Production and partial properties of an extracellular polysaccharide from Streptomyces sp. A-1845

An extracellular polysaccharide was isolated from culture broth of Streptomyces sp. A-1845 by ethanol precipitation, DEAE-Toyopearl column chromatography and gel filtrations in Toyopearl HW75f and HW65s. The purified polysaccharide gave a single peak on Toyopearl HW65s gel filtration. Nitrogen and phosphorus content of the purified preparation were 4 and 2.5%, respectively. It was composed of d-mannose, d-galactose, d-galacturonic acid, d-xylose, d-glucosamine, l-rhamnoe, d-glucose, l-fucose, d-ribose and d-galactosamine in the ratio of 7.6, 4.0, 3.4, 3.1, 2.6, 1.9, 1.7, 1.1, 1.0 and 0.6.     

Specificity of sugar-phospholipid interactions

Previous studies by Lefevre et al. (6) have shown that phospholipids stimulate uptake of glucose and other sugars by lipid solvents and enhance transfer of glucose through solvent layers into water. In this paper the specificity of the process for different sugars is investigated by following uptake from thin films of sugars or from glass fiber strips coated with radioactive sugars. Hexoses were taken up slowly to molar ratios of sugar to lipid phosphorus of about 1:1. Pentoses and deoxy sugars were taken up 5–10 times more rapidly to molar ratios of between 1.5 and 2.5:1. Relative rates of formation of the complexes at 25 °C were (d-glucose = 1.0):l-fucose, 9.1; d-ribose, 6.1; d-arabinose, 5.5; l-rhamnose, 3.8; l-arabinose, 3.7; d-xylose, 3.6; d-lyxose, 3.1; 3-O-methyl-d-glucose, 1.52; d-mannose, 1.36; d-galactose, 1.13; sucrose, 0.03; and lactose, 0.015. Radioactive sugars bound to phospholipids exchanged readily with unlabeled sugar in the anhydrous state and the sugars passed slowly into the aqueous phase when the complexes were shaken with water. The relative rates of dissociation (d-glucose = 1.0): l-arabinose, 2.82; d-arabinose, 2.49; l-rhamnose, 2.26; l-fucose, 1.96; d-xylose, 1.65; 3-O-methyl-d-glucose, 0.37; d-galactose, 0.28 were in the same general order as formation, suggesting that a common intermediate may be involved in both processes. In general, sugars with high mutarotation rates reacted most rapidly indicating a possible relationship between the structural features which favor interaction with phospholipids and those which enhance mutarotation.     

Some properties of polysaccharides of microorganisms from degraded straw

Extracellular polysachcarides from bacteria and yeasts isolated from decomposed straw contained various proportions of d-galactose, d-glucose, d-mannose, uronic acid, d-xylose, l-fucose and l-rhamnose. Molecular weights of the polymers determined by viscometry and gel filtration were in the range 40 000–1800 000. All the polysaccharides stabilized aggregates of volcanic ash and most were more effective than the polysaccharide from Lipomyces starkeyi. Effectiveness seemed to be more related to molecular weight than to chemical composition.     

Composition of a methylated,acidic polysaccharide associated with coccoliths of Emiliania huxleyi (Lohmann) Kamptner

The water-soluble, acidic polysaccharide isolated from the coccoliths of the alga Emiliania huxleyi (Lohmann) Kamptner contains residues of the following sugars: l-galactose, d-glucose, d-mannose, l-mannose, l-rhamnose, l-arabinose, d-ribose, d-xylose, 6-O-methyl-d-mannose, 6-O-methyl-l-mannose, 2,3-di-O-methyl-l-rhamnose, 3-O-methyl-d-xylose, and d-galacturonic acid. l-Mannose, 6-O-methyl-d-mannose, 6-O-methyl-l-mannose, and 2,3-di-O-methyl-l-rhamnose are novel constituents of a polysaccharide. In addition, the presence of sulphate groups was found. Galacturonic acid and sulphate in the polysaccharide bind Ca²⁺ ions apparently in a ratio of one mol of Ca²⁺ per mol of acidic residue. This feature is relevant for the proposed matrix function of the polysaccharide in the formation of the calcified cell-wall plates (coccoliths) of the alga.     

Carbohydrates of Padina tetrastromatica

Extraction with hydrochloric acid (pH 2.5) of the brown alga Padina tetrastromatica afforded water-soluble and water-insoluble polysaccharides. The water-soluble polysaccharide was fractionated using cetyltritmethyl ammonium bromide and chromatography on DEAE-cellulose and Sephadex G-100. A neutral laminaran like glucan and two new sulphated heteropolysaccharides comprising d-glucuronic acid, l-fucose, l-rhamnose, d-xylose, d-arabinose, d-galactose, d-glucose and half-ester sulphate were obtained. The alginic acid isolated from this brown seaweed was found to be predominantly of poly 1 → 4β-d-mannuronic acid type. The water-soluble sulphated polymer showed high anticoagulant activity.     

