Cyanobacteria produce a wide range of metabolites of interest for industrial or medical use. The cultivation of freshwater Nostoc cf. linckia yielded 5.4 g/L of a crude exopolysaccharide (cEPS) with a molecular weight of 1.31 × 105 g/mol. Ion-exchange chromatography of cEPS yielded two dominant fractions, EPS-1 and EPS-2, differing in molecular weight. The lower molecular weight fraction (EPS-1) was subjected to structural studies. Results of chemical and spectroscopic analyses showed that three of the four dominant sugars, glucose, galactose and xylose are 1,4-linked in the backbone in the following order: [→4)-β-D-Xylp-(1 → 4)-β-D-Glcp-(1 → 4)-α-D-Galp-(1 → 4)-β-D-Glcp-(1→]n. Terminal mannose residues were identified as side chains linked at C3 of every third backbone xylose and every second glucose is branched at C6 by 3-O-lactyl-β-D-glucuronic acid (nosturonic acid). Antioxidant properties of EPS were tested using two in vitro methods. Both assays showed that the cEPS was more active than purified EPS-1 and EPS-2 fractions and deproteinized EPS.
- MeSH
- antioxidancia chemie MeSH
- bakteriální polysacharidy analýza chemie MeSH
- galaktosa chemie MeSH
- glukosa chemie MeSH
- kyselina glukuronová chemie MeSH
- magnetická rezonanční spektroskopie metody MeSH
- molekulární struktura MeSH
- molekulová hmotnost MeSH
- Nostoc chemie MeSH
- xylosa chemie MeSH
- Publikační typ
- časopisecké články MeSH
Complex structure of cyanobacterium Nostoc sp. exopolysaccharide (EPS), with apparent molecular weight 214 × 103 g/mol, can be deduced from its composition. Chemical and NMR analyses found four dominant sugar monomers, namely (1 → 4)-linked α-l-arabinopyranose, β-d-glucopyranose, β-d-xylopyranose and (1 → 3)-linked β-d-mannopyranose, two different uronic acids and a lactyl group, with (1 → 4,6)-linked β-d-glucopyranose as the only branch point suggest a complex structure of this polymer. The dominant uronic acid is α-linked, but it remained unidentified. β-d-Glucuronic acid was present in lower amount. Their position as well as that of lactyl remained undetermined too. Different doses of orally administered EPS in guinea pigs evoked a significant decrease in cough effort and a decrease in airway reactivity. The antitussive efficacy and bronchodilator effect of higher doses of EPS were found to be similar to that of the antitussive drug codeine and the antiasthmatic salbutamol. Without significant cytotoxicity on the RAW 264.7 cells, EPS stimulated the macrophage cells to produce pro-inflammatory cytokines tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6), and prostaglandins (PGs) and nitric oxide (NO) via induction of COX-2 and iNOS expression, respectively, suggesting that this biopolymer potentiates an early innate immune response and can therefore be used as a new immune modulator.
- MeSH
- albuterol farmakologie MeSH
- bakteriální polysacharidy chemie farmakologie MeSH
- biopolymery chemie MeSH
- bronchodilatancia farmakologie MeSH
- buněčné linie MeSH
- cytokiny metabolismus MeSH
- interleukin-6 metabolismus MeSH
- kašel farmakoterapie MeSH
- kodein farmakologie MeSH
- kyselina glukuronová chemie MeSH
- kyseliny uronové chemie MeSH
- makrofágy účinky léků metabolismus MeSH
- morčata MeSH
- myši MeSH
- Nostoc metabolismus MeSH
- oxid dusnatý metabolismus MeSH
- RAW 264.7 buňky MeSH
- sinice metabolismus MeSH
- TNF-alfa metabolismus MeSH
- zvířata MeSH
- Check Tag
- morčata MeSH
- myši MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
