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Iu S Ovodov

Publications and source records attributed to Iu S Ovodov.

At least 19 recordsLinked to original sources
PubMed2000

[The isolation, preliminary study of structure and physiological activity of water-soluble polysaccharides from squeezed berries of Snowball tree Viburnum opulus].

Water-soluble polysaccharide fractions VO1-VO4 were isolated from the squeezed berries of snowball tree (Viburnum opulus) by successive extraction with water at various temperatures and pH and with aqueous solutions of ammonium oxalate. These fractions were purified by ion-exchange chromatography on DEAE cellulose, and the homogeneity of the purified polysaccharides was determined by gel filtration on Sephacryl S-500. Acidic polysaccharides close to pectins in their sugar composition were found in all the extracts (fractions VO1-1, VO2-1, VO3-2, and VO4-2). Residues of galacturonic acid, galactose, arabinose, and (to a lesser extent) rhamnose are their main constituents. Neutral polysaccharides composed mainly of galactose and mannose residues were additionally found in fractions extracted with acidified water (pH 4.0) and with aqueous ammonium oxalate solutions. Partial acidic hydrolysis and digestion with pectinase of acidic polysaccharides indicated that their carbohydrate backbone consists of alpha-1,4-linked residues of D-galacturonic acid. NMR spectra of acidic polysaccharides (fractions VO3-2 and VO3-3) confirmed this and demonstrated that their side oligosaccharide chains are composed of beta-1,4-linked galactopyranose residues and of terminal and 2,5- and 3,5-substituted residues of alpha-arabinofuranose at a Gal: Ara ratio of 3:1. Some polysaccharides from V. opulus were found to possess an immunostimulating activity: they enhance phagocytosis, in particular, the phagocytic index and the secretion of lysosomal enzymes with peritoneal macrophages. Calcium ions were found to be necessary for the appearance of the stimulating effect of acidic polysaccharides from V. opulus.

Adjuvants, Immunologic↗
PubMed2000

[Isolation and structural study of polysaccharides from campion Silene vulgaris].

Silenan SV, a pectic polysaccharide, was isolated from the aerial part of Silene vulgaris (Moench) Garke (Oberna behen (L.) Ikonn.), widespread through the European North of Russia. The polysaccharide was found to contain residues of galacturonic acid (63%), arabinose, galactose, and rhamnose as the main constituents. The results of a partial acidic hydrolysis, pectinase digestion, and NMR studies of silenan SV indicated that its molecule contains a linear alpha-1,4-D-galacturonan backbone and ramified regions. The core of the ramified regions is composed of residues of alpha-1,4-D-galacturonic acid along with 2-substituted alpha-rhamnopyranose residues. The NMR data showed that the silenan SV side chains are composed of the blocks built from the terminal alpha-1,5-linked arabinofuranose and beta-1,4-linked galactopyranose residues; these most likely are the side chains of rhamnogalacturonan, characteristic of other pectic polysaccharides. The nonreducing ends of these side chains contain alpha-arabinofuranose residues.

Hydrolysis↗
PubMed2000

[Structure and physiological activity of lemnan, Lemna minor L. pectin].

A pectic polysaccharide, lemnan, was isolated from freshly collected duckweed Lemna minor L. Its sugar chain was shown to be mainly composed of the residues of D-galacturonic acid (64%), galactose, arabinose, xylose, and D-apiose, a branched chain sugar. The high content of D-apiose (25%) indicated that lemnan is an apiogalacturonan type pectin similar to zosteran, a pectic polysaccharide from a sea phanerogam of the Zosteraceae family. The results of partial acidic hydrolysis, pectinase digestion, and NMR studies of lemnan demonstrated that its macromolecule contains regions of the linear alpha-1,4-D-galacturonan and branched apiogalacturonan. The side chains of apiogalacturonan were found to be formed of single and 1,5-linked residues of D-apiofuranose attached to 2- and 3-positions of the D-galacturonic acid residues of the apiogalacturonan backbone. Lemnan was shown to exhibit an immunomodulatory effect by activating the system of phagocytosis.

