Essential oil camphor-rich of Artemisia herba-alba (Asteraceae) obtained from herb by steam distillation

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Study period:

From 28th to 29th June 2017

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:

iSafeRat® High-Accuracy-Quantitative Structure-Activity Relationship (HA-QSAR) based on a holistic approach for predicting physicochemical and ecotoxicological endpoints: Water solubility

1. SOFTWARE
iSafeRat® toolbox – in Silico Algorithms For Environmental Risk And Toxicity version 2.3

2. MODEL (incl. version number)
iSafeRat® holistic HA-QSAR v1.7

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
LogKOW of the constituents predicted using the iSafeRat® Log KOW module with the molecular structure (SMILES code) as the input (see attached QPRF).

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
See attached QMRF

5. APPLICABILITY DOMAIN
See attached QPRF

6. ADEQUACY OF THE RESULT
See attached QPRF

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

QSAR model

Principles of method if other than guideline:

The water solubility was determined using a calculation method for the substances generally classified as MOA 1 substances (non-polar narcotics) and ethers, esters, ketones, aldehydes, alcohols, acids and phenols. This algorithm is based on Quantitative Structure-Property Relationship (QSPR) models which have been validated as QSAR models to be compliant with the OECD recommandations for QSAR modeling (OECD, 2004). The determination was performed using regression method in which validated log KOW values are plotted against the log of sub-cooled liquid water solubility from studies of high quality. These have been carried out using one of the methods recommended in the OECD 105 guideline or an adaptation of these. Further to this the water solubility of the WAF is determined by using a series of calculation steps using phase equilibrium thermodynamics.

GLP compliance:

no

Type of method:

other: QSAR

Key result

Water solubility:

340 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 1

Key result

Water solubility:

198 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 2

Key result

Water solubility:

0.951 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 3

Key result

Water solubility:

322 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 4

Key result

Water solubility:

38.4 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 5

Key result

Water solubility:

1.34 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 6

Key result

Water solubility:

78.8 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 7

Key result

Water solubility:

0.315 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 8

Key result

Water solubility:

58.6 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 9

Key result

Water solubility:

38.3 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 10

Conclusions:

Ten major components (more than 70% of the composition) ranging between 0.315 and 340 mg test item/L each at 25°C.

Executive summary:

A calculation method prediction was performed to assess the water solubility of the test item. This calculation method predicts the endpoint value which would be expected when testing the substance under experimental conditions in a laboratory following Guideline for Testing of Chemicals No. 105, "Water Solubility" adapted for testing as a mixture using the WAF method. The criterion predicted was the solubility in pure water in mg.L-1 at 25°C.

The water solubility determination of the individual constituents of the mixture was performed using regression method in which validated log Kow values are plotted against the log of sub-cooled liquid water solubility from studies of high quality. These have been carried out using one of the methods recommended in the OECD 105 guideline or an adaptation of these. Further to this the water solubility of the WAF is determined by using a series of calculation steps using phase equilibrium thermodynamics.

The water solubility is predicted as follows (mg/L at 25°C):

Constituent 1	340
Constituent 2	198
Constituent 3	0.951
Constituent 4	322
Constituent 5	38.4
Constituent 6	1.34
Constituent 7	78.8
Constituent 8	0.315
Constituent 9	58.6
Constituent 10	38.3

Description of key information

Ten major components (more than 70% of the composition) ranging between  0.315 and 340 mg test item/L each at 25°C (QSAR estimation).

Additional information

A calculation method prediction was performed to assess the water solubility of the test item. This calculation method predicts the endpoint value which would be expected when testing the substance under experimental conditions in a laboratory following Guideline for Testing of Chemicals No. 105, "Water Solubility" adapted for testing as a mixture using the WAF method. The criterion predicted was the solubility in pure water in mg.L-1 at 25°C.

The water solubility determination of the individual constituents of the mixture was performed using regression method in which validated log Kow values are plotted against the log of sub-cooled liquid water solubility from studies of high quality. These have been carried out using one of the methods recommended in the OECD 105 guideline or an adaptation of these. Further to this the water solubility of the WAF is determined by using a series of calculation steps using phase equilibrium thermodynamics.

The water solubility is predicted as follows (mg/L at 25°C):

Constituent 1	340
Constituent 2	198
Constituent 3	0.951
Constituent 4	322
Constituent 5	38.4
Constituent 6	1.34
Constituent 7	78.8
Constituent 8	0.315
Constituent 9	58.6
Constituent 10	38.3

Considering that as a UVCB with constituents of different solubility, the global solubility of the substance will depend on the composition and the loading rate (with varying ratio of constituents in the dissolved phase), we reported the water solubility of the 10 major components of the substance ranging between 0.315 and 340 mg/L each at 25°C and no single key value was retained (nor calculated weighted WS nor worst-case).