Mucilage from a fresh-water red alga of the genus Batrachospermum

The gelatinous polysaccharides of a Batrachospermum species have been extracted from the alga. The major polysaccharide is acidic and has been separated from neutral polysaccharides by chromatography on DEAE-cellulose. The constituent sugars of the acidic polysaccharide include d- and l-galactose, d-mannose, d-xylose, l-rhamnose, d-glucuronic acid, and two O-methyl sugars, which have been characterized as 3-O-methyl-l-rhamnose (l-acofriose and 3-O-methyl-d-galactose. Partial acid hydrolysis of this polysaccharide has given a complex mixture of neutral and acidic oligosaccharides. The two preponderant acidic oligosaccharides contained galactose and glucuronic acid in 1:1 ratio, suggesting the presence of a repeating sequence of these two residues as a major structural feature of the polysaccharide.     

A galactoglucomannan from extracellular polysaccharides of suspension-cultured cells of Nicotiana tabacum

A polysaccharide containing d-xylose, l-arabinose, d-mannose, d-galactose and d-glucose residues in the molar ratio of 0.07:0.16:1.     

Structural studies on Klebsiella type 61 capsular polysaccharide

The capsular polysaccharide from klebsiella type 61 was found to contain d-galactose, d-glucose, d-mannose, and d-glucuronic acid in the ratios 1:2:1:1. Acid hydrolysis of the polysaccharide gave one aldobiouronic acid, whose structure was established. Methylation analysis of the polysaccharide provided information about the linkages in the polysaccharide. The polysaccharide is composed of a pentasaccharide repeating unit for which structures are proposed.     

Isolation and structural elucidation of a water-soluble polysaccharide (PS-I) of a wild edible mushroom, Termitomyces striatus

A heteropolysaccharide (PS-I), isolated from the hot aqueous extract of an edible mushroom, Termitomyces striatus, is composed of d-glucose, d-galactose, d-mannose and l-fucose in a molar ratio 2:1:1:1. Structural investigation of the native as well as the Smith-degraded polysaccharide was carried out using methylation analysis, periodate oxidation studies and 1D and 2D NMR spectroscopy, and the repeating unit of the polysaccharide is established as follows: [carbohydrate structure: see text]     

Isolation and characterization of β-d-glucan,heteropolysaccharide, and trehalose components of the basidiomycetous lichen Cora pavonia

Cora pavonia, a lichen having a basidiomycetous mycobiont, is rich in protein (36%), of which 10% is tyrosine. α,α-Trehalose is present and was isolated in 4.4% yield. The lichen was found to contain polysaccharides typical of basidiomycetes and different from those of ascomycetes and ascomycetous lichens. Isolated and characterized were a β-d-glucan and a heteropolysaccharide containing l-rhamnose, l-fucose, d-xylose, d-mannose, d-glucose, and d-galactose. The β-d-glucan was highly branched with 21% of nonreducing end-groups, contained 3-O-, 6-O-, and 3,6-di-O-substituted β-d-glucopyranosyl units, and had a main chain consisting of (1→3)- and (1→6)-links. The heteropolysaccharide component contained mainly mannose and xylose, having a mannose-containing nucleus and a main chain with preponderant (1→3)-linked α-d-mannopyranosyl residues. These were unsubstituted (10%), and 4-O- (10%) and 2,4-di-O-substituted (10%) with residues of β-d-xylopyranose. On methylation analysis of the heteropolysaccharide, a capillary column of DB-210 proved to be particularly useful for gas-liquid chromatographic resolution of partially O-methylated alditol acetates.     

Utilization of degraded peach gum polysaccharide by Aspergillus flavus

d-Galactose, d-mannose, d-xylose, l-arabinose, and d-glucuronic acid and its γ-lactone were examined as carbon sources for the culture of Aspergillus flavus. d-Mannose was taken up the most rapidly and d-glucuronic acid and its γ-lactone the least rapidly. A partially degraded polysaccharide from peach tree gum (Prunus persica [L.] Batsch containing the above sugars together with d-glucuronic acid and its 4-O-methyl ether was used as substrate for another A. flavus culture. It was found that d-galactose was the major sugar passing into the culture medium with lower proportions of d-xylose, l-arabinose, 2-O-β-d-glucopyranuronosyl-d-mannose, and 6-O-β-d-glucopyranuronosyl-d-galactose. This indicates that the fungus produces extracellular exo- and endo-glycanohydrolases which may be useful in structural studies on polysaccharides.     

