Carbamodithioic acid, bis(mixed 2-ethylhexyl and 2-methylbutyl and pentyl) derivs., antimony (3+) salts

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

16 May 2019

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 : US EPA KowWIN v1.68a

2. MODEL (incl. version number) : US EPA KowWIN v1.68a

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL : N(CCCCC)(CCCCC)C(=S)S[Sb](SC(=S)N(CCCCC)CCCCC)SC(=S)N(CCCCC)CCCCC and CCCCC(CC)CN(CC(CC)CCCC)C(=S)S[Sb](SC(=S)N(CCCCC)CCCCC)SC(=S)N(CCCCC)CCCCC, representing two lowest MW substances present and >90% of the molecules present.

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL: KOWWIN uses a "fragment constant" methodology to predict log P.  In a "fragment constant" method, a structure is divided into fragments (atom or larger functional groups) and coefficient values of each fragment or group are summed together to yield the log P estimate.   KOWWIN’s methodology is known as an Atom/Fragment Contribution (AFC) method.  Coefficients for individual fragments and groups were derived by multiple regression of 2447 reliably measured log P values. A more complete description of KOWWIN’s methodology is available at Meylan, W.M. and P.H. Howard.  1995.  Atom/fragment contribution method for estimating octanol-water partition coefficients.  J. Pharm. Sci. 84: 83-92. The following validation statistics have been reported for the model:

  - number in dataset      = 10946
  - correlation coef (r2)  = 0.943
  - standard deviation     = 0.479
  - absolute deviation     = 0.356
  - avg Molecular Weight   = 258.98

5. APPLICABILITY DOMAIN: There is no universally accepted definition of the model domain but the model is reported to be most reliable when the target substance falls within the molecular weight range of the training set and/or that have more instances of a given fragment than the maximum for all training set compounds used to estimate the log Kow. In that regard, the target substance, with a molecular weight > 819.03 and antimony (Sb) at the center of the molecule, the substance does not fall perfectly within the training set but the -CH3, -CH2-, -N<, -S-, and N-C(=S)-S fragments will represent the soluble parts of the molecule and these fragments do fit well within the domain. This is evident in that the -CH2- and -CH3- fragments contributed the most to the calculation.

6. ADEQUACY OF THE RESULT: The predicted log Kow was 13.09 and 15.89 for the two molecules modeled. There is no measured value against which to compare but an estimated Log Kow calculated using the solubility ratio method resulted in a slightly lower Log Kow of 8.88. Nonetheless, the result clearly demonstrates that, as would be expected for a molecule of this type, the substance is very highly lipophilic.

Data source

Reference

Reference Type:

other company data

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

no guideline required

Principles of method if other than guideline:

QSAR Estimate using US EPA KowWIN v1.68a

GLP compliance:

no

Type of method:

other: QSAR Model

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Carbamodithioic acid, bis(mixed 2-ethylhexyl and 2-methylbutyl and pentyl) derivs., antimony (3+) salts

Molecular formula:

C33H66N3S6Sb to C51H102N3S6Sb

IUPAC Name:

Carbamodithioic acid, bis(mixed 2-ethylhexyl and 2-methylbutyl and pentyl) derivs., antimony (3+) salts

Test material form:

liquid: viscous

Specific details on test material used for the study:

PYSICAL DESCRIPTION: Highly viscous amber liquid.

PURITY: >99%

SOURCE OF TEST MATERIAL
- Source and lot/batch number of test material: WT05-19
- Expiration date of the lot/batch: not applicable

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: room temp.
- Stability under storage conditions: stable for the duration of testing.

Results and discussion

Partition coefficient

Key result

Type:

log Pow

Partition coefficient:

>= 13.09 - <= 15.89

Temp.:

20 °C

pH:

> 6 - < 8

Applicant's summary and conclusion

Conclusions:

The estimated octanol-water partition coefficient (log Kow) is 13.09 - 15.89.

Executive summary:

QSAR estimation using U.S. EPA KowWIN v1.68a predicts an octanol-water partition coefficient (log Kow) of 13.09 - 15.89 at 25 deg C for the substance.