2-Naphthalenesulfonic acid, 7-amino-4-hydroxy-3-[2-[4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-8-[2-[2-sulfo-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-, sodium salt (1:4)

Endpoint summary

Description of key information

Biodegradation in water:

Estimation Programs Interface Suite (EPI suite, 2018) was run to predict the biodegradation potential of the test compound 2-Naphthalenesulfonic acid, 7-amino-4-hydroxy-3-[2-[4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-8-[2-[2-sulfo-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-, sodium salt (1:4)  (CAS no. 607724 -37 -8 ) in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical 2-Naphthalenesulfonic acid, 7-amino-4-hydroxy-3-[2-[4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-8-[2-[2-sulfo-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-, sodium salt (1:4) is expected to be readily biodegradable.

Additional information

Biodegradation in water:

Predicted data study for target chemical 2-Naphthalenesulfonic acid, 7-amino-4-hydroxy-3-[2-[4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-8-[2-[2-sulfo-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-, sodium salt (1:4)  (CAS no. 607724 -37 -8 ) and supporting weight of evidence from study reports and journals for its structurally similar read across chemicals have been reviewed for biodegradation in water endpoint and their results are summarized below.

 

The first study was predicted data study in this study the Estimation Programs Interface Suite (EPI suite, 2018) was run to predict the biodegradation potential of the test compound 2-Naphthalenesulfonic acid, 7-amino-4-hydroxy-3-[2-[4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-8-[2-[2-sulfo-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-, sodium salt (1:4)  (CAS no. 607724 -37 -8 ) in the presence of mixed populations of environmental microorganisms. The biodegradability of the substance was calculated using seven different models such as Linear Model, Non-Linear Model, Ultimate Biodegradation Timeframe, Primary Biodegradation Timeframe, MITI Linear Model, MITI Non-Linear Model and Anaerobic Model (called as Biowin 1-7, respectively) of the BIOWIN v4.10 software. The results indicate that chemical 2-Naphthalenesulfonic acid, 7-amino-4-hydroxy-3-[2-[4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-8-[2-[2-sulfo-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-, sodium salt (1:4) is expected to be readily biodegradable.

 

Next study was experimental study reviewed from study report in this 28-days Closed Bottle test following the OECD guideline 301 D was performed to determine the ready biodegradability of the test item. The study was performed at a temperature of 20°C. The test system included control, test item and reference item. Polyseed were used for this study. 1 polyseed capsule were added in 500 ml D.I water and then stirred for 1 hour for proper mixing and functioning of inoculum. This gave the bacterial count as 10E7 to 10E8 CFU/ml. At the regular interval microbial plating was also performed on agar to confirm the vitality and CFU count of microorganism. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32 ml/L . OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test item and reference item. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 76.5  %. Degradation of Sodium Benzoate exceeds 39.15 % on 7 days & 70.48 on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be     1.05    mgO2/mg. ThOD was calculated as 1.08 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 97.22 %. Based on the results, the test item, under the test conditions, was considered to be readily in nature.

 

Another study was also reviewed from study report in this study the 28-days Closed Bottle test following the OECD guideline 301 D was performed to determine the ready biodegradability of the test chemical. The study was performed at a temperature of 20°C. The test system included control, test item and reference item. Polyseed were used for this study. 1 polyseed capsule were added in 500 ml D.I water and then stirred for 1 hour for proper mixing and functioning of inoculum. This gave the bacterial count as 10E7 to 10E8 CFU/ml. At the regular interval microbial plating was also performed on agar to confirm the vitality and CFU count of microorganism. The concentration of test and reference item (Sodium Benzoate) chosen for both the study was 4 mg/L, while that of inoculum was 32 ml/l. OECD mineral medium was used for the study. ThOD (Theoretical oxygen demand) of test and reference item was determined by calculation. % degradation was calculated using the values of BOD and ThOD for test item and reference item. The % degradation of procedure control (reference item) was also calculated using BOD & ThOD and was determined to be 75.3%. Degradation of Sodium Benzoate exceeds 46.38 % on 7 days & 61.44 % on 14th day. The activity of the inoculum is thus verified and the test can be considered as valid. The BOD28 value of test chemical was observed to be 1.1 mgO2/mg. ThOD was calculated as 1.2 mgO2/mg. Accordingly, the % degradation of the test item after 28 days of incubation at 20 ± 1°C according to Closed Bottle test was determined to be 91.66%. Based on the results, the test item, under the test conditions, was considered to be readily biodegradable in nature.

 

Last study was reviewed from Journal of Environmental Sciences (2007) in this study the Biodegradability of test substance was estimated using the Quantitative structure-biodegradability relationships (QSBRs).The QSBRs models include predictive model and mechanism-based QSBR model. With a total of four descriptors, molecular weight (MW), energies of the highest occupied molecular orbital (EHOMO), the lowest unoccupied molecular orbital (ELUMO), and the excited state (EES), calculated using quantum chemical semi-empirical methodology, a series of models were analyzed between the dye biodegradability and each descriptor. Out of these, three descriptors i.e, energies of the highest occupied molecular orbital (EHOMO), the lowest unoccupied molecular orbital (ELUMO), and the excited state (EES) were computed by PM3 Hamiltonian.The energies of frontier orbitals, EHOMO and ELUMO, which directed the nucleophilic and electrophilic reactivity of a compound respectively, were calculated using the PM3 Hamiltonian contained in the quantum chemical computation software HYPER (version 5.0).The method of PM3 was selected because it was a recently developed semi-empirical molecular orbital algorithm and the computational time was much shorter than needed by the ab initio methods. All statistical analyses were carried out by ORIGIN software (version 6.0). The regression analysis was used to establish the model. Model quality was characterized by the number of observations (n), the correlation coefficient (R), the standard deviation (SD), the Fisher criterion (F), and the significance level (P). The percentage degradation of test chemical was estimated to be 95% by QSBR models, test chemical can be considered to be readily biodegradable in nature.

 

By considering results of all the studies mentioned above for target chemical and its structurally similar areda across chemical it can be concluded that target chemical 2-Naphthalenesulfonic acid, 7-amino-4-hydroxy-3-[2-[4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-8-[2-[2-sulfo-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-, sodium salt (1:4)  (CAS no. 607724 -37 -8 ) is readily biodegradable.