Discovery of novel 2-anilinopyrazolo[1,5-a]pyrimidine derivatives as c-Src kinase inhibitors for the treatment of acute ischemic stroke

We synthesized a series of novel 2-anilinopyrazolo[1,5-a]pyrimidine derivatives and evaluated their ability to inhibit c-Src kinase; 7-(2-amino-2-methylpropylamino)-5-cyclopropyl-2-(3,5-dimethoxyphenylamino)pyrazolo[1,5-a]pyrimidine-3-carboxamide 7o and 7-(2-amino-2-methylpropylamino)-2-(3,5-dimethoxyphenylamino)-5-methylpyrazolo[1,5-a]pyrimidine-3-carboxamide 7f showed potent inhibitory activity. Compound 7f inhibited c-Src selectively and exhibited satisfactory central nervous system (CNS) penetration. Furthermore, 7f.HCl reduced the infarct volume in vivo in a rat middle cerebral artery (MCA) occlusion model when administrated intraperitoneally.     

Antioxidant hydroxycinnamic acid derivatives isolated from Brazilian bee pollen

One novel and three known hydroxycinnamic acid derivatives having antioxidant activities were isolated from a Brazilian bee pollen. They were identified as kaempferol 3-O-[2-O-p-coumaroyl]-alpha-L-arabinopyranoside, N(1), N(5), N(10)-tri-p-coumaroyl spermidine, N(1), N(5), N(10), N(14)-tetra-p-coumaroyl spermine, and monocaffeoyl-tri-p-coumaroyl spermine, respectively. The structure of the kaempferol glycoside was established on the basis of spectroscopic and chemical investigations. Among the isolated compounds, monocaffeoyl-tri-p-coumaroyl spermine showed the strongest free radical-scavenging activity, which was almost identical to that of alpha-tocopherol. On the other hand, the antioxidant effect of tri-p-coumaroyl spermidine on autooxidation of linoleic acid was strongest and nearly equal to that of alpha-tocopherol.     

Dye-sensitized TiO2 solar cells using imidazolium-type ionic liquid crystal systems as effective electrolytes

A novel ionic liquid crystal (ILC) system (C(12)MImI/I(2)) with a smectic A phase used as an electrolyte for a dye-sensitized solar cell (DSSC) showed the higher short-circuit current density (J(SC)) and the higher light-to-electricity conversion efficiency than the system using the non-liquid crystalline ionic liquid (C(11)MImI/I(2)), due to the higher conductivity of ILC. To investigate charge transport properties of the electrolytes in detail, the exchange reaction-based diffusion coefficients (D(ex)) were evaluated. The larger D(ex) value of ILC supported that the higher conductivity of ILC is attributed to the enhancement of the exchange reaction between iodide species. As a result of formation of the two-dimensional electron conductive pathways organized by the localized I(3)- and I- at S(A) layers, the concentration of polyiodide species exemplified by I(m)- (m = 5, 7, ...) was higher in C(12)MImI/I(2). However, as the increment of the concentration of polyiodide species is less than that of D(ex), the contribution of a two-dimensional structure of the conductive pathway through the increase of collision frequency between iodide species was proposed. Furthermore, a quasi-solid-state ionic liquid crystal DSSC was successfully fabricated by employing a low molecular gelator. Addition of the 5.0 g/L gelator to ILC improved light-to-electricity conversion efficiency through the increase of J(SC) due to the enhancement of the conductivity in C(12)MImI/I(2)-gel.     

Rheological properties of hemoglobin vesicles (artificial oxygen carriers) suspended in a series of plasma-substitute solutions

Hemoglobin vesicles (HbV) or liposome-encapsulated Hbs are artificial oxygen carriers that have been developed for use as transfusion alternatives. The extremely high concentration of the HbV suspension (solutes, ca. 16 g/dL; volume fraction, ca. 40 vol %) gives it an oxygen-carrying capacity that is comparable to that of blood. The HbV suspension does not possess a colloid osmotic pressure. Therefore, HbV must be suspended in or co-injected with an aqueous solution of a plasma substitute (water-soluble polymer), which might interact with HbV. This article describes our study of the rheological properties of HbV suspended in a series of plasma substitute solutions of various molecular weights: recombinant human serum albumin (rHSA), dextran (DEX), modified fluid gelatin (MFG), and hydroxylethyl starch (HES). The HbV suspended in rHSA was nearly Newtonian. Other polymers-HES, DEX, and MFG-induced HbV flocculation, possibly by depletion interaction, and rendered the suspensions as non-Newtonian with a shear-thinning profile (10(-4)-10(3) s(-1)). These HbV suspensions showed a high storage modulus (G') because of the presence of flocculated HbV. However, HbV suspended in rHSA exhibited a very low G'. The viscosities of HbV suspended in DEX, MFG, and high-molecular-weight HES solutions responded quickly to rapid step changes in shear rates of 0.1-100 s(-1) and a return to 0.1 s(-1), indicating that flocculation is both rapid and reversible. Microscopically, the flow pattern of the flocculated HbV that perfused through microchannels (4.5 microm deep, 7 microm wide, 20 cmH2O applied pressure) showed no plugging. Furthermore, the time required for passage was simply proportional to the viscosity. Collectively, the HbV suspension viscosity was influenced by the presence of plasma substitutes. The HbV suspension provides a unique opportunity to manipulate rheological properties for various clinical applications in addition to its use as a transfusion alternative.     

