Effect of ASP2151, a herpesvirus helicase-primase inhibitor, in a guinea pig model of genital herpes

ASP2151 is a herpesvirus helicase-primase inhibitor with antiviral activity against varicella zoster virus and herpes simplex virus types 1 (HSV-1) and 2 (HSV-2). Here, we examined the potency and efficacy of ASP2151 against HSV in vitro and in vivo. We found that ASP2151 was more potent in inhibiting the replication of HSV-1 and HSV-2 in Vero cells in the plaque reduction assay and had greater anti-HSV activity in a guinea pig model of genital herpes than did acyclovir and valacyclovir (VACV), respectively. Oral ASP2151 given from the day of infection reduced peak and overall disease scores in a dose-dependent manner, resulting in complete prevention of symptoms at the dose of 30 mg/kg. The 50% effective dose (ED(50)) values for ASP2151 and VACV were 0.37 and 68 mg/kg, respectively, indicating that ASP2151 was 184-fold more potent than VACV. When ASP2151 was administered after the onset of symptoms, the disease course of genital herpes was suppressed more effectively than by VACV, with a significant reduction in disease score observed one day after starting ASP2151 at 30 mg/kg, whereas the therapeutic effect of VACV was only evident three days after treatment at the highest dose tested (300 mg/kg). This indicated that ASP2151 possesses a faster onset of action and wider therapeutic time window than VACV. Further, virus shedding from the genital mucosa was significantly reduced with ASP2151 at 10 and 30 mg/kg but not with VACV, even at 300 mg/kg. Taken together, our present findings demonstrated the superior potency and efficacy of ASP2151 against HSV.     

Deprotonation‐Induced Aromaticity Enhancement and New Conjugated Networks in meso‐Hexakis(pentafluorophenyl)[26]hexaphyrin

meso‐Hexakis(pentafluorophenyl)‐substituted neutral hexaphyrin with a 26π‐electronic circuit can be regarded as a real homolog of porphyrin with an 18π‐electronic circuit with respect to a quite flat molecular structure and strong aromaticity. We have investigated additional aromaticity enhancement of meso‐hexakis(pentafluorophenyl)[26]hexaphyrin(1.1.1.1.1.1) by deprotonation of the inner N? H groups in the macrocyclic molecular cavity to try to induce further structural planarization. Deprotonated mono‐ and dianions of [26]hexaphyrin display sharp B‐like bands, remarkably strong fluorescence, and long‐lived singlet and triplet excited‐states, which indicate enhanced aromaticity. Structural, spectroscopic, and computational studies have revealed that deprotonation induces structural deformations, which lead to a change in the main conjugated π‐electronic circuit and cause enhanced aromaticity.     

Fe2+ localized excitations in the random antiferromagnet with competing spin anisotropies, Fe(1−x)CoxBr2

The Fe²⁺ localized magnetic excitations observed in the Co-rich antiferromagnetic phase of the randomly mixed system with competing Ising and XY spin anisotropies, Fe(_1?x)Co_xBr₂ have been analyzed quantitatively. The calculated frequency-field diagram reproduces well the experiments. The expectation values of the Fe²⁺ spin components in the ground state are calculated. It is shown that even in the Co-rich antiferromagnetic phase Fe²⁺ spins make an angle with the c-plane of the crystal in which Co²⁺ spins are confined.     

Tritium level in Japanese diet and human tissue

Tritium concentrations are reported for diet and human tissue samples collected in the Akita district of northern Japan. Sixteen separate food group samples and a total diet sample were collected for Akita City during April and May 1987. Six samples of heart and nine samples of kidney tissue were collected from 10 decreased individuals in Akita Prefecture from January to July 1986. Five serum and four blood samples were also obtained in Akita Prefecture from December 1985 to June 1986. Free water³H concentration as well as tissue-bound³H were determined separately. Specific activity ratios of tissue-bound³H to free water³H in the samples were almost between 1.0 and 2.0 and were similar to our previous results for food samples and other tissue samples. The specific activity ratio was also found to be lower than that reported in the U.S.A. and significantly lower than in Europe.     

Degradation of carbofuran in aqueous solution by Fe(III) aquacomplexes as effective photocatalysts

The photodegradation of carbofuran by excitation of iron(III) aquacomplexes was investigated under UV irradiation. The degradation rate was strongly influenced by the pH, and initial concentration of Fe(III). The degradation efficiency of carbofuran at the difference pH was in good agreement with the initial concentration of Fe(OH)²⁺ in the solution. An initial carbofuran concentration of 10 mg L⁻¹ was completely degraded within 50 min at pH 2.8 with original Fe(III) concentration of 8 × 10⁻⁴ mol L⁻¹. This degradation reaction was found to follow the first order kinetics law and the rate constant of 1.60 × 10⁻³ s⁻¹ was observed. The decrease of TOC content was observed during the photocatalytic process and the removal percentage obtained was about 70% after 25 h. Furthermore, ammonium ion as an end-product was detected in the solution. Therefore, this process based on the catalytic reaction of Fe(II, III) is responsible for the continuous production of hydroxyl radicals in such system. A gas chromatography-mass spectrometry analysis showed the formation of four photoproducts, such as 2,2-dimethyl-2,3-dihydro-benzofuran-7-ol, etc., revealing that the carbamate branch, C-3 and C-2 positions in furan ring were attack targets of hydroxyl radicals. Based on these results, the photocatalytic system could be useful technology for the treatment and the mineralization of compounds like carbofuran.     

