Makoto Hisamatsu

Antitumor effects of (1->3)-β-D-glucan and (1->6)-β-D-glucan purified from newly cultivated mushroom, Hatakeshimeji (Lyophyllum decastes Sing.).

Eleven polysaccharides were isolated from a hot-water extract of fruiting bodies of Lyophyllum decastes Sing. by ion-exchange chromatography and gel permeation chromatography. Three polysaccharides (IV-1, IV-2, and IV-3) composed mainly of glucose showed marked antitumor activities against Sarcoma 180 and their average molecular weights were 305 kDa, 130 kDa and 14 kDa, respectively. From methylation analyses and 13C-NMR spectra, it was suggested that IV-1 was a (1→3)-β-d-glucan-type polysaccharide, IV-3 was a (1→6)-β-d-glucan-type polysaccharide, and IV-2 was a (1→3, 1→6)-β-d-glucan-type polysaccharide or a mixture of both polysaccharides. Increases in the number of peritoneal macrophages and third component of complement (C3)-positive fluorescent cells in mice treated with IV-1 suggested that the inhibitory effect on tumor growth is due to immunological host-mediated mechanisms.

Adhesion of β-d-glucans to cellulose

Schizophyllan, a Schizophylium communeβ-d-glucan, a Tamarindus xyloglucan, locust bean gum, a galactomannan, a barley β-d-glucan, and chitosan show specific adhesion to microcrystalline cellulose (cellulose I). Xyloglucan, locust bean gum, barley β-d-glucan, and chitosan also show the ability to adhere mercerized cellulose (cellulose II), while schizophyllan does not. As the molecular weight of schizophyllan decreases, both its ability to form triple-helical structures and its adhesion to cellulose I diminish and finally disappear, indicating that the adhesion of schizophyllan to cellulose I depends on high-molecular-weight domains that adopt the triple-helical structures. On the other hand, the adhesion of locust bean gum, chitosan, and xyloglucan to celluloses was found to be largely independent of molecular weight. Furthermore, it is thought that the adhesion of barley β-d-glucan occurs because it belongs to a group of xyloglucans.

Cyclic (1→2)-β-d-Glucan and the Octasaccharide Repeating-unit of Succinoglycan Produced by Agrobacterium

SUMMARY: Nine strains of Agrobacterium produced extracellular cyclic (1→2)-β-d-Glucan. Most of the strains produced an octasaccharide repeating-unit of succinoglycan. Mutant strains of Agrobacterium sp. and mutant strain 10C3K derived from Alcaligenes faecalis var. myxogenes, producing curdlan without succinoglycan or with a slight amount of succinoglycan, produced only cyclic (1→2)-β-d-Glucan. Cyclic (1→2)-β-d-Glucan was shown by paper chromatography and methylation analysis to be composed of two components without other glucosidic linkages. These were confirmed to be heptadecaose and octadecaose by field desorption mass spectrometric analysis.

Efficient Regioselective Synthesis of Mono-2-O-Sulfonyl-cyclodextrins by the Combination of Sulfonyl Imidazole and Molecular Sieves

Abstract Cyclodextrins are cyclic oligosaccharides consisting of six or more α-1,4-linked D-glucopyranose units, which possess primary hydroxyl groups at the C-6 positions and secondary hydroxyl groups at the C-2 and C-3 positions. Because cyclodextrins have a hydrophobic and optically active interior, they have been utilized as transporters of hydrophobic molecules and small molecular mimics of enzymes. The chemical modification of cyclodextrins has been investigated in order to improve these characteristics. Sulfonations of the primary or secondary hydroxyl groups of cyclodextrin have been applied for further functionalization of cyclodextrin, and several methods for regioselective sulfonations have been developed. Among these strategies, selective monotosylation of the C-6 hydroxyl group is done relatively easily by reaction of α or β-cyclodextrin and p-toluenesulfonyl chloride in pyridine1,2 or in alkaline aqueous solution.3,4 However, sulfonation of the secondary hydroxyl groups is more difficult and...

