Composition,structural characteristics,and antitumor properties of polysaccharides from the brown algae <Emphasis Type="Italic">Dictyopteris polypodioides</Emphasis> and <Emphasis Type="Italic">Sargassum</Emphasis> sp.

The polysaccharide compositions of the brown algae Dictyopteris polypodioides and Sargassum sp. from the Mediterranean Sea were determined. The principal polysaccharide of the studied algae (about 12% of the dry alga weight) was alginic acid. The content of water-soluble polysaccharides was low. The amount of fucoidan was less than 1% of the dry alga weight; of neutral polysaccharides, less than 0.25%. The monosaccharide compositions of fucoidans and neutral polysaccharides were investigated. Experiments on soft agar-agar models showed that fucoidans from D. polypodioides and Sargassum sp. exhibited antitumor activity against RPMI-7951 human melanoma cells.     

Polysaccharides of algae 65. Unusual polysaccharide composition of the pacific brown alga Punctaria plantaginea

Quantitative determination revealed the presence of storage glucan (6.0%), fucoidan (19.2%) and alginate (12.7%) in the biomass of the brown alga Punctaria plantaginea collected from the Sea of Japan. The polysaccharides were isolated from the alga by fractional extraction followed by additional purification procedures. Unlike the well-known laminarans the storage polysaccharide from P. plantaginea was shown to be a linear (1→6)-β-d-glucopyranan, which is new for brown alga. The content of guluronic acid (G) residues in the alginate molecules exceeded the content of mannuronic acid residues (M), M/G = 0.5. Poly-G and poly-MG blocks were isolated from the products of partial hydrolysis of alginic acid; however, a heterogeneous mixture of polysaccharide fragments was obtained instead of the expected poly-M fraction. Preliminary data suggests that fucoidan from this alga is a new for brown algae type of sulfated polysaccharide (xylofucan) with a main backbone built of α-l-fucopyranose residues. This chain contains multiple sulfate groups and single non-sulfated β-d-xylopyranose residues as substituents.     

Seasonal variations of the composition and structural characteristics of polysaccharides from the brown alga <Emphasis Type="Italic">Costaria costata</Emphasis>

Seasonal variations of the polysaccharide composition of the brown alga Costaria costata were studied. It was found that the alga synthesized in April-May a high-molecular-weight (200–800 kDa) low-sulfated heterofucan; in July, primarily a low-molecular-weight (20–300 kDa) sulfated and acetylated galactofucan. A small amount (<0.01% of total alga mass) of laminaran (1,3;1,6-β-D-glucan) was observed in mature alga.     

Characteristics of polysaccharides and protein associated with them from dried and freshly collected red alga <Emphasis Type="Italic">Tichocarpus crinitus</Emphasis>

Polysaccharides isolated by successive extraction with water at 20 and 80°C from freshly collected and dried alga T. crinitus were compared. It was shown that the yield of polysaccharides from freshly collected alga was 40–44%; from dried material, less than 25%. It was found that the amount of extracted polysaccharides and their molecular weights decreased upon storage of dried alga for three years. Polysaccharides isolated from freshly collected and dried alga had identical structures and were a mixture of κ/β- and a new X-type of carrageenan. It was shown that protein, the amount of which reached 24% in the extracts obtained at 20°C, was strongly bound to the carrageenan. The amino-acid compositions of the proteins associated with the polysaccharides isolated at 20 and 80°C were identical and had an elevated content of serine, glutamic acid, glycine, and alanine.     

Determination of Polysaccharides in Undaria pinnatifida by Ionic Liquid-Modified Silica Gel Size Exclusion Chromatography

Ionic liquid-modified silica particles with a large pore size were synthesized and used as the stationary phase for size exclusion chromatography coupled with a refractive index detector for the determination of polysaccharides, such as fucoidan, alginic acid, and laminarin from Undaria pinnatifida (seaweed). The molecular weight of polysaccharide was determined by a dextran standard curve (5–1100?kDa). The ionic liquid-modified silica column exhibited excellent size exclusion properties in separating laminarin from other components. The 1-butyl-3-methyl-imidazolium bis-(trifluoromethylsulfonyl)-amino silica column has superior resolution in laminarin separation than the other columns because the amino-group in ionic liquid provide π–π interactions due to aromaticity of the ring structure, which enhances the effect of the hydroxyl group in the target compound separation. The concentrations of polysaccharides were calculated using a standard linear equation to be 0.332–0.484?mg/g of fucoidan, 0.207–0.301?mg/g of alginic acid, and 0.154–0.297?mg/g of laminarin.     

