Saccharomyces cerevisiae cell wall, extracted

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

calculation (if not (Q)SAR)

Adequacy of study:

key study

Study period:

December 2020

Reliability:

1 (reliable without restriction)

Data source

Reference

Reference Type:

other: Expert statement

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

no guideline available

Guideline:

other: Expert statement

Principles of method if other than guideline:

The expert statement is based on the composition of this UVCB subtance which does not allow to perform any test or calculation to estimate the log Kow

GLP compliance:

no

Type of method:

other: It is demonstrated that the methods available are not applicable to this complex UVCB substance.

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Saccharomyces cerevisiae cell wall, extracted

EC Number:

949-711-6

Molecular formula:

Not applicable (UVCB substance)

IUPAC Name:

Saccharomyces cerevisiae cell wall, extracted

Test material form:

solid: particulate/powder

Study design

Analytical method:

other: Substance specific analytical methods cannot be developed due to the complex nature of this UVCB substance. And non-specific analytical methods, like TOC, provide sum parameters that are not relevant for log Kow determination.

Results and discussion

Partition coefficient

Key result

Type:

log Pow

Temp.:

20 °C

pH:

7

Remarks on result:

not measured/tested

Remarks:

Based on the composition of the substance "Saccharomyces cerevisiae cell wall, extracted" it is technically not feasible to perform an experimental test because the cell wall fraction does not dissolve in water and in octanol. So according to REACH, the study does not need to be conducted. The non-testing approach for the log Kow determination are not applicable to the constituents of this UVCB substance, since the exact structure of the biological macromolecules (e.g. proteins) are not known. Moreover, the main constituents do not fit in the applicability domain of the QSARs due to their high molecular weight (e.g.polysaccharides)

Applicant's summary and conclusion

Conclusions:

The log Kow of the substance SACCHAROMYCES CEREVISIAE CELL WALL, EXTRACTED cannot be estimated based on all available experimental and calculation methods.

Executive summary:

Due to the complex composition of the substance constituted by the insoluble cell wall of yeast extract, it is not feasible to determine its partition coefficient experimentally. Indeed, the shake flask method, the HPLC method and the slow-stirring method are not applicable to this substance. QSARs calculations are not possible due to the complex composition and the unknown precise structure of the constituents. Even the estimation of log Kow based on the solubility in water and in n-octanol is technically not feasible because the cell walls extracted during the process, are naturally neither soluble in water, nor soluble in octanol.