Extracellular polysaccharides from suspension-cultured sycamore cells

1969 ◽  
Vol 47 (11) ◽  
pp. 1063-1070 ◽  
Author(s):  
G. O. Aspinall ◽  
J. A. Molloy ◽  
J. W. T. Craig

Three polysaccharides have been isolated from the culture medium of suspension-cultured sycamore cells (Acer pseudoplatanus L.). A pectinic acid which contains 67% of galacturonic acid residues has been shown to have features in common with other pectins, with arabinose, galactose, and rhamnose as constituent sugars. Methylation and partial hydrolysis have indicated that the arabinogalactan is similar to those from coniferous woods in containing a highly branched framework of D-galactopyranose residues mutually joined by (1 → 3) and (1 → 6) linkages with the majority of side chains terminated by L-arabinofuranose residues. A fucoxyloglucan has been shown by methylation and enzymic hydrolysis to possess a structure similar to those of the so-called seed 'amyloids' with a cellulose-like (1 → 4)-linked β-D-glucan chain with side chains terminated by L-fucopyranose and D-xylopyranose residues.

1965 ◽  
Vol 43 (4) ◽  
pp. 758-765 ◽  
Author(s):  
S. S. Bhattacharjee ◽  
T. E. Timell

A pectic material has been isolated from the bark of Abies amabilis (Dougl.) Forbes in a yield of 2%. On hydrolysis it yielded D-galacturonic acid, D-galactose, and L-arabinose in a ratio of 85:4:11, and also traces of rhamnose. The product, when submitted to several conventional fractionation methods, appeared homogeneous. Further resolution could be effected by acidification of an aqueous solution of the pectin, followed by ultracentrifugation. The insoluble portion (50%) was an electrophoretically homogeneous galacturonan with [α]D + 246°. The material remaining in solution (30%), here referred to as a pectic acid, had [α]D + 225° and on hydrolysis gave D-galacturonic acid, D-galactose, and L-arbabinose in a ratio of 74:7:19, as well as traces of rhamnose.The structure of the galacturonan was established by partial hydrolysis and methylation. It consisted of α-D-galacturonic acid residues linked together by (1 → 4)-glycosidic bonds to a linear macromolecule. The same techniques were applied to the pectic acid. While a unique structural formula could not be assigned in this case, one probable alternative involved a framework of (1 → 4)-linked α-D-galacturonic acid residues together with a few residues of 1,2,4-linked L-rhamnose. Some of the galacturonic acid units carried at C-2 and C-3 side chains which were terminated by D-galactopyranose and L-arabinofuranose residues. A few of the latter also occurred as inner units, probably in the side chains. This appears to be the first time a pectic material has been resolved into a galacturonan and a pectic acid containing the four sugar residues usually found in pectins. It is probable that the pectin occurring to a limited extent in wood has a similar composition.


1977 ◽  
Vol 55 (19) ◽  
pp. 2530-2534 ◽  
Author(s):  
F. Maillard ◽  
J.-P. Zrÿd

Incubation of cell suspensions of sycamore (Acer pseudoplatanus) with β-indoyl-3-acetic acid (IAA) first led to the formation of IAA-glycosides, then to that of IAA-aspartate. Great differences are observed between the kinetics of IAA transformed by two distinct strains: one, auxin dependent (S), the other, auxin independent (MB). Other degradation products are only found in the culture medium. The localization of IAA-degrading systems in the cell wall is postulated. The auxin requirement of the S strain is discussed.


1973 ◽  
Vol 51 (3) ◽  
pp. 219-224 ◽  
Author(s):  
C. G. Fraser ◽  
H. J. Jennings ◽  
P. Moyna

An acidic polysaccharide has been isolated from the culture medium of T. mesenterica NRRL Y-6158. The heteropolymer contained D-xylose, D-mannose, D-glucuronic acid, and O-acetyl in the molar ratios of 7:5:1:0.7, respectively. Methylation analysis of the heteropolymer indicated that it was essentially a 1 → 3-α-linked mannopyranose backbone having approximately 80% of the backbone units substituted, thus forming a very highly branched structure. The substituents on the backbone were found to be D-glucopyranosyluronic acid end-group, β-linked to the O-2 positions of the mannopyranose units, and 2-O-β-D-linked xylopyranose side-chains, linked both to the O-2 and O-4 positions of the mannopyranose backbone. The methylation analysis suggests that these side-chains are probably two or three xylopyranose units long, although a limited variation in the length of the side-chains is a possibility.


