L-arabinose

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2018-06-08 to 2018-07-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Deviations:

yes

Remarks:

The stock solution of the test item was prepared in water saturated with n-octanol. This procedure deviates from the guideline, but is considered scientifically valid.

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Deviations:

yes

Remarks:

The stock solution of the test item was prepared in water saturated with n-octanol. This procedure deviates from the guideline, but is considered scientifically valid.

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7550 (Partition Coefficient, n-octanol / H2O, Shake Flask Method)

Deviations:

yes

Remarks:

The stock solution of the test item was prepared in water saturated with n-octanol. This procedure deviates from the guideline, but is considered scientifically valid.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Partition coefficient type:

octanol-water

Analytical method:

liquid chromatography

Key result

Type:

Pow

Partition coefficient:

0.002

Temp.:

20 °C

pH:

6.58

Key result

Type:

log Pow

Partition coefficient:

-2.8

Temp.:

20 °C

pH:

6.58

Details on results:

The partition coefficient Pow of the test item in n-octanol/water two-phase system was determined to be 0.0015 at 20 °C corresponding to a logPow of -2.8.

Table 1. Calculated (extrapolated) partition coefficient (P_ow) and log P_ow

Ratio of solvents (n-Octanol : Water)	Partition coefficient	Log Partition coefficient
	Pow	Log Pow
40:1	0.00183	-2.74
20:1	0.00179*	-2.75*
80:1	0.00121	-2.92
Mean all	0.0015	-2.8
95 % Confidence limit	0.004	1.126

*     The measured L-Arabinose concentration in the n-octanol phaseswas found to be < LOQ.

      Therefore, this value was excluded from the mean and the confidence limit.

 

Conclusions:

The logPow of the test item was determined to be -2.8 at 20 °C.

Executive summary:

A study was conducted in accordance with OECD TG 107, Regulation (EC) No 440/2008 method A.8 and OPPTS 830.7550 to determine the partition coefficient of the test substance using the shake flask method. A stock solution of the test substance was prepared in water pre-saturated with n-octanol. The two phases were measured with established LC-MS/MS method. Three tests were carried out using different phase ratio. In the first 40:1 volume ratio was applied, in the second 20:1 (divided by two) and in the third 80:1 (the ratio is multiplied by two). Three parallel tests were carried out at all solvent ratios, each. The test vessels were shaken by hand through 180° about its transverse axis a hundred times during five minutes. The separation of the two phases was achieved by centrifugation at 20 °C. The partition coefficient of the test item was determined to be 0.0015 at 20 °C corresponding to a log Pow of -2.8.

Reference 2

Endpoint:

partition coefficient

Type of information:

(Q)SAR

Adequacy of study:

supporting study

Study period:

2018

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:

Please refer to the QMRF and QPRF files provided under the section attached justification.

Qualifier:

according to guideline

Guideline:

other: REACH guidance on QSAR R.6

Principles of method if other than guideline:

Estimates the log octanol-water partition coefficient, log KOW, of chemicals using an atom/fragment contribution method.

GLP compliance:

no

Type of method:

calculation method (fragments)

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

SMILES: O=CC(O)C(O)C(O)CO

Key result

Type:

log Pow

Partition coefficient:

-1.98

Temp.:

25 °C

Remarks on result:

other: QSAR predicted value. The substance is within the applicability domain of the model.

KOWWIN Program (v1.68) Results:

===============================

 

Log Kow(version 1.68 estimate): -1.98

 

SMILES : O=CC(O)C(O)C(O)CO

CHEM  : L-Arabinose

MOL FOR: C5 H10 O5

MOL WT : 150.13

TYPE	NUM	LOGKOW FRAGMENT DESCRIPTION	COEFF	VALUE
Frag	1	-CH2-  [aliphatic carbon]	0.4911	0.4911
Frag	3	-CH    [aliphatic carbon]	0.3614	1.0842
Frag	4	-OH    [hydroxy, aliphatic attach]	-1.4086	-5.6344
Frag	1	-CHO   [aldehyde, aliphatic attach]	-0.9422	-0.9422
Factor	1	Multi-alcohol correction	0.4064	0.4064
Factor	2	HO-CH-C(-OH)-CH-OH  structure correction	0.5944	1.1888
Factor	1	HO-C-C(-OH)-C(=O)-  structure correction	1.2000	1.2000
Const		Equation Constant		0.2290

Log Kow  = -1.9771

Conclusions:

Using KOWWIN v1.68 the logPow of the test item was calculated to be -1.98 at 25 °C. The substance is within the applicability domain of the model.

