Tadashi Kiho

Anti-inflammatory activity and conformational behavior of a branched (1→3)-β-d-glucan from an alkaline extract of dictyophora indusiata fisch☆

A (1→6)-branched (1→3)-β-d-glucan (T-5-N), isolated from a m sodium hydroxide extract of the fruit bodies of Dictyophora indusiata Fisch., markedly exhibited anti-inflammatory effects on both carrageenan-induced edema and scalded edematous hyperalgesia in rats hindpaws. The activities of T-5-N (25 mg/kg i.p. × 2) were more potent than those of phenylbutazone (25–50 mg/kg i.p. × 2). The conformational behavior of T-5-N was studied. Its molecular weight in neutral solution was about three times that in 0.25m sodium hydroxide. This finding, in addition to the results of optical rotatory measurement and complex-formation with Congo Red, indicated that T-5-N has an ordered, triple-helical structure in neutral or slightly alkaline solution (< 0.15m NaOH), and has single chains in highly alkaline solution (0.25m NaOH). The conformational transition occurs at concentrations of sodium hydroxide in the range of 0.15–0.25m.

Tomato paste fraction inhibiting the formation of advanced glycation end-products.

A water-soluble and low-molecular-weight fraction (SB) was obtained from tomato paste. The effects of SB on the formation of advanced glycation end-products (AGE) in protein glycation were studied by the methods of specific fluorescence, ELISA and a Western blot analysis, using the anti-AGE antibody after incubating protein with sugar. The results suggest that SB had strong inhibitory activity, in comparison with aminoguanidine as a positive control, and that the inhibitory mechanism of SB differed from that of aminoguanidine to involve trapping of reactive dicarbonyl intermediates in the early stage of glycation. SB contained an antioxidant, rutin, which showed potent inhibitory activity. The results also suggest that rutin chiefly contributed to inhibiting the formation of AGE, and that other compounds in SB may also have been related to the activity.

(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.

Structural features and hypoglycemic activities of two polysaccharides from a hot-water extract of Agrocybe cylindracea

A glucan (AG-HN1, [alpha]D +24 degrees) and a heteroglycan (AG-HN2, [alpha]D +26 degrees) were isolated from a hot-water extract of the fruiting bodies of Agrocybe cylindracea. The structures were investigated by a combination of chemical and spectroscopic methods. The results indicated that high molecular weight glucan AG-HN1 is primarily a beta-(1-->6)-branched (1-->3)-beta-D-glucan containing small amounts of (1-->4)-linked and (1-->6)-linked glucopyranosyl residues. Low molecular weight heteroglycan AG-HN2 gives galactose, glucose, fucose, and mannose on hydrolysis and appears to be chiefly composed of (1-->6)-linked gluco- and galacto-pyranosyl residues, many of them branched, and various nonreducing terminal residues. AG-HN1 showed a remarkable hypoglycemic activity in both normal and streptozotocin-induced diabetic mice by ip administration, and its activity was higher than that of AG-HN2.

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.

Membrane trafficking of aquaporin 3 induced by epinephrine

We investigated the membrane trafficking of AQP3 induced by epinephrine in Caco-2 cells to clarify the digestive absorption of glycerol permeated by AQP3. Epinephrine was found to promote within 60 min the translocation of AQP3 from the cytoplasmic fraction to the plasma membrane. This increased trafficking of AQP3 was suppressed by phospholipase C and protein kinase C (PKC) inhibitors and a phorbol ester accelerated the trafficking of AQP3 to the membrane fraction. In contrast, adenylyl cyclase (AC) and protein kinase A (PKA) inhibitors did not have any effect on the increased in trafficking of AQP3 by epinephrine and an AC activator did not affect the trafficking of AQP3. Phosphorylation of a threonine (514) residue in PKC was detected upon the treatment with epinephrine and the temporal transitional pattern of this phosphorylation paralleled that of the increased trafficking of AQP3. These results suggest that PKC modulates the trafficking of AQP3.

