Characterization of immunomodulatory polysaccharides from Salvia officinalis L

Crude polysaccharide fractions, rich mainly in arabinogalactans (A), pectin (B) and glucuronoxylan-related polymers (D), have been obtained from aerial parts of sage (Salvia officinalis L.) by sequential extraction with various reagents. Arabinogalactans displayed on HPLC a dominance of lower molecular-mass polymers (MW < 10,000), while pectin and glucuronoxylan-related polysaccharides showed predominance of polymers with MW > 50,000. Individual polysaccharide fractions were examined for their immunomodulatory activity in the in vitro comitogenic thymocyte test. The polysaccharide fractions tested possessed the capacity to induce rat thymocyte proliferation in the order D>B>A. Besides, fraction D possessed a significant comitogenic effect, and the SIcomit/SImit ratio 3-4 indicates potential adjuvant properties of this glucuronoxylan-rich material.     

Bioactive polysaccharides from the stems of the Thai medicinal plant Acanthus ebracteatus: their chemical and physical features

Crude water-soluble polysaccharides were isolated from Acanthus ebracteatus by hot water extraction followed by ethanol precipitation after pre-treatment with 80% ethanol. The crude polysaccharides were separated into neutral and acidic polysaccharides by anion-exchange chromatography. The neutral polysaccharide (A1001) was rich in galactose, 3-O-methylgalactose and arabinose, whereas the acidic polysaccharide (A1002) consisted mainly of galacturonic acid along with rhamnose, arabinose and galactose as minor components indicating a pectin-type polysaccharide with rhamnogalacturonan type I (RG-1) backbone. 3-O-Methylgalactose is also present in the acidic fraction. Both neutral and acidic fractions showed potent effects on the complement system using pectic polysaccharide PM II from Plantago major as a positive control. A small amount of 3-O-methylgalactose present in the pectin seemed to be of importance for activity enhancement in addition to the amount of neutral sugar side chains attached to RG-1. The relationship between chemical structure and effect on the complement system of the isolated polysaccharides is considered in the light of these data. The presence of the rare monosaccharide 3-O-methylgalactose may indicate that this can be used as a chemotaxonomic marker. The traditional way of using this plant as a medical remedy appears to have a scientific basis.     

In Vitro Anti-influenza Virus Activities of Sulfated Polysaccharide Fractions from Gracilaria lemaneiformis

In this paper, in vitro anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were investigated. Cytotoxicities and antiviral activities of Gracilaria lemaneiformis polysaccharides (PGL), Gracilaria lemaneiformis polysaccharide fraction-1 (GL-1), Gracilaria lemaneiformis polysaccharide fraction-2 (GL-2) and Gracilaria lemaneiformis polysaccharide fraction-3 (GL-3) were studied by the Methyl thiazolyl tetrazolium (MTT) method, and the inhibitory effect against Human influenza virus H1-364 induced cytopathic effect (CPE) on MDCK cells were observed by the CPE method. In addition, the antiviral mechanism of PGL was explored by Plaque forming unit (PFU), MTT and CPE methods. The results showed: i) Cytotoxicities were not significantly revealed, and H1-364 induced CPE was also reduced treated with sulfated polysaccharide fractions from Gracilaria lemaneiformis; ii) Antiviral activities were associated with the mass percentage content of sulfate groups in polysaccharide fractions, which was about 13%, in polysaccharides (PGL and GL-2) both of which exhibited higher antiviral activity; iii) A potential antiviral mechanism to explain these observations is that viral adsorption and replication on host cells were inhibited by sulfated polysaccharides from Gracilaria lemaneiformis. In conclusion, Anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were revealed, and the antiviral activities were associated with content of sulfate groups in polysaccharide fractions.     

