Methyl N-(2,6-dimethylphenyl)-DL-alaninate

Endpoint summary

Description of key information

Hydrolysis

HYDROWIN v2.00 program of Estimation Programs Interface (EPI Suite, 2017) prediction model was used to predict the hydrolysis half-life of test compound 2 -(2,6 -dimethyl-phenylamino)- propionic acid methyl ester (CAS No. 5288 -49 -0). The estimated half-life of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester was estimated to be 4.746 yrs at pH 7.0 and 173.333 days at pH 8.0 (at 25 deg C), indicating that it is not hydrolysable.

Biodegradation in water

Biodegradability of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (CAS no. 52888 -49 -0) is predicted using QSAR toolbox version 3.3 (2017) with logKow as the primary descriptor. Test substance undergoes 0.166% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester was estimated to be not readily biodegradable in water.

Biodegradation in water and sediment

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (CAS No. 52888 -49 -0). If released in to the environment, 21.6% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester in water is estimated to be 37.5 days (900 hrs). The half-life (37.5 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is moderate to low whereas the half-life period of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester in sediment is estimated to be 337.5 days (8100 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.228%), indicates that 2 -(2,6 -dimethyl-phenylamino)- propionic acid methyl ester is not persistent in sediment.

 

Biodegradation in soil

The half-life period of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (CAS No. 52888 -49 -0) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 78% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 2 -(2,6 -dimethyl- phenylamino)-propionic acid methyl ester in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.

Bioaccumulation: aquatic / sediment

BCFBAF model (v3.01) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the bioconcentration factor (BCF) of test chemical 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (CAS No. 52888 -49 -0). The bioconcentration factor (BCF) of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester was estimated to be 27.08 L/kg whole body w.w (at 25 deg C) which does not exceed the bio concentration threshold of 2000, indicating that the chemical 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester is not expected to bioaccumulate in the food chain.

Adsorption / desorption

KOCWIN model (v2.00) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the soil adsorption coefficient i.e Koc value of test chemical 2 -(2,6 -dimethyl-phenylamino)- propionic acid methyl ester (CAS No. 52888 -49 -0). The soil adsorption coefficient i.e Koc value of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester was estimated to be 176.5 L/kg (log Koc=2.2468) by means of MCI method (at 25 deg C). This Koc value indicates that the substance 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

Additional information

Hydrolysis

HYDROWIN v2.00 program of Estimation Programs Interface (EPI Suite, 2017) prediction model was used to predict the hydrolysis half-life of test compound 2 -(2,6 -dimethyl-phenylamino)- propionic acid methyl ester (CAS No. 5288 -49 -0). The estimated half-life of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester was estimated to be 4.746 yrs at pH 7.0 and 173.333 days at pH 8.0 (at 25 deg C), indicating that it is not hydrolysable.

Biodegradation in water

Various predicted data for the target compound 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (CAS No. 52888-49-0) and supporting weight of evidence studies for its structurally similar read across substance were reviewed for the biodegradation end point which are summarized as below:

 

In a prediction done by SSS (2017) using OECD QSAR toolbox version 3.3 with logKow as the primary descriptor, percentage biodegradability of test chemical 2 -(2,6 -dimethyl- phenylamino)-propionic acid methyl ester(CAS No. 52888-49-0) was estimated.Test substance undergoes 0.166% degradation by BOD in 28 days. Thus, based on percentage degradation, the test chemical2-(2,6-dimethyl-phenylamino)-propionic acid methyl esterwas estimated to be not readily biodegradable in water.

 

In another prediction using the Estimation Programs Interface Suite (EPI suite, 2017), the biodegradation potential of the test compound-(2,6-dimethyl-phenylamino)-propionic acid methyl ester(CAS No. 52888-49-0) in the presence of mixed populations of environmental microorganisms was estimated.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 chemical2-(2,6-dimethyl-phenylamino)-propionic acid methyl esteris expected to be not readily biodegradable.

 

In a supporting weight of evidence study from authoritative database (J-CHECK and HSDB, 2017 & EnviChem, 2014) for the read across chemical 3,4-dimethylaniline (CAS no. 95-64-7),biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of read across substance 3,4-dimethylaniline. The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I)). Concentration of inoculum i.e, sludge used was 100 mg/l and initial test substance conc. used in the study was 30 mg/l, respectively. The percentage degradation of substance 3,4-dimethylaniline was determined to be 7.1 and 4.8% by BOD and GC parameter in 28 days. Thus, based on percentage degradation, 3,4 -dimethylaniline is considered to be not readily biodegradable in nature.

