2,4,6-trimethylpyridine

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

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:

1. SOFTWARE: WATERNT v1.01; integrated within the Estimation Programme Interface (EPI) Suite programme for Microsoft Windows v4.11; September 2010 (model development); November 2012 (model publication)
2. MODEL (incl. version number): WATERNT v1.01
3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL: CAS RN
4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL: There is no overt mechanistic basis for the model.
The model correlates thermodynamic relationships of surrogates to chemical activity. The WATERNT run in standalone mode allows water solubility to be estimated based on measured values of analogues with in the training set (if available). Then the model applies by adding/subtracting fragment constants and correction factors from the measured value. This therefore improves prediction since calculations are based on structural differences between target and analogue. The model domain ideally has at least one or more structurally similar substances to target substances on which to then apply ACF methodology.

Whilst there appears to be no direct analogues within the training set. The model has been has been validated externally (using > 4000) substances with a correlation coefficient (r2) = 0.815. The model is nonproprietary and the training sets and validation sets can be downloaded from the internet. A summary of this information is presented by the applicant. Model predictivity could be improved by the assignment of additional substances into the training set. Inclusion of additional structural fragments and expansion of sub-structure correction factors and related rules. In addition, rules for stereochemical effects could feasibly improve modelling.

5. APPLICABILITY DOMAIN:
(i) All constituents fall within the Molecular Weight and Water Solubility (mol/L) training set domain ranges.
(ii) No substances have functional groups or features not in the training set of the model and/or for which no fragment constants and correction factors available. No constituents contain multiple fragment instances than the maximum of the training set.

6. ADEQUACY OF THE RESULT:
1) QSAR model is scientifically valid.
2) The substance falls within the applicability domain of the QSAR model.
3) The prediction is fit for regulatory purpose.

The prediction is adequate as supporting information for the Classification and Labelling or risk assessment of the substance as indicated in REACH Regulation (EC) 1907/2006: Annex XI Section 1.3.

Data source

Reference

Reference Type:

other: QSAR predicted value

Title:

WATERNT v 1.01 (Epi Suite) - Water Solubility

Year:

2012

Bibliographic source:

Meylan, W.M. 1995. Preliminary Report: Water Solubility Estimation by Base Compound Modification. prepared for: Gary Thom & Robert S. Boethling, US EPA, OPPT, Washington, DC, USEPA Contract 68-D2-0141 (Task 3-14), Sep, 1995.

Materials and methods

Principles of method if other than guideline:

WATERNT uses a "fragment constant" methodology to predict water solubility. 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 solubility estimate. We call WATERNT’s methodology the Atom/Fragment Contribution (AFC) method. Coefficients for individual fragments and groups in WATERNT were derived by multiple regression of 1000 reliably measured water solubility values.

GLP compliance:

no

Type of method:

other: QSAR predicted value

Test material

Test material information

Constituent 1

Reference substance name:

2,4,6-trimethylpyridine

EC Number:

203-613-3

EC Name:

2,4,6-trimethylpyridine

Cas Number:

108-75-8

Molecular formula:

C8H11N

IUPAC Name:

2,4,6-trimethylpyridine

Specific details on test material used for the study:

No specific details on test material used for the study was provided. QSAR predicted value.

Results and discussion

Water solubility

Key result

Water solubility:

ca. 10 065 mg/L

Conc. based on:

act. ingr.

Temp.:

25 °C

Remarks on result:

other: QSAR predicted value

Applicant's summary and conclusion

Conclusions:

WATERNT v 1.01 (Epi Suite) predicted that 2,4,6-collidine has a water solubility of 10065 mg/L at 25°C.

Executive summary:

WATERNT v 1.01 (Epi Suite) predicted that 2,4,6-collidine has a water solubility of 10065 mg/L at 25°C. The training dataset of WATERNT also includes the experimental water solubility data of 2,4,6–collidine which is 35000 mg/L at 20°C. Further, this is a valid model for this substance which falls into its applicability domain as explained in the attached reports.