In vitro anti-influenza virus activities of sulfated polysaccharide fractions from <Emphasis Type="Italic">Gracilaria lemaneiformis</Emphasis>

In this paper, in vitro anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were investigated. Cytotoxicities and antiviral activities of Gracilaria lemaneiformis polysaccharides (PGL), Gracilaria lemaneiformis polysaccharide fraction-1 (GL-1), Gracilaria lemaneiformis polysaccharide fraction-2 (GL-2) and Gracilaria lemaneiformis polysaccharide fraction-3 (GL-3) were studied by the Methyl thiazolyl tetrazolium (MTT) method, and the inhibitory effect against Human influenza virus H1-364 induced cytopathic effect (CPE) on MDCK cells were observed by the CPE method. In addition, the antiviral mechanism of PGL was explored by Plaque forming unit (PFU), MTT and CPE methods. The results showed: i) Cytotoxicities were not significantly revealed, and H1-364 induced CPE was also reduced treated with sulfated polysaccharide fractions from Gracilaria lemaneiformis; ii) Antiviral activities were associated with the mass percentage content of sulfate groups in polysaccharide fractions, which was about 13%, in polysaccharides (PGL and GL-2) both of which exhibited higher antiviral activity; iii) A potential antiviral mechanism to explain these observations is that viral adsorption and replication on host cells were inhibited by sulfated polysaccharides from Gracilaria lemaneiformis. In conclusion, Anti-influenza virus activities of sulfated polysaccharide fractions from Gracilaria lemaneiformis were revealed, and the antiviral activities were associated with content of sulfate groups in polysaccharide fractions.     

Characterization of cell wall polysaccharides from the medicinal plant Panax notoginseng

Panax notoginseng is a commonly used medicinal plant in south-western China. Recent studies indicate that wall polysaccharides are responsible for some of the immunostimulatory activity. Fractionation of the P. notoginseng root powder alcohol insoluble residue (AIR) and its compositional analysis enabled us to deduce the polysaccharide and protein composition of the root cell walls. P. notoginseng walls are composed primarily of polysaccharide (approximately 97% w/w) and some protein. The polysaccharides include pectic polysaccharides (neutral Type I 4-galactan (21%), arabinan (5%), acidic rhamnogalacturonan I (RG I, 2%) and homogalacturonan (HGA, 24%), non-cellulosic polysaccharides (heteroxylan, 3%), xyloglucan (XG, 3%) and heteromannan (1%)) and cellulose (24%). The root AIR also contains Type II AG/AGPs (5% w/w) typically associated with the plasma membrane and extracellular matrix. Thus, P. notoginseng roots contain polysaccharides typical of Type I primary cell walls but are distinguished by their very high levels of Type I 4-galactans and low levels of XGs. The major amino acids in the AIR were Leu (14 mol%), Asx (16 mol%), Glx (10 mol%), Ala (9 mol%), Thr (9 mol%) and Val (9 mol%).     

Purification, structure and immunobiological activity of an arabinan-rich pectic polysaccharide from the cell walls of Prunus dulcis seeds

The structure and bioactivity of a polysaccharide extracted and purified from a 4M KOH + H3BO3 solution from Prunus dulcis seed cell wall material was studied. Anion-exchange chromatography of the crude extract yielded two sugar-rich fractions: one neutral (A), the other acidic (E). These fractions contain a very similar monosaccharide composition: 5:2:1 for arabinose, uronic acids and xylose, respectively, rhamnose and galactose being present in smaller amounts. As estimated by size-exclusion chromatography, the acidic fraction had an apparent molecular mass of 762 kDa. Methylation analysis (from the crude and fractions A and E), suggests that the polysaccharide is an arabinan-rich pectin. In all cases, the polysaccharides bear the same type of structural Ara moieties with highly branched arabinan-rich pectic polysaccharides. The average relative proportions of the arabinosyl linkages is 3:2:1:1 for T-Araf:(1-->5)-Araf:(1-->3,5)-Araf:(1-->2,3,5)-Araf. The crude polysaccharide extract and fractions A and E induced a murine lymphocyte stimulatory effect, as evaluated by the in vitro and in vivo expression of lymphocyte activation markers and spleen mononuclear cells culture proliferation. The lymphocyte stimulatory effect was stronger on B- than on T-cells. No evidence of cytotoxic effects induced by the polysaccharide fractions was found.     

