Asymmetric hydrogenation of N-sulfonylated-alpha-dehydroamino acids: toward the synthesis of an anthrax lethal factor inhibitor

A novel and highly enantioselective Ru-catalyzed hydrogenation of N-sulfonylated-alpha-dehydroamino acids has been discovered and demonstrated in the synthesis of an anthrax lethal factor inhibitor (LFI). Herein, this methodology is used to prepare N-sulfonylated amino acids in up to 98% ee. This unprecedented hydrogenation uses a chiral Ru catalyst rather than Rh as typical for acylated dehydroamino acids and esters, and this work reports the first asymmetric hydrogenation of a tetrasubstituted dehydroamino acid derivative using a Ru catalyst. [reaction: see text]     

Azo benzene derivatives

Pressure-volume isotherms for 4-(trans-4-butylcylohexyl)benzonitrile were measured by means of piston-cylinder method. This substance has a monotropic nematic phase at atmospheric pressure. But over a pressure, the nature of isotropic to nematic phase transition changed from monotropic to enantiotropic phase transition. It is the first observation in P-V-T experiments that the monotropic isotropic-nematic transition changes enantiotropic under pressure.     

On idempotents and isomorphisms of multiplication algebras of bernstein algebras

The purpose of this paper is twofold. First of all we characterize Bernstein algebras having a nilpotent kernel using idempotents of their multiplication algebras. Secondly, we describe some properties of Bernstein algebras which are preserved by isomorphisms of their multiplication algebras.     

Application of analytical isotachophoresis in the study of platelet membrane proteins in patients with chronic myeloproliferative disorders

The supernatants of dispase-treated platelets from normal persons and patients with myeloproliferative disorders were analysed by capillary isotachophoresis. The examined myeloproliferative disorders were three cases of chronic myelogeneous leukemia, one case of chronic neutrophilic leukemia, one case of essential thrombocythemia and one case of polycythemia vera. An additional peak was revealed in the samples from the patients with chronic myelogeneous leukemia. Platelets from the other three patients showed no additional bands. Isotachophoresis will be useful not only to analyse the superficial peptide on the cell membrane but also to define the peptide associated with malignant transformation.     

Swelling-shrinking behavior of chemically cross-linked polypeptide gels from poly(α-L-lysine), poly(α-DL-lysine), poly(ɛ-L-lysine) and thermally prepared poly(lysine): effects of pH, temperature and additives in the solution

We synthesized the glutaraldehyde cross-linked hydrogels using four kinds of poly(lysine)s (PLs) and measured the equilibrium swelling ratio (Q) as a function of pH. Also measured was the temperature change of Q at a fixed pH (11.6) in the absence and presence of additives (LiBr, methanol and urea) that affect the secondary structure of PLs. The swelling data were examined using a force balance approach in which the repulsive and attractive interactions among the cross-linked PL chains were considered based on the conformational properties of PLs in aqueous solutions. It was found that the formation of the helical segments in the cross-linked chain has little effect in the gel collapse, but their association acts as the attractive interaction causing the gel to shrink. The formation of the beta-sheet structure within the network also acts as the attractive interaction. These attractive interactions are mainly due to the hydrogen bonding, but hydrophobic interactions between the lysine side chains should be considered. In addition, in the swelling behavior of all the PL gels the polyampholyte nature appears due to electrostatic interactions of the basic groups with the C-terminal carboxyl group.     

Abnormal phospholipids distribution in the prefrontal cortex from a patient with schizophrenia revealed by matrix-assisted laser desorption/ionization imaging mass spectrometry

Schizophrenia is one of the major psychiatric disorders, and lipids have focused on the important roles in this disorder. In fact, lipids related to various functions in the brain. Previous studies have indicated that phospholipids, particularly ones containing polyunsaturated fatty acyl residues, are deficient in postmortem brains from patients with schizophrenia. However, due to the difficulties in handling human postmortem brains, particularly the large size and complex structures of the human brain, there is little agreement regarding the qualitative and quantitative abnormalities of phospholipids in brains from patients with schizophrenia, particularly if corresponding brain regions are not used. In this study, to overcome these problems, we employed matrix-assisted laser desorption/ionization imaging mass spectrometry (IMS), enabling direct microregion analysis of phospholipids in the postmortem brain of a patient with schizophrenia via brain sections prepared on glass slides. With integration of traditional histochemical examination, we could analyze regions of interest in the brain at the micrometric level. We found abnormal phospholipid distributions within internal brain structures, namely, the frontal cortex and occipital cortex. IMS revealed abnormal distributions of phosphatidylcholine molecular species particularly in the cortical layer of frontal cortex region. In addition, the combined use of liquid chromatography/electrospray ionization tandem mass spectrometry strengthened the capability for identification of numerous lipid molecular species. Our results are expected to further elucidate various metabolic processes in the neural system.     

Molecular states of p-dimethylaminobenzonitrile coground with β-cyclodextrin investigated using solid-state fluorescence spectroscopy

Changes in molecular states of p-dimethylaminobenzonitrile (DMABN) coground with β-cyclodextrin (β-CD) were examined using solid-state fluorescence measurements. Formation of a DMABN/β-CD inclusion complex by coprecipitation was confirmed by powder X-ray diffraction measurement. The powder X-ray diffraction pattern of the ground mixture was a halo pattern and differed from the pattern of the mixture prepared by coprecipitation. Solid-state fluorescence measurements revealed emission by DMABN crystals in a twisted intermolecular charge-transfer state at 473 nm. DMABN in the DMABN/β-CD coprecipitate had a fluorescence emission peak at 393 nm due to its planar structure. In contrast, DMABN in a DMABN/β-CD ground mixture had an emission peak at 473 nm due to its twisted structure. Grinding time-dependent structural changes in DMABN were evaluated using fluorescence lifetime and relative quantum yield measurements. Structural changes in DMABN in the DMABN/β-CD coprecipitate from a planar to a twisted structure were observed with grinding. DMABN, dispersed in microcrystalline cellulose (CC) molecules in a DMABN/CC ground mixture, had a fluorescence emission peak at 473 nm. However, the excitation spectrum of a DMABN/β-CD ground mixture differed from that of DMABN in CC. These results indicated that the molecular state of DMABN accommodated in the β-CD cavity differs between the coprecipitate and the ground mixture.     

Shedding light on hidden reaction pathways in radical polymerization by a porous coordination network

A coordination network comprising 2-vinyltriphenylene was treated with AIBN at a high temperature, but the radical polymerization of the vinyl monomer was completely suppressed by spatial separation and otherwise hidden aerobic oxidation pathways are enhanced.     

Localization of the Grover Walks on Spidernets and Free Meixner Laws

In the first part, we have constructed several families of interacting wedge-local nets of von Neumann algebras. In particular, we discovered a family of models based on the endomorphisms of the U(1)-current algebra ${\mathcal{A} ^{(0)}}$ of Longo-Witten. In this second part, we further investigate endomorphisms and interacting models. The key ingredient is the free massless fermionic net, which contains the U(1)-current net as the fixed point subnet with respect to the U(1) gauge action. Through the restriction to the subnet, we construct a new family of Longo-Witten endomorphisms on ${\mathcal{A} ^{(0)}}$ and accordingly interacting wedge-local nets in two-dimensional spacetime. The U(1)-current net admits the structure of particle numbers and the S-matrices of the models constructed here do mix the spaces with different particle numbers of the bosonic Fock space.