Phosphorylation of 5'-deoxy-5-fluorouridine with inorganic phosphorylating agents

The phosphorylation of 5'-deoxy-5-fluorouridine (doxifluridine, 5'-DFUR) has been achieved using inorganic cyclo-triphosphate (P(3m), Na(3)P(3)O(9)) and monoimido-cyclo-triphosphate (MCTP, Na(3)P(3)O(8)NH) in aqueous solution. In the reaction of 5'-DFUR with P(3m), 2'-monophospho-5'-DFUR and 3'-monophospho-5'-DFUR were synthesized with a total yield of more than 95%. In the reaction of 5'-DFUR with MCTP, 2'-diphosphoramidophosphono-5'-DFUR and 3'-diphosphoramidophosphono-5'-DFUR were synthesized with a total yield of more than 40%. The phosphorylated products with P(3m) and MCTP were stable in neutral and alkaline solutions.     

Thermoresponsive polymer brush on monolithic-silica-rod for the high-speed separation of bioactive compounds

Poly(N-isopropylacrylamide), one of the most utilized thermoresponsive polymers, brush-grafted monolithic-silica columns were prepared through surface-initiated atom transfer radical polymerization (ATRP) for effective thermoresponsive-chromatography matrices. ATRP initiator was grafted on monolithic silica-rod surfaces by flowing a toluene solution containing ATRP initiator into monolithic silica-rod columns. N-Isopropylacrylamide (IPAAm) monomer and CuCl/CuCl(2)/Me(6)TREN, an ATRP catalytic system, were dissolved in 2-propanol, and the reaction solution was pumped into the preprepared initiator-modified columns at 25 °C for 16 h. The constructed PIPAAm-brush structure on the monolithic silica-rod surface was confirmed by XPS, elemental analysis, SEM observation, and GPC measurement of grafted PIPAAm. The prepared monolithic silica-rod columns were also characterized by chromatographic analysis. PIPAAm-brush-modified monolithic silica-rod columns were able to separate hydrophobic steroids with a short analysis time (10 min), compared to PIPAAm-brush-modified silica-beads-packed columns, because of the horizontally limited diffusion path length of monolithic supporting materials. Additionally, diluted PIPAAm-brush monolithic silica-rod column gave a further shorting analysis time (5 min). These results indicated (1) surface-initiated ATRP constructed PIPAAm-brush structures on monolithic silica-rod surfaces and (2) PIPAAm-brush grafted monolithic silica-rod column prepared by ATRP was a promising tool for analyzing hydrophobic-bioactive compounds with a short analysis time.     

Simple,fast, and ultrasensitive method for textile dye determination based on luminol electrochemiluminescence (ECL) inhibition

Journal of Solid State Electrochemistry - Textile dyes are considered micropollutants or emerging pollutants since they can be present in the environment at very low concentrations and show...     

Structure and sorption properties of the polyion complex between poly(acrylic acid) and poly(4-vinylpyridine)

A polyion complex was formed from poly(acrylic acid) (PAA) and poly(4-vinylpyridine) (PVP). Its structure and composition were examined by means of infrared spectroscopy (IR), x-ray photoelectron spectroscopy (XPS), and elemental analysis. The polyion complex was obtained by dissolving PAA and PVP together in methanol. The composition of the polyion complex was independent of stirring speed, mixing sequence, and standing time after mixing. However, the composition depended on the concentrations and the ratio of the components in the reaction mixture. Excess of PAA in the product was observed when concentrated solutions (2.0 × 10^?1M) were used for the preparation or when an excess of PAA was added to PVP. The sorption of water vapor by an equimolar PAA/PVP complex at 293 and 303 K was higher than that by the pure components, especially in the low- and middle-pressure regions. In the high-pressure region, however, the uptake was not affected by the complex formation. While hydrogen bond interactions in general decrease sorption, Coulombic interactions between polymer chains increased the sorption capacity.     

Evaluation of the compaction properties of a solid dispersion of indomethacin with crospovidone by tableting process analyzer

A powder solid dispersion system (SD) of indomethacin (IM) with crospovidone (CrosPVP) possesses good fluidity and can be used for tablet formulation. Tablets of SD can be prepared by direct compression and have adequate hardness and a small variation in weight. Forces during the tableting process were measured with a tableting process analyzer (TabAll) equipped with a single-punch. The pressure transmission ratio (PTR) from the upper to the lower punch and the die wall force (DWF) were examined during the tableting process. Ejection force (EF) and scraper pressure (SP) were measured for determining the capping and sticking properties during the tableting process. Adding 1% magnesium stearate (MS) to the SD resulted in high PTR and DWF values and a low EF value. PTR and DWF values increased and EF value decreased when MS and microcrystalline cellulose (MCC) were added to the SD. A thousand tablets could be manufactured without problems such as sticking or capping when 1% MS and 50% MCC were added to the SD containing 25% IM.     

Determination of acidic saponins in crude drugs by high- performance liquid chromatography on octadecylsilyl porous glass

High-performance liquid chromatographic (HPLC) analysis on octadecylsilyl porous glass was investigated for acidic saponins in ginseng, bupleurum root and senega. The acidic saponins, malonyl-ginsenosides, malonyl-saikosaponins and senegins, as well as neutral saponins in the crude drugs were separated rapidly by HPLC on this column with aqueous acetonitrile containing KH₂ PO₄ as the mobile phase at room temperature.     

Formation of η′(958) Meson Bound States and Chiral Symmetry In-Medium

We theoretically discuss the feasibility to observe the η′(958)-mesic nuclei by using the missing mass spectroscopy. We evaluate the η′-nucleus optical potential including the contribution of lowest order in density together with the second order terms account for η′ absorption by two nucleons, based on a recent model of the η′N interaction. We show the calculated formation cross section of the η′ bound states from (π, N) reaction with pion beam momentum p _π = 1.8 GeV/c and (p, d) reaction with proton kinetic energy T _p = 2.5 GeV.     

Solid-state photochemistry of the mixed crystals between benzoquinones and polymethylbenzenes

Nine mixed crystals combined 1,4-benzoquinone (1), 2,5-xyloquinone (2) and duroquinone (3) with durene (a), pentamethylbenzene (b) and hexamethylbezene (c) were prepared by a melting-resolidifying process and characterized by powder X-ray diffractometry, DSC and IR. Only the mixed crystal of 3 and a formed a 2:1 novel molecular crystal (4); other eight mixed crystals were simple polycrystalline mixtures of the two components. Irradiation of the molecular crystal 4 (3/a) and the mixed crystals 1/a, 1/b and 3/b caused intermolecular hydrogen abstraction to give hydroquinones and in some cases adducts. Product selectivities in the solid state were different from those in solution. Correlation between the crystal structure and the reactivity of 4 is discussed.