Polynucleotide-loaded nanoparticles are potentially useful for the regulation of intracellular nucleotide levels. Polyadenylic acid and polyguanylic acid were used as model compounds for encapsulation into poly(lactic-co-glycolic acid) nanoparticles. The properties of the produced nanoparticles, as well as the effect of the polynucleotide molecular size on encapsulation into the nanoparticles were investigated.
Charging and discharging reactions of lithium metal oxides in lithium-ion batteries are accelerated by adding a catalytic amount of redox-active polymer, poly(dimethylfluoflavin-substituted norbornene). The potential difference between the polymer (E1/2 = 3.5 and 4.1 V vs. Li/Li+) and metal oxides induce redox mediation reactions. Their heterogeneous charge-transfer processes are analyzed to estimate the acceleration effects of mediation.
Amphiphilic small molecules (1), constructed from two sugar moieties and a gallic acid bearing tris-alkoxy group via an L-lysine linkage, were synthesized. Amphiphile (1a) exhibited fibrous self-assembly through emulsification in a water-organic solvent biphasic system and showed efficient removal of various organic dyes with varying degrees of hydrophobicity from the aqueous phase.
Two Schiff base compounds that differ only in halogen substituent (Cl or Br) showed contrasting chromic properties. By exchanging their molecular environments in the crystal, the molecules exhibited a photo-response opposite to the initial state, clearly demonstrating the importance of the environment over molecular nature. Crystal structure analysis and single-crystal microscope absorption and emission spectra of the compounds were presented in this paper.
Block copolymerization of dibenzofulvene (DBF) forming a sequence having π-stacked conformation and methyl methacrylate (MMA) forming a flexible sequence was conducted by atom-transfer radical polymerization (ATRP) where MMA was polymerized first and DBF was then blocked. The block copolymer contained a fraction with number-averaged molar mass of 873400 (vs. polystyrene) which was found to be raspberry-like aggregates with sizes of hundreds of nanometers composed of smaller spherical particles with sizes of a few to low tens of nanometers. The aggregates are considered to have a core-shell structure where strong inter-chain interaction between poly(DBF) segments form the core and flexible poly(MMA) segments are the shell, and the formation appeared to be thermally driven. The aggregates having a rigid structure stabilized the π-stacked conformation of poly(DBF) segments both in the ground state and in excited states as found by NMR and fluorescence spectra, respectively, and restricted molecular motion of both the poly(DBF) segments and poly(MMA) segments.
A divergent asymmetric synthesis of two nerolidol-type sesquiterpenoids with a five- or a six-membered ether ring was established from an identical commercially available trans,trans-farnesyl acetate through the cyclization of diepoxide precursors under simple acidic or neutral conditions, respectively. In addition, the relative configuration of a nerolidol-type sesquiterpenoid with a tetrahydrofuran ring was revised. Its absolute configuration was determined by its asymmetric synthesis and a modified Mosher’s analysis. Furthermore, the cytotoxicity and nitric oxide production inhibitory activity of the synthesized compounds were assessed.
We report carbon nanotube (CNT) gels, formed by mechanically mixing CNTs, organic solvents, and a small molecule, Trip-Phz, that have a strong affinity for fullerene materials. There is a clear threshold value in the amount of Trip-Phz needed for the transition from soft to hard gels.
A technique for immobilizing unprotected silver nanoparticles formed in the gas phase on a glass plate was developed. The nanoparticles immobilized on the substrate maintained their plasmonic properties, and oxidation of silver was not observed. The proposed synthesis strategy combined with the evaporation/condensation method enabled the preparation and immobilization of nanoparticles on a substrate via a single process.
Silver nanoparticles (NPs) including spherical and triangular plates were prepared. These NP films were constructed on the self-assembled monolayer of 3-aminopropyltrimethoxysilane using a simple dipping method. The tape-peeling method was applied to the films, and only the spherical nanoparticles were removed from the substrate. As a result, a triangular silver nanoplate combined substrate has been obtained.
A new diterpenoid endoperoxide showing cytotoxicity named amitorin (1) was isolated from an extract of a sponge Halichondria sp. Its structure along with relative stereochemistry was elucidated with spectral analysis and calculation studies. The structure and cytotoxicity (IC50 2.3 µM against NBT-II cells) of the molecule are described herein.
The local structure of WO3 photocatalyst in the photoexcited metastable state created 150 ps after laser irradiation have been determined by pump-probe L3-edge EXAFS and constrained thorough search analysis. A highly distorted octahedral local structure was found where one of the shortest W-O bonds was further shortened to 1.66 Å while the other five bonds were rather elongated even though theoretical calculations predicted the reverse change. We discuss this contradiction and propose a possible structure for the metastable state.
This study shows that β-annulus peptide modified with boron-dipyrromethene (BODIPY) at the C-terminal self-assembled into stable artificial viral capsid even at 1 µM, in contrast to unmodified or N-terminally modified peptides, which cannot self-assemble. Even when sodium dodecyl sulfate was present, the artificial viral capsid, which was stabilized by presumably π–π stacking interactions between BODIPYs at the surface, nearly retained the apparent diameter and formation ratio.
The alpha-emitting radioisotope astatine-211 (211At) is a potential candidate for targeted alpha therapy. For low toxic astatination of FAPI(s) with dihydroxyboryl group (B-FAPI), a dihydroxyboryl-astatine substitution reaction was developed without using any toxic reagents. We achieved efficient astatination with less than 10 µg of B-FAPI, which is feasible in drug manufacturing conditions. Additionally, the FAPα selectivity and cell uptake of 211At-labeled FAPI(s) (211At-FAPI) exhibited promising results for high antitumor efficacy.
Recently, we found a unique visible light-induced photocyclization reaction in a diarylethene-perylenebisimide dyad based on multiplicity conversion via intramolecular energy transfer. Here we report on the remarkable enhancement of photocyclization quantum yield under visible light irradiation by changing the spacer unit from an ester to a ketone group. This simple modification lifts the restrictions of solvent choice and oxygen quenching.
AMPO4 and MPO4 systems (A = alkali metal, M = metal) exhibit various optical and electrochemical functions. This study shows that such systems can be synthesized via an alkali metal–metal exchange reaction between A3PO4 and the metal salt of an acid with lower pKa than phosphoric acid. This method significantly improves the material designs and syntheses of various phosphate salts.