Isolation and stereostructures of neocitreoviridinol and epineocitreoviridinol

Both neocitreoviridinol and epineocitreoviridinol with a 2,5-dioxabicyclo[2.2.1]-heptane ring have been isolated as new metabolises of $\text{Penicillium citreo-viride}$ B., and their stereostructures have also been elucidated on the basis of their spectral data coupled with molecular mechanics calculations. In addition, a promising synthetic intermediate for neocitreoviridinol has been made.     

One-step synthesis of 2,6-naphthalenedicarboxylic acid from naphthalene using cyclodextrin as catalyst

The one-step synthesis of 2,6-naphthalenedicarboxylic acid from naphthalene with carbon tetrachloride, copper powder and aqueous alkali has been achieved under mild conditions by the use of β-cyclodextrin as catalyst, producing 2,6-naphthalenedicarboxylic acid in 65 mol-% yield with 79% selectivity.     

Inclusion and Release of Hinokitiol into/from MCT-β-CD Fixed on Japanese Washi Paper

The potential for surface modification of paper by modified cyclodextrins was demonstrated by the model system of Japanese washi paper and monochlorotriazinyl-β-cyclodextrin (MCT-β-CD). MCT-β-CD was covalently bonded to the paper. The optimal bonded reaction conditions were found to be 10 min at 150 °C with a moisture content of less than 2.5 (g water/g dry paper). The bounded MCT-β-CD on the paper was able to include and release hinokitiol representing the group of antibacterial agents. The maximum molar inclusion ratio of hinokitiol in the immobilized MCT-β-CD was around 0.8. The release rates of hinokitiol, included in the fixed MCT-β-CD, were monitored at 50 °C for different relative humidities. The release rate was strongly influenced by the relative humidity. These results demonstrate that the antibacterial agent can be included and released from MCT-β-CD fixed on the paper. The antibacterial activity of the fixed hinokitiol against airborne microorganisms was demonstrated.     

Chemical analysis of semiconducting and metallic SmS thin films by X-ray photoelectron spectroscopy

We studied the chemical state of semiconducting and metallic SmS thin films by X-ray photoelectron spectroscopy (XPS), which were fabricated using dual-target magnetron sputtering by controlling the power applied to both metal and chalcogenide targets. On the basis of the valence band spectra obtained, it was suggested that semiconducting SmS has the final state corresponding to the Sm²⁺(4f⁶) configuration below the Fermi level, and metallic SmS has mainly the Sm³⁺(4f⁵) final state and a virtual band state in the Sm 5d band, contributing to the delocalization of 4f electrons and the emergence of metallic conductivity (4f⁶d⁰-4f⁵d¹). Thus, the spectra of our fabricated SmS thin films correspond to the band structure obtained from the dielectric property. This is the first work performed on the intrinsically prepared metallic SmS while the former works done for the sample transformed from semiconductor to metal phase by hard polishing.