Synthesis and evaluation of alpha-fucosidase inhibitory activity of 5a-carba-alpha-L-fucopyranose and alpha-DL-fucopyranosylamine

5a-Carba-alpha-L-fucopyranose and -alpha-DL-fucopyranosylamine were synthesized in conventional manner starting from 2,3,4-tri-O-acetyl-6-bromo-6-deoxy-5a-carba-beta-D- and -DL-glucopyranosyl bromides, respectively, and assayed for inhibitory activity against alpha-fucosidase (bovine kidney). Although the former proved to be only a moderate inhibitor (Ki = 4.3 x 10(-5) M), the latter could be shown to possess strong inhibitory potential (Ki = 2.3 x 10(-7) M). Diastereoisomeric imino-linked 5a'-carbadisaccharides were synthesized by coupling of the racemic 5a-carba-alpha-fucopyranosylamine and 1,6:3,4-dianhydro-2-azido-2-deoxy-beta-D-galactopyranose, in order to estimate approximately the inhibitory activity of individual optical antipodes of 5a-carba-alpha-fucopyranosylamine.     

Synthesis of dl-coriolin

The total synthesis of dl-coriolin has been achieved in a stereoselective way. The key tricyclic intermediate was synthesized from dicyclopentadiene through a route which involved an S_N2 reaction at a neopentylic position.     

113Sn-113mIn generator with a glass beads column

The adsorption characteristics of ¹¹³Sn(IV) and ^113mIn(III) on glass beads from NaCl solutions have been studied. On the basis of these studies, ¹¹³Sn-^113mIn generator has been prepared by adsorbing ¹¹³Sn on the glass beads column. ^113mIn has been eluted by the 0.16M NaCl solution with pH 3.0, remaining ¹¹³Sn adsorbed on the glass beads. The yield of ^113mIn has been about 73% in the first 6 ml of eluate, while the breakthrough of ¹¹³Sn has been about 0.042%.     

Synthesis and metal binding properties of novel sulfur-containing functional oligomer

The synthesis and metal ion binding properties of a new class of functional oligomers are described. Oligo[1-(N-phenylthiocarbamoyl)aziridine] (DP ca. 8) and its analogs are prepared by ring-opening oligomerization of the corresponding aziridine monomers in good yields. These oligomers contain sulfur groups capable of binding “soft” metal ions, and the selective binding properties of the novel oligomer for Cu(II) and Hg(II) ions are investigated by liquid-solid adsorption and liquid-liquid extraction experiments.     

A convenient and one-pot synthesis of 9-substituted carbazoles from primary amine hydrochlorides and 2,5-dimethoxytetrahydrofuran

Carbazoles are the very important compounds in material science, nevertheless conventional syntheses required severe and complicated reaction conditions. In the process of preparation of pyrrole derivatives, we found that a primary amine hydrochloride 1 and 2,5-dimethoxytetrahydrofuran 2 were refluxed in a benzenewater (100:4 (v/v)) mixture to be obtained 9-substituted carbazole 5 in a high yield. This method is the one-pot synthesis of 9-substituted carbazoles 5 under mild and convenient conditions.     

Kinetics of Photoinduced Reactions at the Single-Molecule Level: The KACB Method

The kinetics of photoinduced reactions can be approached by laser flash photolysis techniques. Although such techniques allow for a detailed understanding of the important photophysics of molecules, they normally require a substantial amount of sample for measurements (>1 nmol), and thus, they are difficult to apply to analytical and diagnostic applications. The photophysics of a fluorescent molecule can be accessed by monitoring the kinetics of the fluctuation of fluorescence, which is called blinking. Blinking is a phenomenon that can be monitored only if molecules are observed at the single-molecule level. In bulk solution, blinking kinetics can be measured by using fluorescence correlation spectroscopy (FCS), which normally requires more than 10⁵ times less sample than that required for laser flash photolysis. Blinking is controlled to extract fruitful microenvironmental information around a fluorescent molecule, by using a method named kinetic analysis based on the control of fluorescence blinking (KACB). This Concept highlights the adaption of the KACB method to investigate the local conformation of DNA with less than 1 pmol of DNA sample.     

Preparation of ureido group bearing polymers and their upper critical solution temperature in water

Poly(2‐ureidoethylmethacrylate) (PUEM_n) was synthesized via reversible addition‐fragmentation chain transfer (RAFT) radical polymerization and following polymer reaction. We prepared two PUEM_n samples with different degrees of polymerization (n = 100 and 49). The polymers exhibited upper critical solution temperature (UCST) in phosphate‐buffered saline (PBS) solution. The phase separation temperature (T_p) in PBS can be controlled ranging from 17 to 55 °C by changing molecular weight of the polymer, polymer concentration, and adding NaCl concentration. The polymers in PBS formed coacervate drops by liquid–liquid phase separations below T_p. Results of the dielectric relaxation measurement, the hydration number per monomeric unit was 5 above T_p. Based on a fluorescence study, the polymer formed slightly hydrophobic environments below T_p. The liquid–liquid phase separation was occurred presumably because of weak hydrophobic interactions and intermolecularly hydrogen bonding interactions between the pendant ureido groups. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2016 , 54, 2845–2854