2-[(4-chloro-2-nitrophenyl)azo]-N-(4-ethoxyphenyl)-3-oxobutyramide

Short-term toxicity to aquatic invertebrates

Link to relevant study record(s)

Reference

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a valid (Q)SAR model and falling into its applicability domain, with limited documentation / justification

Justification for type of information:

QMRF report has been attached

Qualifier:

according to guideline

Guideline:

other: Estimated data

Principles of method if other than guideline:

Prediction was done using the OECD QSAR toolbox version 3.4

GLP compliance:

not specified

Specific details on test material used for the study:

- Name of test material (IUPAC name): 2-[(E)-2-(4-chloro-2-nitrophenyl)diazen-1-yl]-N-(4-ethoxyphenyl)-3-oxobutanamide
- Molecular formula: C18H17ClN4O5
- Molecular weight: 404.808 g/mol
- Smiles notation: O=C(Nc1ccc(OCC)cc1)[C@@H](\N=N\c1c([N+](=O)[O-])cc(cc1)Cl)C(=O)C
- InChl: 1S/C18H17ClN4O5/c1-3-28-14-7-5-13(6-8-14)20-18(25)17(11(2)24)22-21-15-9-4-12(19)10-16(15)23(26)27/h4-10,17H,3H2,1-2H3,(H,20,25)/b22-21+
- Substance type: Organic
- Physical state: Solid

Analytical monitoring:

not specified

Vehicle:

not specified

Test organisms (species):

Daphnia magna

Test type:

static

Water media type:

freshwater

Total exposure duration:

48 h

Reference substance (positive control):

not specified

Key result

Duration:

48 h

Dose descriptor:

EC50

Effect conc.:

0.134 mg/L

Nominal / measured:

estimated

Conc. based on:

not specified

Basis for effect:

other: Intoxication

Remarks on result:

other: Other details not known

The prediction was based on dataset comprised from the following descriptors: EC50
Estimation method: Takes average value from the 7 nearest neighbours
Domain  logical expression:Result: In Domain

(((((((("a" or "b" or "c" or "d" or "e" )  and ("f" and ( not "g") )  )  and "h" )  and "i" )  and ("j" and ( not "k") )  )  and ("l" and ( not "m") )  )  and ("n" and ( not "o") )  )  and ("p" and "q" )  )

Domain logical expression index: "a"

Referential boundary: The target chemical should be classified as Radical AND Radical >> Radical mechanism via ROS formation (indirect) AND Radical >> Radical mechanism via ROS formation (indirect) >> Nitroarenes with Other Active Groups AND SN1 AND SN1 >> Nucleophilic attack after diazonium or carbenium ion formation AND SN1 >> Nucleophilic attack after diazonium or carbenium ion formation >> Nitroarenes with Other Active Groups AND SN1 >> Nucleophilic attack after reduction and nitrenium ion formation AND SN1 >> Nucleophilic attack after reduction and nitrenium ion formation >> Nitroarenes with Other Active Groups AND SN2 AND SN2 >> SN2 attack on activated carbon Csp3 or Csp2 AND SN2 >> SN2 attack on activated carbon Csp3 or Csp2 >> Nitroarenes with Other Active Groups by DNA binding by OASIS v.1.4

Domain logical expression index: "b"

Referential boundary: The target chemical should be classified as SN1 AND SN1 >> Nitrenium Ion formation AND SN1 >> Nitrenium Ion formation >> Aromatic azo AND SN1 >> Nitrenium Ion formation >> Aromatic nitro by DNA binding by OECD

Domain logical expression index: "c"

Referential boundary: The target chemical should be classified as Acylation AND Acylation >> Acylation involving an activated (glucuronidated) carboxamide group AND Acylation >> Acylation involving an activated (glucuronidated) carboxamide group >> Carboxylic Acid Amides AND Acylation >> Direct acylation involving a leaving group AND Acylation >> Direct acylation involving a leaving group >> Carboxylic Acid Amides AND Acylation >> Ester aminolysis AND Acylation >> Ester aminolysis >> Amides AND AN2 AND AN2 >> Michael-type addition to quinoid structures  AND AN2 >> Michael-type addition to quinoid structures  >> Carboxylic Acid Amides by Protein binding by OASIS v1.4

Domain logical expression index: "d"

Referential boundary: The target chemical should be classified as Acylation AND Acylation >> Direct Acylation Involving a Leaving group AND Acylation >> Direct Acylation Involving a Leaving group >> Acetates AND SN2 AND SN2 >> SN2 reaction at sp3 carbon atom AND SN2 >> SN2 reaction at sp3 carbon atom >> Alkyl diazo by Protein binding by OECD

