Polysaccharides of algae 68. Sulfated polysaccharides from the Kamchatka brown alga Laminaria bongardiana

Several fucoidan fractions were isolated from the biomass of the Kamchatka brown alga Laminaria bongardiana by hot water extraction followed by anion-exchange chromatography. Fucoidans were found to be composed of l-fucose, d-galactose, and sulfate as the major components, whereas d-xylose, d-mannose, d-glucuronic acid, and acetate were detected as the minor constituents. Highly sulfated fucoidan fractions F-2 and F-3 were solvolytically desulfated by heating in dimethyl sulfoxide in the presence of pyridine. The structures of native and desulfated polysaccharides were investigated by the methylation analysis and NMR spectroscopy. It was shown that F-2 contains fucan sulfate, the backbone of which is made of 1→3-linked α-l-fucopyranose residues with single α-l-Fucp branches at positions 2 and sulfate groups predominantly at positions 4. Sulfated fucoglucuronomannan, fucoglucuronan, and fucogalactan were detected in F-2 as concomitant polysaccharides. Fucan sulfate and sulfated fucogalactan were the major components of the fraction F-3. The anticoagulant properties of fucoidan fractions were assessed. It was demonstrated that the activity of the fraction F-3 is comparable with that of low-molecular-weight heparin (enoxaparin), whereas the activity of total fucoidan F and the fraction F-2 is ~2/3 and ~1/2, respectively, of the activity of F-3, which is in accordance with the lower sulfate content in these samples. Desulfated preparations F-2deS and F-3deS were completely devoid of anticoagulant activity.

     

Polysaccharides of Algae 58. The polysaccharide composition of the Pacific brown alga <Emphasis Type="Italic">Alaria fistulosa</Emphasis> P. <Emphasis Type="Italic">et</Emphasis> R. (Alariaceae,Laminariales)

Quantitative determination of mannitol, fucoidan and alginate in different parts of the thallus (the blade, the midrip, the sporophylls, and the stipe with rhizoids) of the brown alga Alaria fistulosa, collected from the coastal waters of Paramushir Island, was carried out. Sporophylls were shown to differ considerably in carbohydrate composition from all other parts of the plant. In particular, the fucoidan content in sporophylls is several times as high as that in the blade. Alginate preparations isolated from sporophylls and from blade have different proportions of monomers (mannuronic acid and guluronic acid residues) and different molecular masses. Fucoidan preparations isolated from these parts of the plant differ slightly in the sulfate content. Their specific feature is a rather high galactose content comparable with the content of fucose. The sporophylls of A. fistulosa may be regarded as a rich source for practical isolation of fucoidan. Dedicated to Academician N. K. Kochetkov on the occasion of his 90th birthday. __________ Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 5, pp. 1245–1249, May, 2005.     

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.     

Structures and Anticoagulant Activities of the Partially Mild Acidic Hydrolysis Products of the Fucosylated Chondroitin Sulfate from Sea Cucumber Pearsonothuria graeffei

Fucosylated chondroitin sulfate from Pearsonothuria graeffei (fCS-Pg) is a unique glycosaminoglycan (GAG), which was reported to have potent antithrombotic and anticoagulant activities. In the present study, the native fCS-Pg was hydrolyzed by mild acid to improve its bioavailability. The structures of the acid-released and acid-resistant sulfated fucose branches of fCS-Pg before and after acidic hydrolysis were characterized by nuclear magnetic resonance spectroscopy (NMR) technology. The results showed the acid-released fucose residues included both α- and β-fucose conformation, containing 2,4-di-O-sulfated fucose (Fuc2,4S), 3,4-di-O-sulfated fucose (Fus3,4S), 3-O-sulfated fucose (Fuc3S), and 4-O-sulfated fucose (Fuc4S), with a mole ratio of 6:26:22:46, respectively. Their difference to the native fCS-Pg in the sulfation pattern of the backbone could be due to selective removal of the sulfated groups during the release of the fucose branches by acid. For the acid-resistant part, the sulfation patterns of fucose were similar to the native polysaccharides, but the signal strength of Fuc3,4S was obviously decreased, whereas Fuc2,4S was kept unchanged, indicating Fuc3,4S is more liable to acid. The anticoagulant activities of the acid-resistant part were tested in vitro, and the results showed that partial degradation could result in significant reduction of anticoagulant activity, which could help to lower the risk of bleeding when developing fCS as an antithrombotic drug.     