Ethanol production from d-galactose and glycerol by Pachysolen tannophilus

Pachysolen tannophilus has recently been shown to be able to convert d-xylose, a pentose, to ethanol. Previously, d-xylose had been considered to be nonfermentable by yeasts. The present study shows that the organism can be used to obtain ethanol from other carbohydrates previously considered as nonfermentable, either by P. tannophilus in particular, d-galactose, or by yeasts in general, glycerol. Such identification for d-galactose allows P. tannophilus to be considered for fermentation of four of the five major plant monosaccharides: d-glucose, d-mannose, d-galactose and d-xylose. The ability to ferment glycerol is of potential use, in part, for the conversion of glycerol derived from algae into ethanol.     

Purification and structural investigation of a water-soluble polysaccharide from Flammulina velutipes

A novel water-soluble heteropolysaccharide FVP60-B was extracted from the fruiting bodies of Flammulina velutipes with boiling water and purified by Sephacryl S-300 and S-400, which molecular weight was estimated to be 1.3 × 10⁴ Da by HPLC. It is composed of l-fucose, d-mannose, d-glucose and d-galactose in a ratio of 1.16:0.82:1.00:3.08. Sugar analysis, methylation analysis together with ¹H, ¹³C and 2D NMR spectroscopy disclosed that FVP60-B is consisted of a α-(1 → 6)-d-galactopyranan backbone with a terminal fucosyl, terminal glucosyl and α-(1 → 6)-d-mannopyranan units on O-2 of 2,6-O-substituted-d-galactosyl units.     

Chemical investigations on the gum exudate from sajna (Moringa oleifera)

The purified, whole-gum exudate from the drum-stick plant (Moringa oleifera) was found to contain l-arabinose, d-galactose, d-glucuronic acid, l-rhamnose, d-mannose, and d-xylose in the molar ratios of ～ 14.5:11.3:3:2:1:1. A homogeneous, degraded-gum polysaccharide consisting of d-galactose, d-glucuronic acid, and d-mannose in the molar ratios of ～ 11.7:3.9:1, was obtained on mild hydrolysis of the whole gum with acid. Permethylation studies were conducted on the whole gum, the degraded gum, and their carboxyl-reduced products, and the results were in good agreement with those obtained from periodate oxidation followed by Smith degradation. Also, isolation and characterization of the oligosaccharides obtained from the mother liquor during preparation of the degraded gum, and by graded hydrolysis of the degraded gum, were achieved. On the basis of the results obtained from these studies, a tentative structure was assigned to the average repeating-unit of the gum.     

Structural features of the mucilage from the stem pith of kiwifruit (actinidia deliciosa): part I,structure of the inner core

The mucilage found in the stem pith of Actinidia deliciosa contains d-glucuronic acid, d-mannose, l-fucose, l-arabinose, and d-galactose in the molar ratios 1.0:1.5:2.0:4.0. The native, carboxyl-reduced, and partially acid-hydrolysed polysaccharides were subjected to methylation analysis. Partial acid hydrolysis of the methylated, carboxyl-reduced glucuronomannan core produced a series of methylated oligosaccharides which, as their alditol derivatives, were isolated by reverse-phase h.p.l.c. and characterised by e.i.- and f.a.b.-m.s. The data suggest that the polysaccharide contains a →4)-β-d-GlcpA-(1→2)-α-d-Manp-(1→ backbone with most of the d-mannosyl and d-glucosyluronic acid residues substituted through positions 3 with oligosaccharides containing l-arabinose, α-l-fucose, and β-d-galactose.     

Structural studies of an acidic polysaccharide from the mucin secreted by Drosera capensis

The polysaccharide of the mucin secreted by the leaves of Drosera capensis is composed of l-arabinose, d-xylose, d-galactose, d-mannose, and d-glucuronic acid in the molar ratio of 3.6:1.0:4.9:8.4:8.2. For structural elucidation, methylation analysis using g.l.c. and g.l.c.-m.s. was performed on the native, the carboxyl-reduced, and the degraded polysaccharides. Partial hydrolysis, periodate oxidation, chromium trioxide oxidation, and uronic acid degradation were also performed on the native and carboxyl-reduced polysaccharides. Partial hydrolysis of the native and carboxyl-reduced polysaccharides gave various oligosaccharides that were characterized and suggest a structure containing a d-glucurono-d-mannan backbone having a repeating unit → 4)-β-d-GlcpA-(1 → 2)-α-d-Manp-(1 →. l-Arabinose and d-xylose are present as nonreducing furanosyl and pyranosyl end-groups, respectively, both attached to O-3 of d-glucuronic acid residues of the backbone. d-Galactose is present as non-reducing pyranosyl end-group linked to O-3 of d-mannose residues.     

