Prospects for the Use of Marine Sulfated Fucose-Rich Polysaccharides in Treatment and Prevention of COVID-19 and Post-COVID-19 Syndrome.

Symptoms of the new coronavirus infection that appeared in 2019 (COVID-19) range from low fever and fatigue to acute pneumonia and multiple organ failure. The clinical picture of COVID-19 is heterogeneous and involves most physiological systems; therefore, drugs with a wide spectrum of mechanism of action are required. The choice of the treatment strategy for post-COVID-19 syndrome is still a challenge to be resolved. Polysaccharides with a high fucose content derived from seaweed and marine animals can form the basis for the subsequent development of promising agents for the treatment of COVID-19 and post-COVID-19 syndrome. This class of biopolymers is characterized by a variety of biological activities, including antiviral, antithrombotic, anticoagulant, hemo-stimulating, anti-inflammatory and immune-regulatory. Low molecular weight derivatives of these polysaccharides, as well as synthetic oligosaccharides with a sufficient amount and sulfation type may be considered as the most promising compounds due to their better bioavailability, which undoubtedly increases their therapeutic potential.

Erratum to: Prospects for the Use of Marine Sulfated Fucose-Rich Polysaccharides in Treatment and Prevention of COVID-19 and Post-COVID-19 Syndrome.

[This corrects the article DOI: 10.1134/S1068162022060152.].

[The distribution of the main types of the papillary patterns on the distal phalanges of human fingers]. / Raspredelenie osnovnykh tipov papilliarnykh uzorov na distal'nykh falangakh pal'tsev ruk cheloveka.

The present study included the investigation of the four main types of the papillary patterns on the distal phalanges of all the ten fingers. As many as three million fingerprint cards have been used for the first time. The investigation yielded the exact quantitative characteristics of the frequency of occurrence of various papillary patterns. The importance of these findings for dactyloscopy and dermatoglyphics is discussed.

Influence of fucoidans and their derivatives on antitumor and phagocytic activity of human blood leucocytes.

The immunotropic activity of structurally different fucoidans and their derivatives towards isolated immune blood cells, effectors of innate immune system, was studied. The most potent effect was observed for high molecular weight fucoidan CF from the alga Chordaria flagelliformis, whose backbone is built of (1→3)-linked units of α-L-fucopyranose, and branches included residues of α-D-glucuronic acid and α-L-fucofuranose. This compound at the concentration of 0.05 mg/ml potentiated phagocytosis of Saccharomyces cerevisiae and Lactobacillus acidophilus by neutrophils, increasing relative quantity of phagocytes as well as their effectiveness. Along with this, 14% increase in the concentration of membrane-bound integrin CD11c molecules was observed. The systemic effect of CF at the dose of 0.01 mg/mouse i.p. led to potentiation of cytotoxic activity of spleen mononuclear leucocytes towards melanoma cells of line B16 by 1.9-fold and towards chronic myelogenous leukemia cells of line K-562 by 1.7-fold. These results indicate that fucoidan CF can stimulate anti-infective and antitumor activity of effectors of the innate immune system via CD11c integrins.

[Antitumor Activity of Polysaccharides from Ganoderma lucidum Mycelium: in vivo Comparative Study].

Fractions of water soluble and alkali soluble polysaccharides, as well as fucogalactan, a water soluble polysaccharide, and xylomannan, an alkali soluble polysaccharide, were isolated from the Ganoderma lucidum submerged mycelium. When administered orally, the polysaccharides showed antitumor activity in vivo on murine models of solid tumors. Xylomannan and fucogalactan showed the highest antitumor activity. Sensitivity to xylomannan was more pronounced in adenocarcinoma Ca755 as compared to the T-cell lymphocytic leukemia P388. The antitumor activity of the water soluble polysaccharides total fractions from the mycelium and fruiting bodies of the G. lucidum strain was almost identical. The maximum antitumor effect of the mycelium water soluble polysaccharides total fraction was observed with the use of the daily dose of 2 mg/kg.

[Trehalose: chemical structure, biological functions, and practical application].

