Essential oil of Cistus ladaniferus L (Cistaceae) obtained from stems and leaves by distillation

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

November 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® HA-QSAR toolbox v2.3

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

3. 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 model

Key result

Water solubility:

1.1 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 1

Key result

Water solubility:

1.71 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 2

Key result

Water solubility:

0.003 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 3

Key result

Water solubility:

760 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 4

Key result

Water solubility:

1 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 5

Key result

Water solubility:

0.352 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 6

Key result

Water solubility:

0.758 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 7

Key result

Water solubility:

82.5 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 8

Key result

Water solubility:

1.08 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 9

Key result

Water solubility:

0.285 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 10

Key result

Water solubility:

0.001 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 11

Key result

Water solubility:

0.17 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 12

Key result

Water solubility:

0.001 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 13

Key result

Water solubility:

23.5 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 14

Key result

Water solubility:

0.001 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 15

Key result

Water solubility:

0.157 mg/L

Temp.:

25 °C

Remarks on result:

other: Consituent 16

Key result

Water solubility:

36.3 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 17

Key result

Water solubility:

65.2 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 18

Key result

Water solubility:

0.079

Temp.:

25 °C

Remarks on result:

other: Constituent 19

Key result

Water solubility:

2 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 20

Key result

Water solubility:

0 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 21

Key result

Water solubility:

0 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 22

Key result

Water solubility:

0.077 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 23

Key result

Water solubility:

0.078 mg/L

Temp.:

25 °C

Remarks on result:

other: Constituent 24

Conclusions:

The water solubility of 24 constituents of the test item is predicted as follows:
Constituent 1   : 1.10 mg/L at 25°C
Constituent 2   : 1.71 mg/L at 25°C
Constituent 3   : 0.00263 mg/L at 25°C
Constituent 4   : 760 mg/L at 25°C
Constituent 5   : 1.00 mg/L at 25°C
Constituent 6   : 0.352 mg/L at 25°C
Constituent 7   : 0.758 mg/L at 25°C
Constituent 8   : 82.5 mg/L at 25°C
Constituent 9   : 1.08 mg/L at 25°C
Constituent 10 : 0.285 mg/L at 25°C
Constituent 11 : 0.00131 mg/L at 25°C
Constituent 12 : 0.170 mg/L at 25°C
Constituent 13 : 0.000530 mg/L at 25°C
Constituent 14 : 23.5 mg/L at 25°C
Constituent 15 : 0.00149 mg/L at 25°C
Constituent 16 : 0.157 mg/L at 25°C
Constituent 17 : 36.3 mg/L at 25°C
Constituent 18 : 65.2 mg/L at 25°C
Constituent 19 : 0.0789 mg/L at 25°C
Constituent 20 : 2.00 mg/L at 25°C
Constituent 21 : 0.000204 mg/L at 25°C
Constituent 22 : 0.0000638 mg/L at 25°C
Constituent 23 : 0.0775 mg/L at 25°C
Constituent 24 : 0.0781 mg/L 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.

Finally the water solubility of 24 components (covering more than 71% of the composition of the substance) has been determined to be between 0.0000638 and 760 mg/L each at 25°C.

Description of key information

24 major components of the substance (more than 71% of the composition) ranging between 0.0000638 and 760 mg/L each at 25°C.

(estimated by QSAR).

Additional information

No study was conducted on the oil itself.

The test item is a natural complex substance (NCS). It is a mixture of several constituents, but 24 of them represent more than 71% of that mixture.

Water solubility of the 24 constituents of the test item were estimated using a valid QSAR model taking into account the interactions between the constituents of the mixture.

Finally, apparent water solubility of each of these 24 major constituents were reported below:

Constituent 1   : 1.10 mg/L at 25°C

Constituent 2   : 1.71 mg/L at 25°C

Constituent 3   : 0.00263 mg/L at 25°C

Constituent 4   : 760 mg/L at 25°C

Constituent 5   : 1.00 mg/L at 25°C

Constituent 6   : 0.352 mg/L at 25°C

Constituent 7   : 0.758 mg/L at 25°C

Constituent 8   : 82.5 mg/L at 25°C

Constituent 9   : 1.08 mg/L at 25°C

Constituent 10 : 0.285 mg/L at 25°C

Constituent 11 : 0.00131 mg/L at 25°C

Constituent 12 : 0.170 mg/L at 25°C

Constituent 13 : 0.000530 mg/L at 25°C

Constituent 14 : 23.5 mg/L at 25°C

Constituent 15 : 0.00149 mg/L at 25°C

Constituent 16 : 0.157 mg/L at 25°C

Constituent 17 : 36.3 mg/L at 25°C

Constituent 18 : 65.2 mg/L at 25°C

Constituent 19 : 0.0789 mg/L at 25°C

Constituent 20 : 2.00 mg/L at 25°C

Constituent 21 : 0.000204 mg/L at 25°C

Constituent 22 : 0.0000638 mg/L at 25°C

Constituent 23 : 0.0775 mg/L at 25°C

Constituent 24 : 0.0781 mg/L at 25°C

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 24 major components of the substance ranging between 0.0000638 and 760 mg/L each at 25°C and no single key value was retained (nor calculated weighted WS nor worst-case)