pectins and zosterin

Zosterin, an apiose-rich pectic polysaccharide, was extracted and purified from the sea grass Zostera marina. Structural studies conducted by gas chromatography and NMR spectroscopy on a purified zosterin fraction (AGU) revealed a typical apiogalacturonan structure comprising an alpha-1,4-d-galactopyranosyluronan backbone substituted by 1,2-linked apiofuranose oligosaccharides and single apiose residues. The average molecular mass of AGU was estimated to be about 4100 Da with a low polydispersity. AGU inhibited proliferation of A431 human epidermoid carcinoma cells with an approximate IC(50) value of 3 microg/mL (0.7 microM). In addition, AGU inhibited A431 cell migration and invasion. Preliminary experiments showed that inhibition of metalloproteases expression could play a role in these antimigration and anti-invasive properties. Autohydrolysis of AGU, which eliminated apiose and oligo-apiose substituents, led to a virtual disappearance of cytotoxic properties, thus suggesting a direct structure-function relationship with the apiose-rich hairy region of AGU.

Topics: Antineoplastic Agents, Phytogenic; Cell Wall; Drug Screening Assays, Antitumor; Humans; Inhibitory Concentration 50; Marine Biology; Molecular Structure; Monosaccharides; Nuclear Magnetic Resonance, Biomolecular; Pectins; Pentoses; Polysaccharides; Structure-Activity Relationship; Zosteraceae

The kinetics of the antibacterial activity of zosterin, a polysaccharide preparation of a sea grass belonging to Zoster, was studied. By its chemical structure zosterin is a low ++methoxylated pectin. In vitro the preparation markedly inhibited the growth of ++Gram-negative and ++Gram-positive organisms: S. aureus, E. coli, Y. pseudotuberculosis, S. typhimurium and Ps. aeruginosa. On a model of experimental pseudotuberculosis++ infection caused by oral contamination of mice F1 (CBA X C57B1) with a suspension of Y. pseudotuberculosis zosterin was shown to have a therapeutic effect. It protected 30 to 40 per cent of the animals when administered per os simultaneously with or 24 hours after the contamination. The results are in favour of the zosterin further investigation as a preparation useful in prevention of intestinal infections in persons being in contact with the patients.

Topics: Animals; Anti-Bacterial Agents; Disease Models, Animal; Enterobacteriaceae; In Vitro Techniques; Mice; Pectins; Plant Extracts; Plants, Medicinal; Polysaccharides; Pseudomonas aeruginosa; Seawater; Staphylococcus aureus; Yersinia pseudotuberculosis Infections