1,4-bis(p-tolylamino)anthraquinone

Biodegradation in water and sediment: simulation tests

Administrative data

Endpoint:

biodegradation in water: simulation testing on ultimate degradation in surface water

Type of information:

(Q)SAR

Adequacy of study:

other information

Study period:

2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

results derived from a (Q)SAR model, with limited documentation / justification, but validity of model and reliability of prediction considered adequate based on a generally acknowledged source

Justification for type of information:

MODEL DESCRIPTION
The EAWAG-BBD Pathway Prediction System (also known as Minnesota Pathway Prediction System) is a web-based tool (http://eawag-bbd.ethz.ch/predict/) and can be used free of charge.

1.1.1 Purpose:
The model predicts plausible pathways for microbial degradation of chemical compounds. Predictions use biotransformation rules, based on reactions found in the EAWAG-BBD database or in the scientific literature. A list of all rules is available and comprises currently 332 different pathways.
PPS predictions are most accurate for compounds that are:
• similar to compounds whose biodegradation pathways are reported in the scientific literature;
• in environments exposed to air, in moist soil or water, at moderate temperatures and pH, with no competing chemicals or toxins; and
• the sole source of energy, carbon, nitrogen, or other essential element for the microbes in these environments, rather than present in trace amounts.
1.1.2 Scope:
There are a number of chemical classes that should not be investigated using the current version of the Pathway Prediction System. Important classes of chemicals whose biodegradation should not be predicted are listed below.
This list is based on a similar list developed for the PBT System by the Environmental Science Center under contract to the Office of Pollution Prevention and Toxics, U.S. Environmental Protection Agency.
• Readily Degraded and Selected Other Compounds
• Inorganic Chemicals
• High Molecular Weight Compounds
• Chemicals with Unknown or Variable Composition
• Mixtures
• Highly Fluorinated Compounds

1.2 Validity of the Model
The model contains currently a high number (332) of different pathways described in the scientific literature. For Solvent Violet 36 the model revealed the following theoretical pathways:
• 1-Amino-2-unsubstituted aromatic -> vic-Dihydroxyaromatic + Amine (bt0065)
• Anthrone derivative -> 2-[(2-Hydroxyphenyl)methyl]benzoate derivative (bt0418)
As a result, the high number of pathways included in the model gave relevant pathways fitting to the substance. Furthermore, the substance is not excluded from the classes of chemicals whose biodegradation should not be predicted.

Data source

Reference

Reference Type:

other company data

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The EAWAG-BBD Pathway Prediction System (also known as Minnesota Pathway Prediction System) is a web-based tool (http://eawag-bbd.ethz.ch/predict/) which predicts plausible pathways for microbial degradation of chemical compounds. Predictions use biotransformation rules, based on reactions found in the EAWAG-BBD database or in the scientific literature. A list of all rules is available and comprises currently 332 different pathways.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

1,4-bis(p-tolylamino)anthraquinone

EC Number:

204-909-5

EC Name:

1,4-bis(p-tolylamino)anthraquinone

Cas Number:

128-80-3

Molecular formula:

C28H22N2O2

IUPAC Name:

1,4-bis[(4-methylphenyl)amino]-9,10-anthraquinone

Test material form:

solid

Details on test material:

Smiles Code: Cc1ccc(cc1)Nc5ccc(Nc2ccc(C)cc2)c4c5C(=O)c3ccccc3C4(=O)

Results and discussion

% Degradation

Remarks on result:

other: Neutral routes for degradation were found by the model, but no likely or very likely routes.

Transformation products:

not measured

Details on transformation products:

Details of possible transformation products are given in the full report attached.

Any other information on results incl. tables

The primary metabolism follows two possible routes which are the oxidative cleavage of the amine group and the cleavage of the anthrone ring system. Both routes were found to occur “neutral”. Neutral means that this pathway is theoretically possible. EAWAG defines reaction to be neutral as follows: Possible reaction (neutral). This applies to reactions that are common but not certain to occur in every system. For example, hydrocarbon oxygenation reactions are quite possible, but may or may not be likely to occur depending on what the substrate is. These must be looked at individually. Some may be likely, some may be possible and some may be unlikely based on current knowledge.

In case of Solvent Green 3, the neutral pathway has to be understood that degradation is more unlikely than likely. This has been shown in a ready biodegradation study yielding very limited mineralization in the low percentage range after 28 days. This means that the first step is expected to occur slowly and subsequent secondary or tertiary pathways would not lead to relevant biodegradation and mineralization.

Applicant's summary and conclusion

Validity criteria

Validity criteria fulfilled:

not applicable

Conclusions:

The outcome of the pathway prediction system is that biodegradation of Solvent Green 3 is negligible or it occurs rather slowly.

Executive summary:

Solvent Green 3 was found to be not readily biodegradable in a test according to OECD 301 series. The EAWAG-BBD Pathway Prediction System is a tool which allows prediction of microbial degradation in order to assess the behavior of the substance in the environment. The model predicts:

Primary degradation:       

Oxidative cleavage of the aromatic amine       “neutral”

Cleavage of the Anthrone ring system              “neutral”

The model predicts that common microbial metabolisation routes can be applied for Solvent Green 3. Beside possible pathways and structure of metabolites, the model predicts a qualitative description of the routes as “very likely”, “likely” and “neutral” with neutral to be the likelihood to be expected in this case. Based on the prediction, the classification as “neutral” means that the primary degradation steps are expected to be possible but that they are not certain to occur in every system.