Up-to-date information concerning the chemical structure and properties of trehalose, its natural occurrence and biological functions in plants, fungi, and prokaryotes, as well as its practical application, mainly in medicine and biotechnology, are reviewed. A special section deals with the role of trehalose and other protective polyols in stress processes in fungi.

[Polysaccharides of the fungus Cunninghamella japonica mycelium].

Preliminary data on the polysaccharide composition of mycelium of the submerged grown fungus Cunninghamella japonica (synonymous with C. echinulata) were obtained. Mild acid hydrolysis of the mycelium led to formation of glucose, mannose and galactose, whereas acid treatment under drastic conditions afforded glucosamine as the hydrolysis product of chitin and chitosan, the summary content of both glucosaminoglycans being estimated as about 35%. Sequential treatment of the mycelium with hot water, 2% aqueous NaOH and 10% AcOH gave rise to several polysaccharide fractions, which were characterized by their monosaccharide composition. The yield ofchitosan extracted by AcOH was negligible. Additional purification of the fraction obtained by the action of alkali afforded a polysaccharide preparation, which was shown to be a linear (1-->3)-alpha-D-glucopyranan according to the data of chemical methods of structural analysis and NMR spectroscopy. It was concluded that Cunninghamella japonica differs from several other known representatives of Mucorales by the presence of this alpha-D-glucan, as well as by low content of chitosan and polyuronides.

[Submerged cultivation of Lentinus edodes strain with broad spectrum biological activity].

A highly potent strain of Lentinus edodes producing lentinomycin B, an erythadenin metabolite showing hypolipidemic activity, and biologically active water soluble endopolysaccharides was isolated. The optimum composition of the medium for the strain submerged cultivation was developed. The medium provided shorter period of the strain cultivation and a 2-fold increase of the biomass yield and production of the endopolysaccharides up to 21 g/l and 4.8 g/l of the culture fluid respectively. The total fraction of the water soluble polysaccharides isolated from the mycelium contained glucose, galactose, mannose, arabinose and xylose as the neutral monosaccharides. Glucose was the main monosaccharide. The procedure of the strain submerged cultivation provided production of several final substances during a single technological cycle.

[Submerged cultivation and chemical composition of Hericium erinaceus mycelium].

Submerged cultivation of Hericium erinaceus in various media was studied. The yield of the biomass was shown to depend mainly on the carbon source, whereas the content of water soluble polysaccharides depended mainly on the nitrogen source. The optimal medium composition provided the biomass yield of 21-23 g/l in 7 days. The biomass was characterized by the content of total protein, lipids and carbohydrates. In addition, the amino acid composition of the biomass was determined and shown to meet all the requirements of FAO/WHO concerning the amounts of essential amino acids (with exception of tryptophane). Oleinic and linoleic acids were identified as the main components of the fatty acids. Two water soluble polysaccharide fractions differing in solubility in aqueous ethanol were isolated and shown to contain rhamnose, fucose, xylose, glucose and galactose in different proportions. Vitamins B1, B2, B6, PP and E, ergosterol and coenzyme Q were also detected in the biomass of H. erinaceus.

[Polysaccharide composition of mycelium and cell walls of the fungus Penicillium roqueforti].

Preliminary data on the polysaccharide composition of mycelium and cell walls of the submergedly grown fungus Penicillium roqueforti were obtained. Mild acid hydrolysis of mycelium and cell walls led to formation of glucose, mannose and galactose, whereas acid treatment under drastic conditions afforded glucosamine as the hydrolysis product of chitin, which content in the cell walls was estimated as 19%. Sequential treatment of the mycelium with hot water and 1 M NaOH at room temperature gave rise to several polysaccharide fractions, which were characterized by their monosaccharide composition. The main fraction obtained by the action of alkali, according to NMR spectroscopy, mass spectrometry and chemical methods of structural analysis data, is a linear alpha-D-glucopyranan containing blocks of (1 --> 3)-linked glucose residues interconnected by (1 --> 4)-linkages. Water-soluble polysaccharides contained linear blocks of (1 --> 5)-linked beta-galactofuranose residues, probably connected with a mannan core. The data obtained may be important for chemotaxonomy of the genus Penicillium.

[Filamentous fungi's cell-wall extraction at different stages of ontogenesis and exploration of their carbohydrate composition].