A minor, protein-containing galactomannan from a sodium carbonate extract of Cordyceps sinensis☆

Abstract A water-soluble, minor, protein-containing galactomannan (CT-4N), [α] D −29.6°, isolated from a 5% sodium carbonate extract of Cordyceps sinensis , showed a homogeneous pattern in gel filtration and one spot in glass-fiber paper-electrophoresis. The molecular weight was estimated by gel filtration to be ∼23,000. It was mainly composed of d -mannose and d -galactose in the molar ratio of 3:5, and contained a small proportion of protein. From the results of methylation analysis, Smith degradation, stepwise hydrolysis, and 13 C-n.m.r. spectroscopy, it was concluded that the polysaccharide has a highly branched structure, and is composed of (1→6)- and (1→2)-linked α- d -mannopyranosyl residues in the main chain. Some of the residues are present as branching points of (1→2,6) and (1→4,6) linkages and the branches contain short chains having a large proportion of (1→5)-linked β- d -galactofuranosyl residues and a small proportion of (1→6)-linked α- d -galactopyranosyl resdues, and the (nonreducing) terminal groups consist of a large proportion of β- d -galactofuranosyl and a small proportion of α- d -mannopyranosyl groups.

A branched (1→3)-β-d-glucan from a sodium carbonate extract of Dictyophora indusiata fisch

Abstract A water-soluble, (1→6)-branched, (1→3)-β- d -glucan (T-4-N), [α] D 20 +19° ( c 0.1, water), was isolated from a 2% sodium carbonate extract of the fruit bodies of Dictyophora indusiata Fisch. T-4-N was homogeneous as judged by gel filtration, Tiselius-type electrophoresis, and ultracentrifugal analysis. By gel filtration on Sepharose CL-2B, with 0.25 m sodium hydroxide as the eluant, the molecular weight of T-4-N was estimated to be ∼5.5 × 10 6 . From the results of methylation analysis, periodate oxidation, Smith degradation (complete, and also mild), partial acetolysis, and enzymic degradation, it was concluded that T-4-N has a main chain composed of β-(1→3)-linked d -glucopyranosyl residues, and two single, β-(1→6)-linked d -glucopyranosyl groups attached as side chains to, on average, every fifth sugar residue of the main chain. In addition, the results of the enzymic hydrolysis suggested that the β-(1→6)-linked d -glucosyl side chains are mainly localized in the neighborhood of the nonreducing end of the main chain. The results of optical rotatory measurement and complex-formation with Congo Red indicated that T-4-N probably takes a triple-helical conformation.

Structure of a new galactomannan from the ascocarps of Cordyceps cicadae shing

Abstract A water-soluble galactomannan (C-3), [α] D 20 +30°, isolated from the rod-like ascocarps of Cordyceps cicadae , was determined to be homogeneous, and the molecular weight was estimated by gel filtration to be 27,000. The polysaccharide is composed of d -mannose and d -galactose in the molar ratio of 4:3. The results of methylation analysis, Smith degradation, stepwise hydrolysis with acid, and 13 C-n.m.r. spectroscopy indicated that the polysaccharide is of highly branched structure, and composed of α- d -(1→2)-linked and α- d -(1→6)-linked mannopyranosyl residues in the core; some of these residues are substituted at O-6 and O-2 with terminal β- d -galactofuranosyl and α- d -mannopyranosyl groups, and with short chains of β- d -(1→2)-linked d -galactofuranosyl units.

Structure of an alkali-soluble polysaccharide from the fruit body of Ganoderma japonicum Lloyd

Abstract A water-insoluble glucan (G-A), [α]D16 + 12.8° (c 0.4, m sodium hydroxide), was isolated from the alkaline extract of the fruit body of Ganoderma japonicum. G-A was homogeneous as judged by gel filtration, electrophoresis, and ultracentrifugal analysis. The molecular weight and degree of polymerization of G-A were respectively estimated to be 82,000 and 330. The 1H-n.m.r. and i.r. spectra, together with the result of chromium trioxide oxidation, indicated that the glucosidic linkages in G-A have the β- d configuration. From the results of methylation analysis, periodate oxidation, Smith degradation, and partial hydrolysis with acid, it was concluded that G-A is composed of a backbone of β-(1 → 3)-linked d -glucopyranosyl residues, and has side-chains of single, β-(1 → 6)-linked d -glucopyranosyl groups attached, on average, to every 30th residue of the backbone.