Influence of composition on the biological activity of pectic polysaccharides from leek
Water-soluble and acid-soluble pectic polysaccharides with significant immunostimulating activity were isolated from alcohol-insoluble solids (AIS) of leek. Pectic polysaccharides characterized with high anhydrouronic acid content and common pectic sugars – L-arabinose, D-galactose, D-glucose, and L...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Plovdiv University Press
2013-01-01
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| Series: | Journal of BioScience and Biotechnology |
| Subjects: | |
| Online Access: | http://www.jbb.uni-plovdiv.bg/documents/27807/59543/jbb_2013-2(1)-pages_13-20.pdf |
| Summary: | Water-soluble and acid-soluble pectic polysaccharides with significant immunostimulating activity were isolated from alcohol-insoluble solids (AIS) of leek. Pectic polysaccharides characterized with high anhydrouronic acid content and common pectic sugars – L-arabinose, D-galactose, D-glucose, and L-rhamnose. It was accomplished that D-galactose content was the highest, which allowed the assumption that pectin sugar side chains were from galactan type. Enzyme modification of acid-extracted pectin was realized. Different pectin-degrading enzymes were used. The first modified pectic fraction, obtained after endopolygalacturonase action and alcohol precipitation contained rhamnogalacturonan I and had high D-galactose content. The second fraction obtained from the first, after β-galactosidase treatment characterized with low D-galactose content. Probably this was result from β-galactosidase hydrolysis of pectin side chains. It was proved by the action of β-galactosidase that galactan side chains were mainly composed of β-(1→4)-linked D-galactose. It was accomplished that rhamnogalacturonan I had higher immunostimulating activity than the initial pectic polysaccharide, which confirmed the statement that pectin hairy regions were responsible for the biological activity. The second fraction had lower D-galactose content and lower activity than the first. Probably galactan side chains were responsible for the immunostimulating activity. |
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| ISSN: | 1314-6238 1314-6246 |