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E V Rao

Publications and source records attributed to E V Rao.

14 recordsLinked to original sources
PubMed1991

Structural studies of a polysaccharide isolated from the green seaweed Chaetomorpha anteninna.

Extraction of the green seaweed Chaetomorpha anteninna with water, followed by fractionation using the copper complex, gave a sulphated heteropolysaccharide, [alpha]D27 +84 degrees, that contained arabinose (57.7%), galactose (38.5%), rhamnose (3.8%), and sulphate (11.9%). Application of methylation analysis, periodate oxidation, and partial acid hydrolysis indicated a branched structure with 4-linked arabinose, 4- and 3-linked galactose, and 4-linked rhamnose residues. Both the arabinose and galactose residues carried branches. Desulphation and analysis of the polymeric product showed that sulphate groups were located at C-2 of some of the interior arabinose residues, C-4 of some of the non-reducing-end arabisoyl groups, and C-3 of the non-reducing-end galactosyl groups.

Carbohydrate Conformation↗
PubMed1991

Structural features of the sulphated polysaccharide from a green seaweed, Cladophora socialis.

A sulphated heteropolysaccharide, [alpha]27D + 59.9 degrees, has been isolated from a green seaweed, Cladophora socialis, by extraction with dilute acid and purified by fractional precipitation. The polymer is composed of galactose (58.3%), arabinose (31.8%), xylose (10.6%) and sulphate (16.9%). The results of methylation analysis, periodate oxidation and partial acid hydrolysis studies indicate that the polymer is a branched one and is composed of 1,3-linked galactose and 1,4-linked arabinose units. Xylose is present at the non-reducing end position of the branches. Both arabinose and galactose carry branches. Desulphation and subsequent analysis of the polymer show that some of the arabinose units carry sulphate groups at C-3 and some of the galactose units carry the sulphate groups at C-4 and some at C-4 and C-6 as well.

Carbohydrate Sequence↗
PubMed1991

Structural features of the sulphated polysaccharide from a green seaweed, Spongomorpha indica.

A sulphated heteropolysaccharide, [alpha]D +59 degrees, was isolated from a green seaweed, Spongomorpha indica, by extraction with ammonium oxalate. The polymer is composed of arabinose, xylose, galactose and glucose in the ratio 8.9:1.0:12.0:1.0. Studies showed that the polysaccharide is a complex and multilinked polymer containing arabinose in both furanose and pyranose forms. The core of the polysaccharide is composed of 1,4-linked galactose units. The arabinofuranose units are present as non-reducing end units, as well as jointed through 1,3- and 1,2-linkages. The majority of the arabinopyranose units are joined through 1,4-linkages. Xylose is present as a branch terminating unit. Glucose is joined through 1,4-linkages. Both arabinose and galactose carry branches. Sulphate groups are present on some of the arabinose units at C-2 and on some of the galactose units at C-2 and C-3.

Carbohydrate Sequence↗
PubMed1969

The type-specific substance from Pneumococcus type 29.

1. A pentasaccharide, corresponding to the dephosphorylated repeating unit of the specific substance, S.29, from Pneumococcus type 29, was obtained by hydrolysis with alkali followed by enzymic dephosphorylation. 2. The pentasaccharide was shown to be O-2-acetamido-2-deoxy-beta-d-galactopyranosyl-(1-->6)-O-beta-d-galactofuranosyl-(1-->3)-O-beta-d-galactopyranosyl-(1-->6)-O-beta-d-galactofuranosyl-(1-->1)-ribitol. 3. The phosphodiester linkages in S.29 join the hydroxyl group at position 5 of ribitol and the hydroxyl group at position 3 or 4 of a 2-acetamido-2-deoxy-d-galactose residue in the next repeating unit. 4. A partial structure for S.29 was deduced from these experiments.

Alkalies↗
PubMed1966

The type-specific substance from Pneumococcus type 10A(34). Structure of the dephosphorylated repeating unit.

1. A hexasaccharide unit was isolated from the specific substance S. 10A from Pneumococcus type 10A (34) by hydrolysis with alkali followed by enzymic dephosphorylation. 2. The hexasaccharide was shown to be O-d-galactofuranosyl-(1-->3)-O-d- galactopyranosyl-(1-->4)-O-[d-galactofuranosyl- (1-->6)]-O-2-acet-amido-2-deoxy-d-galactopyranosyl- (1-->3)-O-d-galactopyranosyl-(1-->2)-ribitol.

Chemical Phenomena↗