Fractionation and characterization of biologically-active polysaccharides from Artemisia tripartita

The leaves of Artemisia species have been traditionally used for prevention and treatment of a number of diseases. In this study, five polysaccharide fractions (designated A-I-A-V) were isolated from the leaves of Artemisia tripartita Rydb. by the sequential use of hot-water extraction, ethanol precipitation, ultra-filtration, and chromatography. The homogeneity and average molecular weight of each fraction were determined by high performance size-exclusion chromatography. Sugar composition analysis revealed that Artemisia polysaccharides consisted primarily of xylose, glucose, arabinose, galactose, and galactosamine. Moreover, all fractions contained at least 3.4% sulfate, and fractions A-II-A-V contained an arabinogalactan type II structure. All fractions exhibited macrophage-activating activity, enhancing production of intracellular reactive oxygen species and release of nitric oxide, interleukin 6, interleukin 10, tumor necrosis factor alpha, and monocyte chemotactic protein 1. In addition, all fractions exhibited scavenging activity for reactive oxygen species generated enzymatically or produced extracellularly by human neutrophils. Finally, fractions A-I and A-V exhibited complement-fixing activity. Taken together, our results provide a molecular basis to explain at least part of the beneficial therapeutic effects of Artemisia extracts, and suggest the possibility of using Artemisia polysaccharides as an immunotherapeutic adjuvant.     

Antioxidative activity of polysaccharide fractions isolated from Lycium barbarum Linnaeus

Antioxidant activity of polysaccharide fractions isolated from Lycium barbarum Linnaeus was evaluated. Polysaccharides were extracted with boiling water, followed by precipitating with ethanol, protein hydrolysis, dialysis, and fractionation with a DEAE–Sepharose CL-6B column. A total of 4 fractions, including 1 neutral polysaccharide (LBPN) and 3 acidic polysaccharides were obtained, and compared with crude polysaccharide (CP), crude extract of polysaccharide (CE), deproteinated polysaccharide (DP), and deproteinated and dialyzed polysaccharide (DDP) for antioxidative activity. With the exception of CE and DDP, most polysaccharides were effective in scavenging DPPH and ABTS⁺ free radicals, superoxide anion and hydroxyl radical at 1000 μg/mL.     

Identification of polysaccharides from pericarp tissues of litchi (Litchi chinensis Sonn.) fruit in relation to their antioxidant activities

A large number of polysaccharides are present in the pericarp tissues of harvested litchi fruits. A DEAE Sepharose fast-flow anion-exchange column and a Sephadex G-50 gel-permeation column were used to isolate and purify the major polysaccharides from litchi fruit pericarp tissues. Antioxidant activities of these major polysaccharide components were also evaluated. An aqueous extract of the polysaccharides from litchi fruit pericarp tissues was chromatographed on a DEAE anion-exchange column to yield two fractions. The largest amount of the polysaccharide fraction was subjected to further purification by gel filtration on Sephadex G-50. The purified product was a neutral polysaccharide, with a molecular weight of 14 kDa, comprised mainly of 65.6% mannose, 33.0% galactose and 1.4% arabinose. Analysis by Smith degradation indicated that there were 8.7% of (1-->2)-glycosidic linkages, 83.3% of (1-->3)-glycosidic linkages and 8.0% of (1-->6)-glycosidic linkages in the polysaccharide. Furthermore, different polysaccharide fractions extracted and purified from litchi fruit pericarp tissues exhibited strong antioxidant activities. Among these fractions, the purified polysaccharide had the highest antioxidant activity and should be explored as a novel potential antioxidant.     

