Distribution of different fractions of cadmium,zinc, lead,and copper in unpolluted and polluted soils

McLaren and Crawford's method for fractionating soil Cu was modified, and used to fractionate soil Cd, Zn, Pb, and Cu in 38 soil samples from 11 soil profiles from industrially polluted and nearby unpolluted areas. Pollutant metals, especially Cd and Zn, were more soluble than the native soil metals. On average, approximately 45% of Cd was present in the CaCl₂ soluble (CA) fraction, whereas corresponding values for the other metals were below 10%. The percentages of each metal in the CA fraction followed the order Cd > Zn > Pb > Cu. The same order was observed for the acetic acid soluble (AAC) fraction. Approximately 30% of total Pb and Cu were present in the pyrophosphate soluble (PYR) fraction, and only 10% of total Cd and Zn. Approximately 20% of total Zn or Pb and 10% of Cd or Cu were present in the free oxide (OX) fraction. Only 20% of Cd and between 40–50% of the other 3 metals were present in the residual (RES) fraction. The results show that Cd is more labile than the other 3 metals.     

Identification of potent odorants in Chinese jasmine green tea scented with flowers of Jasminum sambac

The odorants in Chinese jasmine green tea scented with jasmine flowers (Jasminum sambac) were separated from the infusion by adsorption to Porapak Q resin. Among the 66 compounds identified by GC and GC/MS, linalool (floral), methyl anthranilate (grape-like), 4-hexanolide (sweet), 4-nonanolide (sweet), (E)-2-hexenyl hexanoate (green), and 4-hydroxy-2,5-dimethyl-3(2H)-furanone (sweet) were extracted as potent odorants by an aroma extract dilution analysis and sensory analysis. The enantiomeric ratios of linalool in jasmine tea and Jasminum sambac were determined by a chiral analysis for the first time in this study: 81.6% ee and 100% ee for the (R)-(-)-configuration, respectively. The jasmine tea flavor could be closely duplicated by a model mixture containing these six compounds on the basis of a sensory analysis. The omission of methyl anthranilate and the replacement of (R)-(-)-linalool by (S)-(+)-linalool led to great changes in the odor of the model. These two compounds were determined to be the key odorants of the jasmine tea flavor.     

Revisiting the mechanism of <Emphasis Type="Italic">β-O</Emphasis>-4 bond cleavage during acidolysis of lignin IV: dependence of acidolysis reaction on the type of acid

The dependence of the acidolysis reaction of a C₆-C₃ dimeric nonphenolic β-O-4 type lignin model compound, 2-(2-methoxyphenoxy)-1-(3,4-dimethoxyphenyl) propane-1,3-diol (veratrylglycerol-β-guaiacyl ether, VG), on the type of acid applied was examined using three different acids [0.2 mol/l HCl, 0.2 mol/l HBr, and 0.1 mol/l (0.2 N) H₂SO₄ in 82% aqueous 1,4-dioxane at 85°C]. In the HCl system, the major reaction modes of the corresponding benzyl cation-type intermediate (BC), which is produced by protonation of the α-hydroxyl group of VG and successive release of the water molecule, are the abstraction of the β-proton and hydride transfer from the β-to the α-position. The liberation of formaldehyde from the γ-hydroxymethyl group of BC is the predominant reaction mode in the H₂SO₄ system. Apparently, an unknown reaction mode or modes is operative in the early stage of the HBr system that causes rapid disappearance of VG accompanied by the quantitative formation of 2-methoxyphenol without affording the common counterpart of a Hibbert’s ketone, 1-hydroxy-3-(3,4-dimethoxyphenyl) propan-2-one. The reaction mode in the HBr system changes with the progress of the reaction and is the same as that in the HCl system after the early stage.     

Melittin-Like Peptides from the Shark-Repelling Defense Secretion of the Sole Pardachirus pavoninus

Three ichthyotoxic peptides, pardaxins P-I to P-3, have been isolated from the defense secretion of the sole Pardachirus pavoninus. Pavoninins, the steroid glycosides with shark-repelling ability, had previously been isolated therefrom. Each pardaxin consists of 33 amino acid residues having a distinctly hydrophilic carboxyl terminal region and a predominantly hydrophobic remainder; the pardaxin is thus strongly surfactant. These peptides show marked physical and pharmacological similarities to melittin, the major active constituent of bee venom, yet they lack sequence homology. They are probably also responsible for the predator-repelling property of the sole.     

Oxygen isotopic compositions of asteroidal materials returned from Itokawa by the Hayabusa mission

Meteorite studies suggest that each solar system object has a unique oxygen isotopic composition. Chondrites, the most primitive of meteorites, have been believed to be derived from asteroids, but oxygen isotopic compositions of asteroids themselves have not been established. We measured, using secondary ion mass spectrometry, oxygen isotopic compositions of rock particles from asteroid 25143 Itokawa returned by the Hayabusa spacecraft. Compositions of the particles are depleted in (16)O relative to terrestrial materials and indicate that Itokawa, an S-type asteroid, is one of the sources of the LL or L group of equilibrated ordinary chondrites. This is a direct oxygen-isotope link between chondrites and their parent asteroid.     

