(1RS,4Z,8E,12RS)-13-oxabicyclo[10.1.0]trideca-4,8-diene

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2019-10-10 to 2020-05-18

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient)

Deviations:

no

GLP compliance:

no

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

- Physical state: Liquid
- Storage condition of test material: Not reported (presume ambient temperature, sealed container)

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

3.47

Temp.:

30 °C

pH:

7

Type:

Pow

Partition coefficient:

2 951

Temp.:

30 °C

pH:

7

Preliminary estimate

A preliminary assessment of the partition coefficient was made based on the KOWWIN calculation method (Epiwin® v4.10, for Microsoft Windows c/William Meylan, 1994,1995) using the structure of the test item.

 

HPLC method

The mean void time (t0) was not reported but was accounted for within the report.

The calibration curves of the log k of the reference substances as function of log Pow had a regression line represented by the equation:

log Pow = 2.880 × log k + 1.1881 (r2 = 0.9689, n = 6).

 

Table 2. Reference items

Reference Item	CAS Number	Log Pow
Anisole	100-66-3	2.1
Ethylbenzoate	93-89-0	2.6
Toluene	108-88-3	2.7
Ethylbenzene	100-41-4	3.2
Isopropylbenzene	98-82-8	3.7
Biphenyl	92-52-4	4.0

 

Test item: one chromatographic peak reported

Mean log Pow: 3.47

Partition coefficient: Pow: 2951

Conclusions:

The partition coefficient of the test item was determined to be Pow = 245 and log Pow = 3.47 at 30 °C and pH ca. 7

Executive summary:

The n-octanol-water partition coefficient was determined using the HPLC method of OECD TG 117 and EU Method A.8. The test was performed with a concentration of up to 2000 mg test item/L in 75 % methanol : 25 % HPLC water. Samples of the test item were analysed via HPLC on a C18 column with refractive index detection. Calibration was performed using six reference items with known log Pow values (given by the guidelines). The void time of the HPLC system was determined with either thiourea or uracil.The mean void time (t0) was not reported but was accounted for within the report. The calibration curves of the log k of the reference substances as function of log Pow had an regression line represented by the equation: log Pow = 2.880 × log k + 1.1881 (r2 = 0.9689, n = 6).The partition coefficient of the test item was determined to be Pow = 2951 and log Pow = 3.47 at 30 °C and pH ca. 7.

Description of key information

Weight of evidence: substance contains constituents with Log Pow = 3.3 at 25°C and pH 7, 2020

Key data:

n-octanol/water: Pow = 1995 and log Pow = 3.3 at 25 ± 1°C and pH ca. 5.8, OECD TG 117 – HPLC method, GLP, 2020a

Supporting information:

n-octanol/water: Pow = 2951 and log Pow = 3.47 at 30°C and pH ca. 7, OECD TG 117 – HPLC method, non-GLP, 2020b

Key value for chemical safety assessment

Log Kow (Log Pow):

3.3

at the temperature of:

25 °C

Additional information

Key study : OECD TG 117, 2020a : The n-octanol/water partition coefficient was determined using the HPLC method within OECD TG 117 and Japanese guideline “Method for Testing the Partition Coefficient (n-octanol/water) under GLP. The n-octanol-water partition coefficient was determined using the HPLC method of OECD TG 117 and EU Method A.8. The test was performed with a concentration of up to 103 mg test item/L in 75 % methanol : 25 % HPLC water. Samples of the test item were analysed via HPLC on a commercial C18 column (L-column 3 C18, 250 mm x 2.1 mm ID and particle size 5 microns) with UV/visible spectrophotometric detection. Calibration was performed using six reference items with known log Pow values (given by the guidelines). The void time of the HPLC system was determined with either thiourea. The mean void time (t0) was 6.34 minutes. The calibration curves of the log k of the reference substances as function of log Pow had a combined regression line represented by the equation: log Pow =2.705 × log k + 2.113(r = 0.966, n = 6). The partition coefficient of the test item was determined to be Pow = 1995 and log Pow = 3.3 at 25 ± 1°C and pH ca. 5.8.

 

Key study : OECD TG 117, 2020b : The n-octanol-water partition coefficient was determined using the HPLC method of OECD TG 117 and EU Method A.8. The test was performed with a concentration of up to 2000 mg test item/L in 75 % methanol : 25 % HPLC water. Samples of the test item were analysed via HPLC on a C18 column with refractive index detection. Calibration was performed using six reference items with known log Pow values (given by the guidelines). The void time of the HPLC system was determined with either thiourea or uracil. The mean void time (t0) was not reported but was accounted for within the report. The calibration curves of the log k of the reference substances as function of log Pow had an regression line represented by the equation: log Pow = 2.880 × log k + 1.1881 (r2 = 0.9689, n = 6).The partition coefficient of the test item was determined to be Pow = 2951 and log Pow = 3.47 at 30 °C and pH ca. 7.