Anti-herpetic activity of a sulfated xylomannan from Scinaia hatei

Many viruses display affinity for cell surface heparan sulfate proteoglycans with biological relevance in virus entry. This raises the possibility of the application of sulfated polysaccharides in antiviral therapy. In this study we have analyzed polysaccharide fractions isolated from Scinaia hatei. The crude water extract (ShWE) as well as one fraction (F1) obtained by size exclusion chromatography had potent anti-HSV activity. Their inhibitory concentration 50% (IC50) values ranging from 0.5 to 4.6 microg/ml were much lower than the cytotoxic concentration 50% (CC50) values (1000 microg/ml). These fractions had very low anticoagulant activity. Furthermore, they had a weak inactivating effect on virions in a virucidal assay at concentrations in the range of 60-100 microg/ml. Chemical, chromatographic and spectroscopic methods showed that the major polysaccharide, which had 0.4 sulfate group per monomer unit and an apparent molecular mass of 160 kDa, contained a backbone of alpha-(1-->3)-linked D-mannopyranosyl residues substituted at C-6, C-4 and C-2 with single stub of beta-d-xylopyranosyl residues. Sulfate groups, when present, are located at C-4 of alpha-(1-->3)-linked D-mannopyranosyl units, and appeared to be very important for the anti-herpetic activity of this polymer.     

Hypoglycemic and hypolipidemic effects and antioxidant activity of fruit extracts from Lycium barbarum

The hypoglycemic and hypolipidemic effects of Lycium barbarum fruit water decoction, crude polysaccharide extracts (crude LBP), and purified polysaccharide fractions (LBP-X) in alloxan-induced diabetic or hyperlipidemic rabbits were investigated through designed sequential trials and by measuring blood glucose and serum lipid parameters. Total antioxidant capacity was also assessed using trolox equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assay. It was found that the three Lycium barbarum fruit extracts/fractions could significantly reduce blood glucose levels and serum total cholesterol (TC) and triglyceride (TG) concentrations and at same time markedly increase high density lipoprotein cholesterol (HDL-c) levels after 10 days treatment in tested rabbits, indicating that there were substantial hypoglycemic and hypolipidemic effects. Hypoglycemic effect of LBP-X was more significant than those of water decoction and crude LBP, but its hypolipidemic effect seemed to be weaker. Total antioxidant capacity assay showed that all three Lycium barbarum extracts/fractions possessed antioxidant activity. However, water and methanolc fruit extracts and crude polysaccharide extracts exhibited stronger antioxidant activity than purified polysaccharide fractions because crude extracts were identified to be rich in antioxidants (e.g., carotenoids, riboflavin, ascorbic acid, thiamine, nicotinic acid). Lycium barbarum polysaccharides (glycocojugates), containing several monosaccharides and 17 amino acids, were major bioactive constituents of hypoglycemic effect. Both polysaccharides and vitamin antioxidants from Lycium barbarum fruits were possible active principles of hypolipidemic effect.     

In vitro and in vivo immunomodulatory activity of sulfated polysaccharides from Enteromorpha prolifera

Water-soluble sulfated polysaccharides extracted from Enteromorpha prolifera and fractionated using ion-exchange chromatography (crude, F₁, F₂ and F₃ fractions) were investigated to determine their in vitro and in vivo immunomodulatory activities. The sulfated polysaccharides, especially the F₁ and F₂ fractions, stimulated a macrophage cell line, Raw 264.7, inducing considerable nitric oxide (NO) and various cytokine production via up-regulated mRNA expression. The in vivo experiment results show that the sulfated polysaccharides (the crude and F₂ fractions) significantly increased Con A-induced splenocyte proliferation, revealing their potential comitogenic activity. In addition, IFN-γ and IL-2 secretions were considerably increased by the F₂ fraction without altering the release of IL-4 and IL-5. This implies that the F₂ fraction can activate T cells by up-regulating Th-1 response and that Th-1 cells might be the main target cells of the F₂ fraction. These in vitro and in vivo results suggest that the sulfated polysaccharides are strong immunostimulators.     

