Betaines, coco alkyldimethyl(3-sulfopropyl)

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

(Q)SAR

Adequacy of study:

key study

Study period:

2018-02-23

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
EPIWIN software by US-EPA

2. MODEL (incl. version number)
KOWWIN v1.68

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
The substance is a organic UVCB, the CAS number 68201-55-8 (EC 269-225-1) is associated with the inventory name Betaines, coco alkyldimethyl(3-sulfopropyl), CAS name Sulfobetaines, coco alkyldimethyl(3-sulfopropyl) and IUPAC name 3-[C8-18 (linear, even-numbered)-alkyl(dimethyl)ammonio]propane-1-sulfonate, and has the molecular formula C7H17NO3S·[CH2]8-16. As indicated by the name, there are several aliphatic moieties with varying chain lengths attached to the nitrogen of the inner salt, resulting in a variable composition. Below there are the possible individual components ordered by the carbon number of the side chain with approximate contents listed:

C8: 0-12%, [O-]S(=O)(=O)CCC[N+](C)(C)CCCCCCCC
C10: 0-10%, [O-]S(=O)(=O)CCC[N+](C)(C)CCCCCCCCCC
C12: 45-57%, CCCCCCCCCCCC[N+](C)(C)CCCS(=O)(=O)[O-]
C14: 14-28%, CCCCCCCCCCCCCC[N+](C)(C)CCCS(=O)(=O)[O-]
C16: 5-13%, CCCCCCCCCCCCCCCC[N+](C)(C)CCCS(=O)(=O)[O-]
C18: 4-12%, [O-]S(=O)(=O)CCC[N+](C)(C)CCCCCCCCCCCCCCCCCC

QSAR estimations are performed for all contained structure, but as the C12 variation is with approx. 50% the main constituent, special emphasis will be laid on the value derived for this structure, and the values for the C8 and C18 constituents will be regarded especially, too, as the cover both possible extremes and give hence and indication of the range of the estimated values.

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
- The model and the training and validation sets are published by US Environmental Protection Agency (USA).
The experimental Log Kow values in the training set and validation set were measured using one or more methods equivalent or similar to the following guidelines:
- Shake Flask method (OECD TG 107)
- HPLC method (OECD TG 117)
- Slow Stirring method (OECD TG 123)
Plus relevant EU (1992 as amended) and US EPA OPPTS (1982 as amended) and ASTM (1993) methods may be also used where appropriate.
A full list of experimental Log Kow reference citations is provided in the KOWWIN help menu with additional reference citations.

5. APPLICABILITY DOMAIN
The intended application domain is organic chemicals. Inorganic and organometallic chemicals generally are outside the domain.
The minimum and maximum values for molecular weight are the following:
Training Set Molecular Weights:
Minimum MW: 18.02
Maximum MW: 719.92
Average MW: 199.98

Validation Molecular Weights:
Minimum MW: 27.03
Maximum MW: 991.15
Average MW: 258.98

Currently there is no universally accepted definition of model domain. However, users may wish to consider the possibility that log P estimates are less accurate for compounds outside the MW range of the training set compounds, and/or that have more instances of a given fragment than the maximum for all training set compounds. It is also possible that a compound may have a functional group(s) or other structural features not represented in the training set, and for which no fragment coefficient was developed. These points should be taken into consideration when interpreting model results.

6. ADEQUACY OF THE RESULT
The organic substance Betaines, coco alkyldimethyl(3-sulfopropyl) lies within the applicability domain with a molecular weight of ranging from 279.4393 (C8) to 419.7051 (C18). The result seems reasonable taking into account the structure of the substance. Due to the magnitude of the results and the suitable training set the result is considered as adequate.

Cross-reference

Reason / purpose for cross-reference:

data waiving: supporting information

Remarks:

Waiver for study

Reference

Endpoint:

partition coefficient

Data waiving:

study scientifically not necessary / other information available

Justification for data waiving:

the study does not need to be conducted because the substance has a high surface activity

Justification for type of information:

JUSTIFICATION FOR DATA WAIVING
The substance is surface active, making the study conduction difficult and the results not absolutely reliable. The surface tension of an aqueous solution of Sulfobetaines, coco alkyldimethyl(3-sulfopropyl) was determined as 35.45 ± 0.07 mN/m at 20.4 °C. As these values were lower than 60 mN/m, Sulfobetaines, coco alkyldimethyl(3-sulfopropyl) was classified as surface active. The surface tension of the negative control lay within the accepted range. According to REACH Annex VII, if the test cannot be performed (e.g. …, has a high surface activity, …), a calculated value for log P as well as details of the calculation method shall be provided.

