2-chloro-6,7-dimethoxyquinazolin-4-amine

Endpoint summary

Description of key information

Short term toxicity to aquatic invertebrates:

Based on the prediction done using the OECD QSAR toolbox version 3.4 with log kow as the primary descriptor and considering the five closest read across substances, toxicity on Daphnia magna was predicted for 2-Chloro-6,7-dimethoxyquinazolin-4-amine (23680-84-4).The EC50 value was estimated to be 151.434 mg/l when 2-Chloro-6,7- dimethoxyquinazolin -4-amine exposed to Daphnia magna for 48hrs. 

 

Short term toxicity to aquatic algae:

Based on the prediction done using the OECD QSAR toolbox version 3.4 with log kow as the primary descriptor and considering the five closest read across substances, toxicity on Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) was predicted for 2-Chloro-6,7-dimethoxyquinazolin-4-amine (23680-84-4).The EC50 value was estimated to be 119.856 mg/l when 2-Chloro-6,7-dimethoxyquinazolin-4-amine exposed to Desmodesmus subspicatus for 72hrs.

 

Additional information

Summarized result of toxicity of 2-Chloro-6,7-dimethoxyquinazolin-4-amine (23680-84-4) on the growth and other activity of aquatic invertebrates, algae and cyanobacteria by considering the data for target as well as RA chemical which was selected on the basis of structure similarity are as follows: 

Short term toxicity to aquatic invertebrates:

Based on the various experimental data and prediction data for the target chemical as well as RA chemical which was selected on the basis of structure similarity study have been reviewed to determine the toxic nature of 2-Chloro-6,7-dimethoxyquinazolin-4-amine (23680-84-4) on the mobility of daphnia magna. The studies are as mentioned below: 

In the first predicted weight of evidence report for the 2-Chloro-6,7-dimethoxyquinazolin-4-amine (23680-84-4) from SSS (QSAR, 2017) toxicity study was carried out. Based on the prediction done using the OECD QSAR toolbox version 3.4 with log kow as the primary descriptor and considering the five closest read across substances, toxicity on Daphnia magna was predicted for 2-Chloro-6,7-dimethoxyquinazolin-4-amine (23680-84-4).The EC50 value was estimated to be 151.434 mg/l when 2-Chloro-6,7- dimethoxyquinazolin -4-amine exposed to Daphnia magna for 48hrs. 

 

Similarly in the second prediction study was performed based on the prediction done by EPI suite, ECOSAR version 1.1, on the basis of similarity of structure to chemicals for which the aquatic toxicity has been previously measured by structure-activity relationships (SARs) program, the LC 50 value for short term toxicity to aquatic invertebrates was predicted. On the basis of this programe, the LC 50 value for short term toxicity to aquatic invertebrates was predicted to be 301.282 mg/l for 2-chloro-6,7-dimethoxyquinazolin-4 -amine in 48 hrs. Based on this value it can be concluded that the substance 2-chloro-6,7-dimethoxyquinazolin-4-amine is considered to be not toxic to aquatic environment and cannot be classified as per the criteria mentioned in CLP regulation.

 

Similarly in the third weight of evidence study for the read across (738-70-5) Ecotoxicology 2008, Study was conducted to determine the toxicity of chemical 2,4-Diamino-5-(3,4,5-trimethoxybenzyl)-pyrimidin (Trimethoprim) on the mobility of daphnia magna. Test was performed according to the US EPA guideline. Effect concentration of chemical on Freshwater daphnia was tested by static system. Different measured concentration was directly prepared in dilution water. Organisms fed daily during the test. All water parameters measured daily. Immobilization was employed as an endpoint and considered to happen if no movement was detected for 15 s after gentle shaking of the test vehicle. Immobilization measured by probit analysis. After the exposure of chemical EC50 was measured at 24 and 48hrs, EC50 at 24hrs was 155.6 mg/l and at 48hrs 92.0 mg/l. Based on the immobilization of daphnia magna due to the exposure of chemical for 24hrs, the EC50 was 155.6 MG/L with 95% CI: 147.44 -163.700 mg/l. And on the basis of EC50 (155.6 mg/l), it is concluded that the chemical was nontoxic and can be consider to be not classified as toxic to aquatic environment as per the CLP classification criteria.

 

Similarly in the fourth weight of evidence study for the read across (738-70-5), Ecotoxicology 2008, Study was conducted to determine the toxicity of chemical 2,4-Diamino-5-(3,4,5-trimethoxybenzyl) pyrimidin (Trimethoprim) on the mobility of Moina macrocopa. Test was performed according to the US EPA guideline. Effect concentration of chemical on Freshwater Moina was tested by static system. Different measured concentration was directly prepared in dilution water.Organisms fed daily during the test. All water parameters measured daily. Immobilization was employed as an endpoint and considered to happen if no movement was detected for 15 s after gentle shaking of the test vehicle. Immobilization measured by probit analysis. After the exposure of chemical EC50 was measured at 24 and 48hrs, EC50 at 24hrs was 144.8 mg/l and at 48hrs 54.8 mg/l. Based on the immobilization of Moina macrocopa due to the exposure of chemical for 24hrs, the EC50 was 144.8 MG/L with (95% CI: 117.3- 172.4 mg/l). And on the basis of EC50 (144.8 mg/l), it is concluded that the chemical was nontoxic and can be consider to be not classified as toxic to aquatic environment as per the CLP classification criteria.

