Shozo Toda

Inhibition of the infectivity and cytopathic effect of human immunodeficiency virus by water-soluble lignin in an extract of the culture medium of Lentinus edodes mycelia (LEM)

Inhibition of the infectivity and cytopathic effect of human immunodeficiency virus type 1 (HIV-1) by the immunoactive fractions obtained from LEM, which is an extract of the culture medium of Lentinus edodes mycelia, is reported. A purified fraction, EPS4, obtained from LEM by ethanol precipitation followed by hydrophobic chromatography and gel filtration chromatography completely inhibited the HIV-1 induced cytopathic effect in vitro at concentrations of greater than or equal to 10 micrograms/ml. Chemical and spectral analysis revealed that EPS4 is composed of water-soluble lignins containing minor amounts of protein (3.2%) and sugars (12.2%). Taken together with the previously reported observation that EPS4 promotes the activation of macrophages and the proliferation of bone marrow cells, the fraction appears to possess both an immunostimulating activity and an anti-HIV effect in vitro.

Interference by mineral acids in inductively coupled plasma atomic emission spectrometry

Interferences caused by low concentrations of mineral acids have been investigated in inductively coupled plasma atomic emission spectrometry. There appear to be two mechanisms that lower the emission intensities: the decrease in the excitation temperature and the reduction in the aspiration rate. The former was predominant at lower concentrations of mineral acids (⩽1 M) and the latter became influential at higher acid concentrations (1 M). The excitation temperature was found to decrease in the presence of mineral acids. The decreases in emission intensities were in fair agreement with those estimated from the decreases in excitation temperature.

Glutathione peroxidase activity of D,L-selenocystine and selenocystamine

The activity of glutathione peroxidase (EC 1.11.1.9) was found for D, L-selenocystine and selenocystamine at the concentration of 10−5M Se. The reaction depends upon the pH and the optimum pHs were 8.0 for D,L-selenocystine and 9.0 for selenocystamine. Based upon the chromatographic separation of the intermediate seleno-sulfur (-S-Se-) compound, the mechanism was discussed in relation to the selenoenzyme, glutathione peroxidase.

Study of metal contents of elasmobranch fishes: part 1—metal concentration in the muscle tissues of a dogfish, squalus mitsukurii

Abstract Concentrations of Hg, Zn, Fe, Cd and Cu in the muscle tissues of a dogfish, Squalus mitsukurii, were determined by atomic absorption spectrometry and found to be in the ranges of f0·019–2·13, 1·8–3·6, 1·5–5·7, 0·001–0·018 and 0·12–0·70 μg/g wet weight, respectively. The frequency distributions of concentrations, with the exception of mercury, were found to be log-normal. The correlation coefficient between mercury content and total length was positive and large and statistically highly significant. For other metals negative correlations were observed. Mercury concentration in the muscle was found to increase in proportion to the total length cubed. Regression of mercury concentration on age of sharks was shown to be linear. Analysis of covariance showed that the difference between sexes was not statistically significant, either in slope or in height. The concentration of mercury in the muscle tissues of embryos was considerably lower, Cd roughly the same and Zn and Fe higher than those of mothers. The concentrations of Zn, Fe and Cu are higher in the embryonic stage and immediately after birth than in later stages of growth.

Identification of β-galactofuranosyl residues and their rapid internal motion in the Penicilliumochro-chloron cell wall probed by 13C NMR

Abstract Polysaccharides, which come into resonances in the 13C NMR spectrum of Penicillium ochro-chloron intact mycelium and give anomeric carbon signals at 107.5 and 108.3 ppm, are associated with the cell wall. By 13C NMR and gas liquid chromatography analysis, it is shown that the polysaccharides are two types of β-galactofuranosyl residues, one of which has (1→2)-β-galactofuranosyl linkages. Both β-galactofuranosyl residues, which are minor cell wall components, experience rapid internal motion in the cell wall.

On the infrared absorption spectra of zinc stearate complex

Abstract The infrared absorption spectra of zinc stearate complex prepared from sodium stearate and zinc thiocyanate were investigated. Patterns of the bands due to COO− group of this compound (complex salt) are different from those of the ordinary zinc distearate. By heating a mixture of sodium stearate (2 mol) and zinc distearate (1 mol) a similar spectrum to that of the complex salt is obtained. The three vas(COO−) are observed at 1622, 1609 and 1595 cm−1. It is presumed that there are different molecular structures with three kinds of COO− groups. Although a band of COO− at 1412 cm−1 is observed very weakly in paste state, it is strong when the sample is prepared in KBr pellet. The reason appears to be that the transition moment of the vs(COO−) band is almost perpendicular to the electric vector of the infrared ray as a result of a notable squamous crystal oriented parallel to the plane of the window plate in paste state. The bands at 675 and 1110 cm−1 are also discussed.

Spin-lattice relaxation time as a useful indicator for the 13CNMR assignment of terminal cis- and trans-methyls in 2-methyl-1-propenyl moiety

Abstract T 1 gives a clue to assign cis- and trans-methyl carbons in 2-methyl-1-propenyl moiety.

31P nuclear magnetic resonance analysis of Penicilliumochro-chloron

Abstract 31P nuclear magnetic resonance (NMR) spectra of a filamentous fungus P. ochro-chloron were obtained at a frequency of 40.3 MHz. The spectra show resonances assignable to sugar phosphates, orthophosphates, glycerol-3-phosphorylethanolamine (GPE), glycerol-3-phosphorylcholine (GPC), ATP-α, UDPG and polyphosphate. The intracellular pH is estimated to be 6.4 in the logarithmic phase of growth, and high levels of GPE and GPC are characteristic of the fungus. The 31P NMR spectra reflect the age of the fungus and show the accumulation of polyphosphate in the stationary phase.

Comparison of Mineral Acids in Wet Digestion of Plant Materials for Flame and Flameless Atomic Absorption Measurement of Metals

Abstract Various mineral acids are compared in measuring metals in plant materials by flame and flameless atomic absorption spectrometry. NBS-SRM 1571, Orchard Leaves, is utilized as the plant material. The combination of H2SO4 and HNO3 is found to be the most suitable for measuring Fe, Mn, Cu and Zn by flame atomic absorption spectroscopy, while HNO3 is found to be the best for measuring Cu, Mn, and Pb by flameless Atomic Absorption spectroscopy.

Determination of Lead in MIBK Extracts Using a Modified Long Path Atomic Absorption Cell

Abstract A long path atomic absorption cell has been modified to achieve high sensitvity in the determination of lead after MIBK extraction. This was achieved by using thermal insulation of the absorption cell and positioning the burner at an optimum angle. Insertion of rings inside the cell and oxygen supply line reduced the background noise to a low level while producing high sensitivities. This resulted in a marked improvement in detection limits for some metals in aqueous solution.