Further studies on the separation of cyclic (1→2)-β-d-glucans (cyclosophoraoses) produced by rhizobium meliloti ifo 13336, and determination of their degrees of polymerization by high-performance liquid chromatography

Abstract Eight pure cyclic (1→2)-β- d -glucans (cyclosophoraoses) varying in size from 17 to 24 residues were previously isolated from culture filtrates of Agrobacterium and Rhizobium. Thereafter further studies on the separation of cyclosophoraoses by high-performance liquid chromatography (HPLC) with small-particle columns showed an occurrence of many cyclosophoraoses having degrees of polymerization (DPs) of more than 24. One sample prepared from Rhizobium meliloti IFO 13336 contained large amounts of higher cyclosophoraoses of up to at least DP 40, which were separated clearly on a 3-μm chemically modified amine column (ERC-NH-1171). Some pure cyclosophoraoses with higher DPs were isolated by liquid chromatography using reversed-phase columns, and their DPs were determined by HPLC of their partial hydrolysates.

A comparative study of ethanol production by Issatchenkia orientalis strains under stress conditions

The ability of 13 strains of multi-stress-tolerant Issatchenkia orientalis yeast to produce ethanol was examined under different stress conditions, including conditions of elevated Na₂SO₄ and Na₂SO₄ concentrations and increased heat. The MF-121 strain produced a significant amount of ethanol after the incubation in acidic media containing high concentrations of salt, e.g., 50 g/l Na₂SO₄ at pH 2.0, or at high temperatures, e.g., 43°C, when compared with other strains.

Multiple Tolerance of Rhodotorula glutinis R-1 to Acid, Aluminum Ion and Manganese Ion, and Its Unusual Ability of Neutralizing Acidic Medium.

A red yeast isolated from the acidic water of Kusatsu hot spring could grow in an acidic medium of pH 1.5 and was identified as Rhodotorula glutinis. Electron microscope observations (scanning electron microscopy [SEM] and transmission electron microscopy [TEM]) showed that cell envelope became wrinkled and thick as the pH values of media became lower. The cell membrane grown at pH 1.5 was about four times as thick as that grown at pH 6.0. It was suggested that the change of cell envelope plays an important role in the acid tolerance. Cellular proteins at pH 1.5 appeared to be different from those at pH 6.0 and the amounts of phospholipids and non-phospholipids increased and decreased under low pH conditions, respectively. The acid-tolerant yeast also showed strong resistance to both aluminum and manganese ions. An acidic medium (pH 3.0) containing these ions (100 mM) was shifted to neutral pH by long-term cultivation of the red yeast, suggesting the potential of using this yeast in the bioremediation of acidic soil containing these ions at a high level.

Introduction of Fatty Acids to Starch Granules by Ultra-High-Pressure Treatment

Introduction of fatty acid into maize starch granule by ultra high pressure treatment (UHPT) was investigated. Starches are normal, waxy and amylo-species. They were treated by ball-mill before UHPT. Fatty acids are linoleic, oleic and oleic-stearic acid mixtures. Removal of oil on granule surface was done with 50% ethanol. The incorporated amount of fatty acids and tendency of effect of ball-mill time on the fatty acid amount are different among the three starch species. Fatty acid introduction to amylose and amylopectin helices was also investigated after washing with chloroform-methanol-water mixture. The introduced fatty acid amount to amylostarch is the largest among three species. It is proved that the less double bond in fatty acid, the more fatty acid introduced to starch. The peak at 13.6° (2T) on X-ray diffraction pattern of starch samples treated by UHP becomes large and their Tp on DSC becomes low as increase of introduced fatty acid.

SYNTHESIS OF HYDROPEROXIDE VIA PHOTOOXYGENATION FOR A MODEL AEQUORIN BIOLUMINESCENCE

Abstract Unstable hydroperoxide of coelenterazine (Oplophorus luciferin) analog has been synthesized by the reaction of coelenterazine analog with polymer-bound Rose Bengal via photooxygenation. This compound may be a key intermediate model in the bioluminescence of aequorin and the chemiluminescence of coelenterazine.

Cyclic (1→2)β-D-glucans (cyclosophorans) produced by Agrobacterium and Rhizobium species

Neutral and acidic cyclic (1----2)-beta-D-glucans (cyclosophorans), obtained from culture filtrates and cells of Agrobacterium and Rhizobiun, are synthesised on the cell surface and then secreted. Eight cyclosophorans with dp 17-24 were isolated; all of the strains of Agrobacterium showed almost the same distribution pattern, whereas there were three other distribution patterns for the strains of Rhizobium.