Infrared spectroscopic investigation of poly(2-methoxyethyl vinyl ether) during thermosensitive phase separation in water

Hydration changes of poly(2-methoxyethyl vinyl ether) (PMOVE) synthesized via living cationic polymerization have been investigated during a temperature-responsive phase separation in water by using infrared spectroscopy. An aqueous PMOVE solution has lower critical solution temperatures (LCSTs) of 66 degrees C in H2O and 65 degrees C in D2O at approximately 15 wt %. During phase separation, the C-H stretching (nu(C-H)) bands of PMOVE shift downward (red shift). In particular, the IR band assigned to the antisymmetric stretching vibration of the terminal methyl groups exhibits a remarkably large red shift by 16 cm-1. The band also exhibits a red shift with increasing polymer concentration at T < Tp. Density functional theory (DFT) calculations of the models of hydrated PMOVE indicate that the shift is due mainly to the breaking of hydrogen bonds (H-bonds) between the oxygen of the methoxy groups and water and partially to the breaking of the CH...O H-bond to them.     

Quenching and vibrational relaxation of SO(B3Sigma-, v' <or= 3) by collisions with Ar and N2

Fluorescence from a single vibronic level of SO(B3Sigma-, v' 相似文献   

Photophysical and electrochemical behavior of thin solid films based on a three-dimensional ruthenium complex network

RuL ₃ ²⁺ (L=2,2′-bipyridine-4,4′-diphosphonic acid) thin solid films were fabricated by three-dimensional linking between the phosphonic acid substituents of L and Zr(O)Cl₂. The RuL₃ chromophores in the films are electronically independent of each other in the ground state and give emission spectra essentially identical to that of RuL ₃ ²⁺ in solution, although the emission lifetime is much shorter. The films are electrochemically active, showing pseudo-reversible oxidation behavior in cyclic voltammetry. A preliminary attempt has been made to apply these films to photoelectrochemical cells.     

Novel synthesis of polyphosphonates by the polyaddition of bis(epoxide) with diaryl phosphonates

The polyaddition of bisphenol A diglycidyl ether (BPGE) with bis(4‐chlorophenyl) phenylphosphonate was carried out using quaternary onium salts or crown ether complexes as catalysts. When the polyaddition was performed using tetrabutylammonium chloride, tetrabutylphosphonium chloride, or 18‐crown‐6/KCl in N‐ methyl‐2‐pyrrolidone at 110°C for 48 h, the corresponding polyphosphonate with moderated molecular weights was obtained in 88–96% yields. The structure of the resulting polyphosphonate was confirmed by IR and ¹H‐NMR spectra. The polyaddition of BPGE with various diaryl phosphonates also proceeded very smoothly to produce the corresponding polyphosphonates with moderate molecular weights. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 959–965, 1999     

Charge transport properties for carbazolyl groups pendant poly(glutamate)

Carbazolyl groups pendant poly(glutamate) (PCLG) was prepared to analyze its charge‐transport properties by employing mobility measurements and thermally‐stimulated current (TSC) measurements. The mobility induced TSC (MITSC) model proposed by I.Chen was employed to evaluate the experimental TSC spectra with mobility results. Simulated MITSC spectra showed good agreement in its peak temperature with experimental TSC spectra for PCLG. This suggests that the carrier transport followed the trap‐limited mechanism estimated by the mobility results. Further, the peaks in experimental TSC spectra appeared over the same temperature range as that in thermally‐stimulated polarization current (TSPC) spectra. Since the TSPC spectra were found to be correlated with the dielectric tan δ spectra for PCLG, the peaks in TSPC spectra are attributed to the side‐chain relaxation for PCLG. Therefore, the similarity between TSPC and TSC spectra indicates that the charge‐transport mechanism for PCLG was considerably affected by side‐chain relaxation for PCLG, which would vary the energy state of trap sites and effectively reduces the energy for the release of the carriers trapped on the illuminated surface. © 1999 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 37: 61–69, 1999