Sorption of Anionic Polysaccharides and Bovine Serum Albumin on a Macroporous Glass

Concentration and time dependences of the sorption of alginic acid and -carrageenan on an MPS-1000 macroporous glass were studied. The character of pH effect on the sorption of these polysaccharides was established. For a number of sorbents prepared by the preliminary adsorption of polysaccharides on an MPS-1000 glass, the dependence of the sorption of bovine serum albumin (BSA) on the surface content of alginic acid and -carrageenan was studied. The model of adsorption in the silica–polysaccharide–protein system accounting for the interaction between polysaccharide ionic groups and active sites at the sorbent surface and protein molecules was proposed. Acid-base properties of silica modified with polysaccharides were investigated by the potentiometric titration, and the results supporting the validity of the proposed model were obtained.     

Effect of the shear rate on pullulan production from beet molasses by Aureobasidium pullulans in an airlift reactor

The effect of the shear rate on pullulan production from beet molasses by Aureobasidium pullulans P56 in an airlift reactor was investigated. A maximum polysaccharide concentration (18.5 g/L), biomass dry weight (14.0 g/L), polysaccharide yield (38.5%), and sugar utilization (96%) was achieved at a shear rate of 42 s⁻¹. A. pullulans grown on beet molasses produced a mixture of pullulan and other polysaccharides. The highest value of pullulan proportion (30% of total polysaccharide) was obtained at a low shear rate (42 s⁻¹). The apparent viscosity of the fermentation broth increased as the shear rate increased up to 42 s⁻¹ and then decreased. On the other hand, the dissolved oxygen concentration and the volumetric mass transfer coefficient increased with the increase of the shear rate from 21 to 84 s⁻¹. The external addition of L-glutamic acid, olive oil, and Tween-80 improved significantly the production of crude polysaccharide (27.0 g/L), but the pullulan content of the polysaccharide was low (20%).     

New data on the structure of laminaran fromChorda filum (L.) Lam. and reserve glucans from other brown algae

M-chains of highly branched (13),(16)--D-glucan (laminaran) isolated previously from the brown algaChorda filum contain 1-glucosylated and 1,6-bis-glucosylatedD-mannitol residues, as shown by methylation analysis and enzymolysis. The latter structural element is found in laminarans for the first time. Structural investigation of laminarans from six other brown algae shows that the polysaccharides consist predominantly of (13)-linked -D-glucopyranose residues with a small number of (16)-glycosidic bonds in chains and branching points. Mannitol residues was not detected in laminarans from twoCystoseira species.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1660–1664, September, 1993.     

Solid-Phase Colorimetric Method for the Quantification of Fucoidan

We described the simple, selective, and rapid method for determination of fucoidans using methylene blue staining of sulfated polysaccharides, immobilized into filter paper and consequent optic density (at A ₆₆₃?nm) measurement of the eluted dye from filter paper. This solid-phase method allows selective determination of 1?C20???g fucoidan in presence of potentially interfering compounds (alginic acid, DNA, salts, proteins, and detergents). Further, we demonstrated the alternative way of using image processing software for fucoidan quantification without extraction of methylene blue dye from stained spots of fucoidan?Cdye complex.     

Magnetic molecularly imprinted polymers for recognition and enrichment of polysaccharides from seaweed

New magnetic molecularly imprinted polymers with two templates were fabricated for the recognition of polysaccharides (fucoidan and alginic acid) from seaweed by magnetic solid‐phase extraction, and the materials were modified by seven types of deep eutectic solvents. It was found that the deep eutectic solvents magnetic molecularly imprinted polymers showed stronger recognition and higher recoveries for fucoidan and alginic acid than magnetic molecularly imprinted polymers, and the deep eutectic solvents‐4‐magnetic molecularly imprinted polymers had the best effects. The practical recovery of the two polysaccharides (fucoidan and alginic acid) purified with deep eutectic solvents‐4‐magnetic molecular imprinted polymers in seaweed under the optimal conditions were 89.87, and 92.0%, respectively, and the actual amounts extracted were 20.6 and 18.7 μg/g, respectively. To sum up, the developed method proved to be a novel and promising method for the recognition of complex polysaccharide samples from seaweed.     