Methods of obtaining cell walls (CW) for specimens of mucoraceous molds and ascomycetic affined fungi are developed at the stage of mycelium and resting cells, or spores. CW purity was assessed by electron microscopy, specific staining methods, scourage control, presence of ribose and desoxyribose, and the comparison of chitin content in whole cells and CW of fungi (a new criteria). The authors discuss the significance of the proposed methods of obtaining pure fractions of CW and of the study of their carbohydrate content for the chemotaxonomy of filamentous fungi.

Polysaccharides of basidiomycetes. alkali-soluble polysaccharides from the mycelium of white rot fungus Ganoderma lucidum (Curt.: Fr.) P. Karst.

Two polysaccharides were isolated from submergedly cultured mycelium of the basidiomycete Ganoderma lucidum by extraction with alkali followed by fractionation with Fehling reagent. The polysaccharides were shown to be a linear (1-->3)-alpha-D-glucan and a highly branched xylomannan containing a backbone built up of (1-->3)-linked alpha-D-mannopyranose residues, the majority of which are substituted at O-4 by single beta-D-xylopyranose residues or by disaccharide fragments beta-D-Manp-(1-->3)-beta-D-Xylp-(1-->. Polysaccharide structures were elucidated by NMR spectroscopy in combination with methylation analysis and periodate oxidation. An interesting feature of the xylomannan is the simultaneous presence of alpha-D-mannopyranose and beta-D-mannopyranose residues, the first forming the backbone, and the second being the non-reducing terminal units of disaccharide side chains.

[Anticoagulant activity of fucoidans from brown algae].

The anticoagulant activity of polysaccharide fucoidans from 11 species of brown algae was studied. The anticoagulant activity was measured by the activated partial thromboplastin time (APTT), prothrombin time and thrombin time. Inhibitory action of fucoidans varied significantly from one species to another. Fucoidans from Laminaria saccharina and Fucus distichus showed high anticoagulant activities, while fucoidans from Cladosiphon okamuranus and Analipus japonicus were almost inactive. The fucoidan inhibitory effect on thrombin and factor Xa in the presence or in the absence of natural thrombin inhibitor, antithrombin III (AT III), was also studied. In contrast to the best studied anticoagulant heparin the most of the fucoidans inhibited thrombin in the absence of AT III. In the presence of AT III inhibitory effect of fucoidans was increased considerably. Unlike heparin, the effect of fucoidans on factor Xa was very weak in the presence of AT III and was not observed in the absence of AT III. The correlation between the anticoagulant activities of this series of fucoidans and their anti-inflammatory action, studied by us earlier, was not found. It is expected that two these types of fucoidan activities depend on different structural features of fucoidans. These findings show the possibility to obtain fucoidans with high anti-inflammatory action and with low anticoagulant activity. Anticoagulant activity of the fucoidans did not depend on the content of fucose, the other neutral sugars and sulfates in the preparations, and also on the structure of the backbone of molecule. Taken together, these results indicate on prospects of fucoidan study as potential therapeutic agents.

[A highly branched storage polyglucan in the thermoacidophilic red microalga Galdieria maxima cells].

The thermoacidophilic red alga Galdieria maxima is capable of heterotrophic growth. The content of carbohydrates in H. maxima grown heterotrophically increases by a factor of 4, reaching as much as 60% of cell dry weight. The increase in the level of carbohydrates in cells is due to accumulation of a storage alpha-glycan. According to a specific cleavage to glucose catalyzed by amyloglucosidase and the high positive specific optical rotation characteristic of polyglucans, this polysaccharide can be classified as a floridean starch. The data of 1H NMR spectroscopy and the results of methylation showed that the average length of the unbranched regions of the polysaccharide molecule is six to seven glucose residues. The degree of branching of the starch molecule of G. maxima is greater than that of storage polysaccharides of other red algae, glycogens of yeast, and phytoglycogens of cyanobacteria.

[Polysaccharides of algae: 60. Fucoidan from the Pacific brown alga Analipus japonicus (Harv.) Winne (Ectocarpales, Scytosiphonaceae)].