Structural and immunological properties of arabinogalactan polysaccharides from pollen of timothy grass (Phleum pratense L.)

Extracts from pollen of timothy grass (Phleum pratense L.) contain up to 20% arabinogalactan proteins (AGPs). Separation of the AGP polysaccharide moieties by tryptic digestion, size exclusion chromatography (GPC), and reverse phase HPLC yielded arabinogalactan fractions AG-1 and AG-2 with molecular weights of approximately 15,000 and approximately 60,000Da, respectively. The backbones of both polysaccharides are composed of (1-->6)-linked beta-D-galactopyranosides with beta-D-GlcUAp or 4-O-Me-beta-D-GlcUAp at their terminal ends as revealed by chemical analysis, FT-IR, MALDI-MS, and NMR spectroscopy. AG-1 contains a small number of beta-l-Araf side chains while AG-2 possesses a variety of (1-->3)-linked units, which consist of beta-l-Araf-(1-->, alpha-l-Araf-(1-->3)-beta-l-Araf-(1-->, and alpha-l-Araf-(1-->5)-beta-l-Araf-(1--> as well as a small number of longer arabinogalactan side chains. In contrast to crude pollen extracts, the immunological properties of the arabinogalactan mixture reveal an IgG4 reactivity instead of IgE reactivity. Structural properties of timothy pollen arabinogalactan might thus influence the immune response.     

Fractionation and characterization of polysaccharides from abaca fibre

Abaca fibre polysaccharides were fractionated into water soluble, pectic, 1% NaOH soluble, hemicellulosic and cellulose fractions by extraction with hot water, dilute hydrochloric acid (pH 1.6), aqueous 1% NaOH and 17.5% NaOH, respectively. Cellulose (60.4–63.6%) and hemicelluloses (20.8%) were the major polysaccharides in abaca fibres. The hot water soluble polysaccharides contained noticeable amounts of pectic substances and a large proportion of neutral polysaccharides. The pectic polysaccharide preparation was enriched in both galacturonic acid and neutral sugars, including xylose, glucose, galactose, arabinose, and rhamnose. Extraction of the fibre with aqueous 1% NaOH produced the hemicellulose–lignin complex, which was enriched in xylose and, to a lesser extent, glucose-, arabinose- and galactose-containing polysaccharides, together with 7.6% associated lignin. Further extraction of the delignified fibre residue with aqueous 17.5%. NaOH removed the hemicellulose fractions, which were strongly enriched in xylose-containing polysaccharides. Besides ferulic and p-coumaric acids, six other phenolic monomers were also detected in the mixtures of alkaline nitrobenzene oxidation of associated lignin in all the polysaccharide fractions. The content of bound lignin in water soluble, pectic, and 1% NaOH soluble polysaccharides (Fractions 1, 2, and 3), isolated directly from the lignified fibres, was 12 times that of the hemicellulosic preparations (Fractions 4 and 5) isolated from the delignified fibre residues.     

Efficient purification of antiproliferative polysaccharides from Hypsizigus marmoreus with radial flow chromatography