 

For the read across chemical 2,6-Xylidine (CAS no. 87-62-7) from authoritative database (J-CHECK and HSDB, 2017) and secondary source (OECD SIDS, 2012), biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of read across substance 2,6-Xylidine (CAS no. 87-62-7). The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I)) at a temperature of 25°C. Activated sludge, non-adapted was used as a test inoculum for the study. Sludge and surface water including surface soil were collected from ten different places in Japan which includes water treatment plants, rivers, lake and inner bays. These sludges and water/soil were mixed and cultivated with glucose and peptone as nutrient in a testing laboratory. Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. For analytical method,10 mL of the test solution was taken out and centrifuged. Then, the supernatant of this solution was employed for the quantitative analysis for HPLC and TOC.BOD was continuously measured by BOD analysis. Direct analysis by HPLC and TOC was conducted after 28 days. Aniline was used as a reference substance for the study. Reference substance aniline undergoes 66% and 78% degradation after 7 and 14 days, respectively. Thus, based on this, pass level criteria was fulfilled. The percentage degradation of substance 2,6-Xylidine was determined to be 0 and 1% by BOD, TOC removal and HPLC parameter in 28 days. Thus, based on percentage degradation, 2,6-Xylidine is considered to be not readily biodegradable in nature.

 

Another biodegradation study was conducted for 70 days for evaluating the percentage biodegradability of read across substance 2,6-Xylidine (CAS no. 87-62-7) (HSDB, 2017). The study was performed according to OECD Guideline 301 F (Ready Biodegradability: Manometric Respirometry Test) under aerobic conditions. Initial test substance conc. used in the study was 100 mg/l, respectively. The percentage degradation of read across substance 2,6-Xylidine was determined to be 4, 8, 25, 38 and 69% by BOD parameter after 7, 13, 36, 42 and 70 days, respectively. Thus, based on percentage degradation, 2,6-Xylidine is considered to be not readily biodegradable in nature.

 

In a supporting weight of evidence study from authoritative database (J-CHECK, 2017) and secondary source (OECD SIDS, 2012) for the read across chemical 2,3-Xylidine (CAS no. 87-59-2),biodegradation study was conducted for 28 days for evaluating the percentage biodegradability of read across substance 2,3-Xylidine. The study was performed according to OECD Guideline 301 C (Ready Biodegradability: Modified MITI Test (I)) at a temperature of 25± 1°C. Activated sludge, non-adapted was used as a test inoculum for the study. Sludge and surface water including surface soil were collected from ten different places in Japan which includes water treatment plants, rivers, lake and inner bays. These sludges and water/soil were mixed and cultivated with glucose and peptone as nutrient in a testing laboratory. Concentration of inoculum i.e, sludge used was 30 mg/l and initial test substance conc. used in the study was 100 mg/l, respectively. For analytical method, After the cultivation period, 10 mL of the test substance was taken out. Then this test solution was centrifuged with 1000 g for 10 minutes. The supernatant was then analyzed with TOC and HPLC.BOD was continuously measured by BOD analysis. Direct analysis by HPLC and TOC was conducted after 28 days. Aniline was used as a reference substance for the study. Inoculum blank was also setup for the biodegradation study. Reference substance aniline undergoes 59% and 76% degradation after 7 and 14 days, respectively. Thus, based on this, pass level criteria was fulfilled. The percentage degradation of substance 2,3-Xylidine was determined to be 3 and 0% by BOD, TOC removal and HPLC parameter in 28 days. Thus, based on percentage degradation, 2,3-Xylidine is considered to be not readily biodegradable in nature.

 

On the basis of above results for target chemical2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester(from OECD QSAR toolbox version 3.3 and EPI suite, 2017) and for its read across substance (authoritative database J-CHECK, HSDB, EnviChem and secondary source OECD SIDS), it can be concluded that the test substance 2 -(2,6 -dimethyl-phenyl amino)-propionic acid methyl ester can be expected to be not readily biodegradable in nature.

