Star anise, Illicium verum, ext.

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(E)-anethole

EC Number:

224-052-0

EC Name:

(E)-anethole

Cas Number:

4180-23-8

Molecular formula:

C10H12O

IUPAC Name:

1-methoxy-4-prop-1-en-1-ylbenzene

Constituent 2

Reference substance name:

4-allylanisole

EC Number:

205-427-8

EC Name:

4-allylanisole

Cas Number:

140-67-0

Molecular formula:

C10H12O

IUPAC Name:

1-allyl-4-methoxybenzene

1

Reference substance name:

Caryophyllene

EC Number:

201-746-1

EC Name:

Caryophyllene

Cas Number:

87-44-5

Molecular formula:

C15H24

IUPAC Name:

4,11,11-trimethyl-8-methylenebicyclo[7.2.0]undec-4-ene

Constituent 3

Reference substance name:

2,6-dimethyl-6-(4-methyl-3-pentenyl)bicyclo[3.1.1]hept-2-ene

EC Number:

241-702-9

EC Name:

2,6-dimethyl-6-(4-methyl-3-pentenyl)bicyclo[3.1.1]hept-2-ene

Cas Number:

17699-05-7

Molecular formula:

C15H24

IUPAC Name:

2,6-dimethyl-6-(4-methylpent-3-en-1-yl)bicyclo[3.1.1]hept-2-ene

Test material form:

liquid

Radiolabelling:

no

Study design

Details on sampling:

Test item: Essential oil of Star Anise Oil (Illicium verum) (1)
Received on: 17/May/2018
Bioagri code: QUIM-0014/18
Analyzed Concentration of a.i. (Bioagri): 96.32% (m/m)
Analysis Certificate (CA): CA TH - 0461/17
Batch number: 18-02-10-1 (1)
Physical state: Light yellow clarified liquid or crystal (1)
Homogeneity data: Homogeneous sample (CA TH - 0461/17)
Manufacture Date: 10/Feb/2018 (1)
Validity Date: 09/Aug/2019 (1)
Manufacturer: Jinxi County Purong Essences MFG Co., Ltd (1)
Address: JiangXi Jinxi County Industrial Park Area C (1)
Source: (1) Information provided by the sponsor.

Buffers:

pHs 4, 7, 9 and 10 sterilized buffers (buffer solution of pH 10 was used only for calibration of pHmeter);
Ultrapure water (sterilized);
Phosforic acid PA - Purity: 85%;
Acetonitrile HPLC grade - Purity: 99.9%;
Ethanol HPLC grade - Purity: 99.9%;
TSA - Tryptone Soya Agar;
SAB - Sabouraud Dextrose Agar.

Duration of test

Duration of test 1

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

ca. 3.48 other: μg/ml

Duration of test 2

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

ca. 4.7 other: μg/ml

Duration of test 3

Duration:

5 d

pH:

9

Temp.:

50 °C

Initial conc. measured:

ca. 3.58 other: μg/ml

Number of replicates:

2

Positive controls:

no

Negative controls:

no

Results and discussion

Preliminary study:

The concentrations of the test item in the solutions prepared for the preliminary test were determined by the HPLC/DAD method described in section 7.1. The analytical method was calibrated by a set of solutions prepared from the reference item. The representative chromatogram of the reference item is shown in Figure 2.

All sets of calibration data were prepared using the reference item at concentrations above and below the nominal concentration and showed excellent linear correlations between the active ingredient concentration and the peak area of the chromatograms. The correlation coefficient for the calibration curve was 0.99 (Figure 1). Thus, the HPLC/DAD method described in section 7.1. was suitable for this study.

Representative chromatograms of the buffers solutions without application of the test item are showed in Figure 3 for pH 4, Figure 4 for pH 7 and Figure 5 for pH 9.

The results of the initial concentration determination, and those performed after 5 days of incubation at 50 ± 0.5oC are presented in Table 5. Figure 6 show a graphic with the variation of temperature during the incubation period. The results of the preliminary test showed that the test item concentration decreased for all tested pH, indicating that the test item is unstable at pHs 4, 7 and 9. Figures 7 and 8 show the chromatograms obtained for pH 4, Figures 9 and 10 show the chromatograms obtained for pH 7, Figures 11 and 12 the chromatograms obtained for pH 9.

To confirm that the peaks observed in the initial and final chromatograms are due solely to the test item, purities were calculated. The results of the purity index calculation, performed by the software of the chromatography workstation, for pHs 4, 7 and 9 buffered solutions following 5 days of incubation returned values above 99%, indicating no co-elution. The results are shown in Figure 13 for pH 4, Figure 14 for pH 7 and Figure 15 for pH 9.

Transformation products:

not measured

Total recovery of test substance (in %)

Total recovery of test substance (in %) 1

% Recovery:

ca. 97.94

St. dev.:

4.19

pH:

4

Temp.:

50 °C

Duration:

ca. 5 d

Total recovery of test substance (in %) 2

% Recovery:

ca. 97.94

St. dev.:

4.19

pH:

7

Temp.:

50 °C

Duration:

ca. 5 d

Total recovery of test substance (in %) 3

% Recovery:

ca. 97.94

St. dev.:

4.19

pH:

9

Temp.:

50 °C

Duration:

ca. 5 d

Dissipation DT50 of parent compound

Dissipation DT50 of parent compound 1

Key result

pH:

4

Temp.:

50 °C

Remarks on result:

other: The test item in function of pH is considered unstable, therefore, a definitive test (Tier II) is required to determine the half-life of the test item.

Dissipation DT50 of parent compound 2

Key result

pH:

7

Temp.:

50 °C

Remarks on result:

other: The test item in function of pH is considered unstable, therefore, a definitive test (Tier II) is required to determine the half-life of the test item.

Dissipation DT50 of parent compound 3

Key result

pH:

9

Temp.:

50 °C

Remarks on result:

other: The test item in function of pH is considered unstable, therefore, a definitive test (Tier II) is required to determine the half-life of the test item.

Details on results:

According to the results of Tier I, the Essential oil of Star Anise Oil (Illicium verum) test item degraded more than 10% of the initial concentration at 50 ± 0.5°C at pHs 4, 7 and 9. The test item in function of pH is considered unstable, therefore, a definitive test (Tier II) is required to determine the half-life of the test item.

Applicant's summary and conclusion

Validity criteria fulfilled:

yes

Conclusions:

According to the results of Tier I, the Essential oil of Star Anise Oil (Illicium verum) test item degraded more than 10% of the initial concentration at 50 ± 0.5°C at pHs 4, 7 and 9. The test item in function of pH is considered unstable, therefore, a definitive test (Tier II) is required to determine the half-life of the test item.

Executive summary:

A study of the hydrolysis ofEssential oil of Star Anise Oil (Illicium verum)performed by Tier I, has been conducted at pHs 4, 7 and 9. In a preliminary test conducted at 50 ± 0.5^oC, it was found that at pHs 4, 7 and 9,the test itemconcentration decrease more than 10% during an incubation period of 5 days, from the initial concentration. The test itemin function of pH is considered unstable for the pHs 4, 7 and 9 and a definitive test (Tier II) is required.