Antioxidant activity and constituents of propolis collected in various areas of Korea

Propolis is a resinous substance collected by honeybees from various plant sources. The composition of propolis depends on time, vegetation, and the area of collection. This study examined the antioxidant activity of propolis from various areas of Korea: Chilgok, Cheongju, Geochang, Muju, Pocheon, and Sangju. Ethanol extracts of propolis (EEP) were prepared and evaluated for their antioxidant activity by beta-carotene bleaching, 1,1-diphenyl-2-picrylhydrazyl free radical scavenging, and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical cation decolorization assays. Furthermore, the major constituents in EEP were identified by high-performance liquid chromatography analysis with a photodiode array and mass spectrometric detection, and each component was quantitatively analyzed. EEP from Cheongju and Muju had relatively strong antioxidant activity accompanied by high total polyphenol contents. Propolis from Cheongju contained large amounts of antioxidative compounds, such as caffeic acid, kaempferol, and phenethyl caffeate. On the other hand, propolis from Pocheon had compounds not seen in propolis from other areas.     

Identification of metabolites in plasma and urine of Uruguayan propolis-treated rats

Propolis is a resinous substance collected by honeybees from various plant sources. It is extensively used in food and beverages to improve health and prevent diseases such as heart disease, diabetes, and cancer. To investigate the absorption and metabolism of the components in propolis, in the present study, we administered ethanol extracts of Uruguayan propolis (poplar type propolis) orally to rats and analyzed their plasma and urine by high-performance liquid chromatography with photodiode array and mass spectrometric detection. After deconjugation of the components by beta-glucuronidase/sulfatase treatment of the specimen, pinobanksin 5-methyl ether, pinobanksin, kaempferol, chrysin, pinocembrin, and galangin were detected in plasma of rats orally administered propolis. These compounds were detected also in urine after beta-glucuronidase/sulfatase treatment. Furthermore, pinobanksin 5-methyl ether, pinobanksin, chrysin, pinocembrin, and galangin were present in the urine also in free form. These results suggest that flavonoids in propolis are metabolized and circulate in the body after oral administration of propolis.     

Relationship between physical property of soil and growth of Monochoria vaginalis under paddy condition of organic farming—analysis using settled soil volume in water of superficial layer.

Field experiments were conducted to analyze the relationship between the settled soil volume in water (SSVW) and the growth of Monochoria vaginalis (Burm. f.) Kunth under organic farming conditions. SSVW corresponds to the mud volume per dry matter weight. Soil was sampled from the superficial layer of the topsoil (<10 mm), which was of a finer texture than the rest of the topsoil. Without the application of rice bran, there was a negative correlation between SSVW and the number of individuals of M. vaginalis. This finding suggests that SSVW is useful as a physical indicator for the growth suppression of M. vaginalis. The application of rice bran dramatically reduced the number of M. vaginalis. The values of SSVW with rice bran were greater than those without rice bran. The analysis of SSVW indicates that the change in soil physical properties following the application of rice bran was one of the factors responsible for the suppression of M. vaginalis growth.     

Soil fabrics of the plowed layer of flooded rice fields

For a long while Japanese agricultural workers have centered their efforts to an increase in rice production, confirming the extreme importance of appropriate water controlling for a good crop. Meanwhile, Japanese farmers have traditionally practiced to keep their fields in a dry state for several days in the mid-summer. They have been convinced of healthy plants with temporarily draining off water. Its season is generally in the dog-days from the end of July to the beginning of August, and the degree of drainage seems to be decided by farmer's private views or experience. For instance, the Japan's No. 1 prize winner in technical skill of rice competition in 1950 withdrew water until light marks remained when stepped in the field, while the 1952's winner drained his field until slight cracking on ground for the period August 11 to 13 (4). They were really successful in obtaining 7.71 and 9.27 tons of brown rice per hectare, respectively. However, it appears to be needed to bring out the scientific meanings of the practice more clearly in order to make it reasonably and universaly, provided the practice is indispensable for a good rice crop.     

ABSTRACT of the Articles Printed in Journal of the Science of Soil and Manure,Japan

A contrasting occurrence of clay minerals was found within a soil profile which was derived from volcanic materials in the suburbs of Fukuoka-city, Northern Kyushu. The soil profile is located on an isolated terrace, and the morphological characteristics of the soil correspond exactly to Andosols, so-called Kuroboku soils or Humic Allophane soils.

