pentasodium 4-amino-3-[{4-[(2,4-disulfonatophenyl)diazenyl]-3-methylphenyl}diazenyl]-5-hydroxy-6-[(4-nitro-2-sulfonatophenyl)diazenyl]naphthalene-1,7-disulfonate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2021

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 adequate and reliable documentation / justification

Justification for type of information:

1. SOFTWARE: Individual model KOWWIN included in the Estimation Programs Interface (EPI) Suite.

2. MODEL (incl. version number): KOWWIN v1.69 included in EPI-Suite v 4.11, ©2000 - 2015

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL: S(=O)(=O)(O[Na])c5ccc(N=Nc1ccc(cc1C)N=Nc3cc(S(=O)(=O)O[Na])c2cc(S(=O)(=O)O[Na])c(c(O)c2c3N)N=Nc4ccc(N(=O)(=O))cc4S(=O)(=O)O[Na])c(S(=O)(=O)O[Na])c5

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: Logarithmic octanol-water partition coefficient (log Pow or log Kow)
- Unambiguous algorithm: KOWWIN v1.69 included in EPI-Suite v 4.11, ©2000 - 2015
- Defined domain of applicability: Because an estmated boiling and melting point is available for the substance the applicablity domain is just described by the molecular weight range. With a molecular weight of 1040.75 g/mol g/mol the substance is slightly above the range of the training set (18.02 - 719.92 g/mol) as well as slightly above the range of the validation set (27.03 - 991.15 g/mol). The structural features of the substance are, however, covered by the training set and the substance does not contain any unusual structural element which is out of scope of the QSAR calculation.
- Appropriate measures of goodness-of-fit and robustness and predictivity:
- Mechanistic interpretation:

5. APPLICABILITY DOMAIN
- Descriptor domain: The molecule is separated into distinct atom/fragments using an Atom/Fragment Contribution method. Based on structure of the molecule, various steric interactions, hydrogen-bondings, and effects from polar functional substructures were identified and individual correction factors were selected through a tedious process of correlating the differences (between log Kow estimates from atom/fragments alone and measured log Kow values) with common substructures. (see table under 'any other information').
- Structural domain: Regarding the structure of pentasodium 4-amino-3-[{4-[(2,4-disulfonatophenyl)diazenyl]-3-methylphenyl}diazenyl]-5-hydroxy-6-[(4-nitro-2-sulfonatophenyl)diazenyl]naphthalene-1,7-disulfonate, the fragment descriptors found by the program are complete and listed in Appendix D (KOWWIN Fragment and Correction Factor descriptors). Additionally, the substance is not listed in Appendix F (Compounds that exceed the Fragment & Molecular Weight Domains).
- Mechanistic domain: no information available
- Similarity with analogues in the training set: no information available
- Other considerations (as appropriate): no information available

6. ADEQUACY OF THE RESULT
The predicted value can be considered reliable yielding a useful result for further assessment.

Guideline:

other: REACH guidance on QSARs R.6, May 2008

GLP compliance:

no

Type of method:

other: QSAR

Partition coefficient type:

octanol-water

Key result

Type:

log Pow

Partition coefficient:

-1.73

Remarks on result:

other: no temperature or pH required.

Conclusions:

The QSAR determination of the octanol-water partition coefficient (log Kow) of pentasodium 4-amino-3-[{4-[(2,4-disulfonatophenyl)diazenyl]-3-methylphenyl}diazenyl]-5-hydroxy-6-[(4-nitro-2-sulfonatophenyl)diazenyl]naphthalene-1,7-disulfonate using the model KOWWIN included in the Estimation Program Interface (EPI) Suite v4.11 revealed a value of -1.73. The predicted value can be considered reliable yielding a useful result for further assessment.

Executive summary:

The octanol-water partition coefficient (log Kow) of pentasodium 4-amino-3-[{4-[(2,4-disulfonatophenyl)diazenyl]-3-methylphenyl}diazenyl]-5-hydroxy-6-[(4-nitro-2-sulfonatophenyl)diazenyl]naphthalene-1,7-disulfonate was predicted using the QSAR calculation of the Estimation Programm Interface EPI-Suite v4.11. A SMILES notation was entered in the initial data entry screen. The molecule is separated into distinct atom/fragments using an Atom/Fragment Contribution method. Based on structure of the molecule, various steric interactions, hydrogen-bondings, and effects from polar functional substructures the octanol-water partition coefficient was estimated to be -1.73. The predicted value can be considered reliable yielding a useful result for further assessment.

Description of key information

The QSAR determination of the octanol-water partition coefficient (log Kow) of pentasodium 4-amino-3-[{4-[(2,4-disulfonatophenyl)diazenyl]-3-methylphenyl}diazenyl]-5-hydroxy-6-[(4-nitro-2-sulfonatophenyl)diazenyl]naphthalene-1,7-disulfonate using the model KOWWIN included in the Estimation Program Interface (EPI) Suite v4.11 revealed a value of -1.73. The predicted value can be considered reliable yielding a useful result for further assessment.

Key value for chemical safety assessment

Log Kow (Log Pow):

-1.73