Katsuyuki Nagai

(1→3)-α-d-glucan from an alkaline extract of Agrocybe cylindracea, and antitumor activity of its O-(carboxymethyl)ated derivatives

The structure of an alkali-soluble D-glucan (AG-AL) from the fruit body of Agrocybe cylindracea was investigated by a combination of chemical and spectroscopic methods indicating that it was a linear (1----3)-alpha-D-glucan (molecular weight, approximately 560,000), [alpha]20D +195 degrees (c 0.5, M sodium hydroxide). Both water-soluble and gelatinous products obtained by O-(carboxymethyl)ation of AG-AL showed potent antitumor activity against the solid form of Sarcoma 180 in mice, although the native D-glucan had little effect on the tumor.

Structure and antitumor activity of a branched (1→3)-β-d-glucan from the alkaline extract of Amanita muscaria☆

A beta-(1----6)-branched (1----3)-beta-D-glucan(AM-ASN) was isolated from the alkaline extract of the fruiting bodies of Amanita muscaria. AM-ASN had [alpha]D - 11 degrees in 0.5 M sodium hydroxide. Its estimated molecular weight was 95,000 in this alkaline solution and 260,000 in a neutral solution. The branches in the glucan were primarily single, (1----6)-linked D-glucopyranosyl groups, two for every seven residues in the (1----3)-linked main chain. AM-ASN exhibited significant antitumor activity against Sarcoma 180 in mice, and a mixture of AM-ASN with mitomycin C was more effective against the tumor than mitomycin C only.

Minor, protein-containing galactomannans from the insect-body portion of the fungal preparation Chán huā (Cordyceps cicadae)☆

Abstract Two minor, water-soluble, protein-containing galactomannans, CI-P ([α]D +15.3°) and CI-A ([α]D +10.6°), isolated from the insect-body portion of the fungal preparation Chan huā (Cordyceps cicadae) showed single peaks on gel filtration, and one spot on glass-fiber paper electrophoresis. The polymers are composed of d -mannose and d -galactose in the molar ratios of 1:0.85 for CI-P and 1:0.57 for CI-A, together with traces of d -glucose, and small proportions of protein. Although both polysaccharides have a molecular weight of ∼25,000, the affinity of CI-A for Con A was stronger than that of CI-P. From the results of methylation analysis, Smith degradation, stepwise hydrolysis, and 13C-n.m.r. spectroscopy, it was concluded that the polysaccharides are highly branched, with structures composed of (1→6)-linked α- d -mannopyranosyl main chains, having most residues substituted at O-2 with single α- or β- d -galactofuranosyl groups, short chains of (1→2)-linked β- d -galactofuranosyl residues, or chains of (1→2)-linked α- d -mannopyranosyl residues. CI-A has fewer and shorter d -galactofuranosyl side-chains and longer (1→2)-linked α- d -mannopyranosyl side-chains than CI-P.

The distribution of carboxymethyl groups in O-(carboxymethyl)ated (1 → 3)-β-d-glucans and (1 → 3)-α-d-glucans☆

Abstract The distribution of the substituents in O -(carboxymethyl)ated, linear (1 → 3)-β- d -glucans, branched (1 → 3)-β- d -glucan, and (1 → 3)-α- d -glucans was analyzed by g.l.c. and g.l.c.-m.s. The results indicated that the distribution of the substituents in O -(carboxymethyl)- d -glucans was characteristic of glucan type, especially at position 2 on the d -glucosyl residues, and suggested that the conformation of the d -glucans affected the O -carboxymethylation pattern.

Preparation and mass-spectral analysis of O-hydroxy-ethyl derivatives of d-glucose

Various hydroxyethyl ethers of d-glucose have been prepared in good yield by treating d-glucose derivatives with 2-bromoethyl tetrahydropyranyl ether in the presence of sodium hydride. The derived O-(hydroxyethyl)-d-glucitol acetates exhibited characteristic mass-spectral fragments. The furanose and pyranose forms of 1,2-O-ethylene-d-glucose derived from 2-O-(2-hydroxyethyl)-d-glucose were identified by mass-spectral analysis.