New solanocapsine-type tomato glycoside from ripe fruit of Solanum lycopersicum

A new solanocapsine-type tomato glycoside, a novel and interesting natural steroidal glycoside, was isolated from a mini tomato, Solanum lycopersicum L. The chemical structure of the new minor glycoside, esculeoside B-5 (3), was determined to be (5S,22R,23S,24R,25S)-22,26-epimino-16β,23-epoxy-3β,23,24-trihydroxycholestane 3-O-β-lycotetraoside.     

Controlling the Emergence and Shift Direction of Mechanochromic Luminescence Color of a Pyridine‐Terminated Compound

In this study, mechanochromic luminescence was induced in a complex of mechano‐inactive compounds. Dye/acid complexes containing the same π‐conjugated backbones were prepared. While the luminophore showed blue and red shifts in photoluminescence spectra when combined with different acids by grinding, it exhibited slight mechanoresponsiveness itself. Also, compounds with similar molecular backbones to the dye/acid complex were synthesized to clarify the color change mechanism. The compounds showed both blue and red shifts in photoluminescence and diffuse reflectance spectra upon grinding, indicating that mechanochromic luminescence in the hydrogen‐bonded complex is like its monomeric analogue and that aggregation structure plays an important role in mechanoresponsive behavior rather than the π‐conjugated structure. It was shown that a color change can be mechanically induced by imitating the solid‐state aggregation structure of other mechanoresponsive compounds without synthetic modification.     

Changes on distribution of absorbed dose rates in air in an urban area after the Fukushima Daiichi Nuclear Power Plant accident

Journal of Radioanalytical and Nuclear Chemistry - Tokatsu area was on one pathway of the radioactive plumes released in the Fukushima Daiichi Nuclear Power Plant accident and absorbed dose rate in...     

EUV and soft X-ray photoelectron spectroscopy of isolated atoms and molecules using single-order laser high-harmonics at 42 eV and 91 eV

Photoelectron spectroscopy of isolated atoms and molecules using single-order high-harmonics of Ti:Sapphire laser pulses (800 nm, 12 fs/30 fs) is demonstrated. Dielectric multilayer mirrors, SiC/Mg and Mo/Si, are used to isolate the 27th (42 eV) and 59th (91 eV) order harmonics, respectively. The obtained harmonics are characterized by valence and inner-shell photoelectron spectroscopy of Xe. The applications to two-color two-photon ionization of He and pump-probe spectroscopy of ultrafast photodissociation of Br₂, Br₂(C¹Π_u) → Br(²P_3/2) + Br(²P_3/2), are presented.     

Radiation Chemical Studies of Protein Reactions: Effect of Sulfur-Containing Compounds on Optical Rotation

Thiourea, thioglycol, and β, β′-thiodiglycolic acid were found to protect against changes in the internal relationships of the atoms in the protein molecule from radiation damage. The optical rotation behavior closely resembles that of amino acid which shows a similar dependence on concentration.     

Synthesis of Polybenzoacenes: Annulative Dimerization of Phenylene Triflate by Twofold C−H Activation

Polycyclic aromatic hydrocarbons (PAHs) represent an emerging class of π-conjugated molecules in the area of optoelectronic devices and materials. Unprecedented synthetic routes to various PAHs from simple phenol derivatives by a palladium-catalyzed annulative dimerization of phenylene triflate through twofold inter- and intramolecular C−H activation have been established. The initially formed partially fused PAHs can be smoothly transformed into a variety of fully fused PAHs by the Scholl reaction. Furthermore, the reactions of phenanthrene-substituted aryl triflates proceeded regioselectively. The findings inspired the development of a rapid and efficient synthesis of polybenzoacene derivatives. This study not only allows transformation of phenyl triflates, but also discloses a new retrosynthetic strategy towards PAHs, especially polybenzoacenes.     

Radiation Chemical Studies of Protein Reactions: Effect of Chelating Agents on Optical Rotation

Abstract

1,2-Diamine and 1,2-dihydroxy derivatives such as ethylene-diamine, ethylenediaminetetraacetic acid and propylene glycol were found to protect against changes in the internal relationships of the atoms in the protein molecule from radiation damage. The optical rotation behavior closely resembles that found with amino acid as shown by a similar dependence on the concentration.     

Radiation Chemical Studies of Protein Reactions: Effect of Post-irradiation on the Breaking of Secondary Bonding in Protein

When protein was irradiated by prays from a ⁶⁰Co source, a post-irradiation effect of the breaking of secondary bonding in protein was caused. An empirical equation for the reactivity decay was obtained, and the phenomena were explained on the basis of molecular mechanism.     

FTIR-ATR evaluation of organic contaminant cleaning methods for SiO2 surfaces.

The effectiveness of cleaning organic contaminants from silicon dioxide (SiO2) surfaces was studied by conducting highly sensitive measurements using Fourier Transform Infrared Attenuated Total reflectance (FTIR-ATR) with a Si prism as the waveguide. To serve as an example, the surface of the prism was oxidized to an order of a few nanometers. The oxidized Si surface film was allowed to stand in the atmosphere and then wet-cleaned in a repeated manner; subsequently its thickness was measured by ellipsometry. Although, various wet-cleaning methods were tested, they only showed values of 0.1-0.2 nm larger than, but not equal to, the original thickness immediately after oxidation. FTIR-ATR measurements of the spectral change after exposure to air revealed that organic species, such as C-CH3 and -(CH2)n-, increased with time. Wet-cleaning the sample failed to remove the C-CH3 species, which indicates that they corresponded to the film thickness increment from the original.