 72 hrs, the ErC50 value was determine to be 17.5 mg/l.

2. The median effective concentration (EC50) for the test substance, in Desmodesmus subspicatus was determined to be 13.4 mg/L on the basis of effects on growth rate in a 72 hour study.

Thus based on the overall studies for the structurally and functionally similar read across chemical for 3-(diethylamino)-7-imino-7H-chromeno[3',2':3,4]pyrido[1,2-a]benzimidazole-6-carbonitrile (52372 -39 -1), it can be concluded that the test chemical was toxic as value ranges from 13.4 -17.5 mg/l and can be consider to be classified as aquatic chronic 3 as per the CLP classification criteria.

Key value for chemical safety assessment

EC50 for freshwater algae:

17.5 mg/L

Additional information

Short term toxicity of 3-(diethylamino)-7-imino-7H-chromeno[3',2':3,4]pyrido[1,2-a]benzimidazole-6-carbonitrile (52372 -39 -1) on the growth and other biological activity of aquatic algae is predicted on the basis of it structurally and functionally similar read across chemicals. The studies are as mentioned below:

 

Toxicity study was performed to determine the toxic effect of the structurally and functionally similar read across chemicals on the growth of aquatic algae and cyanobacteria. Aim of this study was to assess the short term toxicity of test chemical to aquatic algae and cyanobacteria. Study was performed according to the OECD Guideline 201 (Alga, Growth Inhibition Test) in a static system for the total exposure period of 72 hrs. The stock solution 100 mg/l was prepared by dissolving white powder in acetone. Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture and performed at various nominal concentrations 0, 0, 6, 12, 24 and 100 mg/L. Effects on growth rate were observed for 72 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. The median effective concentration (EC50) for the test substance, in Desmodesmus subspicatus was determined to be 17.5 mg/L on the basis of effects on growth rate in a 72 hour study. Based on the ErC50 value, it can be concluded that the substance is likely to be hazardous to aquatic algae and can be consider to be classified as aquatic chronic 3 as per the CLP classification criteria.

 

Similarly short term toxicity study was performed to determine the toxic effect of the structurally and functionally similar read across chemicals. Aim of this study was to assess the short term toxicity of test chemical to aquatic algae and cyanobacteria. Study was performed according to the OECD Guideline 201 (Alga, Growth Inhibition Test) in a static system for the total exposure period of 72 hrs. The stock solution (100 mg/L) was prepared by dissolving pinkish red powder in OECD growth medium. The stock solution was kept in ultrasonic bath for 20min Test solutions of required concentration were prepared by mixing the stock solution of the test sample with OECD growth medium and inoculum culture and performed at various nominal concentrations 0, 2.5, 5, 10, 20 and 40 mg/L. Effects on growth rate were observed for 72 hours. With the test substance one positive control Potassium dichromate (K2Cr2O7) was also run simultaneously. After the exposure of chemical, effect concentration EC50 was calculated using nonlinear regression by the software Prism 4.0. The median effective concentration (EC50) for the test substance, in Desmodesmus subspicatus was determined to be 13.4 mg/L on the basis of effects on growth rate in a 72 hour study. Based on the EC50 value, it can be concluded that the substance is likely to be hazardous to aquatic algae and cyanobacteria and can be consider to be classified as aquatic chronic 3 as per the CLP classification criteria.

Thus based on the overall studies for the structurally and functionally similar read across chemical for 3-(diethylamino)-7-imino-7H-chromeno[3',2':3,4]pyrido[1,2-a]benzimidazole-6-carbonitrile (52372 -39 -1), it can be concluded that the test chemical was toxic and can be consider to be classified as aquatic chronic 3 as per the CLP classification criteria.