Primary structural features, physicochemical and biological properties of two water-soluble polysaccharides extracted from the brown Tunisian seaweed Halopteris scoparia.

Marine algae are the most abundant resource in the marine environment and are still a promising source of bioactive compounds including hydrocolloids. This study contributes to the evaluation of the biological and biotechnological potentials of two water soluble polysaccharides, namely alginates (AHS) and fucoidan (FHS), extracted and purified from Halopteris scoparia, an abundant Tunisian brown macroalgae collected in Tunisia (Tabarka region). The total sugars, neutral monosaccharides, uronic acids, proteins, polyphenols, and sulfate groups contents were quantified for both fractions, as well as their functional groups and primary structural features by Fourier transform infrared spectroscopy, ionic and/or gas chromatography and nuclear magnetic resonance analyses.

Structural Characterization and Rheological and Antioxidant Properties of Novel Polysaccharide from Calcareous Red Seaweed.

A novel sulfated xylogalactan (JASX) was extracted and purified from the rhodophyceae . JASX was characterized by chromatography (GC/MS-EI and SEC/MALLS) and spectroscopy (ATR-FTIR and H/C NMR) techniques. Results showed that JASX was constituted by repeating units of (→3)-β-d-Gal-(1,4)-3,6-α-l-AnGal-(1→) and (→3)-β-d-Gal-(1,4)-α-l-Gal-(1→) substituted on -2 and -3 of the α-(1,4)-l-Gal units by methoxy and/or sulfate groups but also on -6 of the β-(1,3)-d-Gal mainly by β-xylosyl side chains and less by methoxy and/or sulfate groups.

Bioactive Polysaccharides from Seaweeds.

Bioactive compounds with diverse chemical structures play a significant role in disease prevention and maintenance of physiological functions. Due to the increase in industrial demand for new biosourced molecules, several types of biomasses are being exploited for the identification of bioactive metabolites and techno-functional biomolecules that are suitable for the subsequent uses in cosmetic, food and pharmaceutical fields. Among the various biomasses available, macroalgae are gaining popularity because of their potential nutraceutical and health benefits.

Structural features and rheological behavior of a water-soluble polysaccharide extracted from the seeds of Plantago ciliata Desf.

A water-soluble polysaccharide (PSPC) was extracted from the seeds of Plantago ciliata Desf., a spontaneous Algerian Saharan plant by a hot aqueous extraction then purified by successive ethanolic precipitations. The final extraction yield for PSPC was close to 18.

Extraction and Characterization of Alginate from an Edible Brown Seaweed () Harvested in the Romanian Black Sea.

Cystoseira barbata is an edible brown seaweed, traditionally used in the Black Sea area as functional food. Both alginate and brown seaweed biomass are well known for their potential use as adsorbents for heavy metals. Alginate was extracted from recovered from the Romanian coast on the Black Sea with a yield of 19 ± 1.

Alkyl-Chitosan-Based Adhesive: Water Resistance Improvement.

A chemical modification by grafting alkyl chains using an octanal (C8) on chitosan was conducted with the aim to improve its water resistance for bonding applications. The chemical structure of the modified polymers was determined by NMR analyses revealing two alkylation degrees (10 and 15%). In this study, the flow properties of alkyl-chitosans were also evaluated.

Structural characterization and antioxidant activity of water-soluble polysaccharides from the Tunisian brown seaweed Cystoseira compressa.

A fucoidan (CCF) and a sodium alginate (CCSA) were extracted and purified from the Tunisian brown seaweed Cystoseira compressa. CCF was a highly sulfated heterogalactofucan composed of α-(1→3), α-(1→4)-linked l-Fucp as main backbone which could be highly branched (31.84%) at O-3 and O-4 positions of α-(1→4)-l-Fucp and α-(1→3)-l-Fucp by terminal monosaccharides and side chains such as terminal α-l-Fucp, terminal β-d-Galp, β-d-Galp-(1→3)-α-l-Fucp and β-d-Galp-(1→4)-α-l-Fucp.

Structural characterization and rheological behavior of a heteroxylan extracted from Plantago notata Lagasca (Plantaginaceae) seeds.

Plantago notata (Plantaginaceae) is a spontaneous plant from Septentrional Algerian Sahara currently used by traditional healers to treat stomach disorders, inflammations or wound healing. A water-soluble polysaccharide, called PSPN (PolySaccharide fraction from Plantago Notata), was extracted and purified from the seeds of this semi-arid plant. The structural features of this mucilage were evaluated by colorimetric assays, Fourier transformed infrared spectroscopy (FT-IR), gas chromatography coupled to mass spectrometry (GC/MS) and H/C Nuclear Magnetic Resonance (NMR) spectroscopy.

Haematococcus pluvialis soluble proteins: Extraction, characterization, concentration/fractionation and emulsifying properties.

A water-soluble matrix was extracted from green vegetative Haematococcus pluvialis through high-pressure cell disruption either at native pH (5.7) or with pH shifting to neutral (7). The resulting supernatant is mainly composed of carbohydrates and proteins, with the highest yield of proteins obtained at neutral pH (73±2% of total biomass proteins).

Separation and fractionation of exopolysaccharides from Porphyridium cruentum.

In this work the extraction of EPSs from culture media of Porphyridium cruentum, by dialysis, solvent-precipitation with 3 polar alcohols (methanol, ethanol and isopropanol) and membrane separation techniques has been studied. Diafiltration (DF) using a membrane with a 300 kDa molecular weight cut off was the most efficient technique compared to solvent-extraction and dialysis methods. After extraction, EPS fraction was characterized in terms of rheological properties and biochemical content.