The increasing commercial significance of natural polysaccharides for use in medicinal products is stimulating the development of efficient and easy scale‐up techniques for polysaccharide purification. In this research, the crude polysaccharides from submerged cultivation broth of Hypsizigus marmoreus were purified using radial flow chromatography (RFC), and the antiproliferative activity of the purified fractions was evaluated in vitro. DEAE Sepharose CL‐6B was selected to be packed in the RFC column based on its good resolution, physical stability, and low cost. Compared with axial flow chromatography (AFC), an efficient chromatographic process with significantly less time and buffer consumption but yielding higher polysaccharide recovery and resolution was established in RFC, which could clearly purify the crude polysaccharides into different fractions. An acceptable linear scale‐up effect of RFC from 100 to 500 mL was successfully achieved without loss of resolution and enhancement of time consumption. 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assays in cell cultures indicated that the purified polysaccharide fractions possess moderate antiproliferative activities in three different human cancer cell lines, but have significantly lower cytotoxicity in normal human cell lines in vitro. Among the polysaccharide fractions, the main purified acidic fraction W‐I could be considered as a novel potential antitumor agent candidate for several tumors, especially for human alveolar epithelial tumors. This research confirmed for the first time that RFC would be a new fast and efficient tool for purification of polysaccharides into different fractions, both at laboratory and commercial scales. © 2014 American Institute of Chemical Engineers Biotechnol. Prog., 30:872–878, 2014     

ARTP诱变猴头菌株的发酵菌丝体多糖理化性质及体外免疫活性

为探讨常压室温等离子体诱变的3株高产多糖猴头菌和出发菌株的多糖组分差异,通过液体发酵获得的菌丝体经水提、分级醇沉获得8个胞内多糖组分,对它们的理化性质、结构特征及体外免疫活性进行了研究。结果表明,3株ARTP诱变菌株414、321、236菌丝体多糖含量较出发菌株有较明显提升;ARTP诱变的猴头菌20%醇沉多糖组分较出发菌株分子量大,所占比例增加;诱变菌株60%醇沉多糖组分的分子量略大于出发菌株,所占比例相近。20%醇沉多糖主要由半乳糖、葡萄糖、甘露糖构成,诱变菌株该多糖组分中葡萄糖和甘露糖的比例较出发菌株均有明显提升,60%醇沉多糖组分单糖组成无明显差异;8个多糖组分均具有体外刺激巨噬细胞释放NO的活性,其中20%醇沉多糖的活性优于60%醇沉多糖,诱变菌株的生物活性优于出发菌株。本研究探讨了ARTP诱变对猴头菌胞内多糖结构及活性的影响,为猴头菌相关产品的开发提供了优质资源。     

Separation of 6-deoxy-heptan [correction of 6-deoxy-heptane] from a smooth-type lipopolysaccharide preparation of Burkholderia pseudomallei

Smooth-type lipopolysaccharide (LPS) of Burkholderia pseudomallei has been reported to contain two kinds of O-antigenic polysaccharides, a 1,3-linked homopolymer of 6-deoxy-heptose and a polymer with a repeating unit of -->3)-glucose-(1-->3)-6-deoxy-talose-(1--> with O-acetyl or O-methyl modifications. A LPS preparation containing these two polysaccharides was separated by gel-permeation chromatography in this study. Chemical analysis of the separated fractions revealed the 6-deoxy-heptan [corrected] to be a polysaccharide without a lipid portion and the polymer of glucose and 6-deoxy-talose to be an O-antigenic polysaccharide of the LPS. This result was further supported by the assay of these polysaccharide molecules for macrophage activation activity. The 6-deoxy-heptan [corrected] showed no macrophage activation, indicating that this polysaccharide was not the LPS, but one of the capsular polysaccharides of B. pseudomallei.     

In vitro antioxidant and antitumor activities of polysaccharides extracted from Asparagus officinalis

Ultrasonic circulating extraction technology was applied for the polysaccharide extraction from Asparagus officinalis. The crude polysaccharides were deproteinized by Sevag method and three main polysaccharide fractions, AOP-4, AOP-6 and AOP-8 were obtained by fractional precipitation with gradient concentrations of ethanol (40%, 60% and 80%). The in vitro antitumor and antioxidant activities of the polysaccharide fractions were evaluated by MTT assay and free radical-scavenging assay, respectively. Deproteinized AOPs showed higher antioxidant and antitumor activities than crude AOP. AOP-4 with molecular weight 5.75 × 10⁴ Da showed significant function of scavenging hydroxyl radical. Three AOP fractions had significant antitumor activity against HeLa and BEL-7404 cells in a dose dependent manner. Furthermore, the inhibit activity of AOP-4 against HeLa cells was higher than those of other AOPs and the inhibition rate reached 83.96% at the concentration of 10 mg/mL. These results indicated that the AOP might be useful for developing natural safe antitumor drugs or health food.     

