2-Thiophenecarboxylic acid, 3-[[(2-methoxy-2-oxoethyl)amino]sulfonyl]-, methyl ester

Short-term toxicity to aquatic invertebrates

Administrative data

Endpoint:

short-term toxicity to aquatic invertebrates

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Justification for type of information:

QSAR prediction: migrated from IUCLID 5.6

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

2014

Materials and methods

Principles of method if other than guideline:

The acute toxicity on Daphnia was estimated by using ACD/Percepta predictor for aquatic toxicity on Water flea (Daphnia magna) and ECOSAR.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

methyl 3-[(2-methoxy-2-oxoethyl)sulfamoyl]thiophene-2-carboxylate

EC Number:

600-780-8

Cas Number:

106820-63-7

Molecular formula:

C9H11NO6S2

IUPAC Name:

methyl 3-[(2-methoxy-2-oxoethyl)sulfamoyl]thiophene-2-carboxylate

Test organisms

Test organisms (species):

Daphnia magna

Results and discussion

Effect concentrations

Dose descriptor:

LC50

Effect conc.:

600.27 mg/L

Remarks on result:

other: Consensus

Any other information on results incl. tables

ACD/PerceptaLC50 (mg/L)	ECOSARLC50 (mg/L)	Consensus predictionLC50 (mg/L)
2700 (Not reliable)	600.27 (Reliable)	600.27 (Reliable)

ACD/Percepta acute aquatic toxicity on Daphnia is provided with a reliability index (RI) parameter which estimates the reliability of the prediction. The reliability index takes into account the similarity of the tested compound with the training set compounds and the consistency of experimental values for similar compounds. Values greater than 0.75 indicate highly reliable predictions, values in the range 0.5-0.75 indicate moderately reliable predictions, values in the range 0.3-0.5 indicate borderline predictions, while for values lower than 0.3 predictions are considered as NOT reliable.

ACD/PerceptaLC50 (mg/L)	ACD/Percepta RI	Reliability assessment
2700	0.21	NOT RELIABLE

ACD/Percepta predicted for 2-Thiophenecarboxylic acid, 3-[[(2-methoxy-2-oxoethyl)amino]sulfonyl]-, methyl ester a LC50 equal to 2700 mg/L, but the prediction is not reliable being the reliability index equal to 0.21. Together with the prediction, ACD/Percepta displays up to 5 most structurally similar structures from the training set along with their experimental test results for the corresponding compounds. The structural similarity is evaluated by a fragmental approach. The information on the structurally similar compounds in the training set is used to further assess the reliability of the prediction, since it illustrates how the test compound, i.e. 2-Thiophenecarboxylic acid, 3-[[(2-methoxy-2-oxoethyl)amino]sulfonyl]-, methyl ester, is represented in the training set. The five mostly similar compounds from the training set, illustrated in the Table, exhibit very little similarity with respect to 2-Thiophenecarboxylic acid, 3-[[(2-methoxy-2-oxoethyl)amino]sulfonyl]-, methyl ester (similarity index ranging from 0.12 to 0.28), meaning that the target compound is not represented in the training set of the model, which is the reason of the prediction being not reliable.

Hydantoin, 2-thio- LC50 (mg/L) = 20 Similarity: 0.28

Sulfathiazole LC50 (mg/L) = 85 Similarity: 0.25

Sulfadimethoxine LC50 (mg/L) = 200 Similarity: 0.15

Sulfamethazine LC50 (mg/L) = 160 Similarity: 0.15

Robenidine LC50 (mg/L) = 0.075 Similarity: 0.12

ECOSAR

ECOSAR predicts the aquatic toxicity of chemicals based on their similarity of structure to chemicals for

which the aquatic toxicity has been previously measured. ECOSAR contains a library of class-based QSARs

for predicting aquatic toxicity, overlaid with an expert decision tree for selecting the appropriate chemical

class. The QSARs in ECOSAR are based on a linear mathematical relationship between the predicted log

Kow values and the corresponding log of the measured toxicity values (mmol/L) for a suite of training set

chemicals within each class of interest. The reliability of ECOSAR prediction is evaluated in terms of

descriptor range (Kow range). ECOSAR predictions are illustrated in Table

ECOSAR (48 hr)LC50 (mg/L)	Applicability domain	Reliability assessment
600.27	Maximum LogKow = 5.0	RELIABLE

 

ECOSAR assigned 2-Thiophenecarboxylic acid, 3-[[(2-methoxy-2-oxoethyl)amino]sulfonyl]-, methyl ester to the class of esters, thiophenes and amides. According to a precautionary approach, the predicted LC50 value was selected as the lowest LC50 value (thiophenes LC50) among the LC50 values of the three classes. Thus, ECOSAR predicted a LC50 equal to 600.27 mg/L, and the prediction is considered reliable since the target does not exceed the upper logKow value of 5.0 (the consensus logKow value estimated in the present report is equal to 0.62).

Applicant's summary and conclusion

Conclusions:

Since ACD/Percepta prediction resulted to be not reliable, based on ECOSAR prediction, the acute aquatic toxicity on Daphnia for the target 2-Thiophenecarboxylic acid, 3-[[(2-methoxy-2-oxoethyl)amino]sulfonyl]-, methyl ester was predicted of LC50 equal to 600.27 mg/L.

Executive summary:

Acute aquatic toxicity on Daphnia for the target 2-Thiophenecarboxylic acid, 3-[[(2-methoxy-2-oxoethyl)amino]sulfonyl]-, methyl ester was estimated by using two predictors: ACD/Percepta and ECOSAR. The two predictors were employed in order to apply a consensus approach to enhance the reliability of the prediction. In the consensus assessment only reliable predictions are to be taken into account. Since ACD/Percepta prediction resulted to be not reliable, based on ECOSAR prediction, the acute aquatic toxicity on Daphnia for the target 2-Thiophenecarboxylic acid, 3-[[(2-methoxy-2-oxoethyl)amino]sulfonyl]-, methyl ester was predicted of LC50 equal to 600.27 mg/L.