Domain logical expression index: "e"

Referential boundary: The target chemical should be classified as Amides by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "f"

Referential boundary: The target chemical should be classified as Acylation AND Acylation >> Acylation involving an activated (glucuronidated) carboxamide group AND Acylation >> Acylation involving an activated (glucuronidated) carboxamide group >> Carboxylic Acid Amides AND Acylation >> Direct acylation involving a leaving group AND Acylation >> Direct acylation involving a leaving group >> Carboxylic Acid Amides AND Acylation >> Ester aminolysis AND Acylation >> Ester aminolysis >> Amides AND AN2 AND AN2 >> Michael-type addition to quinoid structures  AND AN2 >> Michael-type addition to quinoid structures  >> Carboxylic Acid Amides by Protein binding by OASIS v1.4

Domain logical expression index: "g"

Referential boundary: The target chemical should be classified as Acylation >> Acylation involving an activated (glucuronidated) ester group OR Acylation >> Acylation involving an activated (glucuronidated) ester group >> Arenecarboxylic Acid Esters OR Acylation >> Acylation involving an activated (glucuronidated) sulfonamide group OR Acylation >> Acylation involving an activated (glucuronidated) sulfonamide group >> Arenesulfonamides OR Acylation >> Direct acylation involving a leaving group >> Azlactones and unsaturated lactone derivatives  OR Acylation >> Direct acylation involving a leaving group >> Carbamates  OR Acylation >> Direct acylation involving a leaving group >> N-Carbonyl heteroaryl amines OR Acylation >> Direct acylation involving a leaving group >> N-Carbonylsulfonamides OR Acylation >> Ester aminolysis or thiolysis OR Acylation >> Ester aminolysis or thiolysis >> Carbamates  OR Acylation >> Ring opening acylation OR Acylation >> Ring opening acylation >> beta-Lactams  OR AN2 >> Michael-type addition to quinoid structures  >> N-Substituted Aromatic Amines OR AN2 >> Michael-type addition to quinoid structures  >> Substituted Anilines OR AN2 >> Michael-type addition to quinoid structures  >> Substituted Phenols OR AN2 >> Nucleophilic addition at polarized N-functional double bond OR AN2 >> Nucleophilic addition at polarized N-functional double bond >> Arenesulfonamides OR AN2 >> Nucleophilic addition to alpha, beta - unsaturated carbonyl compounds OR AN2 >> Nucleophilic addition to alpha, beta - unsaturated carbonyl compounds >> Propargyl Alcohol derivatives OR AN2 >> Nucleophilic addition to pyridonimine tautomer of aminopyridoindoles or aminopyridoimidazoles (hypothesized) OR AN2 >> Nucleophilic addition to pyridonimine tautomer of aminopyridoindoles or aminopyridoimidazoles (hypothesized) >> Heterocyclic Aromatic Amines OR Michael addition OR Michael addition >> Michael addition on conjugated systems with electron withdrawing group OR Michael addition >> Michael addition on conjugated systems with electron withdrawing group >> alpha,beta-Carbonyl compounds with polarized double bonds  OR No alert found OR Nucleophilic addition OR Nucleophilic addition >> Addition to carbon-hetero double bonds OR Nucleophilic addition >> Addition to carbon-hetero double bonds >> Ketones OR Radical reactions OR Radical reactions >> ROS generation and direct attack of hydroxyl radical to the C8 position of nucleoside base OR Radical reactions >> ROS generation and direct attack of hydroxyl radical to the C8 position of nucleoside base >> Heterocyclic Aromatic Amines OR Schiff base formation OR Schiff base formation >> Direct acting Schiff base formers OR Schiff base formation >> Direct acting Schiff base formers >> 1,2-Dicarbonyls and 1,3-Dicarbonyls  OR Schiff base formation >> Schiff base on pyrazolones and pyrazolidinones OR Schiff base formation >> Schiff base on pyrazolones and pyrazolidinones >> Pyrazolones and Pyrazolidinones OR SE reaction (CYP450-activated heterocyclic amines) OR SE reaction (CYP450-activated heterocyclic amines) >> Direct attack of arylnitrenium cation to the C8 position of nucleoside base  OR SE reaction (CYP450-activated heterocyclic amines) >> Direct attack of arylnitrenium cation to the C8 position of nucleoside base  >> Heterocyclic Aromatic Amines OR SN2 OR SN2 >> Interchange reaction with sulphur containing compounds OR SN2 >> Interchange reaction with sulphur containing compounds >> Thiols and disulfide compounds  OR SN2 >> Nucleophilic substitution at sp3 carbon atom OR SN2 >> Nucleophilic substitution at sp3 carbon atom >> (Thio)Phosphates  OR SN2 >> Nucleophilic substitution at sp3 carbon atom >> alpha-Activated haloalkanes  OR SN2 >> SN2 Reaction at a sp3 carbon atom OR SN2 >> SN2 Reaction at a sp3 carbon atom >> Activated alkyl esters and thioesters  OR SN2 >> SN2 reaction at a sulfur atom OR SN2 >> SN2 reaction at a sulfur atom >> Isothiazolidin-3-ones (sulphur) and Isothiazolone derivatives  OR SR reaction (peroxidase-activated heterocyclic amines) OR SR reaction (peroxidase-activated heterocyclic amines) >> Direct attack of arylnitrenium radical to the C8 position of nucleoside base OR SR reaction (peroxidase-activated heterocyclic amines) >> Direct attack of arylnitrenium radical to the C8 position of nucleoside base >> Heterocyclic Aromatic Amines by Protein binding by OASIS v1.4

