Jump to main content
Jump to site search

Issue 5, 2009
Previous Article Next Article

Pressurized liquid extraction of betulin and antioxidants from birch bark

Author affiliations

Abstract

Pressurized hot (subcritical) water and ethanol were used to extract betulin and antioxidants from birch bark. Betulin was found to be the major compound (around 26% (w/w)), which was able to be extracted with ethanol (120 °C, 50 bar, 15 minutes) but not with water at any of the temperatures tested (40–180 °C, 50 bar). The obtained extraction result for betulin is supported by theoretical solvation parameter calculations. Furthermore, high antioxidant activity of the extract was obtained using both ethanol and water as solvent. The antioxidant activity, as determined by a DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, was found to be highest for the water extract of finely ground bark and it markedly increased with elevated extraction temperatures (90–180 °C). To elucidate if this was due to increased extraction efficiency or chemical reactions, a set of experiments was performed in which the samples were pre-treated with water at different temperatures before extraction. Results from liquid chromatography showed some differences in molecular composition between samples pre-treated at ambient and 180 °C, respectively. However, more detailed studies have to be performed to distinguish between hot-water extraction and reaction kinetics.

Graphical abstract: Pressurized liquid extraction of betulin and antioxidants from birch bark

Back to tab navigation

Publication details

The article was received on 10 Nov 2008, accepted on 03 Apr 2009 and first published on 17 Apr 2009


Article type: Paper
DOI: 10.1039/B819965E
Green Chem., 2009,11, 668-674

  •   Request permissions

    Pressurized liquid extraction of betulin and antioxidants from birch bark

    M. Co, P. Koskela, P. Eklund-Åkergren, K. Srinivas, J. W. King, P. J. R. Sjöberg and C. Turner, Green Chem., 2009, 11, 668
    DOI: 10.1039/B819965E

Search articles by author

Spotlight

Advertisements