oligomeric Reaction products from Hydrogenation and Hydrolysation of Starch

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Jan 2005 - Feb 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

473-690-8

EC Name:

-

Cas Number:

738602-93-2

Molecular formula:

not applicable for UVCB

IUPAC Name:

(2R,3R,4S,5S,6R)-2-{[(2R,3R,4R,5S,6R)-5-{[(2R,3R,4R,5S,6R)-3,4-dihydroxy-6-(hydroxymethyl)-5-{[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}oxan-2-yl]oxy}-3,4-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}-6-(hydroxymethyl)oxane-3,4,5-triol; (2S,3R,5R)-4-{[(2R,3R,4R,5S,6R)-5-{[(2R,3R,4R,5S,6R)-3,4-dihydroxy-6-(hydroxymethyl)-5-{[(2R,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}oxan-2-yl]oxy}-3,4-dihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}hexane-1,2,3,5,6-pentol

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source (i.e. manufacturer or supplier) and lot/batch number of test material: Sponsor, Batch 4G08
- Purity, including information on contaminants, isomers, etc.: 54.2 % Maltotriosyl glucoside


STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature at about 20 °C away from direct sunlight

Study design

Analytical monitoring:

yes

Details on sampling:

100 µl aliquots of the test solutions at each pH value were analysed without dilution by measuring the ELSD signal of MG-60 after HPLC separation of the injected sample solution.

Buffers:

buffer pH 4:
6.8 g potassium dihydrogen phosphate were dissolved in 1000 ml of water and adjusted to pH 4.0 with phosphoric acid
Buffer pH 7:
obtained from Baker
Buffer pH 9
obtained from Fluka

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: not stated
- Sterilisation method: rinsing with sterile buffer
- Lighting: not stated
- Measures taken to avoid photolytic effects: not stated
- Measures to exclude oxygen: glassware stoppered with inert material, nitrogen was passed through the test solutions for 5 miunutes
- Details on test procedure for unstable compounds: substance is stable
- Details of traps for volatile, if any - none
- If no traps were used, is the test system closed
- Is there any indication of the test material adsorbing to the walls of the test apparatus? not stated
TEST MEDIUM
- Volume used/treatment 100 ml, in two aliquotes
- Kind and purity of water: Water prepared by Milli-Q supply
- Preparation of test medium: test item is solved in an appropriate amount of buffer
- Renewal of test solution: no
- Identity and concentration of co-solvent: none used
OTHER TEST CONDITIONS
- Adjustment of pH: not stated
- Dissolved oxygen: not stated

Duration of test

Duration of test 1

Duration:

5 d

pH:

9

Temp.:

25

Initial conc. measured:

>= 68.65 - <= 69.5 mg/L

Duration of test 2

Duration:

5 d

pH:

7

Temp.:

25 °C

Remarks:

Due to interferences from the buffer salts, the test item peak could not be separated from the peak of the buffer solutions at pH 4 and pH7, respectively.

Duration of test 3

Duration:

5 d

pH:

4

Temp.:

25 °C

Remarks:

Due to interferences from the buffer salts, the test item peak could not be separated from the peak of the buffer solutions at pH 4 and pH7, respectively.

Number of replicates:

2

Positive controls:

no

Negative controls:

not specified

Statistical methods:

mean value calculated

Results and discussion

Preliminary study:

Only a preliminary study was done.

Test performance:

Due to interferences from the buffer salts, the test item peak could not be separated from the peak of the buffer solutions at pH 4 and pH 7, respectively. Thus, the test item could not be detected in these buffer solutions. Hence, no hydrolysis experiments could be performed at pH 4 and pH 7.

Transformation products:

not measured

Dissipation DT50 of parent compound

Key result

Remarks on result:

hydrolytically stable based on preliminary test

Details on results:

Due to interferences from the buffer salts, the test item peak could not be separated from the
peak of the buffer solutions at pH 4 and pH 7, respectively. Thus, the test item could not be
detected in these buffer solutions. Hence, no hydrolysis experiments could be performed at
pH 4 and pH 7.
The hydrolytic stability of the test item was therefore assessed from its chemical structure:
The test item contains only ether functional groups R-O-R’ that could potentially be
susceptible to hydrolytic degradation. Ether cleavage of the functional ether types present in
the test item most commonly would occur via a reaction mechanism according to SN2. The
pKa of ethers is in the range from –2 to -41). That requires strong acids like hydrochloric acid
(HCl) or hydrobromic acid (HBr) for the ether cleavage. At environmental pH’s in the range
from 4 to 9, ethers are known to be stable and it is very unlikely that hydrolysis will occur.



The experimental results of pH 9.0 showed no significant degradation of MG-60 at 50°C. The
degradation of MG-60 was less than 10 % after 5 days. According to the EEC Directive 92/69,
Section C.7, it can be concluded, that the estimated half-life time is higher than one year
under representative environmental conditions (25°C). Therefore, MG-60 was considered to
be hydrolytically stable, and no further testing was necessary.



In conclusion, the test item MG-60 contains no functional groups that can be hydrolysed in
the pH range from 4 to 9. The test item will therefore be hydrolytically stable in the
environmental pH range from 4 to 9. The hydrolytically stability at pH 9 was also verified by
experimental testing.

Applicant's summary and conclusion

Validity criteria fulfilled:

not specified

Conclusions:

In conclusion, the test item MG-60 contains no functional groups that can be hydrolysed in
the pH range from 4 to 9. The test item will therefore be hydrolytically stable in the
environmental pH range from 4 to 9. The hydrolytically stability at pH 9 was also verified by
experimental testing.

Executive summary:

The hydrolysis determination of MG-60 at different pH values was based on the OECD
Guideline No. 111, “Hydrolysis as a Function of pH”; adopted May 12, 1981 and on the EEC
Directive 92/69, Section C.7, “Abiotic Degradation: Hydrolysis as a Function of pH”, L383 A,
December 1992.

 

 

Due to interferences from the buffer salts, the test item peak could not be separated from the
peak of the buffer solution. Thus, the test item could not be detected in buffer solutions at
pH 4 and pH 7, respectively. Hence, no hydrolysis experiments could be performed at pH 4
and pH 7. The hydrolytic stability of the test item was therefore assessed from its chemical
structure. Thus, it is very unlikely that hydrolysis will occur.

 

The experimental results of pH 9.0 showed no significant degradation of MG-60 at 50°C. The
degradation of MG-60 was less than 10 % after 5 days. According to the EEC Directive 92/69,
Section C.7 it can be concluded, that the estimated half-life time is higher than one year
under representative environmental conditions (25°C). Therefore, MG-60 was considered to
be hydrolytically stable at pH 9.0, and no further testing was necessary.