Structure and hypolipidaemic activity of fucoidan extracted from brown seaweed Sargassum henslowianum

The aim of this study is to elucidate the structure and investigate the hypolipidaemic activity of a fucoidan extracted from brown seaweed Sargassum henslowianum collected at Hai Van–Son Cha peninsula, Hue province, Vietnam by using tandem electrospray ionisation mass spectrometry. The results demonstrated that the fucoidan has α(1 → 3)-linked l-fucopyranose backbone and sulphate groups occupied mostly at C-2, C-4 and sometimes at C-3 position of fucose residues. The results of in vivo bioactivity examination revealed that the fucoidan in the dose of 100 mg/kgP/day by oral administration helped decrease cholesterol, triglyceride and LDL-cholesterol levels on obese mice.     

A Modular Approach to a Library of Semi‐Synthetic Fucosylated Chondroitin Sulfate Polysaccharides with Different Sulfation and Fucosylation Patterns

Fucosylated chondroitin sulfate (fCS)—a glycosaminoglycan (GAG) found in sea cucumbers—has recently attracted much attention owing to its biological properties. In particular, a low molecular mass fCS polysaccharide has very recently been suggested as a strong candidate for the development of an antithrombotic drug that would be safer and more effective than heparin. To avoid the use of animal sourced drugs, here we present the chemical transformation of a microbial sourced unsulfated chondroitin polysaccharide into a small library of fucosylated (and sulfated) derivatives thereof. To this aim, a modular approach based on the different combination of only five reactions was employed, with an almost unprecedented polysaccharide branching by O‐glycosylation as the key step. The library was differentiated for sulfation patterns and/or positions of the fucose branches, as confirmed by detailed 2D NMR spectroscopic analysis. These semi‐synthetic polysaccharides will allow a wider and more accurate structure–activity relationship study with respect to those reported in literature to date.     

海带褐藻多糖硫酸酯的降解与岩藻寡糖的制备

采用稀酸水解的方法降解粗褐藻多糖硫酸酯(FPS)制备了硫酸化岩藻寡糖.通过考察降解及沉降条件研究了FPS的水解及沉降规律.通过理化性质分析发现,沉降所得上层清液为杂合硫酸化岩藻寡糖[岩藻糖(Fuc)含量55%].进一步采用Bio-Gel P4低压凝胶渗透色谱分离纯化,得到4种以岩藻糖为主的低聚合度硫酸化寡糖.单糖组成分析和电喷雾质谱(ESI-MS)分析结果表明,各组分主要为系列低聚合度硫酸化岩藻寡糖或硫酸化岩藻糖,包括Fuc_(1~3)S_(1~3),Fuc_(1~2)S_(1~2),Fuc_(1~2)S_1及FucGlcAS.     

Polysaccharides in fungi. XXIX. Structural features of two antitumor polysaccharides from the fruiting bodies of Armillariella tabescens.

An antitumor polysaccharide containing peptide moieties AT-HW ([alpha]D + 31 degrees in water) and an antitumor polysaccharide AT-AL ([alpha]D + 209 degrees in 1 M sodium hydroxide) were isolated from hot-water extract and the alkaline extract of the fruiting bodies of Armillariella tabescens, respectively. Chemical structures of AT-HW and AT-AL were investigated by a combination of chemical and spectroscopic methods. The results indicate that the major constituent of AT-HW (molecular weight, 105000), a heteroglycan, is composed primarily of beta-(1----6)-linked D-glucopyranosyl and D-galactopyranosyl residues, and contains their branched residues and terminal sugar (gluco-, manno-, and fucopyranose) residues, in addition to beta-(1----3)-linked D-glucopyranosyl residues, while AT-AL (molecular weight, 93000) is chiefly composed of alpha-(1----3)-linked D-glucopyranosyl residues.     

