GUM JEOL: THE STRUCTURE OF THE DEGRADED GUM DERIVED FROM IT

1964 ◽  
Vol 42 (1) ◽  
pp. 107-112 ◽  
Author(s):  
A. K. Bhattacharyya ◽  
C. V. N. Rao

Gum Jeol has been shown to be composed of residues of D-galactose, L-arabinose, and D-galacturonic acid. On mild acid hydrolysis the gum gave an aldobiouronic acid, viz. 3-O-(D-galactopyranosyl uronic acid)-D-galactopyranose. Hydrolysis of the fully methylated degraded gum yielded 2,3,4,6-terra-(3 moles); 2,3,4-tri-(2 moles); 2,4-di-(1 mole); and 2-O-methyl-D-galactose (1 mole) in the neutral fraction of the hydrolyzate. The reduced acidic fraction yielded 2,3,4-tri-(2 moles) and 2,4-di-O-methyl-D-galactose (2 moles). Based on these results a partial structure of the degraded gum has been proposed, the additional evidence of which was deduced from periodate oxidation studies of the degraded gum.


1971 ◽  
Vol 133 (1) ◽  
pp. 39-52 ◽  
Author(s):  
Ten Feizi ◽  
Elvin A. Kabat ◽  
Giuseppe Vicari ◽  
Byron Anderson ◽  
W. Laurence Marsh

A partially purified blood group-like substance obtained from milk showed I activity with 2 of 21 anti-I sera. With these antisera, certain human ovarian cyst substances considered to be precursors of the A, B, H, Lea, and Leb substances also showed I activity comparable to the milk material. Strong I activity could be produced by one-stage periodate oxidation and Smith degradation of human ovarian cyst A and B substances, or of hog mucin A + H substance, or by mild acid hydrolysis of human saliva or ovarian cyst blood group B substance. The two sera indicate that I specificity appears at intermediate stages in the biosynthesis of the A, B, H, Lea, and Lea substances. Anti-I sera differ strikingly in their specificities, indicating substantial heterogeneity of the I determinants.



1964 ◽  
Vol 42 (12) ◽  
pp. 2862-2871 ◽  
Author(s):  
F. Blank ◽  
M. B. Perry

The water-soluble polysaccharide preparation from Trichophytoninterdigitale was fractionated to give two distinct galactomannans and a glucan. A galactomannan isolated via its insoluble copper complex had [α]D +75° (water) and was composed of D-galactose (12%) and D-mannose (88%). On periodate oxidation, the galactomannan consumed 1.73 mole periodate and released 0.67 mole formic acid and 0.12 mole formaldehyde per anhydrohexose unit. Hydrolysis of the methylated galactomannan gave 2,3,5,6-tetra-O-methyl-D-galactose (1 part), 2,3,4,6-tetra-O-methyl-D-mannose (1 part), 2,3,4-tri-O-methyl-D-mannose (4 parts), and3,4-di-O-methyl-D-mannose (2 parts). Mild acid hydrolysis of the galactomannan removed all the galactose residues, leaving a mannan having [α]D +84° (water) whose structure was analyzed by periodate oxidation and methylation techniques.



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.



1962 ◽  
Vol 40 (7) ◽  
pp. 1266-1279 ◽  
Author(s):  
K. Hunt ◽  
J. K. N. Jones

Linseed mucilage has been separated into an acidic and a neutral fraction. The acidic fraction was further separated, by the use of cupric acetate solution, into two fractions, CuI and CuII. Fraction CuI contained L-rhamnose, L-galactose, and D-galacturonic acid. The methylated reduced polysaccharide gave on hydrolysis 2,3,4-tri-O-methyl-L-rhamnose, 3,4-di-O-methyl-L-rhamnose, 4-O-methyl-L-rhamnose, 2,3,4,6-tetra-O-methyl-D-galactose, 2,3,6-tri-O-methyl-D-galactose, and 2,3-di-O-methyl-D-galactose (?); L-galactose was lost during the methylation process. Periodate oxidation studies on the material indicated that the polymer was composed of a main chain of L-rhamnose units with most of the L-galactose units attached as non-reducing end groups. Fraction CuII contained L-rhamnose, L-fucose, L-galactose, and D-galacturonic acid. The methylated reduced polysaccharide gave on hydrolysis 2,3,4-tri-O-methyl-L-fucose, 2,3,4,6-tetra-O-methyl-L-galactose, 2,3,6-tri-O-methyl-D-galactose, 4-O-methyl-L-rhamnose, L-rhamnose, and possibly 2,3-di-O-methyl-D-galactose and 3-O-methyl-D-galactose. Periodate oxidation studies and a degradation by the Smith procedure indicated the presence of a L-rhamnose backbone with L-fucose and L-galactose units attached as non-reducing end groups.The neutral fraction yielded a periodate-oxidizable material after one Smith-type degradation. Periodate oxidation studies indicated that the degraded material was branched. Methylation of the degraded polysaccharide followed by hydrolysis yielded 2,3,4-tri-O-methyl-D-xylose, 2,3-di-O-methyl-D-xylose, 2,4-di-O-methyl-D-xylose, 4-O-methyl-D-xylose, D-xylose, and traces of 2,3,4-trt-O-methyl- or 2,5-di-O-methyl-L-arabinose, 2,4-di-O-methyl-D-xylose, and 3-O-methyl-D-xylose. The main backbone of the degraded polysaccharide appeared to consist of (1 → 4)-linked D-xylose units. Linkages of the (1 → 3) type were also present. The smaller fragments from the Smith-type degradation, L-arabinose, 2-O-α-L-arabinosyl glycerol, and glycerol were characterized. A partial acid hydrolysis of the neutral fraction yielded a number of oligosaccharides.



1974 ◽  
Vol 139 (3) ◽  
pp. 633-643 ◽  
Author(s):  
James A. Lomax ◽  
George W. Gray ◽  
Stephen G. Wilkinson

Studies of the lipopolysaccharide of Pseudomonas alcaligenes strain BR 1/2 were extended to the polysaccharide moiety. The crude polysaccharide, obtained by mild acid hydrolysis of the lipopolysaccharide, was fractionated by gel filtration. The major fraction was the phosphorylated polysaccharide, for which the approximate proportions of residues were; glucose (2), rhamnose (0.7), heptose (2–3), galactosamine (1), alanine (1), 3-deoxy-2-octulonic acid (1), phosphorus (5–6). The heptose was l-glycero-d-manno-heptose. The minor fractions from gel filtration contained free 3-deoxy-2-octulonic acid, Pi and PPi. The purified polysaccharide was studied by periodate oxidation, methylation analysis, partial hydrolysis, and dephosphorylation. All the rhamnose and part of the glucose and heptose occur as non-reducing terminal residues. Other glucose residues are 3-substituted, and most heptose residues are esterified with condensed phosphate residues, possibly in the C-4 position. Free heptose and a heptosylglucose were isolated from a partial hydrolysate of the polysaccharide. The location of galactosamine in the polysaccharide was not established, but either the C-3 or C-4 position appears to be substituted and a linkage to alanine was indicated. In its composition, the polysaccharide from Ps. alcaligenes resembles core polysaccharides from other pseudomonads: no possible side-chain polysaccharide was detected.



2019 ◽  
Vol 12 (2) ◽  
pp. 419-432 ◽  
Author(s):  
Fernando Roberto Paz-Cedeno ◽  
Eddyn Gabriel Solórzano-Chávez ◽  
Levi Ezequiel de Oliveira ◽  
Valéria Cress Gelli ◽  
Rubens Monti ◽  
...  




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