Executive summary:

The logPow was calculated using KOWWIN v1.68 as part of EPISuite v4.11 from US Environmental Protection Agency.

Using KOWWIN v1.68 the log Kow of the test item was calculated to be -1.98 at 25 °C (EPI Suite, 2014).

The adequacy of a prediction depends on the following conditions:

a) the (Q)SAR model is scientifically valid: the scientific validity is established according to the OECD principles for (Q)SAR validation;

b) the (Q)SAR model is applicable to the query chemical: a (Q)SAR is applicable if the query chemical falls within the defined applicability domain of the model;

c) the (Q)SAR result is reliable: a valid (Q)SAR that is applied to a chemical falling within its applicability domain provides a reliable result;

d) the (Q)SAR model is relevant for the regulatory purpose.

 

For assessment and justification of these 4 requirements the QMRF and QPRF files were developed and attached to this study record.

 

Description of the prediction Model

The prediction model was descripted using the harmonised template for summarising and reporting key information on (Q)SAR models. For more details please refer to the attached QSAR Model Reporting Format (QMRF) file. 

 

Assessment of estimation domain

The assessment of the estimation domain was documented in the QSAR Prediction Reporting Format file (QPRF). Please refer to the attached document for the details of the prediction and the assessment of the estimation domain.

Description of key information

The logPow of the test item was determined experimentally to be -2.8 at 20 °C.

Key value for chemical safety assessment

Log Kow (Log Pow):

-2.8

at the temperature of:

20 °C

Additional information

A study was conducted in accordance with OECD TG 107, Regulation (EC) No 440/2008 method A.8 and OPPTS 830.7550 to determine the partition coefficient of the test substance using the shake flask method. A stock solution of the test substance was prepared in water pre-saturated with n-octanol. The two phases were measured with established LC-MS/MS method. Three tests were carried out using different phase ratio. In the first 40:1 volume ratio was applied, in the second 20:1 (divided by two) and in the third 80:1 (the ratio is multiplied by two). Three parallel tests were carried out at all solvent ratios, each. The test vessels were shaken by hand through 180° about its transverse axis a hundred times during five minutes. The separation of the two phases was achieved by centrifugation at 20 °C. The partition coefficient of the test item was determined to be 0.0015 at 20 °C corresponding to a log Pow of -2.8.

Additionally, the logPow was calculated using KOWWIN v1.68 as part of EPISuite v4.11 from US Environmental Protection Agency.

Using KOWWIN v1.68 the log Kow of the test item was calculated to be -1.98 at 25 °C (EPI Suite, 2014).

The adequacy of a prediction depends on the following conditions:

a) the (Q)SAR model is scientifically valid: the scientific validity is established according to the OECD principles for (Q)SAR validation;

b) the (Q)SAR model is applicable to the query chemical: a (Q)SAR is applicable if the query chemical falls within the defined applicability domain of the model;

c) the (Q)SAR result is reliable: a valid (Q)SAR that is applied to a chemical falling within its applicability domain provides a reliable result;

d) the (Q)SAR model is relevant for the regulatory purpose.

 

For assessment and justification of these 4 requirements the QMRF and QPRF files were developed and attached to this study record.

 

Description of the prediction Model

The prediction model was descripted using the harmonised template for summarising and reporting key information on (Q)SAR models. For more details please refer to the attached QSAR Model Reporting Format (QMRF) file. 

 

Assessment of estimation domain

The assessment of the estimation domain was documented in the QSAR Prediction Reporting Format file (QPRF). Please refer to the attached document for the details of the prediction and the assessment of the estimation domain.