OENO One ◽  
1988 ◽  
Vol 22 (2) ◽  
pp. 135
Author(s):  
Luc Saulnier ◽  
Jean-Marc Brillouet ◽  
Michel Moutounet

<p style="text-align: justify;">Après une mise au point rapide sur les connaissances actuelles des polyosides pectiquesdans les végétaux, les résultats acquis sur la structure des substances pectiques de la pulpe deraisin sont exposés, avec un rappel de la méthodologie utilisée.</p><p style="text-align: justify;">Un matériel insoluble à l'alcool (MIA) a été préparé à partir de pulpe de raisin. Quatre fractionspectiques en ont été isolées après traitements successifs par l'eau (25°C; PSE), l'oxalate(25°C; PSOX, l'acide (HCI 0.05M, 80°C; PSH) et la soude (O,05M, 4°C; PSOH).</p><p style="text-align: justify;">Les PSE (35 p.100) et PSH (55 p. 100) représentent l'essentiel du matériel pectique extrait.Les PSE sont séparées par chromatographie d'échange d'ions en fractions neutre (PSEn~ 13 p. 100) et acide (PSEa ~ 87 p. 100). Les PSEa et les PSH sont constituées principalementd'acide galacturonique (PSEa 63 p. 100, PSH 53 p. 100), fortement estérifié par du méthanol(degré d'estérification : PSEa 77 p. 100, PSH 68 p. 100), tandis que des quantités faibles d'acideglucuronique sont détectées dans les PSEn (2 p. 100). Les oses neutres (PSEn 65 p. 100, PSEa28 p. 100, PSH 19 p. 100) sont principalement de l'arabinose et du galactose suivis dans unordre décroissant du rhamnose, glucose, xylose, mannose et fucose. Des protéines sont égaIementdétectées en association avec les polyosides.</p><p style="text-align: justify;">L'action d'une endopolygalacturonase et d'une endopectine-Iyase sur PSEa et PSH met enévidence des zones «lisses» homogalacturoniques dégradées par les enzymes et des zones«hérissées» rhamnogalacturoniques riches en chaînes latérales d'oses neutres, insensibles àl'attaque enzymatique. Le traitement du MIA par une endopectine-Iyase solubilise un matérielpectique (ZH-MIA) riche en oses neutres (56 p. 100) particulièrement en arabinose, et contenantde l'acide galacturonique (23 p. 100) et des protéines (11 p. 100).</p><p style="text-align: justify;">La perméthylation associée à l'hydrolyse spécifique de l'arabinose par une α-L-arabinofuranosidaseet à la RMN du <sup>13</sup>C a permis d'établir la structure des chaînes latérales. Des (1 → 3) / (1 → 6) arabinogalactanes, où l'arabinose est essentiellement sous forme terminale non réductrice, dominent dans les ZH-PSE, tout comme dans les PSEn confirmant leur caractère d'arabinogalactane-protéine. En revanche ces structures ainsi que les (1 → 4) arabinogalactanes sont minoritaires dans les ZH-PSH et ZH-MIA où les structures de type (1 → 5) arabinanes et rhamnogalacturonanes sont prédominants.</p><p style="text-align: justify;">+++</p><p style="text-align: justify;">After a brief review of available knowledges on plant pectic polysaccharides, structural data on pectic substances from the pulp or grape berries and related analytical techniques are reported.</p><p style="text-align: justify;">An alcohol insoluble residue (MIA) was prepared from pulp of grape berries, which was sequentially extracted with water (25°C), oxalate (25°C), acid (0,05N HCI, 80°C) and sodium  hydroxide (0,05N 4°C) yielding four pectic fractions, respectively, PSE, PSOX, PSH and PSOH. PSE (35 p. 100) and PSH (55 p. 100) represented the main part of extracted pectic material.</p><p style="text-align: justify;">PSE were fractionated by ion-exchange chromatography into neutral (PSEn ~ 13 p. 100) and acidic (PSEa ~ 87 p. 100) fractions. PSEa and PSH were constituted mainly of galacturonic acid (PSEa 63 p. 100, PSH 53 p. 100) highly methylesterified (esterification degree : PSEa 77 p. 100; PSH 68 p. 100), whereas PSEn contained minute amounts of glucuronic acid (2 p. 100). Neutral sugars (PSEn 65 p. 100, PSEa 28 p. 100, PSH 19 p. 100) were mainly arabinose and galactose followed by decreasing amounts of rhamnose, xylose, glucose, mannose and fucose. Proteins were also detected along with the polysaccharides.</p><p style="text-align: justify;">Degradation of PSEa and PSH by endopolygalacturonase and endopectin-lyase evidenced «smooth» homogalacturonic areas sensitive to enzymatic degradation and «hairy» rhamnogalacturonic zones highly substituted by neutral sugar side-chains and resistant to enzyme action. Treatment of MIA With endopectinlyase released pectic material (ZH-MIA) rich in neutral sugars (56 p. 100), especially arabinose, and containing galacturonic acid (23 p. 100) and proteins (11 P. 100).</p><p style="text-align: justify;">Structure of neutral sugar side-chains was investigated using methylation analysis associated with specific hydrolysis of arabinose residues with an α-L-arabinofuranosidase, and <sup>13</sup>C NMR spectroscopy. ZH-PSE exhibited a structure of 3,6 -linked arabinogalactan substitued by monomeric terminal arabinose. Similar structures were detected in PSEn which relates them to arabino-3,6-galactan-proteins. Conversely PSH or ZH-MIA showed mainly arabinan-like and rhamnogalacturonan structures associated with minor proportions of 3,6- and 4-linked arabino-galactans.</p>


