Adenosine phosphate

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28 - 30 March 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Version / remarks:

1995

Deviations:

yes

Remarks:

Test not performed with non-charged species, as the amount of non-charged species in the environmentally relevant pH range is negligible. Test was conducted at ca. pH 6.25, were the once and twice negatively charged species are present in equal parts.

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - Shake Flask Method)

Version / remarks:

Regulation (EC) No 440/2008

Deviations:

yes

Remarks:

Test not performed with non-charged species, as the amount of non-charged species in the environmentally relevant pH range is negligible. Test was conducted at ca. pH 6.25, were the once and twice negatively charged species are present in equal parts.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Adenosine phosphate

EC Number:

200-500-0

EC Name:

Adenosine phosphate

Cas Number:

61-19-8

Molecular formula:

C10H14N5O7P

IUPAC Name:

adenosine phosphate

impurity 1

Reference substance name:

Water

EC Number:

231-791-2

EC Name:

Water

Cas Number:

7732-18-5

Molecular formula:

H2O

IUPAC Name:

Oxidane

Test material form:

solid: crystalline

Remarks:

crystalline powder

Details on test material:

Batch No: 11679700
Storage: at room temperature, protected from light

Study design

Analytical method:

high-performance liquid chromatography

Results and discussion

Partition coefficient

Key result

Type:

log Pow

Partition coefficient:

< -1.94

Temp.:

22 °C

pH:

6.26

Remarks on result:

other: The determined log POW values ranged from <-1.95 to <-1.93 for all three volume ratios and all replicates. Std. deviation from six determinations: ±0.004.

Details on results:

Calculation method
The log Pow of the test item was calculated to be -1.68 using EPI Suite™ v4.11, KOWWIN v1.68. However, KOWWIN only calculates the log Pow of the uncharged molecule, but the test item is ionisable. The determination of the log Pow of the test item should be performed in its non-ionised form. However, in the environmentally relevant pH range of pH 5 to 9, the amount of non-charged species is negligible. Instead, the once- and twice negatively charged species dominate. Therefore, an even lower log Pow than -1.68 is expected.

Flask method
The determined log Pow values ranged from <-1.93 to <-1.95 for all three volume ratios and all replicates. For each replicate, the mass balance calculation showed that the experiment was reliably conducted, as the recovery rates ranged from 98% to 101%. The log Pow of the test item is given as the mean value of all measurements. Detailed results are given in the table in the field 'Any other information on results incl. tables'.

Any other information on results incl. tables

Ratio n-octanol:water (v:v)	Analysed concentration n-octanol (mg/L)	Analysed concentration water (mg/L)		Pow	log Pow	pH
1:4	<34.2	2994	<0.0114		<-1.94	6.26
1:4	<34.2	3004	<0.0114		<-1.94	6.26
1:9	<34.2	3000	<0.0114		<-1.94	6.26
1:9	<34.2	3002	<0.0114		<-1.94	6.26
1:19	<34.2	2937	<0.0117		<-1.93	6.26
1:19	<34.2	3018	<0.0113		<-1.95	6.26
Mean					<-1.94

Further remarks

The result obtained is lower than the predicted log Pow value of -1.68 for the uncharged molecule (EPI Suite™ v4.11, KOWWIN v1.68). However, this was to be expected, as the amount of non-charged species is negligible in the environmentally relevant pH range of 5 to 9, where the once and twice negatively charged species dominate, whose log Pow are expected to be significantly lower.

Applicant's summary and conclusion

Conclusions:

The shake flask method according to TG OECD 107 was applied for the determination of the log Pow of AMP (CAS 61-19-8). The determined log Pow value of AMP at pH 6.26 is <-1.94 with a standard deviation of ± 0.004.

Executive summary:

The log Pow of the test item Adenosine-5’-monophosphate (AMP, CAS no. 61 -19 -8) was determined according to TG OECD 107.

Aqueous phosphate buffer at pH 6.26, 1-octanol and the test item were equilibrated in test vessels by shaking, applying three different volume ratios of the two solvents. Subsequently, the test item concentrations were determined in both solvent phases. The determined log Pow values ranged from <-1.93 to <-1.95 for all three volume ratios and all replicates. For each replicate, the mass balance calculation showed that the experiment was reliably conducted, as the recovery rates ranged from 98% to 101%. The determined log Pow value of Adenosine-5’-monophosphate (AMP) at pH 6.26 is <-1.94 with a standard deviation of ± 0.004. The validity criterion was fulfilled.