The clay fraction of upper horizons of the soil consists largely of alumina-rich gel-like materials, gibbsite, and layer silicates such as chlorite and chloritevermiculite intergrades, while that of lower horizons is composed of allophane and gibbsite or halloysite. There was no positive indication of allophane in the upper horizons. Corresponding with the clay mineralogical composition, quartz is abundant in the fine sand fraction of the upper horizons, while the mineral is very scarce or none in the lower horizons, suggesting a close relation between the petrological nature of parent volcanic materials and the mineralogical composition of weathering products. The dominant clay mineral in the volcanic 1.10il might be dependent on the petrological nature of parent materials, and allophane is mostly formed from andesitic materials, and alumina-rich gel-like materials and layer silicates have come from quartz andesitic materials. Allophane would transform to gibbsite or halloysite according to weathering conditions, and aluminarich gel-like materials change to gibbsite under a well-drained condition.

The soil materials have been so greatly weathered that some horizons contain gibbsite of even more than 40 per cent or halloysite over 70 per cent. The morphology and mineralogy are quite similar to so-cailed “non-volcanic Kuroboku soils.”     

Influence of dispersion treatments on the properties of soil colloids

The identification and characterization of clay minerals in the soil have been carried out on the clay fraction separated from a dispersed soil suspension. The process of dispersion includes the replacement of exchangeable divalent cations with H-ions by the dilute acid treatment, the removal of organic matter with hydrogen peroxide, and the dissolution of free iron oxides with reducing and/or chelating agents.     

Grade of weathering and fertility of volcanic ash soils of Aso volcano

Texture is one of the major criterions in soil classification, probably because it has a decisive influence on soil properties. This is particularly true for volcanic ash soils. Most ashes are largely composed of sand and silt particles with little clay (11, 15). The ash weathers very rapidly (1), and clay site particles less than 2 microns in diameter occur even within a few months, as shown by Ishii at the authors' laboratory. Those clay size particles produced in the early stage of weathering are slightly weathered ones (2), and are still subject to rapid weathering, losing bases and silica under humid and well drained conditions. In consequence the clay fraction of volcanic ash soils is composed of particles which vary in degree of weathering from slightly altered glass and feldspar to true clay mineraloids and minerals. The clay fraction of younger soils as a whole is less and that of older ones is more weathered. Weathering brings a remarkable change in the properties of volcanic ash soils; for example, an inerease in soil acidity, lowering of base saturation and bulk density, or accumlation of organic matter. These changes must exert a great influence on soil fertility directly or indirectly.     

Heat of immersion of soil allophanic clays

Amorphous soil inorganic materials, specifically allophane. are believed to have a marked effect on soil properties and soil productivity, even in a relatively small amount, due to their large specific surface area, peculiar nature of surface and high chemical reactivity. They seem be present in soils, more or less, but determination of their content is generally semiquantitative or not fully reliable, because allophane includes aluminosilicates in a wide range of chemical composition and of properties, and any satisfactory, quantitative analytical method has not been established.     

中日合作水稻品质·食味研究的现状和展望

介绍了中国水稻食味研究取得的成果和正在开展的研究工作,对今后水稻食味研究的发展做了展望。随着中国社会经济的迅速发展,人们的饮食结构发生了变化,对主食稻米的需求正在由数量型向品质食味型转变。影响水稻食味的三大因素包括遗传特性、产地特点和生产技术,其中,首选遗传特性。中国水稻食味育种工作已经展开,优质食味米配套生产技术的研...     

Development of microsatellite markers in cultivated and wild species of sections <Emphasis Type="Italic">Cepa</Emphasis> and <Emphasis Type="Italic">Phyllodolon</Emphasis> in <Emphasis Type="Italic">Allium</Emphasis>

The potential of microsatellite markers for use in genetic studies has been evaluated in Allium cultivated species (Allium cepa, A. fistulosum) and its allied species (A. altaicum, A. galanthum, A. roylei, A. vavilovii). A total of 77 polymerase chain reaction (PCR) primer pairs were employed, 76 of which amplified a single product or several products in either of the species. The 29 AMS primer pairs derived from A. cepa and 46 microsatellites primer pairs from A. fistulosum revealed a lot of polymorphic amplicons between seven Allium species. Some of the microsatellite markers were effective not only for identifying an intraspecific F₁ hybrid between shallot and bulb onion but also for applying to segregation analyses in its F₂ population. All of the microsatellite markers can be used for interspecific taxonomic analyses among two cultivated and four wild species of sections Cepa and Phyllodolon in Allium. Generally, our data support the results obtained from recently performed analyses using molecular and morphological markers. However, the phylogeny of A. roylei, a threatened species with several favorable genes, was still ambiguous due to its different positions in each dendrogram generated from the two primer sets originated from A. cepa and A. fistulosum.