The chemistry of Pinus radiata. VI. The water-soluble galactoglucomannan

1983 ◽  
Vol 36 (5) ◽  
pp. 947 ◽  
Author(s):  
DJ Brash

The two major components of the water-soluble polysaccharides extracted from the sapwood of Pinus radiata were a galactoglucomannan and an arabinogalactan. The galactoglucomannan had a number average degree of polymerization of approximately 30, and on complete acid hydrolysis it yielded D-mannose, D-galactose and D-glucose in the ratio 4.5 : 1.3 : 1.0. The structural determination of this polysaccharide by methylation analysis and 13C n.m.r. suggested that it is a linear glucomannan with α-D-galactopyranosyl residues as single side units. No evidence could be found of any branches in the polymer, although the possibility of a small degree of branching cannot be dismissed.

1973 ◽  
Vol 14 (36) ◽  
pp. 3397-3400 ◽  
Author(s):  
T. Usui ◽  
M. Kobayashi ◽  
N. Yamaoka ◽  
K. Matsuda ◽  
K. Tuzimura ◽  
...  

1963 ◽  
Vol 41 (10) ◽  
pp. 2621-2627 ◽  
Author(s):  
H. Alfes ◽  
C. T. Bishop ◽  
F. Blank

A levorotatory glucan with a minimum degree of polymerization of 36 has been isolated from the water-soluble polysaccharides of the dermatophyte Microsporum quinckeanum. Hydrolysis of the methylated glucan yielded the following O-methyl-D-glucoses: 2,3,4,6-tetra-(10.2 mole%); 2,3,4-tri- (57.7 mole%); 2,4,6-tri- (22.2 mole%); 2,4-di- (8.2 mole%); and 2-mono- (1.6 mole%). The glucan consumed 1.53 moles of periodate with production of 0.70 mole of formic acid per mole anhydroglucose. Reduction and hydrolysis of the periodate-oxidized glucan yielded glycerol, erythritol, and D-glucose in a molar ratio of 72.3:0.6:27.1. The results showed that the glucan consisted of β-D-glucopyranose units joined in straight chains by 1 → 6 (57%) and 1 → 3 (24%) linkages. Approximately 3 in every 37 glucose residues constitute branch points in the glucan with branches occurring at the C6 and C3 positions of the same glucose unit. The glucan bears some resemblance to the yeast glucans of Saccharomyces cerevisiae and Candida albicans but differs from them in the relative number of 1 → 6 and 1 → 3 linkages and in the degree of branching.


1962 ◽  
Vol 40 (2) ◽  
pp. 348-352 ◽  
Author(s):  
G. G. S. Dutton ◽  
A. M. Unrau

By determining the amount of formaldehyde produced on periodate oxidation of borohydride-reduced apple- and cherry-wood xylans the degree of polymerization was shown to be 155 and 100 respectively. Acid hydrolysis of the polyols obtained by periodate oxidation and borohydride reduction gave ethylene glycol in amounts indicating that these xylans have a small degree of branching. Mild acid hydrolysis of the polyols demonstrated that in these xylans D-glucuronic acid as well as 4-O-methyl-D-glucuronic acid was present and that some of the former occupied non-terminal positions.


2010 ◽  
Vol 56 (5) ◽  
pp. 367-372 ◽  
Author(s):  
Evgeny Vinogradov ◽  
Leann L. MacLean ◽  
Malcolm B. Perry

The structure of the antigenic O-polysaccharide isolated from the lipopolysaccharide produced by enterohemorrhagic Escherichia coli O103:H2 was determined and shown to be composed of d-glucose (1 part), 2-acetamido-2-deoxy-d-glucose (2 parts), 2-acetamido-2-deoxy-d-galactose (1 part), and 3-deoxy-3-(R)-3-hydroxybutyramido-d-fucose (1 part). From the results of methylation analysis, Smith-type periodate oxidation degradation studies, and the use of one- and two-dimensional1H and13C NMR spectroscopy, the O-polysaccharide antigen was found to be an unbranched polymer of a repeating pentasaccharide unit having the following structure: →2)-β-d-Glcp-(1→2)-β-d-Fucp3NBu-(1→6)-α-d-GlcpNAc-(1→4)-α-d-GalpNAc-(1→3)-β-d-GlcpNAc-(1→, where Bu is (R)-3-hydroxybutyramido.


2000 ◽  
Vol 83 (4) ◽  
pp. 1013-1019 ◽  
Author(s):  
Kazuhiro Ohkuma ◽  
Isao Matsuda ◽  
Yasuo Katta ◽  
Keisuke Tsuji

Abstract The molecular weight limit of water-soluble dietary fiber (SDF) determined by the Prosky method was studied by liquid chromatography (LC). It was confirmed that only SDF with an average degree of polymerization of 12 or higher can be determined by the Prosky method. Total dietary fiber (TDF) was determined by 2 additional methods using LC. In the first method, the total quantity of insoluble dietary fiber (IDF) and high molecular weight SDF (HMSDF) was determined according to the modified Prosky method (MES-TRIS buffer-based). The quantitatively collected final filtrate was analyzed by LC for the quantity of low molecular weight SDF (LMSDF), and the 2 quantities were totaled to obtain TDF. TDF values thus determined for rice, polished or unpolished, soybean flour, and pressed barley were higher than those determined by the Prosky method by approximately 6, 3.5, and 3.5%, respectively. In the second method, direct determination by LC analysis was done on samples after enzymatic treatment according to the Prosky method. Results showed that the determination of LMSDF, in particular, was highly accurate and more effective. In both of these methods, the quantity of LMSDF was determined from its chromatographic peak area ratio to glucose as an internal standard, which was produced by hydrolysis.


Author(s):  
Hind Hadi ◽  
Gufran Salim

A simple, rapid and sensitive spectrophotmetric method for trace determination of salbutamol (SAL) in aqueous solution and in pharmaceutical preparations is described. The method is based on the diazotization coupling reaction of the intended compound with 4-amino benzoic acid (ABA) in alkaline medium to form an intense orange, water soluble dye that is stable and shows maximum absorption at 410 nm. A graph of absorbance versus concentration indicates that Beer’s law is obeyed over the concentration range of 0.5-30 ppm, with a molar absorbtivity 3.76×104 L.mol-1 .cm-1 depending on the concentration of SAL. The optimum conditions and stability of the colored product have been investigated and the method was applied successfully to the determination of SAL in dosage forms.


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