Propanoic acid, 3-mercapto-, C11-14-isoalkyl esters, C13-rich

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

(Q)SAR

Adequacy of study:

supporting study

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 limited documentation / justification

Justification for type of information:

1. SOFTWARE
EpiSuite v4.11, US EPA, 2012

2. MODEL (incl. version number)
KOWWIN v1.68

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
O=C(CCS)OCCCCCCCCCCC(C)C

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- Defined endpoint: n-octanol-water partition coefficient
- Unambiguous algorithm: KOWWIN uses a "fragment constant" methodology to predict log P, 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.
Results of the two successive multiple regressions (first for atom/fragments and second for correction factors) yield the following general equation for estimating log P of any organic compound:
log P = Σ(fini ) + Σ(cjnj ) + 0.229
(num = 2447, r2 = 0.982, std dev = 0.217, mean error = 0.159)

where Σ(fini ) is the summation of fi (the coefficient for each atom/fragment) times ni (the number of times the atom/fragment occurs in the structure) and b is the linear equation constant; Σ(cjnj ) is the summation of cj (the coefficient for each correction factor) times nj (the number of times the correction factor occurs (or is applied) in the molecule).

- Defined domain of applicability:
Currently there is no universally accepted definition of model domain. However, users may wish to consider the possibility that log P estimates are less accurate for compounds outside the MW range of the training set compounds, and/or that have more instances of a given fragment than the
maximum for all training set compounds. It is also possible that a compound may have a functional group(s) or other structural features not represented in the training set, and for which no fragment coefficient was developed. These points should be taken into consideration when interpreting
model results.

Training Set Molecular Weights:
Minimum MW: 18.02
Maximum MW: 719.92
Average MW: 199.98

Validation Molecular Weights:
Minimum MW: 27.03
Maximum MW: 991.15
Average MW: 258.98

- Appropriate measures of goodness-of-fit and robustness and predictivity:
The model has been tested on an external validation dataset of 10,946 compounds.
Total Validation Set Statistics:
number in dataset = 10946
correlation coef (r2) = 0.943
standard deviation = 0.479
absolute deviation = 0.356
avg Molecular Weight = 258.98

Validation Set Estimation Error:
within <= 0.20 - 39.6%
within <= 0.40 - 66.0%
within <= 0.50 - 75.6%
within <= 0.60 - 82.5%
within <= 0.80 - 91.6%
within <= 1.00 - 95.6%
within <= 1.20 - 97.7%
within <= 1.50 - 99.1%

5. APPLICABILITY DOMAIN
[Explain how the substance falls within the applicability domain of the model]
- Descriptor domain: The components of the substance are within the molecular weight range of the training set compounds, and all fragments are represented in the training set. Thus, it is concluded, that the substance is within the applicability domain.

6. ADEQUACY OF THE RESULT
The QSAR prediction is valid and of good reliability. Thus, the result is adequate for chemical safety assessment.

Principles of method if other than guideline:

Estimation of the log Kow by QSAR (EpiSuite v4.11, US EPA, 2012; KOWWIN v1.68)

GLP compliance:

no

Remarks:

not applicable for in silico study

Partition coefficient type:

octanol-water

Type:

log Pow

Partition coefficient:

6.63

Temp.:

25

Remarks on result:

other: QSAR, pH not determined

Log Kow(version 1.68 estimate): 6.63

 

SMILES : O=C(CCS)OCCCCCCCCCCC(C)C

CHEM   :

MOL FOR: C16 H32 O2 S1

MOL WT : 288.49

-------+-----+--------------------------------------------+---------+--------

 TYPE  | NUM |        LOGKOW FRAGMENT DESCRIPTION         |  COEFF  |  VALUE

-------+-----+--------------------------------------------+---------+--------

 Frag  |  2  |  -CH3    [aliphatic carbon]                | 0.5473  |  1.0946

 Frag  | 12  |  -CH2-   [aliphatic carbon]                | 0.4911  |  5.8932

 Frag  |  1  |  -CH     [aliphatic carbon]                | 0.3614  |  0.3614

 Frag  |  1  |  -C(=O)O  [ester, aliphatic attach]        |-0.9505  | -0.9505

 Frag  |  1  |  -SH     [aliphatic attach]                |-0.0001  | -0.0001

 Const |     |  Equation Constant                         |         |  0.2290

-------+-----+--------------------------------------------+---------+--------

                                                         Log Kow   =   6.6276

Reference 2

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1997

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

GLP compliance:

no

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

>= 6

Temp.:

21 °C

pH:

ca. 7

Remarks on result:

other: pH not determined, but estimated

Conclusions:

The log Pow of the test item was determined to be >/= 6

Executive summary:

In this study the octanol-water partition coefficient of Reaction mass of isotridecyl 3-mercaptopropionate and isododecyl 3-mercaptopropionate was determined with the HPLC method according to EU Method A.8 and OECD Guideline 117. o, p-DDT was used as reference substance (log Pow >/= 6.2). The log Pow of the test item was determined to be >/= 6.

Description of key information

The octanol-water partition coefficient of the test substance Reaction mass of iso-tridecyl 3-mercaptopropionate and iso-dodecyl 3-mercaptopropionate was determined with the HPLC method according to EU Method A.8 and OECD Guideline 117. In this study o, p-DDT was used as reference substance.

Key value for chemical safety assessment

Log Kow (Log Pow):

6.63

at the temperature of:

20 °C

Additional information

The log Pow of the test substance Reaction mass of iso-tridecyl 3-mercaptopropionate and iso-dodecyl 3-mercaptopropionate was determined in one experimental study to be >/= 6.