3,5-dihydroxy-2,6,6-tris(3-methylbuten-2-yl)-4-(3-methyl-1-oxobutyl)cyclohexa-2,4-dien-1-one

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption, other

Remarks:

Natural plant extract, UVCB - modelling via EPISuite

Type of information:

(Q)SAR

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

accepted calculation method

Justification for type of information:

Beta acids are extracted from Hop extract, which is a natural plant extract and is well known as an ingredient for brewing beer. The substance is of type UVCB. The principal components are well known - see boundary composition. The log Koc values of the principal components were estimated using EPISuite. Full details are given in the attached study report.

Qualifier:

no guideline followed

Version / remarks:

Modelling of hop extract, beta acids, by calculating log Koc of the principal components using EPISuite

Principles of method if other than guideline:

Modelling of hop extract, beta-acids by calculating log Koc of the principal components using EPISuite.

Note: Beta acids are extracted from Hop extract, which is a natural plant extract and is well known as an ingredient for brewing beer. The substance is of type UVCB. The principal components are well known - see boundary composition. The log Koc values of the principal components were estimated using EPISuite. Full details are given in the attached study report.

GLP compliance:

no

Type of method:

other: Estimation and modelling

Computational methods:

EPISuite used to estimate log Koc for the principal components

Key result

Type:

log Koc

Value:

>= 2.7 - <= 2.9 dimensionless

Validity criteria fulfilled:

not applicable

Remarks:

Modelling via EPISuite

Conclusions:

Hop extract – beta acids, potassium salt is a UVCB substance, extracted and purified from a natural extract of hop cones, itself also a UVCB substance, obtained using either liquid or supercritical CO2, or ethanol, as extraction solvents. The principal components of the substance in question are listed in Table 1 of the attached report.

The results (Table 2 of the attached report) show that the principal homologues of the β-acids have log KOC values of 2.7 – 2.9, indicating “moderate sorption to soil/sediment, slow migration to ground water”*.

Although the substance contains the potassium salt of the hop β-acids, at pH 7 the substance will be in a resinous form and the β-acids will not dissolve well in water (see attached report). Therefore, the calculated values for the homologues of the β-acids are appropriate for this substance. The other components of the β-acid extract are mostly other resins (including oxidised bitter acids, which are estimated to behave in a similar fashion to the β-acids), and hop fats and waxes, which due to their hydrophobicity and large molecular structure, will adsorb more strongly to soil.


* interpreting the values as discussed in Section 5.4.1 of https://www.epa.gov/sites/production/files/2015-05/documents/05.pdf

Key value for chemical safety assessment

Koc at 20 °C:

794

Additional information

The results (Table 2 of the attached report for endpoint 5.4.1) show that the principal homologues of the β-acids have log KOC values of 2.7 – 2.9, indicating “moderate sorption to soil/sediment, slow migration to ground water”*.

* interpreting the values as discussed in Section 5.4.1 of  https://www.epa.gov/sites/production/files/2015-05/documents/05.pdf

[LogKoc: 2.9]

[LogKoc: 2.9]