Baryon resonances as hadronic molecule states with kaons

We investigate hadronic molecule states of $K \bar K N$ and $\bar K \bar K N$ systems with I?=?1/2 and J ^P ?=?1/2^?+?, assuming that Λ(1405) and the scalar mesons, f ₀(980), a ₀(980), are reproduced as quasi-bound states of $\bar KN$ and $K \bar K$ . Performing non-relativistic three-body calculations for these systems, we find weakly bound states for $K \bar K N$ and $\bar K \bar K N$ around 1900 MeV, which correspond to new baryon resonances of N ^* and Ξ ^* with J ^P ?=?1/2^?+?. We find that these resonances have cluster structure of the two-body bound state keeping its properties as in the isolated two-particle system.     

Reaction of arylmethanesulfonyl and styrylmethanesulfonyl chlorides with triethylamine

A series of arylmethanesulfonyl chlorides were treated with triethylamine in THF to give stilbenes in excellent yields. Workup of the mixtures below 10 °C permits isolation of stilbene episulfones which on warming decompose to yield the corresponding stilbenes stereospecifically. Application of the reaction to 9-fluorenylsulfonyl chloride affords bifluorenylidene, while trans-styrylmethanesulfonyl chloride gives 4,5-dihydro- 4,5-diphenylthiepin 1,1-dioxide and 1,6-diphenylhexatriene.     

Design and synthesis of a novel ring-expanded 4′-thio-apio-nucleoside derivatives

The synthesis of a ring-expanded 4′-thio-apio-nucleoside derivative 4, designed to serve as a potential anti-HIV agent, is described. The epoxy alcohol derivative 10, prepared from 2-butene-1,4-diol, was converted to an allylsulfide derivative 13 in 3 steps. Ring-closing-metathesis of 13 gave the dihydrothiopyran derivative 20, which was further converted into sulphoxide 24. A Pummerer-type thioglycosylation reaction of 24 with a persilylated uracil derivative, followed by conversion to a cytosine derivative and deprotection, gave a racemic mixture of the ring-expanded 4′-thio-apio-nucleoside derivative 4 in good yield.     

Triacylglycerol/phospholipid molecular species profiling of fatty livers and regenerated non-fatty livers in cystathionine beta-synthase-deficient mice, an animal model for homocysteinemia/homocystinuria

Fatty liver is one of the typical manifestations in homocysteinemia/homocystinuria patients and their genetic animal model, mice lacking cystathionine ??-synthase (Cbs ^?/?). The vast majority of Cbs ^?/? die within 4?weeks after birth via yet unknown mechanisms, whereas a small portion survive to adulthood, escaping fatty degeneration of the liver during lactation periods, through regeneration. To investigate the molecular basis of such fatty changes, we analyzed lipid components in fatty livers of 2-week-old Cbs ^?/? and regenerated non-fatty livers of 8-week-old Cbs ^?/? survivors using a chip-based nanoESI (electrospray ionization)-MS system, which allows quantitative detection of triacylglycerol/phospholipid molecular species. Hepatic levels of all major triacylglycerol species were much higher in Cbs ^?/? than in wild-type mice at 2?weeks, although not at 8?weeks. Levels of some phospholipid species were either up- or downregulated in 2-week-old Cbs ^?/?; e.g. saturated (16:0 and 18:0) or mono-unsaturated (16:1 and 18:1) fatty acids-containing phosphatidylcholine/phosphatidylethanolamine species were upregulated, while poly-unsaturated fatty acids-containing phosphatidylcholine (18:2?C18:2 and 18:2?C20:5), phosphatidylethanolamine (18:1?C20:4), and phosphatidylinositol (18:0?C20:4) were downregulated. Capillary electrophoresis-MS analysis identified high-level accumulation of S-adenosylmethionine and S-adenosylhomocysteine in fatty livers of 2-week-old Cbs ^?/? but much less in non-fatty livers of 8-week-old Cbs ^?/?. Although hepatic S-adenosylmethionine/S-adenosylhomocysteine ratios were comparable between 2-week-old Cbs ^?/? and wild-type, global protein arginine methylation was disturbed in fatty livers of Cbs ^?/?. Our results suggest that cellular signaling mediated by altered phospholipid contents might be involved in pathogenesis of fatty liver in Cbs ^?/?C.     