Adjuvants, Immunologic↗
PubMed1998

[Polysaccharides of flower plants: structure and physiological activity].

The results of studies on the chemical structure and physiological activity of phanerogam polysaccharides, accumulated within the last two decades, are reviewed. Three types of polysaccharides are considered: rhamnogalacturonans (pectins and related gums and mucilages, type A), acidic arabinogalactans (mainly plant mucilages, gums, and some hemicelluloses, type B), and neutral glucans and heteroglycans (reserve polysaccharides, type C). Various physiological activities of these plant polysaccharides are discussed, with particular emphasis being placed on their immunomodulatory action. The data available on the relationship between chemical structure and physiological activity of plant polysaccharides are considered. Information on the medicinal use of some plants containing physiologically active polysaccharides is presented.

Adjuvants, Immunologic↗
PubMed1994

[Structure of O-specific polysaccharide chains of the Yersinia bercoviery O:10 lipopolysaccharide].

O-specific polysaccharide composed of D-rhamnose and 3,6-dideoxy-4-C-(L- glycero-1-hydroxyethyl)-D-xylo-hexopyranose (yersiniose A) residues was obtained on mild acid degradation of the Yersinia bercovieri lipopolysaccharide. On the basis of 1H- and 13C-NMR data, methylation studies and Smith degradation, the following structure was suggested for the polysaccharide repeating unit: [formula: see text]

Carbohydrate Conformation↗
PubMed1993

[Structure of the repeating unit of O-specific polysaccharide from Vibrio fluvialis].

O-Specific polysaccharide of Vibrio fluvialis, strain AQ-0002B, is built up to pentasaccharide repeating units contained of D-mannose, 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-galactose, D-galacturonic acid and 3-0-[(R)-1'-carboxyethyl]-L-rhamnose (rhamnoactylic acid, Rha3Lac) residues. On the basis of methylation studies, solvolysis with HF, Smith degradation, 1H and 13C NMR-spectroscopy including homo- and heteronuclear correlation spectroscopy and NOE experiments, the following structure was suggested for the polysaccharide repeating unit: [formula: see text]

Carbohydrate Conformation↗
PubMed1993

[Effect of the method of extracting the pore-forming protein from Yersinia pseudotuberculosis on its macromolecular organization].

By means of physico-chemical methods, lipid bilayer reconstitution and immunoenzyme assay, macromolecular organization of porin oligomers from Yersinia pseudotuberculosis, isolated by two extraction methods, was studied. Use of SDS and high temperature in the course of the extraction led to a partial denaturation of porin trimers at the level of the tertiary structure, these conformational changes affecting the porin's pore-forming activity and antigenic structure. At the same time, the partially denatured trimers are as stable under the treatment of urea and guanidine hydrochloride as the native protein.

Bacterial Outer Membrane Proteins↗
PubMed1993

[Structure of the Yersinia rohdei O-specific polysaccharide].

An O-specific polysaccharide composed of L-rhamnose was obtained on mild acid degradation of the Yersinia rohdei lipopolysaccharide. On the basis of methylation studies and 13C NMR data, the O-specific polysaccharide is shown to be a linear L-rhamnan built up of trisaccharide repeating units of the following structure: -->3)-alpha-L-Rhap-(1-->3)-alpha-L-Rhap-(1-->3)-beta-L-Rh ap-(1--> The structure was confirmed by calculations with the use of the known glycosylation effect on 13C chemical shifts.

Carbohydrate Sequence↗
PubMed1993

[Structure of the repeating unit of acid polysaccharide from Alteromonas sp. 4MS17].

An acidic polysaccharide from Alteromonas sp. 4MC17 is built up of trisaccharide repeating units containing D-glucose, D-mannose and D-galacturonic acid residues. On the basis of methylation studies, 1H and 13C NMR-spectroscopy data, including two-dimensional homonuclear correlation spectroscopy and nuclear Overhauser effects, the following structure was suggested for the polysaccharide repeating unit: -->4)-beta-D-Glcp-(1-->4)-beta-D-GalpA-(1-->4)-beta-D-Manp-( 1-->.