Systematic study of photoluminescence upon band gap excitation in perovskite-type titanates R1/2Na1/2TiO3:Pr (R=La, Gd, Lu, and Y)

Pr³⁺-doped perovskites R_1/2Na_1/2TiO₃:Pr (R=La, Gd, Lu, and Y) were synthesized, and their structures, optical absorption and luminescent properties were investigated, and the relationship between structures and optical properties are discussed. Optical band gap of R_1/2Na_1/2TiO₃ increases in the order R=La, Gd, Y, and Lu, which is primarily due to a decrease in band width accompanied by a decrease in Ti-O-Ti bond angle. Intense red emission assigned to f-f transition of Pr³⁺ from the excited ¹D₂ level to the ground ³H₄ state upon the band gap photo-excitation (UV) was observed for all compounds. The wavelength of emission peaks was red-shifted in the order R=La, Gd, Y, and Lu, which originates from the increase in crystal field splitting of Pr³⁺. This is attributed to the decrease in inter-atomic distances of Pr-O together with the inter-atomic distances (R, Na)-O, i.e., increase in covalency between Pr and O. The results indicate that the luminescent properties in R_1/2Na_1/2TiO₃:Pr are governed by the relative energy level between the ground and excited state of 4f² for Pr³⁺, and the conduction and valence band, which is primarily dependent on the structure, e.g., the tilt of TiO₆ octahedra and the Pr-Ti inter-atomic distance and the site symmetry of Pr ion.     

Support and mixing effect of an Fe2O3 catalyst for oxidative dehydrogenation of 1-butene

The support and mixing effects of Fe₂O₃ for the activity of 1-butene oxidative dehydrogenation were examined. Alumina and titania which were able to catalyze the isomerization of butene via an allyl intermediate, stimulated remarkably the formation of butadiene from butene when they were used as support or mixing component of Fe₂O₃ catalyst. Otherwise Fe₂O₃ supported on SO ₄ ^2– ion containing Al₂O₃ or TiO₂–Al₂O₃, which catalyze the isomerization via a cationic intermediate, is almost inactive for the formation of butadiene.

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Fe₂O₃ 1-. , , , Fe₂O₃. , Fe₂O₃, Al₂O₃, SO ₄ ^–2 , TiO₂–Al₂O₃, , .

     

High-efficiency electrochemical CO<Subscript>2</Subscript>-to-methane reduction method using aqueous KHCO<Subscript>3</Subscript> media at less than 273 K

The electrochemical reduction of CO₂ with a Cu electrode in a KHCO₃ aqueous solution was investigated at low temperature. A divided H-type cell was employed; the electrolyte was a 1.1 mol dm^–3 KHCO₃ aqueous solution. The temperature during the electrolysis of CO₂ was reduced to 269 K. Methane, ethylene, and formic acid were obtained from CO₂ as the main products. The maximum faradaic efficiency of methane was 44% at a relatively negative potential and 269 K. The efficiency of hydrogen formation, as the competition against CO₂ reduction, significantly decreased with lowering the temperature. On the basis of this work, the high-efficiency electrochemical CO₂ to methane conversion method appears to be achieved. Electronic Publication     

Preconcentration of diazinon using multiwalled carbon nanotubes as solid-phase extraction adsorbents

A sensitive and selective column adsorption method is proposed for the preconcentration and determination of diazinon. Diazinon was preconcentrated on multiwalled carbon nanotubes (MWCNTs) as an adsorbent and then determined by high-performance liquid chromatography (HPLC). Several parameters on the recovery of the analyte were investigated. The experimental results showed that it was possible to obtain quantitative analysis when the solution pH was 6 using 200 mL of validation solution containing 2 μg of diazinon and 5 mL of acetonitrile as an eluent. Recovery of diazinon was 95.2 ± 4.2% with a relative standard deviation for seven determinations of 4.9% under optimum conditions. The maximum preconcentration factor was 200 for diazinon when 1000 mL of sample solution volume was used. The linear range of calibration curve was 0.3 to 10,000 ng mL^− 1 with a correlation coefficient of 0.997 and the detection limit (3S/N) was 0.06 ng mL^− 1. The proposed method was successfully applied to the determination of diazinon in tap water with high precision and accuracy.     

High-pressure synthesis, structure, and characterization of a post-perovskite CaPtO3 with CaIrO3-type structure

A new ternary platinum oxide, CaPtO3 was synthesized under a pressure of 7 GPa and a temperature of 1000 degrees C. The crystal structure of CaPtO3 was determined by Rietveld analysis of the X-ray powder diffraction data. CaPtO3 has a layered CaIrO3-type structure (orthorhombic, space group: Cmcm), which is the same as that of a post-perovskite MgSiO3 in the Earth's lower mantle. The magnetic susceptibility data indicate that the Pt ion in CaPtO3 is tetravalent in the low spin state with an electron configuration of t2g(6)eg(0)(S = 0). This finding is consistent with the insulating behavior.