1994 ◽  
Vol 59 (12) ◽  
pp. 2714-2720 ◽  
Author(s):  
Alžbeta Kardošová ◽  
Peter Capek

A rhamnoarabinogalactan isolated from the leaves of Plantago lanceolata L. var. libor has been investigated by methylation analysis, partial hydrolysis, and 13C NMR spectroscopy. The structural conclusions obtained by 13C NMR measurements were consistent with the data from methylation analysis. The polysaccharide has a β-(1→6)-D-galactan core branched on O-3 by side chains of (1→5)-linked α-L-arabinofuranosyl units, some of which bear in position O-5 terminal β-D-galactopyranosyl residues. L-Rhamnose occurs as nonreducing ends.


1978 ◽  
Vol 5 (4) ◽  
pp. 457
Author(s):  
R.E Paull ◽  
R.L Jones

Regulation of the synthesis and secretion of sycamore extracellular polysaccharides (SEPS) was studied in cultured cells of Acer pseudoplatanus L. cv. Pope by monitoring the incorporation of L-[3H]fucose, a specific marker for the polysaccharide, into cell wall, soluble intracellular polysaccharide and secreted fractions. Actively growing cultures of sycamore cells produce SEPS, and it reaches a concentration in the incubation medium of up to 0.7 mg ml-� after 25 days of growth. Addition of SEPS at 10 mg ml-� to cells during the phase of active growth causes a marked and rapid inhibition of secretion of the polysaccharide into which [3H]fucose is incorporated without markedly affecting uptake of the label. Added SEPS also inhibits the incorporation of [3H]fucose into the homogenate fraction although this inhibition is less marked and requires higher concentrations of added SEPS. This inhibitory effect of SEPS can be mimicked by other charged polymers, for example polygalacturonic acid, polylysine and polyglycine, while uncharged polymers like polyethylene glycol and dextran are without effect. Furthermore, the incorporation of [3H]fucose into secreted polysaccharides of isolated protoplasts is relatively unaffected by added SEPS. We propose that SEPS and other charged polymers interact with the cell wall causing it to become impermeable to synthesized SEPS, which then accumulates between the plasmalemma and the cell wall and eventually inhibits polysaccharide synthesis.


2021 ◽  
Author(s):  
Juliana Campos Vieira ◽  
Jaime Aparecido Cury ◽  
Antonio Pedro Ricomini Filho