Preparation of anomeric pairs of 1-thioglycosides: use of anomerization catalyzed by boron trifluoride

Anomeric pairs of some alkyl 1-thioaldopyranosides of d-galactose, d-glucose, d-mannose, 2-acetamido-2-deoxy-d-glucose, 2-acetamido-2-deoxy-d-galactose, and l-fucose were prepared. The per-O-acetylated, 1,2-trans anomers of 6-(trifluoroacetamido)hexyl 1-thioaldopyranosides and 5-(methoxycarbonyl)pentyl 1-thioaldopyranosides were anomerized with boron trifluoride in dichloromethane. The anomeric mixtures were then separated by chromatography, using columns of either silica gel or an ion-exchange resin. De-blocking of the separated compounds provided pure anomers of 6-aminobexyl 1-thioaldopyranosides or 5-carboxypentyl 1-thioaldopyranosides. The aglycons of the latter glycosides were further extended by reaction with aminoacetaldehyde diethyl acetal, which, after deacetalization of the products, provided an ω-aldehydo group. These series of glycosides could be readily coupled to proteins or solid matrices.     

Structural investigation of the sodium hydroxide-soluble polysaccharides of tobacco (Nicotiana tabacum): An arabinoxyloglucan

An arabinoxyloglucan (amyloid) isolated from bright tobacco (Nicotiana tabacum, L. cv., Delhi 76) consists of l-arabinose, d-xylose, and d-glucose residues in the molar ratios 1:2.2:6.8. Sedimentation data indicate that the polysaccharide is homogeneous. The methylation analysis data show a statistical unit of 20 sugar residues with 5 terminal, non-reducing end-groups (3 d-xylosyl and 2 l-arabinosyl). There are 5 residues of d-glucose involved in branching through positions 4 and 6. The remaining 10 non-terminal residues consist of two (1→2)-linked d-xylosyl residues and eight (1→4)-linked d-glucosyl residues. The proposed statistical unit accords with the periodate-oxidation results.The formation of ∼0.1 mol each of 2,3,4,6-tetra-O-methyl- and 2,3,4-tri-O-methyl-d-glucose suggests that an average unit may contain ∼200 sugar residues.     

Isolation and characterisation of lignin-carbohydrate complexes from the milled-wood lignin fraction of Pinus densiflora sieb. et zucc.

The lignin-carbohydrate complex (LCC-W), isolated from the milled-wood, lignin fraction of Pinus densiflora Sieb. et Zucc., comprised three fractions (W-1,2,3) by gel filtration on Sepharose 4B. W-1 was eluted at the void volume, whereas W-2 and W-3 were included in the gel and had apparent weight-average molecular weights of 5.0 × 10⁵ and 5.0 × 10³, respectively. W-2 and W-3 were homogeneous in ultracentrifugal and electrophoretic analyses. The sedimentation coefficients of W-2 and W-3 were 25.7 and 0.4S, respectively. The chemical composition of W-2 was 38.0% of neutral sugar, 6.2% of uronic acid, 51.5% of lignin, and the corresponding values for W-3 were 73.1, 11.0, and 22.2%. The neutral carbohydrate residues of W-2 and W-3 were l-arabinose, d-xylose, d-mannose, d-galactose, and d-glucose in the ratios 15.8:16.2:37.3:16.7:14.0 and 27.6:16.5:26.1:19.3:10.5, respectively. Based on the results of methylation and Smith-degradation analyses, the carbohydrate moiety of the LCC-W fractions was found to be multiply branched. The major backbone structure was composed of (1→4)-linked d-mannopyranosyl residues. By hydrophobicinteraction chromatography on Phenyl- and Octyl-Sepharsoe CL-4B gels, it is concluded that the LCC-W fractions have a hydrophobic property that is exclusively ascribed to the lignin moiety.     

Formation of glucose from hexoses, pentoses, polyols and related substances in kidney cortex

1. Slices of rat kidney cortex, on incubation in a saline medium, formed d-glucose from the following substances: d-fructose, d-galactose, d-mannose, l-sorbose, l-arabinose, d-xylose, glycerol, myo-inositol, l-iditol, sorbitol, xylitol, ribitol, methylglyoxal, dihydroxyacetone, l-glyceraldehyde, d-glyceraldehyde, dl-glyceraldehyde, dl-glycerate. Values for the rates of glucose formation from these precursors are given. 2. No glucose was formed from l-rhamnose, d-arabitol, d-arabinose, d-ribose, l-fucose, d-lyxose, mannitol, dulcitol, d-glucuronate, propane-1,2-diol and propan-2-ol. 3. The pathways of glucose formation from the various precursors are discussed (Scheme 1). 4. l-Glyceraldehyde inhibited the formation of glucose from d-glyceraldehyde.