Structure and physiological activity of lemnan, Lemna minor L. pectin
Ovodova, R.G.; Golovchenko, V.V.; Shashkov, A.S.; Popov, S.V.; Ovodov, I.S.
Bioorganicheskaia Khimiia 26(10): 743-751
2000
ISSN/ISBN: 0132-3423 PMID: 11221255 Document Number: 519710
A pectic polysaccharide, lemnan, was isolated from freshly collected duckweed Lemna minor L. Its sugar chain was shown to be mainly composed of the residues of D-galacturonic acid (64%), galactose, arabinose, xylose, and D-apiose, a branched chain sugar. The high content of D-apiose (25%) indicated that lemnan is an apiogalacturonan type pectin similar to zosteran, a pectic polysaccharide from a sea phanerogam of the Zosteraceae family. The results of partial acidic hydrolysis, pectinase digestion, and NMR studies of lemnan demonstrated that its macromolecule contains regions of the linear alpha-1,4-D-galacturonan and branched apiogalacturonan. The side chains of apiogalacturonan were found to be formed of single and 1,5-linked residues of D-apiofuranose attached to 2- and 3-positions of the D-galacturonic acid residues of the apiogalacturonan backbone. Lemnan was shown to exhibit an immunomodulatory effect by activating the system of phagocytosis.