Effect of culture media on the chemical and physical characteristics of polysaccharides isolated from Poria cocos mycelia

Mycelia of a wild strain Poria cocos were cultured in two media differing in one constituent: bran extract or corn steep liquor, and are designated as wb and wc, respectively. Six polysaccharide fractions were isolated sequentially from the two mycelia by 0.9% NaCl (PCM1), hot water (PCM2), 0.5 M NaOH (PCM3-I and -II) and 88% formic acid (PCM4-I and -II). Their chemical and physical characteristics were determined by infrared spectroscopy (IR), gas chromatography (GC), 13C NMR, light scattering (LS) and viscometry. The results indicated that wb-, wc-PCM1, and PCM2 were heteropolysaccharides mainly composed of alpha-D-glucose, mannose, and galactose, whereas wb-PCM3-I and wc-PCM3-I were mainly (1-->3)-alpha-D-glucans, and wb- and wc-PCM3-II, PCM4-I and PCM4-II were (1-->3)-beta-D-glucans. Interestingly, (1-->3) alpha- and (1-->3)-beta-D-glucans co-existed in the 0.5 M NaOH fraction and were separated individually into the two fractions (PCM3-I and PCM3-II) after neutralizing with acetic acid. The polysaccharides from wc-PCM cultured in media containing corn steep liquor contained relatively more protein. The polysaccharide fractions also existed in conformations including random coil (as in PCM0 and PCM1) and expanded chain (as in PCM3), and differed molecular mass. In addition, two exo-polysaccharides isolated from the two culture media by methanol precipitation (wb- and wc-PCM0) also differed in their monosaccharide composition.     

Structural characterization of laminaran and galactofucan extracted from the brown seaweed Saccharina longicruris

Brown seaweed contains several polysaccharides like laminaran, fucoidan and alginate. Laminaran is a β-glucan that has shown anti-apoptotic and anti-tumoral activities, while galactofucan (fucoidan) is a sulfated polysaccharide that has displayed anticoagulant, anti-tumor, anti-thrombosis, anti-inflammatory and antiviral properties. In this study, crude laminaran and galactofucan (fucoidan) were extracted from the brown seaweed Saccharina longicruris at four harvest periods (M05, A05, N05 and J06). The galactofucan M05 and N05 fractions were depolymerized (RDP) over 2 or 4 h to give 4 RDP fractions (M05 RDP 2H, M05 RDP 4H, N05 RDP 2H and N05 RDP 4H) whose molecular weights, monosaccharide compositions and glycosidic linkages were determined by GC-MS. The laminaran fraction gave a molecular weight range from 2900 to 3300 Da and contained between 50.6% and 68.6% d-glucose and an average of 1.3% d-mannitol. The presence of a β-(1,3) linkage between d-glucose in the main chain was observed, with branching at positions 6 and 2. The M05 fraction contained less branching than other laminaran fractions, which might have influenced its conformation in solution and thus its activity. The crude galactofucan fractions displayed a molecular weight range from 638 to 1529 kDa, whereas the RDP fractions had molecular weights <30 kDa. The structure of the galactofucan fractions remained complex after depolymerization, with these also being more sulfated (30-39%) than the crude fractions (13-20%). The crude and RDP fractions contained 3-linked fucopyranose 4-sulfate and 6-linked galactopyranose 3-sulfate moieties, although the galactofucans isolated from M05 and J06 contained less 6-linked galactopyranose 3-sulfate than the A05 and N05 fractions.