Effect of vinegar steaming on the composition and structure of Schisandra chinensis polysaccharide and its anti-colitis activity

In this study, infrared spectroscopy, high-performance liquid chromatography, and matrix-assisted laser desorption ionization-time-of-flight-mass spectrometry (MALDI-TOF-MS) technology were applied to systematically explain the Schisandra chinensis’s polysaccharide transformation in configuration, molecular weight, monosaccharide composition, and anti-ulcerative colitis (UC) activity after vinegar processing. Scanning electron microscopic results showed that the appearance of S. chinensis polysaccharide changed significantly after steaming with vinegar. The MALDI-TOF-MS results showed that the mass spectra of raw S. chinensis polysaccharides (RSCP) were slightly lower than those of vinegar-processed S. chinensis polysaccharides (VSCP). The RSCP showed higher peaks at m/z 1350.790, 2016.796, and 2665.985, all with left-skewed distribution, and the molecular weights were concentrated in the range of 1300–3100, with no higher peak above m/z 5000. The VSCPs showed a whole band below m/z 3000, with m/z 1021.096 being the highest peak, and the intensity decreased with the increase of m/z. In addition, compared to RSCPs, VSCPs can significantly increase the content of intestinal short-chain fatty acids (SCFAs). This study showed that the apparent morphology and molecular weight of S. chinensis’s polysaccharides significantly changed after steaming with vinegar. These changes directly affect its anti-UC effect significantly, and its mechanism is closely related to improving the structure and diversity of gut microbiota and SCFA metabolism.     

Effects of polysaccharide elicitors from endophytic Fusarium oxysporium Dzf17 on growth and diosgenin production in cell suspension culture of Dioscorea zingiberensis

Three polysaccharides, namely exopolysaccharide (EPS), water-extracted mycelial polysaccharide (WPS) and sodium hydroxide-extracted mycelial polysaccharide (SPS), were prepared from the endophytic fungus Fusarium oxysporium Dzf17 isolated from the rhizomes of Dioscorea zingiberensis. The effects of the time of addition and polysaccharide concentration on the growth and diosgenin accumulation in cell suspension culture of D. zingiberensis were studied. Among them, WPS was found to be the most effective polysaccharide. When WPS was added to the medium at 20 mg/L on the 25th day of culture, the cell dry weight was increased 1.34-fold, diosgenin content 2.85-fold, and diosgenin yield 3.83-fold in comparison to those of control. EPS and SPS showed moderate and relatively weak enhancement effects on cell growth and diosgenin accumulation, respectively. The dynamics of cell growth and diosgenin accumulation when WPS was added to the medium at 20 mg/L on the 25th day of culture were investigated, and results showed that dry weight of cells reached a maximum value on day 30 but the maximum diosgenin content was achieved on day 31.     

Retention of Large Biological Molecules by Size-Exclusion Chromatography

Size-exclusion chromatography has been developed for the separation of large biological molecules including proteins, polymers, peptides, nucleic acids, and polysaccharide according to their molecular size. This study determined the retention factors for dextran (5, 25, 50, 270, 670, and 1100?kDa) and polysaccharides, such as fucoidan, alginic acid, and laminarin, in the size-exclusion chromatography stationary phase. In addition, the molecular weights and retention factor of three polysaccharides were calculated from the dextran standard curve. The largest retention factor was 4.26 using the size-exclusion chromatography columns (5?kDa dextran). The molecular weights of fucoidan, alginic acid, and laminarin were determined to be 250, 200, and 5 to 64?kDa, respectively.     