 

In the fifth weight of evidence study for the read across chemical (6753-47-5) from ECOTOX 2017, Evaluation of short term toxicity of 1-hydroxy-N,N-bis(2 hydroxypropyl) propan-1-aminium 4-amino-3,5,6-trichloropyridine-2-carboxylate on the growth of aquatic invertebrates. Test conducted by using static method carried out for 96hrs. After the exposure of chemical lethal concentration was measured at which 50% growth inhibited. Based on the rate of mortality of daphnia magna due to the exposure of chemical 1-hydroxy-N,N-bis(2-hydroxypropyl) propan-1-aminium 4-amino-3,5,6-trichloropyridine- 2-carboxylate  with daphnia, the LC50 was 125 mg/l.

 

Thus based on the above data sources for target chemical 2-Chloro-6,7-dimethoxyquinazolin-4-amine (23680-84-4) from various experimental studies and predicted studies from QSAR, EPIsuite, Ecotoxicology 2008, ECOTOX, it was summarized that the chemical was nontoxic and can be consider to be not classified as toxic as per the CLP classification criteria. 

 

Short term toxicity to aquatic algae:

Based on the various experimental data and prediction data for the target chemical as well as RA chemical which was selected on the basis of structure similarity study have been reviewed to determine the toxic nature of 2-Chloro-6,7-dimethoxyquinazolin-4-amine (23680-84-4) on the growth of algae. The studies are as mentioned below:  

In the first predicted weight of evidence report for the 2-Chloro-6,7-dimethoxyquinazolin-4-amine (23680-84-4) from SSS (QSAR, 2017) toxicity study was carried out. Based on the prediction done using the OECD QSAR toolbox version 3.4 with log kow as the primary descriptor and considering the five closest read across substances, toxicity on Desmodesmus subspicatus (previous name: Scenedesmus subspicatus) was predicted for 2-Chloro-6,7-dimethoxyquinazolin-4-amine (23680-84-4).The EC50 value was estimated to be 119.856 mg/l when 2-Chloro-6,7-dimethoxyquinazolin-4-amine exposed to Desmodesmus subspicatus for 72hrs.

 

Similarly in the second prediction study was performed based on the prediction done using the EPI Suite ECOSAR version 1.10, the short term toxicity on green algae was predicted for test substance 2-chloro-6,7-dimethoxyquinazolin- 4-amine (23680 -84 -4). On the basis of effects observed in a static freshwater system, the effect concentration EC50 value for the substance 2-chloro-6,7-dimethoxyquinazolin-4- amine is estimated to be 185.347 mg/l for green algae for 96 hrs duration. Based on this value, it can be concluded that the test chemical 2-chloro-6,7-dimethoxyquinazolin-4-amine can be considered as non-toxic to green algae at environmentally relevant concentrations and can be considered not-classified as toxic as per the CLP classification criteria.

 

Similarly in the third weight of evidence study for the read across Aminobenzene (62-53-3) (From j-check, 2017) Determination of short-term toxicity of chemical Aminobenzene on aquatic green algae. Test was performed in the static system. After the exposure of chemical effect concentration was measured at which 50% growth inhibited by chemical. Based on the growth inhibition of green algae, the EC50 was 110 mg/l and the NOEC was 3.7 mg/l. based on the biomass and area under the growth curve, the EC50 was 41 mg/l and the NOEC was 11 mg/l. Thus based on the EC50 (110 mg/l) chemical Aminobenzene (Aniline) consider as nontoxic and cannot be classified as per the CLP classification criteria.

 

Similarly in the fourth weight of evidence study for the RA chemical (738 -70 -5), chemosphere, 2014. Determination of short term toxicity of chemical 2,4-Diamino-5-(3,4,5-trimethoxybenzyl)- pyrimidin (Trimethoprim) on the growth of aquatic algae Pseudokirchneriella subcapitata CCAP 278/4 for 72hrs. Green algae were cultivated and tested in the OECD TG 201 medium and in the growth medium BG 11. Test performed in 250 ml Erlenmeyer flasks filled with 100 mL of the test medium. 3 replicates were used in the test. After the exposure of chemical for 72hrs, the ErC10 was 65 mg/l with the 95% CI of 0.01-103 mg/l and the ErC50 was 129 mg/l with 95% CI 123-136 mg/l. Based on the growth inhibition of Selenastrum capricornutum CCAP 278/4, due to the exposure of chemical, the ErC50 was 129 mg/l with 95% CI 123-136 mg/l. Based on the ErC50, it is concluded that the chemical was nontoxic and can be consider to be not classified as toxic to aquatic environment as per the CLP classification criteria.

Thus based on the above data sources for target chemical 2-Chloro-6,7-dimethoxyquinazolin-4-amine (23680-84-4) from various experimental studies and predicted studies from QSAR, EPIsuite, j-check it was summarized that the chemical was nontoxic and can be consider to be not classified as toxic as per the CLP classification criteria.