Preparation of 3-(4-chlorophenyl)-2-(2-aminothiazol-4-yl)-5-methoxybenzo[b]furan derivatives and their leukotriene B(4) inhibitory activity

A series of 3-(4-chlorophenyl)-2-(2-aminothiazol-4-yl)benzo[b]furan derivatives 6-10 were prepared and their leukotriene B(4) inhibitory activity was evaluated. We found that several compounds showed strong inhibition of calcium mobilization in CHO cells overexpressing human BLT(1) and BLT(2) receptors. Among them, 3-(4-chlorophenyl)-2-[5-formyl-2-[(dimethylamino)methyleneamino]thiazol-4-yl]-5-methoxybenzo[b]furan 9b showed the most potent and selective inhibition for the human BLT(2) receptor, and its IC(50) value was smaller than that of the selected positive control compound, ZK-158252.     

Application of fluorescence correlation spectroscopy to the measurement of local temperature in solutions under optical trapping condition

Fluorescence correlation spectroscopy (FCS) was applied to the quantitative evaluation of the local heating in small domains <1 microm in solutions under the laser trapping condition in the presence of a near-infrared (NIR) laser beam at 1064 nm. On the basis of the translational diffusion coefficient of fluorescent molecules obtained by FCS, the relationship between temperature rise and the incident NIR laser power, DeltaT/DeltaP, were determined to be 62 +/- 6, 49 +/- 7, and 23 +/- 1 deg K/W in ethylene glycol, ethanol, and water, respectively, while no remarkable temperature increase was observed for deuterated water. The value of DeltaT/DeltaP linearly increased as a function of alpha/lambda (alpha is the extinction coefficient of solvent at the wavelength and lambda is the thermal conductivity of the medium). The validity and the applicability of the present method for the measurement of the local temperature increase were discussed by comparing the present results with previous ones by other various methods.     

(p, ρ, T, x) properties for CO2/isobutane binary mixtures at T = (280 to 440) K and (3 to 200) MPa

The (p, ρ, T, x) properties for binary mixtures of CO₂ (volume fraction purity 0.99999) and isobutane (mole fraction purity 0.99988) {x₁ CO₂ + x₂ isobutane (x₁ = 0.2482, 0.4718, and 0.7506)} were measured in the compressed liquid phase using a metal-bellows variable volumometer. Measurements were conducted from T = (280 to 440) K and (3 to 200) MPa. The expanded uncertainties (k = 2) were estimated to be: temperature, <3 mK; pressure, 1.5 kPa (p ? 7 MPa), 0.06% (7 MPa < p ? 50 MPa), 0.1% (50 MPa < p ? 150 MPa), 0.2% (p > 150 MPa); density, 0.10%; and composition, 4.4 · 10⁻⁴. At >100 MPa and T = (280 or 440) K, the uncertainties in the density measurements increased to 0.14% and 0.22%, respectively. The data are compared with the available equation of state. The excess molar volumes, , of the mixtures were calculated and plotted as a function of temperature and pressure.     

Insertion of cyclopropanes between a carbonyl carbon and an α-carbon of carbonyl compounds with cyclopropylmagnesium carbenoids

The reaction of the lithium enolates of α-aryl carbonyl compounds with cyclopropylmagnesium carbenoids, derived from 1-chlorocyclopropyl p-tolyl sulfoxides with i-PrMgCl at low temperature, resulted in the formation of β-aryl carbonyl compounds bearing a cyclopropane ring at the α-position with one-carbon homologation in variable yields. The reaction was found to be highly stereospecific with respect to the stereochemistry of the cyclopropylmagnesium carbenoids. Mechanism and origin of the stereospecificity of the reaction are also discussed. This is the first example for the insertion of cyclopropanes in between a carbonyl carbon and an α-carbon of carbonyl compounds.     

High-throughput walkthrough detection portal for counter terrorism: detection of triacetone triperoxide (TATP) vapor by atmospheric-pressure chemical ionization ion trap mass spectrometry

With the aim of improving security, a high‐throughput portal system for detecting triacetone triperoxide (TATP) vapor emitted from passengers and luggage was developed. The portal system consists of a push‐pull air sampler, an atmospheric‐pressure chemical ionization (APCI) ion source, and an explosives detector based on mass spectrometry. To improve the sensitivity of the explosives detector, a novel linear ion trap mass spectrometer with wire electrodes (wire‐LIT) is installed in the portal system. TATP signals were clearly obtained 2 s after the subject under detection passed through the portal system. Preliminary results on sensitivity and throughput show that the portal system is a useful tool for preventing the use of TATP‐based improvised explosive devices by screening persons in places where many people are coming and going. Copyright © 2011 John Wiley & Sons, Ltd.     

Two-dimensional DNA origami assemblies using a four-way connector

Two-dimensional self-assembly of DNA origami structures was carried out using a connector that has connection sites at all four edges. By utilizing this four-way connector, five and eight origami monomers were assembled to form a cruciate and a hollow square structure, respectively.     

Structure of the inhibitor complex of old yellow enzyme from Trypanosoma cruzi

Old yellow enzyme (OYE) is an NADPH oxidoreductase which contains flavin mononucleotide as prosthetic group. The X-ray structures of OYE from Trypanosoma cruzi (TcOYE) which produces prostaglandin (PG) F(2α) from PGH(2) have been determined in the presence or absence of menadione. The binding motif of menadione, known as one of the inhibitors for TcOYE, should accelerate the structure-based development of novel anti-chagasic drugs that inhibit PGF(2α) production specifically.     

Asymptotic Behavior of Solutions to the Drift-Diffusion Equation with Critical Dissipation

In this paper, the initial value problem for the drift-diffusion equation which stands for a model of a semiconductor device is studied. When the dissipative effect on the drift-diffusion equation is given by the half Laplacian, the dissipation balances to the extra force term. This case is called critical. The goal of this paper is to derive decay and asymptotic expansion of the solution to the drift-diffusion equation as time variable tends to infinity.     

Sequence-specific alkylation by Y-shaped and tandem hairpin pyrrole-imidazole polyamides

To extend the target DNA sequence length of the hairpin pyrrole-imidazole (Py-Im) polyamide 1, we designed and synthesized Y-shaped and tandem hairpin Py-Im polyamides 2 and 3, which possess 1-(chloromethyl)-5-hydroxy-1,2-dihydro-3H-benz[e]indole (seco-CBI) as DNA-alkylating moieties. High-resolution denaturing polyacrylamide gel electrophoresis by using 5'-Texas-Red-labeled 465 base pair (bp) DNA fragments revealed that conjugates 2 and 3 alkylated the adenine of the target DNA sequences at nanomolar concentrations. Conjugate 2 alkylated adenine N3 at the 3' end of two 8 bp match sequences, 5'-AATAACCA-3' (site A) and 5'-AAATTCCA-3' (site C), while conjugate 3 recognized one 10 bp match sequence, 5'-AGAATAACCA-3' (site A) in the 465 bp DNA fragments. These results demonstrate that seco-CBI conjugates of Y-shaped and tandem hairpin polyamides have extended their target alkylation sequences.