Asymmetric reduction of prochiral inclusion complex in aqueous media

Abstract

In the formation of an inclusion compound, the interaction of both ionic and hydrogen bonds were shown to be involved in the asymmetric reduction of a keto acid in the presence of 6-deoxy-6-amino-β-cyclodextrin with NaBH₄ in an aqueous buffer solution. Furthermore, multiple interactions were elucidated and the enatioface differentiating reduction was induced in the concerted interactions. Asymmetric reduction of a keto acid in the presence of newly prepared alkylamino-substituted β-cyclodextrin (CD) gave a higher optical yield. There should be a steric effect by a substituent group on the CD to form the conformation favoured by the multi-interaction between host and guest A mechanistic scheme for the enatioface differentiating attack of a reducing reagent on the included substrate is suggested.     

Uncertainty relation on Wigner-Yanase-Dyson skew information

We give a trace inequality related to the uncertainty relation of Wigner-Yanase-Dyson skew information. This inequality corresponds to a generalization of the uncertainty relation derived by S. Luo (2005) [8] for the quantum uncertainty quantity excluding the classical mixture.     

Highly activatable and environment-insensitive optical highlighters for selective spatiotemporal imaging of target proteins

Optical highlighters are photoactivatable fluorescent molecules that exhibit pronounced changes in their spectral properties in response to irradiation with light of a specific wavelength and intensity. Here, we present a novel design strategy for a new class of caged BODIPY (4,4-difluoro-4-bora-3a,4a-diaza-s-indacene) fluorophores, based on the use of photoremovable protecting groups (PRPGs) with high reduction potentials that serve as both a photosensitive unit and a fluorescence quencher via photoinduced electron transfer (PeT). 2,6-Dinitrobenzyl (DNB)-caged BODIPY was efficiently photoactivated, with activation ratios exceeding 600-fold in aqueous solutions. We then combined this photoactivatable fluorophore with a SNAP (mutant of O(6)-alkylguanine DNA alkyltransferase) ligand to obtain a small-molecule-based optical highlighter for visualization of protein dynamics, using the well-established SNAP tag technology. As proof of concept, we demonstrate spatiotemporal imaging of the fusion protein of epidermal growth factor receptor (EGFR) with SNAP tag in living cells. We also demonstrate highlighting of cells of interest in live zebrafish embryos, using the fusion protein of histone 2A with SNAP tag.     

Hypoxia-sensitive fluorescent probes for in vivo real-time fluorescence imaging of acute ischemia

Based on the findings that the azo functional group has excellent properties as the hypoxia-sensor moiety, we developed hypoxia-sensitive near-infrared fluorescent probes in which a large fluorescence increase is triggered by the cleavage of an azo bond. The probes were used for fluorescence imaging of hypoxic cells and real-time monitoring of ischemia in the liver and kidney of live mice.     

Polar antiferromagnets produced with orbital order

Polar states are realized in pseudocubic manganite films fabricated on high-index substrates, in which a Jahn-Teller (JT) distortion remains an active variable. Several types of orbital orders (OOs) were found to develop large optical second harmonics, signaling broken-inversion symmetry distinct from their bulk forms and films on (100) substrates. The observed symmetry lifting and first-principles calculation both indicate that the modified JT q2 mode drives Mn-site off centering, which can be controlled by a magnetic-field-induced phase transition via a coupling of OO and spin orders.     

Design and synthesis of an enzyme activity-based labeling molecule with fluorescence spectral change

Methods of covalent labeling of a specific tag protein with small-molecular dyes play an important role in studying dynamic behaviors of proteins in living cells. On the basis of quinone methide chemistry, we designed and synthesized a beta-galactosidase labeling probe, CMFbeta-gal, which shows a fluorescence wavelength change accompanying the labeling reaction, owing to fluorescence resonance energy transfer (FRET). Since the FRET efficiency changes accompanying the labeling reaction, fluorescence of labeled protein can be observed separately from that of the unreacted probe, so immediate detection of the target protein is possible. This is the first report of a protein labeling probe which features a change of fluorescence wavelength upon reaction, allowing the labeled protein to be detected even in the presence of unreacted probe.     

1,17‐Hepta­decane­diol

In the title compound, C₁₇H₃₆O₂, one of the hydroxyl groups has a gauche conformation with respect to the hydro­carbon skeleton, which is all‐trans, whereas the other has a trans conformation. The molecular shape is rod‐like and the compound has a rotator phase in which mol­ecules are assured greater motional freedom, as in liquid crystals. In addition, the mol­ecules arranged along the longest axis, b, form layers which are very similar to those of the smectic A liquid crystals.     

Photocatalytic Reduction of Nitrate in Water on Meso-Porous Hollandite Catalyst: A New Pathway on Removal of Nitrate in Water

Photocatalysis of a hollandite compound K _x Ga _x Sn_8–x O₁₆ (x = ca. 1.8) was examined for the reduction of nitrate to N₂ with a reducing agent of methanol in water under UV irradiation. Hollandites have a characteristic one-dimensional tunnel structure. The meso-porous hollandite was prepared by sol-gel method. This hollandite was used as the photocatalyst and its reaction process was quantitatively analyzed by using ion chromatograph and on-line mass spectrometry. The hollandite photocatalyst showed a significant activity for the formation of N₂ from NO ₃ ^– . Two factors, an increase in UV intensity and a lowering in pH of the solution, contributed to improvement in the selectivity for N₂. The selectivity for N₂ was improved to reach the perfect level by adjusting the factors. Although, in the previous report, the nitrate was mainly reduced to NH ₄ ⁺ or NO ₂ ^– , the present photocatalytic conditions converted it to N₂. The observed photocatalytic reduction of NO ₃ ^– to N₂ with reducing agent CH₃OH was conjugated to the partial oxidation of CH₃OH to HCOOH. This high selective photocatalytic decomposition of NO ₃ ^– to N₂ may be a new pathway among the others reported so far, and it would be useful for environmental protection of water.     

Über die mit einer Matrix vertauschbaren Matrizen

Ohne Zusammenfassung     

Über die Galoissche Theorie der halbeinfachen hyperkomplexen Systeme

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