Carbohydrate Conformation↗
PubMed1993

[Structure of the repeating unit of acid polysaccharide from Alteromonas macleodii 2MM6].

An acidic polysaccharide from Alteromonas macleodii 2MM6 is shown to consist of tetrasaccharide repeating units containing D-galactose, 3-O-acetyl-2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-L-guluronic acid and 3,6-dideoxy-3-(4-hydroxybutyramido)-D-galactose residues. On the basis of sugar analysis, 1H and 13C NMR-spectroscopy data including NOE and one-dimensional HOHAHA experiments, the following structure was suggested for the polysaccharide repeating unit: [formula: see text] R: -CO-CH2-CH2-CH2-OH.

Carbohydrate Conformation↗
PubMed1993

[Structure of the repeating link of the acid polysaccharide of Alteromonas haloplanktis KMM 156].

An acidic capsular and an O-specific polysaccharide were isolated from the marine microorganism Alteromonas haloplanktis KMM 156. Both polysaccharides have the identical structure and are built up of tetrasaccharide repeating units, containing two residues of L-rhamnose as well as a 2-acetamido-2-deoxy-D-glucose and a 3-O-[(R)-1-carboxyethyl]-D-glucose (Glc3Lac) residue. On the basis of methylation studies, 1H- and 13C-NMR-spectroscopy including nuclear Overhauser effect and two-dimensional heteronuclear 13C/1H correlation spectroscopy, the following structure was suggested for the polysaccharide repeating unit: [formula: see text]

Carbohydrate Sequence↗
PubMed1992

[Structure of the polysaccharide component of the bioglycan from the sea scallop Patinopecten uessoensis].

A bioglycan, [alpha]20D + 144 degrees (c 0.7, water), was isolated from the mantle of the scallop Patinopecten yessoensis, which is widespread in the Sea of Japan. The bioglycan represents a complex of alpha-D-glucan (83%) and protein (13%) and was homogeneous as judged by gel-filtration and ultracentrifugation. By means of molecular-sieve chromatography on Sepharose CL-4B, its average molecular weight was estimated as 4 MDa. Methylation studies, periodate oxidation and amylolysis showed that the polysaccharide part of the bioglycan consisted of alpha-1,4-linked D-glucopyranose residues, with side chains attached to every fourth sugar unit of the backbone through alpha-1,6-linkages (some side chains seem to be 1,3-linked). The structure of the bioglycan was confirmed by NMR spectral data. Amino acid composition of the protein part of the bioglycan was elucidated. The scallop bioglycan is related to the known bioglycans-immunomodulators of marine invertebrates with regard to the structure and immunological behaviour.

Amino Acids↗
PubMed1992

[Spatial structure and antigenic activity of non-glycosylated forms of embryonal prealbumin-1 (EPA-1NG)].

The influence of temperature and pH on the spatial structure of EPA-1NG has been studied by means of circular dichroism and differential UV-spectroscopy, indicating the molecule to consist mainly of beta-structures. A conformational transition in the molecule was observed within the range of 40-50 degrees C. The further temperature elevation (up to 70 degrees C) was accompanied to the complete distortion of the parent conformation, which is reversed after cooling down to 20 degrees C. A correlation of the spectral data with the antigenic activity of genuine EPA-1NG and its carboxymethylated, heat-degraded and pH-denatured derivatives demonstrates that some antigenic determinants of EPA-1NG appear to be topographic.

Antigens↗
PubMed1992

[Physico-chemical and immunochemical characteristics of molecular forms of carcinoembryonic antigen (CEA) not bound with concanavalin A].

A molecular form of CEA non-binding Con A (CEAnC) was isolated from colon adenocarcinoma metastases in liver as a fraction of CEA having no affinity to Con-A-Sepharose. CEAnC was shown to be immunochemically identical to CEA, but to differ substantially with regard to the amino acid and sugar composition, and structure of the sugar moiety, possibly containing non only N-, but also O-glycosyl carbohydrate chains. The antigens studied were also found to possess different spatial structures. The differences between CEA and CEAnC suggest CEAnC to be a new molecular form of CEA.

Adenocarcinoma↗