Minoru Terazawa

A Phytochemical in the Edible Tamogi-take Mushroom (Pleurotus cornucopiae), D-Mannitol, Inhibits ACE Activity and Lowers the Blood Pressure of Spontaneously Hypertensive Rats

D-Mannitol, one of the main phytochemicals of the edible Tamogi-take mushroom (Pleurotus cornucopiae), was found to inhibit an angiotensin I converting enzyme (ACE). The antihypertensive effect of D-mannitol and a hot water extract of Tamogi-take mushroom was demonstrated in spontaneously hypertensive rats (SHR) by oral administration.

Chemical constituents ofInonotus obliquus II: a new triterpene, 21,24-cyclopentalanosta-3β,21,25-triol-8-ene from sclerotium

A new lanostane-type triterpene with a cyclopentanol partial structure in the side chain was isolated from the sclerotium of the wood rotting fungusInonotus obliquus along with four known compounds: lanosterol, inotodiol, trametenolic acid, and 3β-hydroxy-8,24-dienlanosta-21,23-lactone. The new compound was determined to be 21,24-cyclopentalanosta-3β,21,25-triol-8-ene by spectroscopic analyses.

Effect of moisture content of a wood matrix on a small-scale biodegradation system for organic solid waste

The optimum working moisture content of a wood matrix for the garbage automatic decomposer-extinguisher (GADE) machine was investigated using a small-scale degradation reactor. A formula feed for rabbits was used as the model waste. The degradation experiment was conducted under controlled conditions such as moisture content, environmental temperature, and airflow rate. The degradation rate was estimated precisely from weight loss and the CO2 evolution rate. The degradation rate were nearly constant at a moisture content of 30%–80% on a-wet-weight basis. Microorganisms from the environment propagated in the reactor with no inoculums added. The number of microorganisms showed a trend similar to that of the degradation rate. The microorganism community changed according to the moisture content of the matrix and were considered to attain a constant degradation rate at a wide range of moisture content of a matrix.

Biodegradation of nonlignocellulosic substances II: physical and chemical properties of sawdust before and after use as artificial soil

The physical properties of sawdust including porosity, water retention, and water drainage were analyzed to prove its suitability for use as an artificial soil in the automatic decomposer-extinguisher (GADE) machine. The physical and chemical properties of residual sawdust from the GADE machine were also analyzed, the mechanical abrasion of sawdust in the GADE machine was tested, and the morphology of this residue was observed through a scanning electron microscope to investigate changes of these properties in the medium of decomposing garbage. Sawdust, which showed a lower specific gravity and larger porosity than soil, is considered capable of supplying air to bacteria. It was found that sawdust became worn from the operation of the machine. The spaces of residual sawdust were still observed, but water drainage decreased. The portion of hollocellulose in residual sawdust decreased, although the extractives in it increased. Results indicated that the capacity of sawdust to function as an artificial soil in the GADE machine was decreased owing not only to the destruction of sawdust grain but also to the adherence of products from decomposition, such that sawdust needed to be replaced every few months.

Allelopathic sesquiterpenoids from rhizomes of Petasites japonicus ssp. giganteus Kitam.

Four sesquiterpenoids were isolated from Petasites japonicus (Siebold and Zucc.) Maxim. ssp. giganteus (F. Schmidt ex Trautv.) Kitam. (Compositae, Japanese name: Akitabuki) as allelochemicals. Their structures were elucidated on the basis of spectroscopic methods and their allelopathic effects were assessed.

Deterrent effect of rosin and wood tar against barking by the gray-sided vole (Clethrionomys rufocanus bedfordiae)

The gray-sided vole (Clethrionomys rufocanus bedfordiae Thomas) is a small wild rodent widely distributed in Hokkaido, northern Japan. Floors of forestry plantations with thick herbage provide gray-sided voles with suitable habitats. The voles eat bark in winter, and because of this, severe damage can occur in many plantations. Deterrent effects on gray-sided voles of rosin and 3 wood tars were evaluated by two-choice tests in the field. These materials were selected because they were promising and economical deterrents. In the test for each material, disks were produced from trunks of Japanese larch, and used as carriers. Pairs of carriers (a material-treated carrier and a control carrier) were fed to gray-sided voles for 24 h, and values of the eaten area of bark were compared between treated carriers and controls. Every material decreased the extent of barking. The treated carriers were significantly less eaten compared to the controls for all the materials (p<0.01 or 0.05). Deterrent effects of three fractions (neutral, phenol, and strong acid fractions) made from wood tar were also evaluated. Every fraction prevented gray-sided voles from barking. The treated carriers were significantly less eaten compared to the controls for all the fractions (p<0.05). The neutral fraction has showed an especially strong deterrent effect; thus this fraction is most promising for future use.

Effect of environmental temperature on a small-scale biodegradation system for organic solid waste

The optimum environmental temperature for a biodegrading machine using wood particles as a matrix was investigated using a small-scale degradation reactor and model waste. The biodegradation rate was evaluated by weight loss of waste and CO2 evolution. The degradation reaction was restricted only by adjusting the environmental temperature while sufficient oxygen and substrates were supplied. Results suggested that the optimum temperature for degradation was 30°–40°C for exploiting biological activity effectively with the lowest use of energy. Bacteria from the environment propagated in the reactor with no inoculum added. The microbial flora changed during the operation time but had no effect on the biodegradation rate.

Two lignan rhamnosides from birch leaves

The extractives of shirakamba (Betula platyphylla Sukatchev var.japonica Hara) leaves were investigated. Two lignan glycosides were isolated, and their structures were elucidated to be 1-(4′-hydroxy-3′-methoxyphenyl)-2-[1″-(3-α-l-rhamnopyranosyloxypropyl)-3″-hydroxyphenoxy]-1,3-propanediol (I) and a new 2,3-dihydro-2-arylbenzofuran configuration neolignan,cis-2,3-dihydro-2-(4′-α-l-rhamnopyranosyloxy-3′-methoxyphenyl)-3-hydroxymethyl-7-hydroxy-5-benzofuranpropanol (II). These neolignan rhamnosides were newly found in shirakamba.

Biodegradation of nonlignocellulosic substances I: system for complete decomposition of garbage using sawdust and aerobic soil bacteria

A system for effective garbage decomposition using sawdust and aerobic soil bacteria was examined. The machinery used in this process, the garbage automatic decomposer-extinguisher (GADS), is composed of a container with an automatic mechanical mixer and a drain for liquid formed by the decomposition of garbage. The aerobic soil bacteria, cultivated in sawdust, degrades garbage within the container. The GADE machine, containing 4kg of sawdust, totally decomposed 59.75 kg of garbage within 3 months (0.66 kg/day). Constant temperature, pH level, and moisture content of the matrix throughout the experimental period suggested stable degrading action. The residual sawdust and drainage water from the GADE machine were converted to fertilizers or soil conditioners (GADE compost) by the garbage decomposition process. Neither inhibited germination or growth of three test crops: komatsuna, Chinese cabbage (Brassica campestris), hatsukadaikon, radish (Raphanus sativus L. var.radicula), and bisai (Raphanus sp.).

Four glucosides of p-hydroxyphenyl derivatives from birch leaves

The extractive of shirakamba (Betula platyphylla Sukatchev var.japonica Hara) leaves was investigated. Four glucosides ofp-hydroxyphenyl derivatives were isolated, and their structures were indentified as betuloside (I), 3,4′-dihydroxy-propiophenone-3-β-d-glucopyranoside (II), salidroside (III), and arbutin (IV). Arbutin was newly found in the leaves of shirakamba.