Registration Dossier

Administrative data

Endpoint:
partition coefficient
Type of information:
(Q)SAR
Adequacy of study:
key study
Study period:
September 15, 2014
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Structurally, laurylimidazole contains chemical functional groups which are utilized by the software to calculate the log D. The training set used by this software is proprietary and was not accessible. The validation data set contains 3601 unique chemicals of which 29 are imidazole derivatives and 49 are aliphatic hydrocarbons, therefore this substance is considered to be within the model applicability domain.
Justification for type of information:
QSAR prediction: migrated from IUCLID 5.6

Data source

Reference
Reference Type:
other company data
Title:
Unnamed
Year:
2014
Report date:
2014

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: REACH guidance on QSARs, R.6, May/July 2008
Deviations:
no
Principles of method if other than guideline:
ACD/Log D DB as implemented through ACD/Labs
GLP compliance:
no
Type of method:
other: QSAR
Partition coefficient type:
octanol-water

Test material

Constituent 1
Chemical structure
Reference substance name:
1-dodecyl-1H-imidazole
EC Number:
224-314-4
EC Name:
1-dodecyl-1H-imidazole
Cas Number:
4303-67-7
Molecular formula:
C15H28N2
IUPAC Name:
1-dodecyl-1H-imidazole
Details on test material:
CAS No. 4303-67-7
SMILES: CCCCCCCCCCCCn1ccnc1

Results and discussion

Partition coefficientopen allclose all
Type:
log Pow
Partition coefficient:
3.56
pH:
5
Remarks on result:
other: QSAR. Error is ± 0.23 log units
Type:
log Pow
Partition coefficient:
5.17
pH:
7
Remarks on result:
other: QSAR. Error is ± 0.23 log units
Type:
log Pow
Partition coefficient:
5.5
pH:
9
Remarks on result:
other: QSAR. Error is ± 0.23 log unit

Any other information on results incl. tables

No temperature available for this model

 

Validity of Model (OECD 5 principles):

1) Defined endpoint: Partition coefficient

2) Unambiguous algorithm:

log D =log (∑[microspeciation concentration in octanol] / ∑[microspeciation concentration in water])

 

3) Applicability domain: the software's training set contains 29 imidazole derivatives and 49 aliphatic hydrocarbons which are structurally related to the test substance, and the test substance is therefore within the applicability domain of this QSAR model. 

 

4) Model performance: The model basis set was divided into training (11387 compounds) and validation sets (4890 compounds). For validation, the developers defined a relatedness index to determine applicability of the model to members of the set, where all substances have RI >0.3 were defined as within the applicability domain. Model performance for the in-domain members of the validation set (4872 of 4890 compounds) was as follows:

R² = 0.940

Std. Dev. = 0.464

RMSE = 0.464

F = 165247.5 (Fisher's F-statistics)

 

5) Mechanistic interpretation: The primary mechanism of partitioning is an inherent property of the chemical and directly related to the elemental composition, function groups, and structural configuration thereof.

 

Please see attached QMRF and QPRF for justification of model and applicability.

Applicant's summary and conclusion

Conclusions:
By this QSAR, the predicted range of log D (partition coefficient) for laurylimidazole is 3.56 ± 0.23 (at pH 5), 5.17 ± 0.23 (at pH 7), and 5.50 ± 0.23 (at pH 9).
Executive summary:

The partition coefficient (log D) of laurylimidazole was determined using the ACD/log D QSAR as implemented through ACD/Labs.

 

The validity of this QSAR to predict the partition coefficient (log D) for these types of substance was determined to be reliable since the training and validation data set contain chemicals with similar functional groups, and include 3601 chemicals of which 29 are imidazole derivatives and 49 are aliphatic hydrocarbons. This study is classified as an acceptable QSAR and satisfies the requirements for partition coefficient study. It is pertinent to the fate of laurylimidazole and may be used for risk analysis, classification and labelling, and PBT analysis.

 

The estimated log D varies with pH from 3.56 ± 0.23 (at pH 5) to 5.50 ± 0.23 (at pH 9) and indicates that laurylimidazole is not anticipated to bioconcentrate by partitioning to the lipid rich tissues of aquatic organisms. At a pH of 6.1, the log D value is 4.5 ± 0.23 and therefore the test substance is likely to bioaccumulate by partitioning into lipid rich tissue above pH 6.1.