Polysaccharides of algae 67. Carrageenan from Pacific red alga Turnerella mertensiana (Gigartinales,Rhodophyta)

A sulfated galactan composed of nearly equimolar amounts of d-galactose, 3,6-anhydro-d-galactose, and sulfate was isolated from the red alga Turnerella mertensiana collected in the Sea of Japan. The structures of native polysaccharide and its alkaline modification products were studied by NMR spectroscopy. The polysaccharide molecules were shown to contain a linear carbohydrate chain consisting of alternating 3-linked β-d-galactopyranose 4-sulfate and 4-linked 3,6-anhydro-α-d-galactopyranose residues (known as к-carrageenan), which is typical of carrageenans, but the regularity of polymer structure is masked by the presence of some 3,6-anhydro-α-d-galactose 2-sulfate (ι-carrageenan units) and α-D-galactose 6-sulfate (µ-carrageenan units) instead of 3,6-anhydro-α-d-galactose. Upon addition of potassium chloride (up to 4%) to a solution of the native polysaccharide, about half of the substance transforms into gel. The gel-forming fraction is к-ι-µ-hybrid carrageenan with the ～65 : 15 : 20 ratio of к-, ι-, and µ-units. The non-gelling fraction contains the к-, ι-, and µ-units at the ratio of ～46 : 12 : 42. The gel-forming carrageenan product free of µ-units can be otained in ～30% yield (based on the dry biomass) by alkaline treatment of the alga prior to extraction of the polysaccharide.

     

A Sustainable Freeze‐Drying Route to Porous Polysaccharides with Tailored Hierarchical Meso‐ and Macroporosity

Bio‐derived polysaccharide aerogels are of interest for a broad range of applications. To date, these aerogels have been obtained through the time‐ and solvent‐intensive procedure of hydrogel fomation, solvent exchange, and scCO2 drying, which offers little control over meso/macropore distribution. A simpler and more versatile route is developed, using freeze drying to produce highly mesoporous polysaccharide aerogels with various degrees of macroporosity. The hierarchical pore distribution is controlled by addition of different quantities of t‐butanol (TBA) to hydrogels before drying. Through a systematic study an interesting relationship between the mesoporosity and t‐butanol/water phase diagram is found, linking mesoporosity maxima with eutectic points for all polysaccharides studied (pectin, starch, and alginic acid). Moreover, direct gelation of polysaccharides in aqueous TBA offers additional time savings and the potential for solvent reuse. This finding is a doorway to more accessible polysaccharide aerogels for research and industrial scale production, due to the widespread accessibility of the freeze drying technology and the simplicity of the method.

     

Polysaccharides and sterols from green algae Caulerpa lentillifera and C. sertularioides

Sterols and polysaccharides of green alga Caulerpa lentillifera grown under laboratory conditions and in mariculture and polysaccharides of green alga C. sertularioides grown under natural conditions were studied. The sterol fraction consisted of C₂₇-C₂₉ steroidal alcohols with Δ⁵-unsaturation in the steroid core regardless of the growth conditions. The dominant (79.9%) steroid component of the sterol fraction was clionasterol. The water-soluble fraction of C. lentillifera grown under laboratory conditions was a mixture of 1,4-α- and 1,3-β-D-glucans and protein. The same fraction isolated from C. lentillifera grown in mariculture contained only protein. The water-soluble fraction of C. sertularioides grown under natural conditions contained 1,3;1,6-β-D-galactan sulfated at C2. The principal components of the base-soluble polysaccharide fractions from all algae samples were 1,4-α-D-glucans. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 5-8, January-February, 2009.     

Large-Scale Purification of Water-Soluble Polysaccharides from Flaxseed Mucilage, and Isolation of a New Anionic Polymer

Summary Viscous flaxseed mucilage has previously been described as a mixture of two polysaccharides (acidic and neutral). In this study, we have shown that a combination of ion exchange and size exclusion chromatography enables purification of three distinct polysaccharides. Molecular weight (Mw) analysis, performed by size-exclusion chromatography on line with a multi-angle laser light-scattering detector, revealed that the main polysaccharide (75%) was a neutral polymer with a Mw of approximately 1.2 × 10⁶ g mol^–1. The two others were acidic polysaccharides denoted AF₁ (3.75%, 6.5 × 10⁵ g mol^–1) and AF₂ (21.25%, 1.7 × 10⁴ g mol^–1).Presented at: International Symposium on Separation and Characterization of Natural and Synthetic Macromolecules, Amsterdam, The Netherlands, February 5–7, 2003     

