D-Xylopyranose, oligomeric, 2-octyldodecyl xylosides

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

04/14/2020

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
EPI Suite v4.11

2. MODEL (incl. version number)
KOWWIN v1.69

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
O1CC(O)C(O)C(O)C1OCC(CCCCCCCC)CCCCCCCCCC

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See the QMRF and QPRF attached documents in the section "attached justification"
- Defined endpoint: Physicochemical properties: Log Octanol-Water partition coefficient (log KOW) (unitless)
- Unambiguous algorithm: See the QMRF and QPRF attached documents in the section "attached justification"
- Defined domain of applicability: See the QMRF and QPRF attached documents in the section "attached justification"
The applicability domain is based on the maximum number of instances of that a fragment can
be used in a chemical (based on the training and validation set) and on molecular weight.
The program gives an automatic warning when the applicability domain is exceeded.
- Appropriate measures of goodness-of-fit and robustness and predictivity:
Due to the nature of the modelisation method (fragmental approach) to the best of our knowledge
there is no method to quantify the uncertainty of the prediction. No uncertainty measure is
provided by the model.
- Mechanistic interpretation:
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
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. KOWWIN "reductionist" fragment constant methodology (i.e. derivation via multiple regression) differs from the "constructionist" fragment constant methodology of Hansch and Leo (1979) that is available in the CLOGP Program (Daylight, 1995). See the Meylan and Howard (1995) journal article for a more complete description of KOWWIN’s methodology.

5. APPLICABILITY DOMAIN
See the QMRF and QPRF attached documents in the section "attached justification"

6. ADEQUACY OF THE RESULT
The test item falls within the applicability domain of the model and was therefore reliably predicted for its log KOW.

Qualifier:

according to guideline

Guideline:

other: OECD (2004b). Principles for the validation, for regulatory purposes, of (Quantitative) Structure Activity-Relationship Models.

Deviations:

not applicable

GLP compliance:

no

Type of method:

calculation method (fragments)

Partition coefficient type:

octanol-water

Key result

Type:

log Pow

Partition coefficient:

ca. 7.69

Temp.:

25 °C

pH:

ca. 7

Conclusions:

The test item falls within the applicability domain of the model and was therefore reliably predicted for its log KOW.
Therefore, this endpoint value can be considered valid and fit for purpose.
The OCTANOL/WATER PARTITION COEFFICIENT (LOG KOW) of the test item was determined as 7.69.

Description of key information

The log KOW has been predicted using the model KOWWIN (v1.69) from EPI Suite software (v4.11) which provides a quantitative prediction of OCTANOL/WATER PARTITION COEFFICIENT (LOG KOW) for the test item.

The log KOW is calculated as: 7.69.

Key value for chemical safety assessment

Log Kow (Log Pow):

7.69

at the temperature of:

25 °C