杂合褐藻糖胶寡糖的制备及结构分析

采用热水提取法从海蒿子(Sargassum pallidum)中得到一个杂合的褐藻糖胶(SPF); 采用稀酸水解和低压凝胶渗透色谱(LPGPC)分离得到一系列杂合硫酸寡糖. 结合单糖组成、 甲基化和电喷雾碰撞诱导串联质谱(ES-CID-MS/MS)分析表明, 所得21个寡糖属于杂化岩藻寡糖硫酸酯, 主要由α1→3连接的Fuc及少量β1→4连接的Xyl和β1→6连接的Gal组成; 硫酸基取代位点主要存在于Fuc的C4或C2位、 Xyl的C2位和Gal的C4位; Fuc主要存在于寡糖的非还原端. 实验结果表明, ES-CID-MS/MS 技术可用于各种杂合褐藻糖胶寡糖的结构序列分析. 这些结构多样的硫酸寡糖可进一步点印到糖芯片上, 研究其与蛋白相互作用.     

Antioxidant and Antisteatotic Activities of a New Fucoidan Extracted from Ferula hermonis Roots Harvested on Lebanese Mountains

Fucoidan is a fucose-rich sulfated polysaccharide with attractive therapeutic potential due to a variety of biological activities, including antioxidant action. Fucoidan is typically found in the cell wall of marine brown algae, but extra-algal sources have also been discovered. In the present work, for the first time we extracted a water soluble fucoidan fraction from the roots of the terrestrial shrub Ferula hermonis. This fucoidan fraction was termed FUFe, and contained fucose, glucose, sulfate, smaller amounts of monosaccharides such as galactose and mannose, and a minor quantity of proteins. FUFe structural features were investigated by FTIR, ¹H NMR and ¹³C NMR spectroscopy. The antioxidant property of FUFe was measured by DPPH, ABTS and FRAP assays, which revealed a high radical scavenging capacity that was confirmed in in vitro cellular models. In hepatic and endothelial cells, 50 μg/mL FUFe could reduce ROS production induced by intracellular lipid accumulation. Moreover, in hepatic cells FUFe exhibited a significant antisteatotic action, being able to reduce intracellular triglyceride content and to regulate the expression of key genes of hepatic lipid metabolism. Altogether, our results candidate FUFe as a possible bioactive compound against fatty liver disease and related vascular damage.     

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.

     

Sulfated Galactans of Champia indica and Champia parvula (Rhodymeniales,Rhodophyta) of Indian Waters

Sulfated galactans of the red seaweed species Champia indica and Champia parvula of Indian waters were extracted and purified by ion exchange chromatography. These were characterized by infrared and ¹³C NMR spectroscopy as well as by GC-MS analysis of alditol acetate derivatives produced by reductive hydrolysis/acetylation of sulfated and desulfated and their methylated samples. The sulfated galactans of these Champia species contained alternating β-(1→3)-linked galactopyranosyl units with sulfation at the 2-position and α-(1→4)-linked galactopyranosyl units having sulfation at both the 2- and 3-positions. Other minor substitutions included 6-O-methyl ether of the β-(1→3)-linked galactose residues only in Champia parvula.     

Novel antiviral fucoidan from sporophyll of Undaria pinnatifida (Mekabu)

Structural characterization and antiviral activities of fucoidan from sporophyll of Undaria pinnatifida (Mekabu) was examined. The fucoidan was composed of fucose and galactose with an approximately ratio of 1.0:1.1. Degree of substitution of sulfate was 0.72 and its apparent molecular weight was 9,000. Methylation analyses showed that fucoidan had various sugar linkages, and revealed that the fucoidan might have complicated structure. This fucoidan showed potent antiviral activities against herpes simplex virus type 1 (HSV-1), HSV-2, and human cytomegalovirus.     

Polysaccharides of brown algae

Conclusions A sulfated peptidoglucuronoglycan, sargassan, has been isolated from the brown algaS. pallidum. The carbohydrate chain of this substance consists of D-galactose, D-mannose, D-xylose, L-fucose, and D-glycuronic acid residues. Some minor monosaccharide components may possibly be present in it. The peptides consist of 16 common amino acids.Khimiya Prirodnykh Soedinenii, Vol. 6, No. 3, pp. 285–289, 1970     

Constituents of seed of Malva verticillata. VII. Structural features and reticuloendothelial system-potentiating activity of MVS-I, the major neutral polysaccharide.

