Fatty acids, C16-18 (even numbered), reaction products with tetraethylenepentamine, acetates (salts)

Dissociation constant

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

dissociation constant

Type of information:

(Q)SAR

Adequacy of study:

key study

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 limited documentation / justification

Justification for type of information:

1. SOFTWARE
ACD PhysChem software ACD/Labs Release 12.00, Product version 12.01 (Build 38056 09 Feb 2010)

2. MODEL (incl. version number)
ACD/ pKa

3. SMILES OR OTHER IDENTIFIERS USED AS INPUT FOR THE MODEL
N-(2-{[2-({2-[(2-aminoethyl)amino]ethyl}amino)ethyl]amino}ethyl)hexadecanamide and N-(2-
{[2-({2-[(2-aminoethyl)amino]ethyl}amino)ethyl]amino}ethyl)octadecanamide

4. SCIENTIFIC VALIDITY OF THE (Q)SAR MODEL
no data available

5. APPLICABILITY DOMAIN
no data available

6. ADEQUACY OF THE RESULT
no data available

Qualifier:

no guideline followed

Principles of method if other than guideline:

calculation with ACD PhysChem software ACD/Labs Release 12.00, Product version 12.01 (Build 38056 09 Feb 2010); ACD/Labs software is listed in the “Guidance on information requirements and chemical saftey assessment, Chapter R.7a: Endpoint specific guidance; May 2008”

GLP compliance:

no

Dissociating properties:

yes

Remarks on result:

other: Due to the complex composition of the substance the dissociation constant can only be estimated for distinct structures. The pKa of the most acidic position was calculated to be 16.08 ± 0.46, for the basic positions from -0.78 ± 0.7 to 9.77 ± 0.19.

Constituent	ACD/ pKa at 25°C (approximated apparent)	Acidic/basic position*
N-(2-{[2-({2-[(2-aminoethyl)amino] ethyl}amino)ethyl]amino}ethyl)hexadecanamide	16.08 ± 0.46 9.77 ± 0.19 9.35 ± 0.19 6.38 ± 0.12 3.41 ± 0.5 -0.78 ± 0.7	3 MA 27 MB 24 B 27 B 24 B 3 B
N-(2-{[2-({2-[(2-aminoethyl)amino] ethyl}amino)ethyl]amino}ethyl)octadecanamide	16.08 ± 0.46 9.77 ± 0.19 9.35 ± 0.19 6.38 ± 0.12 3.41 ± 0.5 -0.78 ± 0.7	3 MA 12 MB 9 B 12 B 9 B 3 B

*Acidic/basic form of a compound: A—acidic, B—basic, MA—most acidic, MB—most basic (note that if a table contains the only A(B) form, this form is the most acidic (most basic))

positions are given in the attached image file

Conclusions:

The pKa of the most acidic position was calculated to be 16.08 ± 0.46. The pKa of the basic positions ranges from -0.78 ± 0.7 to 9.77 ± 0.19.

Executive summary:

Due to the complex composition of C16-18FA-TEPA-compound(UVCB substance) the dissociation constant (pKa) can only be estimated for distinct structures. An estimation of the mixture cannot be given.The dissociation constant of representative structures was estimated by calculation usingACD PhysChem software ACD/Labs Release 12.00, Product version 12.01.

By way of example the amidoamines (1) and (2), see attached image file, were chosen for the determination of the dissociation constant. These compounds are expected to be the major reaction products. The acetates, formed at the neutralisation step are not taken into account as it does not make sense to determine the dissociation constant of salts.

The pKa of the most acidic position was calculated to be 16.08 ± 0.46 for both structures. The pKa of the basic positions ranges from -0.78 ± 0.7 to 9.77 ± 0.19.

Reference 2

Endpoint:

dissociation constant

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Qualifier:

no guideline available

Principles of method if other than guideline:

no details on method available, data published in peer-reviewed database

GLP compliance:

no

Dissociating properties:

yes

No.:

#1

pKa:

4.76

Temp.:

25 °C

Conclusions:

The pKa of Acetic acid is reported to be 4.76 at 25°C.

Executive summary:

Due to the complex composition of C16-18FA-TEPA-compound (UVCB substance) the dissociation constant (pKa) can only be given for distinct structures, not for the complete mixture. Acetic acid is one of the constituents of C16-18FA-TEPA-compound. The pKa of Acetic acid is reported to be 4.76 at 25°C.

Description of key information

Due to the complex composition of C16-18FA-TEPA-compound (UVCB substance) the dissociation constant (pKa) can only be given for distinct structures.
The pKa of the most acidic position was calculated to be 16.08 ± 0.46 for both structures. The pKa of the basic positions ranges from -0.78 ± 0.7 to 9.77 ± 0.19.
Acetic acid is one of the constituents of C16-18FA-TEPA-compound. The pKa of Acetic acid is reported to be 4.76 at 25°C (date from SRC PhysProp database).

Additional information

Due to the complex composition of C16-18FA-TEPA-compound (UVCB substance) the dissociation constant (pKa) can only be given for distinct structures.

An estimation of the mixture cannot be given. The dissociation constant of representative structures was estimated by calculation using ACD PhysChem software ACD/Labs Release 12.00, Product version 12.01.

By way of example the amidoamines (1) and (2), see attached image file, were chosen for the determination of the dissociation constant. These compounds are expected to be the major reaction products. The acetates, formed at the neutralisation step are not taken into account as it does not make sense to determine the dissociation constant of salts.

The pKa of the most acidic position was calculated to be 16.08 ± 0.46 for both structures. The pKa of the basic positions ranges from -0.78 ± 0.7 to 9.77 ± 0.19.

Acetic acid is one of the constituents of C16-18FA-TEPA-compound. The pKa of Acetic acid is reported to be 4.76 at 25°C (date from SRC PhysProp database).