Photodynamic Efficiency of Protoporphyrin IX: Comparison of Endogenous Protoporphyrin IX Induced by 5-Aminolevulinic Acid and Exogenous Porphyrin IX

Abstract— Photodynamic efficiency of protoporphyrin IX (PP) accumulated in HeLa cells by the incubation of PP with HeLa cells was compared with that of accumulated PP formed from 5-aminolevulinic acid (ALA) as a precursor. The ALA-induced PP was photodynamically more efficient than exogenous PP. The difference is caused by monomelic PP concentration and PP localization site in HeLa cells. Exogenous PP was accumulated mainly in plasma membrane, and the membrane was strongly damaged by irradiation. The ALA-induced PP was selectively accumulated in mitochondria and inactivated the mitochondrial function by irradiation.     

Selection of DNA aptamers recognizing small cell lung cancer using living cell-SELEX

We applied Systematic Evolution of Ligands by EXponential enrichment using Small Cell Lung Cancer (SCLC) cells. A DNA aptamer was identified and evaluated by fluorescent confocal microscopy and flow cytometry. Our results showed that the DNA aptamer binds to molecules that exist predominantly on target SCLC cell surfaces compared with other types of SCLC cells.     

Asymmetric shock heating and the terrestrial magma ocean origin of the Moon

One of the difficulties of the current giant impact model for the origin of the Moon is to explain the marked similarity in the isotopic compositions and the substantial differences in the major element chemistry. Physics of shock heating is analyzed to show that the degree of heating is asymmetric between the impactor and the target, if the target (the proto-Earth) had a magma-ocean but the impactor did not. The magma ocean is heated much more than the solid impactor and the vapor-rich jets come mainly from the magma-ocean from which the Moon might have been formed. In this scenario, the similarity and differences in the composition between the Moon and Earth would be explained as a natural consequence of a collision in the later stage of planetary formation. Including the asymmetry in shock heating is the first step toward explaining the chemical composition of the Moon.     

Rhodium-HMPT-catalyzed direct ortho arylation of phenols with aryl bromides

Direct ortho arylation of phenols with aryl bromides catalyzed by a rhodium complex and hexamethylphosphorous triamide (HMPT) have been developed. A plausible reaction mechanism involving in situ generation of arylphosphites from phenols and HMPT, phosphorus-directed ortho metalation, and transesterification of the arylated arylphosphites with the substrate phenols is proposed.     

Micronization of phenylbutazone by rapid expansion of supercritical CO2 solution

Rapid expansion of supercritical solutions (RESS) technique was applied for the preparation of phenylbutazone fine particles. The operating temperature and pressure affected the yield of the drug fine particles, which was evaluated by dissolving the sprayed product of drug into ethanol. Effect of pre- and post-expansion conditions on the particle size distribution of phenylbutazone was investigated and the smallest sample (mean particle size: 1.59 microm) was obtained when the RESS method was operated at a pressure of 26 MPa combined with a temperature of 32 degrees C. Physicochemical properties of the fine particles were investigated by powder X-ray diffraction and differential scanning calorimetry. It was found that the phenylbutazone fine particles obtained were meta-stable beta form under the experimental conditions tested, suggesting polymorphic transformation during the RESS process.     

Highly Regioselective 5-endo-tet Cyclization of 3,4-Epoxy Amines into 3-Hydroxypyrrolidines Catalyzed by La(OTf)3

Highly regioselective intramolecular aminolysis of 3,4-epoxy amines has been achieved. Key features of this reaction are (1) chemoselective activation of epoxides in the presence of unprotected aliphatic amines in the same molecules by a La(OTf)₃ catalyst and (2) excellent regioselectivity for anti-Baldwin 5-endo-tet cyclization. This reaction affords 3-hydroxy-2-alkylpyrrolidines stereospecifically in high yields. DFT calculations revealed that the regioselectivity might be attributed to distortion energies of epoxy amine substrates. The use of this reaction was demonstrated by the first enantioselective synthesis of an antispasmodic agent prifinium bromide.     

Measurement of 4-nonylphenol and 4-tert-octylphenol in human urine by column-switching liquid chromatography-mass spectrometry

We report a method for determining 4-nonylphenol (NP) and 4-tert-octylphenol (OP) levels in human urine samples by column-switching liquid chromatography-electrospray mass spectrometry after enzymatic deglucuronidation. The method involves enzymatic deconjugation by β-glucuronidase and correction by the stable isotopically labeled internal standard, 4-(1-methyl)octylphenol-d₅. The compounds were separated by reversed-phase chromatography with a C₁₈ column, and detected by selected ion monitoring in the negative mode. After adding an internal standard to urine samples, a direct analysis was carried out. The average recoveries of OP and NP were above 85.0% with correction using the added internal standard. The quantitation limit in the urine samples was 0.3 ng ml⁻¹. The method enables the precise determination of standards and may be applied to the detection of trace amounts of OP and NP in human urine samples.     

Kinetics of surface droplet epitaxy and its application to fabrication of mushroom-shaped metal/Si heterostructure on nanometer scale

The variation in interfacial reaction between Au islands and Si substrates and the fabrication of a Au/Si heterojunction on a nanometer scale are described. Morphologies and elemental distribution were drastically changed around the interface between Au islands and the Si substrate on changing the surface conditions of the substrate. In particular, the Au/Si bilayer structure was formed on the clean Si surface by thermal annealing instead of the well-known interdiffusion of the two elements. This structure was fabricated through liquid phase epitaxy (LPE), in which migrating Si atoms on the surface play an important role. These results suggest that the kinetics of the interfacial reaction are variable and controllable even within the same material system. On the basis of this phenomenon, mushroom-shaped bilayer dots of Au/Si and Ag/Si were fabricated on a nanometer scale by employing metal particles as the transport medium for Si growth.     

Comprehensive predictions of target proteins based on protein-chemical interaction using virtual screening and experimental verifications

ABSTRACT: BACKGROUND: Identification of the target proteins of bioactive compounds is critical for elucidating the mode of action; however, target identification has been difficult in general, mostly due to the low sensitivity of detection using affinity chromatography followed by CBB staining and MS/MS analysis. RESULTS: We applied our protocol of predicting target proteins combining in silico screening and experimental verification for incednine, which inhibits the anti-apoptotic function of Bcl-xL by an unknown mechanism. One hundred eighty-two target protein candidates were computationally predicted to bind to incednine by the statistical prediction method, and the predictions were verified by in vitro binding of incednine to seven proteins, whose expression can be confirmed in our cell system. As a result, 40% accuracy of the computational predictions was achieved successfully, and we newly found 3 incednine-binding proteins. CONCLUSIONS: This study revealed that our proposed protocol of predicting target protein combining in silico screening and experimental verification is useful, and provides new insight into a strategy for identifying target proteins of small molecules.