Domain logical expression index: "h"

Referential boundary: The target chemical should be classified as Class 3 (unspecific reactivity) by Acute aquatic toxicity classification by Verhaar (Modified) ONLY

Domain logical expression index: "i"

Referential boundary: The target chemical should be classified as Reactive unspecified by Acute aquatic toxicity MOA by OASIS ONLY

Domain logical expression index: "j"

Referential boundary: The target chemical should be classified as Amides by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "k"

Referential boundary: The target chemical should be classified as Acid moiety by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "l"

Referential boundary: The target chemical should be classified as Amides by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "m"

Referential boundary: The target chemical should be classified as Nitro-/Nitroso-Benzamides by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "n"

Referential boundary: The target chemical should be classified as Amides by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "o"

Referential boundary: The target chemical should be classified as Vinyl/Allyl Ethers by Aquatic toxicity classification by ECOSAR

Domain logical expression index: "p"

Parametric boundary:The target chemical should have a value of log Kow which is >= 2.72

Domain logical expression index: "q"

Parametric boundary:The target chemical should have a value of log Kow which is <= 6.45

Validity criteria fulfilled:

not specified

Conclusions:

Based on the immobility of test organism the EC50 value was estimated to be 0.133 mg/l when 2-[(E)-2-(4-chloro-2-nitrophenyl)diazen-1 -yl]-N-(4-ethoxyphenyl)-3-oxobutanamide exposed to daphnia magna for 48 hrs.   
    

Executive summary:

Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the seven closest read across substances, toxicity on daphnia magna was predicted for 2-[(E)-2-(4-chloro-2-nitrophenyl)diazen-1-yl]-N-(4-ethoxyphenyl)-3-oxobutanamide (52320-66-8). Based on the immobility of test organism the EC50 value was estimated to be 0.133 mg/l when 2-[(E)-2-(4-chloro-2-nitrophenyl)diazen-1 -yl]-N-(4-ethoxyphenyl)-3-oxobutanamide exposed to daphnia magna for 48 hrs.   

    

Based on this value it can be concluded that the substance 2-[(E)-2-(4-chloro-2-nitrophenyl)diazen-1-yl]-N-(4-ethoxyphenyl)-3-oxobutanamideis considered to be toxic to aquatic environment and can classified as aquatic acute 1 as well as chronic 1 category as per the criteria mentioned in CLP regulation.      

Description of key information

Based on the prediction done using the OECD QSAR toolbox version 3.4 with log kow as the primary descriptor and considering the seven closest read across substances, toxicity on daphnia magna was predicted for 2-[(E)-2-(4-chloro-2-nitrophenyl)diazen-1-yl]-N-(4-ethoxyphenyl)-3-oxobutanamide (52320-66-8). Based on the immobility of test organism the EC50 value was estimated to be 0.133 mg/l when 2-[(E)-2-(4-chloro-2-nitrophenyl)diazen-1 -yl]-N-(4-ethoxyphenyl)-3-oxobutanamide exposed to daphnia magna for 48 hrs. Based on this value it can be concluded that the substance 2-[(E)-2-(4-chloro-2-nitrophenyl)diazen-1-yl]-N-(4-ethoxyphenyl)-3-oxobutanamideis considered to be toxic to aquatic environment and can classified as aquatic acute 1 as well as chronic 1 category as per the criteria mentioned in CLP regulation.      