We have hypothesized that the association between human milk and caries in breastfeeding children could be explained by the combination of a diurnal cariogenic diet with the nocturnal lactose fermentation, conditions simulated in this experimental study. Cariogenic biofilm was formed on bovine enamel slabs, which were exposed 8x/day for 3 min to a 10% sucrose solution, simulating a highly cariogenic diurnal diet, or 50 mM NaCl solution (control). Simulating the nocturnal retention of milk in mouth, biofilms were transferred to culture medium containing 0.7% lactose for 2 h, or only to culture medium (control). Four groups were designed (n=12): Ctrl, no exposure to diurnal sucrose or nocturnal lactose; Lac, only nocturnal exposure to lactose (2 h); Suc, only diurnal exposure to sucrose (8x/day); and Suc→Lac, diurnal exposure to sucrose (8x/day) followed by nocturnal exposure to lactose (2 h). The medium was changed 3x/day, at the beginning of the day, and after diurnal and nocturnal exposures. Calcium in the medium was determined as chemical indicator of partial demineralizations occurred during the diurnal and the nocturnal treatments; the medium pH was also determined. After 96 h of growth, biofilms were harvested to evaluate CFU, biomass, and extracellular polysaccharides, soluble and insoluble. The percentage of enamel surface hardness loss (%SHL) was evaluated as cumulative demineralization. Data were analyzed by one-way ANOVA, Tukey’s test (α=5%). Highest %SHL (p<0.05) was found for Suc→Lac (40.6%) group when compared to Suc (32.1%), Lac (7.7%), and Ctrl (3.8%). Calcium released during the diurnal and nocturnal treatments were respectively: Suc→Lac=Suc>Lac=Ctrl and Suc→Lac=Lac>Suc=Ctrl (p<0.05). Regarding Ctr group, calcium released from nocturnal lactose fermentation by Suc→Lac group was 4-fold greater than that provoked by Lac group. The findings were supported by the pH of the media. The data suggest that the biofilm formed under diurnal exposure to sucrose enhances the cariogenicity of nocturnal exposure to lactose.


1963 ◽  
Vol 41 (9) ◽  
pp. 2357-2361 ◽  
Author(s):  
P. A. J. Gorin ◽  
J. F. T. Spencer

The extracellular polysaccharide formed from Xanthomonas hyacinthi is shown to be a branched polymer containing glucuronic acid, mannose, and glucose. Acid and enzymic hydrolysis show the presence of β-D-Glp 1 → 4 D-Man and the 4-unit sequence β-D-GlpA1 → 2 D-Manp 1 → 3 β-D-Glp 1 → 4 D-Gl. Examination by the methylation technique showed the presence of a considerable proportion of 2-linked mannopyranose units. The spectrum of methyl glycosides formed from this polysaccharide and those from Xanthomonas maculofoliigardeniae and Xanthomonas translucens are similar, and in terms of sugar linkages differentiate them from that of Xanthomonas stewartii, which contains glucuronic acid, glucose, and galactose.


1963 ◽  
Vol 41 (6) ◽  
pp. 1389-1395 ◽  
Author(s):  
A. R. Mills ◽  
T. E. Timell

An arabino-4-O-methylglucuronoxylan (10:70:12), a water-soluble galactoglucomannan (1:1:3), and an alkali-soluble galactoglucomannan (0.2:1:3) have been isolated in yields of 8.0, 1.0, and 8.1% from the wood of Engelmann spruce (Picea engelmanni). The xylan consisted of a linear framework of (1 → 4)-linked β-D-xylose residues to which were directly attached single side chains of (1 → 2)-linked 4-O-methyl-α-D-glucuronic acid and (1 → 3)-linked α-L-arabinofuranose residues. The galactoglucomannans were both composed of a backbone of (1 → 4)-linked β-D-mannose and β-D-glucose residues, some of which carried directly attached side chains of (1 → 6)-linked α-D-galactopyranose residues. Partial hydrolysis of the water-soluble galactoglucomannan yielded, among other oligosaccharides, a trisaccharide composed of galactose, glucose, and mannose residues. It is concluded that the main polysaccharides in the wood of Engelmann spruce are the same as those in most other gymnosperms. In the bark of this tree, the water-soluble galactoglucomannan is replaced by one or several polysaccharides of an entirely different composition.


1959 ◽  
Vol 37 (5) ◽  
pp. 893-898 ◽  
Author(s):  
T. E. Timell

Partial hydrolysis of the main hemicellulose constituent of sugar maple (Acersaccharum) has yielded D-xylose, D-galacturonic acid, 4-O-methyl-D-glucuronic acid, and 2-O-(4-O-methyl-α-D-glucosyluronic acid)-D-xylose. Hydrolysis of the fully methylated polysaccharide gave a mixture of 2-O- and 3-O-methyl-D-xylose, 2,3-di-O-methyl-D-xylose, 2,3,4-tri-O-methyl-D-xylose, and 2-O-(2,3,4-tri-O-methyl-α-D-glucosyluronic acid)-3-O-methyl-D-xylose in a mole ratio of 3:111:1:12. The number-average degrees of polymerization of the native and the methylated polysaccharide were 205 and 149, respectively. These data indicate that the hemicellulose is composed of a linear chain of 1,4-linked β-D-xylose residues and that on the average every tenth residue of the chain carries a terminal 4-O-methyl-D-glucuronic acid residue attached through its C2. The structure of the polysaccharide is similar to that of the main hemicellulose component of European beech, white birch, and yellow birch.


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