The structural features of MVS-I, the major neutral polysaccharide isolated from the seeds of Malva verticillata L., were elucidated by controlled Smith degradation, methylation analysis, partial acid hydrolysis and enzymic degradation studies. It has a backbone chain composed of beta-1,3-linked D-glucose and D-galactose residues having branches composed of alpha-1,5-linked L-arabinosyl beta-1,4-linked D-galactose and of beta-1,4-linked D-galactosyl beta-1,3-linked D-glucose residues at position 6 of a part of D-galactose units as side chains. MVS-I showed remarkable reticuloendothelial system-potentiating activity in a carbon clearance test.     

Studies on Sulfation of Lycium barbarum Polysaccharides

Polysaccharides can anti-virus, such as human immunodeficiency virus (HIV-1),[1] herpes simplex virus (HSV-1,HSV-2) and cytomegalovirus. Some of them are sulfates, e.g. dextran sulfate, heparin, sulfonation of chitosan and sulfated derivatives of Lentinan. Our results showed that sulfated derivatives of Lycium barbarum polysaccharides (LBP)have anti-HIV activity. Because the anti-HIV activity of LBP was deeply dependent on the molecular weight, the sulfation pattern and glycosidic branches besides degree of sulfation (DS), so we emphasized our work on the factors of DS.     

Structural Features of a Polysaccharide from Centella asiatica

Centella asiatica has been used as remedy for sodation, stabilization and against lepra, anabrosis1 in the oriental countries. The low-molecular-weight constituents in Centella asiatica have been investigated1. However, no polysaccharides have been reported. 1BI was the first polysaccharide isolated from C. asiatica, which had immunostimulating activity in vitro. In present study, we report the structural features of 1BI. Experimental Extraction, isolation and purification Dried C.…     

Structural studies of the extracellular polysaccharide produced by the diatom chaetoceros curvisetus cleve.

Methylation studies and partial acid hydrolysis have been carried out on the extracellular polysaccharide produced by the diatom Chaetoceros curvisetus. The polysaccharide contains the sugars galactose, rhamnose, and fucose and is partially sulfated. The presence of fucose in both furanose and pyranose forms within one molecule is reported for the first time. The fucofuranose is present as end groups, 1,2-linked and as branch points. Fucopyranose is mainly present as branch points in the polysaccharide, some being 1,3-linked, and a small fraction as end groups. The main part of rhamnose is 1,2-linked and galactose is mainly 1,3-linked.     

Structural features of semi-synthetic galactomannan sulfates

The positions of sulfate groups in two specimens of sulfated galactomannan from Cyamopsis tetragonoloba seeds were established by analysis of ¹H and ¹³C NMR spectra. For the degree of substitution of 0.6, the signals of galactopyranose residues sulfated at position O(6) or simultaneously at positions O(2) and O(3) were the most intense. Minor signals were due to O(2)- or O(3)-monosubstituted and 2,3,4-tri-O-substituted galactose residues. The substitution of mannopyranose residues involved positions O(6) > O(2,3) > O(2) > O(3). At higher degree of substitution (1.0), the pattern of distribution of sulfate groups over various positions in the residues did not change, the molar content of 2,3-di-O-substituted galactopyranose residues being higher than the content of 6-O-monosubstituted residues. Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1745–1749, August, 2008.     

Polysaccharides fromSpirulina platensis

A lipoglucan and a lipopolysaccharide have been isolated from an aqueous phenol extract of the cells ofSpirulina platensis. The carbohydrate moiety of the lipopolysaccharide consists of residues of rhamnose, glucose, 2-keto-3-deoxymanno-octanic acid, and glucosamine. A 2,3-di-O-methylpentose and a 2-O-methyl-6-deoxyhexose have been detected as minor components, and the presence of galactose, mannose, and xylose residues in trace amounts is possible. The lipid component of the biopolymers includes residues of glucosamine and of fatty acids: myristic, palmitic, and stearic. The carbohydrate chain of the lipoglucan is constructed of 1,4-bound glucose residues. The side chains are attached to the main chain by 1,6-glycosidic bonds. The polysaccharide component of the liposaccharide is constructed mainly of rhamnose residues linked by 1,3- and 1,2-bonds and of glucose residues linked by 1,4-bonds.Pacific Ocean Institute of Bioorganic Chemistry, Far Eastern Scientific Center, Academy of Sciences of the USSR, Vladivostok. Translated from Khimiya Prirodnykh Soedinenii, No. 2, pp. 135–139, March–April, 1983.