Hot-water extracts from the inner bark of Norway spruce with immunomodulating activities

A1 Journal article (refereed)

Internal Authors/Editors

Publication Details

List of Authors: Myriam Le Normand, Hugo Mélida, Bjarne Holmbom, Terje E. Michaelsen, Marit Inngjerdingen, Vincent Bulone, Berit Smestad Paulsen, Monica Ek
Publication year: 2014
Journal: Carbohydrate Polymers
Volume number: 101
Start page: 699
End page: 704


The inner bark of Norway spruce (Picea abies) was sequentially extracted with hot water at 100 °C, 140 °C, and 160 °C. The hot-water extracts (IB 100 °C, IB 140°C and IB 160 °C) contained pectic polysaccharides and showed immunostimulating activities. Structural analyses of their carbohydrate content, including glycosidic linkage analyses, revealed the presence of pectins with large rhamnogalacturonen RG-1 domain ramified with highly-branched arabinans. IB 100 °C also contained a large amount of terminal glycosyl residues, indicating the presence of highly substituted polymers. IB 160 °C was mainly composed of starch. The hot-water extracts were tested for two biological activities, namely complement fixation and macrophage stimulation. IB 100 °C exhibited the highest compliment fixation activity, with a 1.7-times higher ICH 50 than the control pectin, while IB 140 °C and IB 160 °C gave similar ICH 50 values as the control. Macrophages were stimulated by IB 100 °C and IB 140 °C in a dose-dependent manner, but not by IB 160 °C. IB 100 °C presented the highest activity towards macrophages, comparable to the control pectin.


Bark, Biorefinery, Compositional analysis, Immunomodulating activities, Pectins

Last updated on 2020-04-08 at 07:25