Mg-promoted facile and selective intramolecular cyclization of aromatic δ-ketoesters

Treatment of various types of aromatic δ-ketoesters 2, 7, and 9 with Mg-turnings for Grignard reaction at −5 to 0 °C in N,N-dimethylformamide (DMF) containing trimethylsilyl chloride (TMSCl) brought about selective and reductive intramolecular cyclization to give the corresponding α-aryl-α-hydroxycyclopentanones 5, 8, and 10, respectively, in moderate to good yields. Similar reductive intramolecular cyclization of aromatic δ-ketodiesters 14, followed by acidic hydrolysis and decarboxylation easily gave the corresponding 2-aryl-2-cyclopenten-1-ones 15. The present facile coupling may be initiated through electron transfer from Mg metal to the aromatic carbonyl groups of 2, 7, 9, and 14 to generate the corresponding radical anions, followed by their intramolecular nucleophilic attack to the ester groups to give the corresponding five-membered ring compounds 5, 8, 10, and 15, respectively.     

Hydrogen-bond-directed giant unilamellar vesicles of guanosine derivative: preparation, properties, and fusion

By mixing a small volume of THF containing guanosine derivative 1 and tetraethylenegrycol dodecyl ether (TEGDE) with water and subsequently removing TEGDE by gel permeation chromatography, micrometer-sized giant unilamellar vesicles (GUV) of 1 were successfully prepared. The vesicle membrane was a 2-D sheet assembly of thickness 2.5 nm, composed of a 2-D inter-guanine hydrogen-bond network. The GUV dispersion showed high stability because of a large negative zeta potential, which allowed repeated sedimentation and redispersion by centrifugation and subsequent gentle agitation. TEGDE-triggered fusion of GUVs took place within 350 ms, which proceeded by fusion of the vesicle membranes in contact. These unique static and dynamic properties of the GUV membrane assembled by the 2-D hydrogen-bond network are discussed.     

Protective effect of small amounts of sodium dodecyl sulfate on the helical structure of bovine serum albumin in thermal denaturation

In the presence of sodium dodecyl sulfate (SDS), the secondary structure of bovine serum albumin (BSA) was almost protected against thermal denaturation above 50 degrees C, where the structural change became irreversible. Beyond 30 degrees C, the helicity (66%) of the protein sharply decreased with rise of temperature. In response to this, the proportions of beta-structure and random coil increased. The helicity and the beta-structural proportion were 44% and 13% at 65 degrees C, respectively. The protective effect was observed upon the coexistence of SDS of extremely low concentrations: the molar ratio of [SDS]/[BSA] of 15 was enough to induce the maximal protective effect on the helical structure of the protein. The maximal protected helicity was 58% at 65 degrees C, increasing to 64% upon cooling down to 25 degrees C. This protective effect became greater with an increase of chain length of alkyl sulfate ion. On the other hand, a cationic surfactant did not protect the BSA structure at all against the thermal denaturation. This protective effect was characterized by the specific amphiphilic nature of anionic surfactant. Such an anionic surfactant is considered to protect the protein structure by building bridges between particular nonpolar residues and particular positively charged residues located on different loops of the protein.     

Listeria monocytogenes cells injured by high hydrostatic pressure and their recovery in nutrient-rich or -free medium during cold storage

ABSTRACT

Cells of Listeria monocytogenes suspended in phosphate-buffered saline (PBS) were treated by high hydrostatic pressure (HHP; 500?MPa, 25°C, 10?min), diluted by ten folds using trypticase soy broth (TSB) or PBS, and stored at cold temperatures of 0–15°C. Viable cell count in TSB increased logarithmically close to the initial count at each storage temperature, while that in PBS increased temporarily and subsequently decreased to almost nondetectable level except the case at 15°C, where it showed logarithmic increase thereafter. Based on proliferation experiments where their healthy cells were inoculated to TSB or to PBS containing their heat-killed dead cells, it was suggested that increase in the viable count of HHP-treated cells in TSB and PBS could be ascribed to the recovery of colony forming ability and/or proliferation depending on the cold storage temperature.     

Separation of a Slater Determinant Wave Function with a Neck Structure into Spatially Localized Subsystems

A method of separating a Slater determinant wave function with a two-center neck structure into spatially localized subsystems is proposed, and it is applied to α + α Margenau–Brink cluster wave functions and antisymmetrized molecular dynamics wave functions of the ground state in ¹⁰Be and a negative-parity largely deformed state in ³⁵S.