Kazutoshi Ogawa

A new trisaccharide, α-d-glucopyranuronosyl-(1→3)-α-l-rhamnopyranosyl-(1→2)-α-l-rhamnopyranose from Chlorella vulgaris

Abstract A new acidic trisaccharide, α- d -glucopyranuronosyl-(1→3)-α- l -rhamnopyranosyl-(1→2)-α- l -rhamnopyranose, was isolated from the hydrolyzate of an acidic polysaccharide, glucuronorhamnan, of Chlorella vulgaris K-22 cells.

New Aldobiuronic Acid, 3-O-α-D-Glucopyranuronosyl-L-rhamnopyranose, from an Acidic Polysaccharide of Chlorella vulgaris.

The new aldobiuronic acid, 3-O-α-D-glucopyranuronosyl-L-rhamnopyranose, was isolated from the acid hydrolyzate of an acidic polysaccharide in cells of Chlorella vulgaris K-22. Its structure was elucidated by NMR spectroscopic analyses.

A new glycoside, 1d-2-O-α-d-galactopyranosyl-chiro-inositol from jojoba beans

Abstract A new inositol glycoside, 1 d -2-O-α- d - galactopyranosyl -chiro- inositol has been isolated from jojoba plant, Simmondsia chinensis.

Cellulose as extracellular polysaccharide of hot spring sulfur-turf bacterial mat

The carbohydrate fraction of a hot spring sulfur-turf bacterial mat was shown to contain cellulose by the examination of neutral sugar composition, methylation analysis, and the identification of free oligosacchrides obtained from an acetolyzate of the desulfurized sulfur-turf mat. This suggested that the sulfur-oxidizing bacteria composing the sulfur-turf were producers of cellulose.

Chemical and Immunochemical Characterization of Polysaccharides of Sasa Veitchii Leaves

A hot water extract of Sasa veitchii is a health-promoting food in general use. To analyze the structure and function of the polysaccharide fraction of the extract, a macromolecular fraction was obtained by dialysis (HMF) and two polysaccharide fractions (NPS and APS) were separated by DEAE-Sephadex chromatography. HMF strongly reacted with human sera and immunoglobulin preparations. All of the IgM, IgG, and IgA classes of antibodies were reacted with HMF. Comparing the reactivity of NPS and APS, NPS showed significantly stronger reactivity to the sera. From physicochemical analysis, their molecular weights are 20,000 and 8,000, respectively. Sugar analyses of the acid hydrolysates indicated rhamnose, arabinose, xylose, mannose, glucose, and galactose in the molar ratio of 1.0 : 2.3 : 1.5 : 3.8 : 0.6 : 5.3 for NPS and 1.0 : 3.0 : 2.6 : 0.8 : 6.3 : 3.0 for APS, and suggested major differences in the ratio of hexoses. APS also contained 2.6% galacturonic acid. Methylation analyses suggested that 1) both NPS and APS have a highly branched structure, 2) only NPS contains galactofuranose residue at the non-reducing terminal. Partial acid hydrolysis of HMF and subsequent dialysis recovered a high molecular weight fraction, but the resulting product had significantly low immunochemical reactivity. Considering the physicochemical and immunochemical analyses, the major epitope structure of NPS was suggested to be galactofuranose residues. Immunochemical reactivity of the polysaccharide is a key molecular mechanism for the health promoting activity of S. veitchii.

A glucomannan from Candida utilis methylation analysis and fragmentation analysis by controlled acetolysis of the glucomannan

Abstract A new chemotype glucomannan isolated from Candida utilis mutant was further studied with the aid of methylation analysis and fragmentation analysis by controlled acetolysis. Thus, it was revealed that the glucomannan has an α-(1→6)-linked d -mannosyl backbone partially substituted with side chains of one, two, three, or four d -mannosyl units connected by α-(1→2) linkages; moreover, it has an additional side chain in which d -glucose residues are linked through an α-(1→6) linkage at the nonreducing ends of four d -mannosyl units. Isolation of 3,4-di- O -methyl- d -mannose, 2- O -α- d -mannopyranosyl- d -mannose, O -α- d -mannopyranosyl-(1→2)- O -α- d -mannopyranosyl-(1→2)- d -mannose, O -α- d -mannopyranosyl-(1→2)- O -α- d -mannopyranosyl-(1→2)- O -α- d -mannopyranosyl-(1→2)- d -mannose, O -α- d -mannopyranosyl-(1→2)- O -α- d -mannopyranosyl-(1→2)- O -α- d -mannopyranosyl-(1→2)- O -α- d -mannopyranosyl- (1→2)- d -mannose, 6- O -α- d -glucopyranosyl- d -mannose, and O -α- d -glucopyranosyl-(1→6)- O -α- d -mannopyranosyl-(1→2)- O -α- d -mannopyranosyl-(1→2)- O -α- d - mannopyranosyl-(1→2)- d -mannose afforded direct evidence of the aforementioned conclusion. A probable structure of the repeating unit of the glucomannan is presented.