Biodegradation in water and sediment

Estimation Programs Interface (EPI Suite, 2017) prediction model was run to predict the half-life in water and sediment for the test compound 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (CAS No. 52888 -49 -0). If released in to the environment, 21.6% of the chemical will partition into water according to the Mackay fugacity model level III and the half-life period of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester in water is estimated to be 37.5 days (900 hrs). The half-life (37.5 days estimated by EPI suite) indicates that the chemical is not persistent in water and the exposure risk to aquatic animals is moderate to low whereas the half-life period of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester in sediment is estimated to be 337.5 days (8100 hrs). However, as the percentage release of test chemical into the sediment is less than 1% (i.e, reported as 0.228%), indicates that 2 -(2,6 -dimethyl-phenylamino)- propionic acid methyl ester is not persistent in sediment.

 

Biodegradation in soil

The half-life period of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (CAS No. 52888 -49 -0) in soil was estimated using Level III Fugacity Model by EPI Suite version 4.1 estimation database (EPI suite, 2017). If released into the environment, 78% of the chemical will partition into soil according to the Mackay fugacity model level III. The half-life period of 2 -(2,6 -dimethyl- phenylamino)-propionic acid methyl ester in soil is estimated to be 75 days (1800 hrs). Based on this half-life value of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester, it is concluded that the chemical is not persistent in the soil environment and the exposure risk to soil dwelling animals is moderate to low.

On the basis of available information, the test substance 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester can be considered to be not readily biodegradable in nature.

Bioaccumulation: aquatic / sediment

Various predicted data for the target compound 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester(CAS No. 52888-49-0) and supporting weight of evidence study for its structurally similar read across substance were reviewed for the bioaccumulation end point which are summarized as below:

 

In aprediction done using theBCFBAF Program(v3.01) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the bioconcentration factor (BCF) of test chemical 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (CAS No. 52888 -49 -0). The bioconcentration factor (BCF) of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester was estimated to be 27.08 L/kg whole body w.w (at 25 deg C).

 

In an another prediction done by using Bio-concentration Factor (v12.1.0.50374) moduleACD (Advanced Chemistry Development)/I-Lab predictive module, 2017), theBio-concentration Factor (BCF) over the entire pH scale of the test substance 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester was estimated to be 1, 5.05, 25.8, 44.7, 48.3 and 48.7 at pH range 0-1, 2, 3, 4, 5 and 6-14, respectively.

 

Bioconcentration Factor (BCF) of test chemical 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester was estimated using Chemspider database(ChemSpider, 2017). The bioconcentration factor of test substance 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester was estimated to be 40.20 at pH 5.5 and 40.31 at pH 7.4, respectively.

 

Another predicted data was estimated usingSciFinder database (American Chemical Society (ACS), 2017) was used for predicting the bioconcentration factor (BCF) of test chemical 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (CAS No. 52888 -49 -0). The bioconcentration factor (BCF) of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester was estimated to be 1, 1.55, 7.93, 13.7, 14.8, 14.9 and 15.0 at pH range 1, 2, 3, 4, 5, 6 and 7-10, respectively (at 25 deg C).

 

In a supporting weight of evidence study from authoritative database (HSDB, 2017) for the read across chemical Metalaxyl (CAS no. 57837-19-1),bioaccumulation experiment was conducted for estimating the BCF (bioaccumulation factor) value of read across chemical Metalaxyl. The bioaccumulation factor (BCF) value was calculated using a log Kow of 1.65 and a regression-derived equation. The estimated BCF (bioaccumulation factor) value of Metalaxyl was determined to be 4 dimensionless.

 

For the read across chemical 3,4-dimethylaniline (CAS no. 95-64-7) from authoritative database (J-CHECK, EnviChem and HSDB, 2017),bioaccumulation study was conducted on test organism Cyprinus carpio for 6 weeks for evaluating the bioconcentration factor (BCF value) of read across 3,4-dimethylaniline.The study was performed according to other guideline "Bioaccumulation test of a chemical substance in fish or shellfish" provided in "the Notice on the Test Method Concerning New Chemical Substances", respectively. Cyprinus carpio was used as a test organism for the study. Test chemical nominal conc. used for the study were 1 mg/l and 0.1 mg/l, respectively. Range finding study involve the TLm (48 hr) 121 mg/l (w/v) on Rice fish (Oryzias latipes).The bioconcentration factor (BCF value) of substance 3,4-dimethylaniline on Cyprinus carpio was determined to bein the range of 1.9-3.3 L/Kg at a conc. of 1 mg/l and ≤ 10 L/Kg at a conc. of 0.1 mg/l, respectively.