Quantification of major grape polysaccharides (Tempranillo v.) released by maceration enzymes during the fermentation process

The influence of commercial enzymes on wine polysaccharide content was studied. Tempranillo wines were made using commercial maceration enzyme preparations along with controls. The analytical method for the quantification of wine polysaccharides was carried out by a multistep procedure. Wine-soluble polysaccharides were isolated by wine concentration polysaccharides precipitation with an acid-alcohol medium and separation of each polysaccharide family by high resolution size-exclusion chromatography on a Superdex-75 HR column. The glycosyl-residue compositions of the fractions obtained were determined by gas chromatography with flame ionisation and mass spectrometry of their trimethylsilyl-ester O-methyl glycosides after acidic methanolysis and derivatization. The content of each fraction was estimated from the concentration of individual glycosyl residues that are characteristic of well-defined wine polysaccharides. The analytical method proposed had good sensitivity, repeatability, reproducibility and accuracy. Soluble polysaccharides in wine were essentially composed of grape cell wall polysaccharides: arabinogalactans and arabinogalactan-proteins (38-41%), and rhamnogalacturonans-II (38-46%). Yeast mannans and mannoproteins were also present but in smaller proportions (14-19%). Wines treated with commercial enzymes had larger concentrations of arabinogalactans, arabinogalactan-proteins and rhamnogalacturonans-II than control wines, but the content of mannans and mannoproteins was similar in both wines. This indicated that the commercial enzymes hydrolysed grape pectic polysaccharides during the maceration-fermentation stage but had no influence on yeast parietal polysaccharides.     

Polysaccharides of Algae 71*. Polysaccharides of the Pacific brown alga <Emphasis Type="Italic">Alaria marginata</Emphasis>

The polysaccharide composition in sporophylls of the brown alga Alaria marginata enriched with laminaran and sulfated polysaccharides was studied. It was shown that laminaran molecules had an average degree of polymerization about 30 and consisted mainly of 3-linked β-D-glucopyranose residues, having no more than 10% of 1→6 linkages. The majority of chains (about 60%) were terminated at "reducing" end by mannitol residue. Alginic acid of sporophylls contained mannuronic (M) and guluronic (G) acids residues distributed along the linear polymer molecules as MM, MG, and GG blocks at a ratio of 4: 1: 1. Fucoidan was found to be composed of fucose, galactose, and sulfate as the major constituents, while xylose, mannose, glucuronic acid, and acetate were the minor components. It was shown that fucoidan contained two major components: fucan sulfate, molecules of which are built up of 3-linked fucopyranose residues with branches and sulfate groups at different positions, and fucogalactan, also containing chains of 3-linked fucopyranose residues with branches at positions 4 together with highly branched galactan chains terminated by fucose residues. The fucoidan contained also sulfated glucuronomannan and sulfated glucuronan as minor components.     

Determination of organophosphate flame retardants in soil and fish using ultrasound‐assisted extraction,solid‐phase clean‐up,and liquid chromatography with tandem mass spectrometry

A solid–liquid extraction method in combination with high‐performance liquid chromatography and tandem mass spectrometry was developed and optimized for extraction and analysis of organophosphorus flame retardants in soil and fish. Methanol was chosen as the optimum extraction solvent, not only in terms of extraction efficiency, but also for its broader analyte coverage. The subsequent clean‐up by solid‐phase extraction is required to eliminate matrix coextractives and reduce matrix effects. Recoveries of the optimized method were 50–121% for soil and 47–123% for biota, both with high precision (RSDs <12% in soil and <23% in biota). The method limits of detection ranged from 0.06 to 0.20 ng/g dry weight and between 0.02 and 0.30 ng/g wet weight for soil and biota samples, respectively. However, samples with a high lipid content produce several problems as solid‐phase extraction cartridge clogging that increase variability and analysis time. The method was successfully applied for the determination of organophosphorus flame retardants in soil and fish from L'Albufera Natural Park (Valencia, Spain). Target compounds were detected in all soil and fish samples with values varying from 13.8 to 89.7 ng/g dry weight and from 3.3 to 53.0 ng/g wet weight, respectively.