A fucoidan containing L-fucose, sulfate, and O-acetyl groups at a molar ratio of 3 : 2 : 1, as well as minor amounts of xylose, galactose, and uronic acids was isolated from the brown alga Analipus japonicus collected in the Sea of Japan. The structures of the native polysaccharide and the products of its desulfation and deacetylation were studied by the methods of methylation, periodate oxidation, and NMR spectroscopy. It was shown that the polysaccharide molecule mainly consists of a linear carbohydrate chain of (1-->3)-linked alpha-L-fucopyranose residues, which bear numerous branches in the form of single alpha-L-fucopyranose residues (three branches at position 4 and one branch at position 2 per each ten residues of the main chain). Sulfate groups occupy positions 2 and (to a lesser extent) 4, most of the terminal nonreducing fucose residues being sulfated twice. The acetyl groups are located predominantly at positions 4. The structural role of minor monosaccharides was not established.

[Complex morpho-functional characteristic of adrenal medulla and cardiac sino-auricular area in dogs after 30 day hypokinesia].

The aim of this study was to characterize tissue components of adrenal medulla and cardiac sino-auricular area in dogs exposed to hypokinesia for 30 days. The material was studied using the methods of light and electron microscopy. The quantitative and qualitative morphological features indicative of high functional activity of both structures were detected at tissue, cellular and subcellular level. Cardiomyocytes in the sino-auricular area demonstrated the reactive changes of energy-producing apparatus and membrane systems, responsible for ion exchange, while myofibrils remained intact. It is concluded that after 30-day hypokinesia adrenomedullary secretory activity was markedly increased, which in association with an increased chronotropic function of the heart may cause negative changes in contractile and conducting cardiomyocytes of sino-auricular area.

Effect of enzyme preparation from the marine mollusk Littorina kurila on fucoidan from the brown alga Fucus distichus.

A fucoidanase preparation from the marine mollusk Littorina kurila cleaved some glycosidic bonds in fucoidan from the brown alga Fucus distichus, but neither fucose nor lower oligosaccharides were produced. The main product isolated from the incubation mixture was a polysaccharide built up of disaccharide repeating units -->3)-alpha-L-Fucp-(2,4-di-SO3(-))-(1-->4)-alpha-L-Fucp-(2SO3(-))-(1-->, the structure coinciding with the idealized formula proposed for the initial substance. A polymer fraction with the same carbohydrate chain but sulfated only at positions 2 and nonstoichiometrically acetylated at positions 3 and 4 of fucose residues was isolated as a minor component. It is suggested that the native polysaccharide should contain small amounts of non-sulfated and non-acetylated fucose residues, and only their glycosidic bonds are cleaved by the enzyme. The enzymatic hydrolysis showed that irregular regions of the native polysaccharide containing acetylated and partially sulfated repeating units were assembled in blocks.

[Polar components of Black sea seaweed Colpomenia peregrina (Sauv.) Hamel]. / Poliarnye komonenty chernomorskoi buroi vodorosli Colpomenia peregrina (Sauv.) Hamel.

GC-MS of trimethylsilyl derivatives of the compounds present in the butanolic extract of biomass of brown seaweed Colpomenia peregrina from the Black Sea aided in identification of 24 components, including aliphatic hydroxy and keto and aromatic acids, glycerol, mannitol, floridoside, and monosaccharides. The polysaccharide composition of the biomass was also studied, with high sodium alginate and laminaran contents and a comparatively low level of fucoidan being revealed. The polysaccharides were isolated from the biomass by fractional extraction and purified by precipitation or ion exchange chromatography. The structures of alginic acid and laminaran were deduced from 13C NMR spectra and confirmed, in the case of laminaran, by methylation analysis. The sodium alginate was shown to contain more guluronic (G) than mannuronic acid (M) residues, the M/G ratio being 0.48. Laminaran was demonstrated to be a beta-glucan with 1-->3 linkages in its backbone and 1-->6 linkages in its branching points, which is characteristic of brown algae. Fucoidan turned out to be a complex heteropolysaccharide containing, in addition to fucose and sulfate, other neutral monosaccharides and uronic acids. The English version of the paper: Russian Journal of Bioorganic Chemistry, 2004, vol. 30, no. 2; see also http://www.maik.ru