Rhatany, Krameria triandra, ext.

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09.01.2019 - 16.01.2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The study was performed in compliance with the Principle of Good Laboratory Practice, confirmed by Statement of GLP Compliance.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - HPLC Method)

Principles of method if other than guideline:

No deviations from the guideline were ascertained.

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Test material

Test material information

1

Reference substance name:

Rhatany, Krameria triandra, ext.

EC Number:

283-919-1

EC Name:

Rhatany, Krameria triandra, ext.

Cas Number:

84775-95-1

Molecular formula:

not available

IUPAC Name:

Extractives and their physically modified derivatives such as tinctures, concretes, absolutes, essential oils, oleoresins, terpenes, terpene-free fractions, distillates, residues, etc., obtained from Krameria triandra, Krameriaceae.

Test material form:

liquid: viscous

Specific details on test material used for the study:

Name Krameria triandra extract obtained from Rhatany root by hydroalcoholic extraction
Batch no. PES180014
Appearance reddish brown viscous substance
Composition Krameria triandra extract obtained from Rhatany root by hydroalcoholic extraction
CAS No. 84775-95-1
EC-No. 283-919-1
Purity not applicable, UVCB
Homogeneity inhomogeneous, warm up to 60 °C and stir
Stability H2O: 96 h; EtOH: 96 h; acetone: 96 h; CH3CN: 96 h; DMSO: 96 h
Solubility H2O: unknown; EtOH: >1 g/L; acetone: >1 g/L; CH3CN: >1 g/L; DMSO: >1 g/L
Production date Jan. 2018
Expiry date Jan. 2019
Storage Fridge (2 – 8 °C)

Study design

Analytical method:

high-performance liquid chromatography

Results and discussion

Partition coefficient

Key result

Type:

log Pow

Partition coefficient:

> 0.3 - < 6.5

Temp.:

25 °C

pH:

ca. 5

Remarks on result:

other: several partition coefficients

Details on results:

The study was performed using a HPLC with a C18 column. Eight reference items with different retention times and thiourea for the determination of the dead time were used to produce a calibration curve, since retention time on hydrophobic columns and POWare correlated. The reference items were chosen based on the results of the pre-test.
One vial was filled with the reference item mix and one vial with the test item solution. The vials were analysed using the HPLC with the program described below, containing an isocratic part with methanol/water 75/25 % (v/v), followed by a washing step with 100 % methanol.The mobile phase was changed to 100 % methanol after elution of DDT to show, that test item components are eluted from the HPLC column after DDT.
First one injection from the solvent blank methanol/water 75/25 (v/v) was made. Then three injections were measured from the reference item mix, three injections from the test item and again three injections from the reference item mix.
For each reference item, the capacity factor k was calculated from the retention time of thiourea and the retention time of the respective reference item.
A calibration function (log k versus log POW, linear fit) was determined using the literature values for POWof the reference items and the retention times in the six determinations.
The chromatogram of the test item gave eight peaks. With the calibration function log k versus log POW, the corresponding log POWvalues of the peaks were determined. Using the correlation log k / log POW, the log POWof the components 3 – 7 of the test itemKrameria triandra extract obtained from Rhatany root by hydroalcoholic extractioncould be calculated. The peaks 1 and 2 eluted before thiourea, the dead time marker. Therefore, the log POW ‘ofthese components is stated as < 0.3 (log POWof 2-Butanone, the reference with the lowest log POW).
Peak 8 eluted in the not isocratic part of the program. Extrapolation is not possible therefore. Because the retention time of the test item peak is higher than the retention time of DDT (32.7 minutes), the log POWof the test item peak 8 is stated as > 6.5 (log POWof DDT).
As the standard deviation of the retention time lay below 0.03 min. for each peak, the determination was precise.
The log POWof the test item is stated as range< 0.3 - > 6.5.

Any other information on results incl. tables

Summary Results:

Peak	Mean Retention Time [min]	Mean Area [mAU*min][1]	Relative Area [%]	log POW ±Standard Deviation
1	0.893	19.337	24.81	n.c.^1
2	1.278	15.259	19.59	n.c.^1
3	7.216	4.951	6.36	4.2 ± 0.0
4	8.802	8.970	11.52	4.5 ± 0.0
5	10.093	0.854	1.10	4.7 ± 0.0
6	13.929	2.533	3.25	5.2 ± 0.0
7	16.251	18.477	23.73	5.4 ± 0.0
8	44.264	7.513	9.65	n.c.^2

¹n.c. = not calculable, because k is negative. As the retention time of peak 1 and 2 lies below the lowestretention timeof the reference items (2-Butanone withlog P_OW0.3), thelog P_OWof this peak is stated as < 0.3.

²n.c. = not calculable, because the test item peak eluted in the not isocratic part of the program. Because the retention time of the test item peak is higher than the retention time of DDT (32.7 minutes) the log P_OWof the test item peak 8 is stated as > 6.5 (log P_OWof DDT).

 

Applicant's summary and conclusion

Conclusions:

There are several partition coefficients of the test item is stated as range< 0.3 - > 6.5.

Executive summary:

This study was performed in order to estimate the partition coefficient P_OWof Krameria triandra extract obtained from Rhatany root by hydroalcoholic extractionusing HPLC.

The partition coefficient (P_OW) is defined as the ratio of the equilibrium concentrations of a dissolved substance in a two-phase system consisting of two largely immiscible solvents (n-octanol and water). The log P_OWis a key parameter in studies of the environmental fate of chemical substances. A highly significant relationship between the P_OWof the non-ionised form of substances and their bioaccumulation in fish has been shown. It has also been shown that P_OWis a useful parameter in the prediction of adsorption on soil and sediments and for establishing quantitative structure-activity relationships for a wide range of biological effects.

The HPLC method covers log P_OWvalues in the range of 0 to 6. Reverse phase HPLC is performed on analytical columns packed with a commercially available solid phase containing long hydrocarbon chains (e.g. C8, C18) chemically bound onto silica.

A test item injected on such a column partitions between the mobile solvent phase and the hydrocarbon stationary phase as it is transported along the column by the mobile phase. The test items are retained in proportion to their hydrocarbon-water partition coefficient, with hydrophilic chemicals eluted first and lipophilic chemicals last. The retention times of the peaks of the test item are compared with retention times of reference substances with known hydrocarbon-water partition coefficients.

Experimental data (retention times of peaks of the test item and of the reference items) are used together with literature values for the log P_OWof the reference items to calculate the log P_OWof the test item. The log P_OWof the test item is stated as range< 0.3 - > 6.5.