Key value for chemical safety assessment

Fresh water invertebrates

Fresh water invertebrates

Effect concentration:

0.133 mg/L

Additional information

Various predicted data for the target compound 2-[(E)-2-(4-chloro-2-nitrophenyl)diazen-1-yl]-N-(4-ethoxyphenyl)-3-oxobutanamide (52320-66-8) and experimental studies for supporting weight of evidence studies for its closest read across substance with log Kow as the primary descriptor and on the basis of structural and functional similarity were reviewed for the toxicity on the invertebrates end point which are summarized as below: 

In a prediction done by SSS (2017), Based on the prediction done using the OECD QSAR toolbox version 3.3 with log kow as the primary descriptor and considering the seven closest read across substances, toxicity on daphnia magna was predicted for 2-[(E)-2-(4-chloro-2-nitrophenyl)diazen-1-yl]-N-(4-ethoxyphenyl)-3-oxobutanamide (52320-66-8). Based on the immobility of test organism the EC50 value was estimated to be 0.133 mg/l when 2-[(E)-2-(4-chloro-2-nitrophenyl)diazen-1 -yl]-N-(4-ethoxyphenyl)-3-oxobutanamide exposed to daphnia magna for 48 hrs. Based on this value it can be concluded that the substance 2-[(E)-2-(4-chloro-2-nitrophenyl)diazen-1-yl]-N-(4-ethoxyphenyl)-3-oxobutanamideis considered to be toxic to aquatic environment and can classified as aquatic acute 1 as well as chronic 1 category as per the criteria mentioned in CLP regulation.      

 

First predicted study was supported by the structurally and functionally similar read across chemical (103-90-2) from Environmental Toxicology and Chemistry 2006. Aim of the study was to assess the effect of chemical 4' Hydroxyacetanilidon (Acetaminophen) the growth of freshwater daphnia magna for the exposure period of 48 hrs. Testing was conducted according to the published Environment Canada biological test method. Test was conducted at 32, 10, 3.2, 1.0, and 0.1 ug/L, as well as a clean-water control. Chemical was analytically monitoring by HPLC and separation done by reverse-phase column using binary gradient elution at a constant temperature of 25°C. The neutral drugs were analyzed individually by full-scan MS in positive-ion mode, and quantitative analyses were performed using selective-ion monitoring mode. Dilutions of the stock sample solution were prepared in culture/dilution water and allowed to equilibrate. Portions of each concentration were then transferred to two glass beakers, one for testing and one for water-quality measurements. D. magna neonates younger than 24 hrs of age was used as a test organism. 10 daphnia magna were used in each test vessel. Water-quality measurements of each test vessel, including temperature, pH, and dissolved oxygen was measured after 48 hrs. Based on the immobility of daphnia magna due to the direct contact with the chemical 4' Hydroxyacetanilidon (Acetaminophen), the lethal concentration was > 0.032 mg/l. Thus based on the LC50, it can be concluded that the chemical was toxic and can be consider to be classified as aquatic acute 1 as well as chronic 1 category as per the CLP classification criteria.

 

 

Similarly in a supporting weight of evidence study for read across chemical (50-65-7) from ECOTOX database 2018 study was conducted. Study was conducted to determine the short term toxicity of 5-Chloro-N-(2-chloro-4-nitrophenyl)-2-hydroxybenzamide (Niclosamide) to water flea daphnia magna. Test was conducted under the static system for the exposure period of 24 hrs. EC50 was measured on the basis of 50 % immobility of daphnia magna. Based on the immobility of freshwater water flea daphnia magna due to chemical 5-Chloro-N-(2-chloro-4-nitrophenyl)-2-hydroxybenzamide (Niclosamide) for the total exposure period of 24 hrs, the EC50 was 0.16 mg/l. Thus based on the EC50 chemical was consider as toxic and can be consider to be classified as aquatic acute1/chronic 1 category as per the CLP classification criteria.

 

On the basis of above results for target chemical 2-[(E)-2-(4-chloro-2-nitrophenyl)diazen-1-yl]-N-(4-ethoxyphenyl)-3-oxobutanamide (52320-66-8) (from OECD QSAR toolbox version 3.4) and for its read across substance from Environmental Toxicology and Chemistry 2006 and ECOTOX database it can be concluded that the test substance 2-[(E)-2-(4-chloro-2- nitrophenyl)diazen-1-yl]-N-(4-ethoxyphenyl)-3-oxobutanamide (52320-66-8) is toxic and can be consider to be classified as aquatic acute1/chronic 1 category as per the CLP classification criteria.