Fumiko Fukuoka

Antitumor polysaccharides from P. ostreatus (Fr.) quél.: Isolation and structure of a β-glucan

We isolated an antitumor glucan (HA beta-glucan) from the neutral polysaccharide fraction (A3) of a hot-water extract of the edible mushroom P. ostreatus (Fr.) Quél. Purification was accomplished by extractions with 20% sodium chloride solution saturated with thymol and by precipitations with ethanol from dimethyl sulfoxide solution. The glucan showed marked antitumor activity at a dose of 0.1 mg/kg. It is a highly branched (1----3)-beta-glucan having an average structure represented by a pentasaccharide segment consisting of one nonreducing terminal, one 3,6-di-O-substituted, and three 3-mono-O-substituted beta-D-glucopyranosyl residues. This structure was confirmed by examining 13C-n.m.r. spectra taken at 75.46 MHz.

A 13C nuclear magnetic resonance study of a gel-forming branched (1→3)-β-D-glucan, A3, from Pleurotus ostreatus (Fr.) quél: Determination of side-chains and conformation of the polymer-chain in relation to gel-structure

In recent years, a number of gel-forming branched (1+3)

The newer concept of cancer toxin.

-D&cans with anti-tumor activity were isolated from various natural sources [l-3] . Evidence was presented that conformation of polysaccharide is closely related to its biological activity [4] . Further, conformational studies of polysaccharides in relation to gel-structure are of considerable importance in view of their biological functions [5,6] . However, conformational behaviour of neutral polysaccharides, especially of (l-+3)

Inhibition of Mouse Sarcoma 180 by a Wheat Hemicellulose B Preparation

-D-glucans, has not been fully investigated in comparison with that of polypeptides and polynucleotides. In this paper, we demonstrate that 13C n.m.r. measurements of polysaccharide A3 from P. ostreutus in the gel state are able to provide insight into structure and conformation.

Isolation, purification, and structure of components from acidic polysaccharides of pleurotus ostreatus (Fr.) Quél.

Publisher Summary This chapter describes the newer concept of cancer toxin. The biological significance of toxohormone has been considered largely from the point of view of its systemic effects on tumor bearing animals. This is natural because the whole toxohormone problem originally arose as an attempt to discover the chemical basis of the tumor–host relations. The ability of toxohormone to inhibit the synthesis of liver catalase raises the question of the consequence to the physiology of the cancer cells themselves, which produce this inhibitor. Catalase is closely associated with aerobic cell respiration and the almost complete absence of catalase in cancer cells may be explained on the basis of its being useless in the metabolism of these cells. Toxohormone action may provide the mechanism, which brings about the deletion of catalase in cancer cells.

Inhibition of Mouse Sarcoma 180 by Polysaccharides from Lentinus edodes (Berk.) Sing.

WE have found that the polysaccharide preparation, termed hemicellulose B, isolated from wheat straw is highly active in inhibiting the growth and inducing regression of sarcoma 180 subcutaneously implanted in mice. The polysaccharide preparation has, however, only a slight effect on subcutaneous grafts of Ehrlich carcinoma and no recognizable effect on the growth of autologous grafts of spontaneous mammary adenocarcinomas. Certain polysaccharides from higher plants have been shown to inhibit growth of transplanted tumours, but the polymers also appeared toxic and none were well characterized1–13. Statolon from P. stoloniferium induces the production of interferon in animal cells14.

Fractionation and Purification of the Polysaccharides with Marked Antitumor Activity, Especially Lentinan, from Lentinus edodes (Berk.) Sing. (an Edible Mushroom)

Isolation of an antitumor component from polysaccharide fraction A5 of some Basidiomyces was achieved by column chromatography on Sephadex G-200. A detection method based on the specific rotatory characteristics of the polysaccharide was applied to estimate components in effluent fractions from the chromatography, and it was confirmed that a series of eluates having similar specific rotation was made up of homogeneous polysaccharide. Three components (H51, H52, and H53) were isolated, in chromatographically pure state, from fraction A5. Component H51 consisted of a skeleton of beta-(1 leads to 3)-linked glucose residues, probably having branches of galactose and mannose residues, and also containing acidic sugars. Component H53 had a main structure similarly consisting of beta-(1 leads to 3)-linked glucose residues and a larger proportion of acidic sugar than H51. Component H52 was a heteropolysaccharide made up of alpha-linked galactose and mannose residues. Components H51 and H53 had a higher and a lower molecular weight, respectively, than H52. The only antitumor-active component was H51.