Reason / purpose for cross-reference:

data waiving: supporting information

Remarks:

Surface tension

Reason / purpose for cross-reference:

reference to other study

Remarks:

QSAR estimation

Data source

Reference

Reference Type:

other: software

Title:

EPI Suite Version 4.10

Year:

2018

Bibliographic source:

KOWWIN - Meylan and Howard (1995)

Materials and methods

Test guideline

Guideline:

other: REACH guidance on QSARs Chapter R.6

Version / remarks:

May 2008

Principles of method if other than guideline:

Meylan, W.M. and P.H. Howard. 1995. Atom/fragment contribution method for estimating octanol-water partition coefficients. J. Pharm. Sci. 84: 83-92

GLP compliance:

no

Type of method:

calculation method (fragments)

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Betaines, coco alkyldimethyl(3-sulfopropyl)

EC Number:

269-225-1

EC Name:

Betaines, coco alkyldimethyl(3-sulfopropyl)

Cas Number:

68201-55-8

Molecular formula:

C7H17NO3S·[CH2]6-16

IUPAC Name:

[3-(dodecyldimethylazaniumyl)propyl]trioxo-λ⁶-sulfanuide

Test material form:

other: not applicable for QSAR estimations

Details on test material:

Below there are the possible individual components ordered by the carbon number of the side chain with approximate contents listed:

C8: 0-12%, [O-]S(=O)(=O)CCC[N+](C)(C)CCCCCCCC
C10: 0-10%, [O-]S(=O)(=O)CCC[N+](C)(C)CCCCCCCCCC
C12: 45-57%, CCCCCCCCCCCC[N+](C)(C)CCCS(=O)(=O)[O-]
C14: 14-28%, CCCCCCCCCCCCCC[N+](C)(C)CCCS(=O)(=O)[O-]
C16: 5-13%, CCCCCCCCCCCCCCCC[N+](C)(C)CCCS(=O)(=O)[O-]
C18: 4-12%, [O-]S(=O)(=O)CCC[N+](C)(C)CCCCCCCCCCCCCCCCCC

Specific details on test material used for the study:

Smiles codes:
C8: 0-12%, [O-]S(=O)(=O)CCC[N+](C)(C)CCCCCCCC
C10: 0-10%, [O-]S(=O)(=O)CCC[N+](C)(C)CCCCCCCCCC
C12: 45-57%, CCCCCCCCCCCC[N+](C)(C)CCCS(=O)(=O)[O-]
C14: 14-28%, CCCCCCCCCCCCCC[N+](C)(C)CCCS(=O)(=O)[O-]
C16: 5-13%, CCCCCCCCCCCCCCCC[N+](C)(C)CCCS(=O)(=O)[O-]
C18: 4-12%, [O-]S(=O)(=O)CCC[N+](C)(C)CCCCCCCCCCCCCCCCCC

Results and discussion

Partition coefficient

Partition coefficient 1

Type:

log Pow

Partition coefficient:

0.27

Remarks on result:

other: QSAR predicted value

Remarks:

for 3-[dimethyl(octyl)ammonio]propane-1-sulfonate

Partition coefficient 2

Type:

log Pow

Partition coefficient:

1.26

Remarks on result:

other: QSAR predicted value

Remarks:

for 3-[decyl(dimethyl)ammonio]propane-1-sulfonate

Partition coefficient 3

Key result

Type:

log Pow

Partition coefficient:

2.24

Remarks on result:

other: QSAR predicted value

Remarks:

for the main component 3-[dodecyl(dimethyl)ammonio]propane-1-sulfonate

Partition coefficient 4

Type:

log Pow

Partition coefficient:

3.22

Remarks on result:

other: QSAR predicted value

Remarks:

for 3-[dimethyl(tetradecyl)ammonio]propane-1-sulfonate

Partition coefficient 5

Type:

log Pow

Partition coefficient:

4.2

Remarks on result:

other: QSAR predicted value

Remarks:

for 3-[hexadecyl(dimethyl)ammonio]propane-1-sulfonate

Partition coefficient 6

Type:

log Pow

Partition coefficient:

5.18

Remarks on result:

other: QSAR predicted value

Remarks:

for 3-[dimethyl(octadecyl)ammonio]propane-1-sulfonate

Applicant's summary and conclusion

Conclusions:

The study report describes a scientifically accepted calculation method for the partition coefficient using the US-EPA software KOWWIN v1.68. No GLP criteria are applicable for the usage of this tool and the QSAR estimation is easily repeatable. The result is adequate for the regulatory purpose.

Executive summary:

The partition coefficient of the substance Betaines, coco alkyldimethyl(3-sulfopropyl) was determined by the computer program KOWWIN v1.68 (EPIWIN software) by US-EPA (2012), estimating the logPow of the individual constituents. The program uses the chemical structure of a compound to predict the logarithmic octanol water partition coefficient (logPow). The structure is denoted in its SMILES notation. As first step the software determines the logPow contributions from individual molecular fragments. Afterwards these fragments are summed up to gain the logPow for the whole molecule. In this case the following logPow values were determined:

 

Carbon number	IUPAC name	LogPow
C8	3-[dimethyl(octyl)ammonio]propane-1-sulfonate	0.27
C10	3-[decyl(dimethyl)ammonio]propane-1-sulfonate	1.26
C12	3-[dodecyl(dimethyl)ammonio]propane-1-sulfonate	2.24
C14	3-[dimethyl(tetradecyl)ammonio]propane-1-sulfonate	3.22
C16	3-[hexadecyl(dimethyl)ammonio]propane-1-sulfonate	4.20
C18	3-[dimethyl(octadecyl)ammonio]propane-1-sulfonate	5.18

 

Adequacy of the QSAR:

- QSAR model is scientifically valid.

- The substance falls within the applicability domain of the QSAR model.

- The prediction is fit for regulatory purpose.