<Emphasis Type="Italic">In silico</Emphasis> genomic subtraction guides development of highly accurate,DNA-based diagnostics for <Emphasis Type="Italic">Ralstonia solanacearum</Emphasis> race 3 biovar 2 and blood disease bacterium

New rapid diagnostic methods are urgently needed to discriminate the quarantine pathogen Ralstonia solanacearum (Rs) race 3 biovar 2 (R3B2) from other populations of Rs that lack the adaptation to cause bacterial wilt disease in temperate regions. We used an in silico bioinformatic approach to identify several genome sequences potentially specific to R3B2 strains. Primer sets were designed to PCR-amplify sequences in these regions, and four sets were ultimately shown to be >99% accurate for detection of R3B2 strains. On the basis of these results, several primers were designed to enable development of a loop-mediated isothermal amplification assay that was rapid, technologically simple, and essentially 100% accurate for identification of R3B2 when applied to a comprehensive collection of geographically diverse Rs strains. We fortuitously found that a sequence in one of the “R3B2-specific” regions has ~90% identity to a sequence present in strains of the blood disease bacterium (BDB), a member of the Rs species complex that infects banana. Alignments of these sequences allowed design of a second PCR primer set that proved 100% accurate for identification of BDB strains when tested on the 22 BDB strains available to us. These results demonstrate the power of in silico genomic subtraction for rapid identification of population-specific DNA sequences and for the development of simple, reliable detection methods for Rs subpopulations.     

Background level of indium and gallium in soil with special reference to the pollution of the soils from zinc and lead smelters

The mean and range of indium content in unpolluted soils (Humic Andosols, Eutric Fluvisols, and Mollic Gleysols) was found to be 0.037 (0.016–0.078) μg/g dry wt. In soils polluted by common heavy metals, elevated values of indium up to 1.92 μg/g dry wt were observed together with an increase of cadmium, zinc, and lead. In contrast to indium, gallium content in polluted soils was nearly the same as that in unpolluted soils throughout the profiles. The mean and range of gallium content in all unpolluted and polluted samples was 14.2 (12.8–16.3) μg/g dry wt. The indium and gallium contents in 4 Canadian reference soils were also analyzed.     

Analysis of glycosidically bound aroma precursors in tea leaves. 1. Qualitative and quantitative analyses of glycosides with aglycons as aroma compounds

Twenty-six synthetic glycosides constituting aglycons of the main tea aroma compounds ((Z)-3-hexenol, benzyl alcohol, 2-phenylethanol, methyl salicylate, geraniol, linalool, and four isomers of linalool oxides) were synthesized in our laboratory as authentic compounds. Those compounds were used to carry out a direct qualitative and quantitative determination of the glycosides as aroma precursors in different tea cultivars by capillary gas chromatographic-mass spectrometric (GC-MS) analyses after trifluoroacetyl conversion of the tea glycosidic fractions. Eleven beta-D-glucopyranosides, 10 beta-primeverosides (6-O-beta-D-xylopyranosyl-beta-D-glucopyranoside) with aglycons as the above alcohols, and geranyl beta-vicianoside (6-O-alpha-L-arabinopyranosyl-beta-D-glucopyranoside) were identified (tentatively identified in the case of methyl salicylate beta-primeveroside) in fresh tea leaves and quantified on the basis of calibration curves that had been established by using the synthetic compounds. Primeverosides were more abundant than glucosides in each cultivar we investigated for making green tea, oolong tea, and black tea. Separation of the diastereoisomers of linalool and four isomers of linalool oxides by GC analyses is also discussed.     

Identification of whale species by thin-layer isoelectric focusing of sarcoplasmic proteins.

Thin-layer isoelectric focusing was applied to the identification of whale (Cetacea) species by using water-soluble sarcoplasmic proteins of skeletal muscles. Twenty-eight samples consisting of 4 species (10 samples) of baleen whales (Mysticeti) and 8 species (18 samples) of toothed whales (Odontoceti) were analyzed. Each sample (approximately 1 g) was electrophoresed with Ampholine PAGplate, pH 3.5-9.5. The electrophoretic profiles were species-specific on the 4 toothed whale species that did not have a marked intra-species difference, and all 4 baleen whale species. However, the profiles were not specific on the 4 other dolphin species, even though they were discriminable from the other 4 toothed whale species. Numerical values of pIs and relative peak heights were obtained by densitometric analysis of the isoelectro-focused protein bands. The bands were also species-specific for the 8 toothed whale species mentioned. The values may be applicable to species identification without the need for a standard sample, which may not be readily obtainable. Experiments on test samples of minke and sel whales showed that bloodletting with ice water made the densities of isoelectro-focused bands thinner, although species identification was still possible by using the inside part of muscles. Heat treatment at below 60 degrees C for 10 min caused little denaturation; at higher temperatures the protein bands were diminished in a temperature-dependent fashion. Therefore, the present isoelectric focusing analysis should be applicable to small samples of whale meat, excluding several species of dolphins.