 

On the basis of above results for target chemical 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (from EPI suite, ACD labs,ChemSpider and Scifinder,  2017) and for its read across substance from authoritative database (HSDB, EnviChem & J-CHECK), it can be concluded that the BCF value of test substance 2-(2,6-dimethyl-phenylamino)-propionic acid methyl esterranges from 15.0 – 48.7 which does not exceed the bioconcentration threshold of 2000, indicating that the chemical 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester is not expected to bioaccumulate in the food chain.

 

Adsorption / desorption

Various predicted data for the target compound 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (CAS No. 52888-49-0) and supporting weight of evidence study for its structurally similar read across substance were reviewed for the adsorption end point which are summarized as below:

 

In aprediction done using theKOCWIN Program(v2.00) of Estimation Programs Interface (EPI Suite, 2017) was used to predict the soil adsorption coefficient i.e Koc value of test chemical 2 -(2,6 -dimethyl-phenylamino)- propionic acid methyl ester (CAS No. 52888 -49 -0). The soil adsorption coefficient i.e Koc value of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester was estimated to be 176.5 L/kg (log Koc=2.2468) by means of MCI method (at 25 deg C). This Koc value indicates that the substance 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

 

The Soil Adsorption Coefficient i.e Koc value of test substance 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (CAS no. 52888 -49 -0) was estimated using Adsorption Coefficient module (v12.1.0.50374) program as Koc 2.40, 7.99, 58.3, 298, 516, 557, 561 and 562 at pH range 0, 1, 2, 3, 4, 5, 6 and 7-14, respectively (log Koc value ranges from 0.4 ± 1.0 to 2.7 ± 1.0)(ACD (Advanced Chemistry Development)/I-Lab predictive module, 2017). This Koc value indicates that the test substance 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester has a moderate sorption to soil and therefore have slow migration potential to groundwater.

 

In an another prediction done by using ChemSpider Database (2017),the Soil Adsorption Coefficient i.e Koc value of test substance 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (CAS no. 52888 -49 -0) was estimated. The adsorption coefficient (Koc) value of test substance 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester was estimated to be 489.27 (Log Koc = 2.689) at pH 5.5 and 490.62 (Log Koc = 2.690) at pH 7.4, respectively. This Koc value indicates that the test substance 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester has a moderate sorption to soil and therefore have slow migration potential to groundwater.

 

Additional soil adsorption coefficient i.e Koc value of test chemical2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (CAS No. 52888 -49 -0)was estimated using the SciFinder database (American Chemical Society (ACS), 2017).The soil adsorption coefficient i.e Koc value of 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester was estimated to be 3.43, 25.0, 128, 222, 239 and 241 at pH range 1, 2, 3, 4, 5 and 6-10, respectively (log Koc value ranges from 0.535 to 2.382) (at 25 deg C). This Koc value indicates that the substance 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

 

In a supporting weight of evidence study from authoritative database (HSDB, 2017) for the read across chemical 3,4-dimethylaniline (CAS no. 95-64-7),adsorption study was conducted for estimating the adsorption coefficient (Koc) value of read across chemical 3,4-dimethylaniline (CAS no. 95-64-7). The adsorption coefficient (Koc) value was calculated using a logKow of 1.84 and a regression derived equation. The adsorption coefficient (Koc) value of test substance 3,4-dimethylaniline was estimated to be 240 (Log Koc = 2.38). This Koc value indicates that the substance 3,4 -dimethylaniline has a low sorption tosoil and sediment and therefore have moderate migration potential to ground water.

 

For the read across chemical 2,6-Xylidine (CAS no. 87-62-7) from authoritative database (HSDB, 2017),adsorption study was conducted for estimating the adsorption coefficient (Koc) value of read across chemical 2,6-Xylidine. The adsorption coefficient (Koc) value was calculated using a structure estimation method based on molecular connectivity indices. The adsorption coefficient (Koc) value of test substance 2,6-Xylidine was estimated to be 190 (Log Koc = 2.278). This Koc value indicates that the substance 2,6 -Xylidine has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

 

On the basis of above overall results for target chemical 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester (from EPI suite, ACD labs,ChemSpider and Scifinder,2017) and for its read across substance from authoritative database (HSDB, 2017), it can be concluded that the Koc value of test substance 2-(2,6-dimethyl-phenylamino)-propionic acid methyl ester ranges from 176.5–562, indicating that the test chemical 2 -(2,6 -dimethyl-phenylamino)-propionic acid methyl ester has a low to moderate sorption to soil and sediment and therefore have moderate to slow migration potential to ground water.