Lyotropic Liquid Crystallinity of Linear and Star Poly(quinoxaline-2,3-diyl)s: Isotropic-Liquid Crystal Phase Equilibria in Tetrahydrofuran

Hasegawa H., Terao K., Sato T., et al. Lyotropic Liquid Crystallinity of Linear and Star Poly(quinoxaline-2,3-diyl)s: Isotropic-Liquid Crystal Phase Equilibria in Tetrahydrofuran. Macromolecules, 52(9), 3158-3164, April 16, 2019. Copyright © 2019, American Chemical Society. https://doi.org/10.1021/acs.macromol.9b00460

Pre-regulation of the planar chirality of pillar[5]arenes for preparing discrete chiral nanotubes

Regulating the chirality of macrocyclic host molecules and supramolecular assemblies is crucial because chirality often plays a role in governing the properties of these systems. Herein, we describe pillar[5]arene-based chiral nanotube formation via pre-regulation of the building blocks' chirality, which is different from frequently used post-regulation strategies. The planar chirality of rim-differentiated pillar[5]arenes is initially regulated by chiral awakening and further induction/inversion through stepwise achiral external stimuli. The pre-regulated chiral information is well stored in discrete nanotubes by interacting with a per-alkylamino-substituted pillar[5]arene. Such pre-regulation is more efficient than post-regulating the chirality of nanotubes

Discrete chiral organic nanotubes by stacking pillar[5]arenes using covalent linkages

Owing to their unique one-dimensional hollow structures, organic nanotubes have been widely explored in recent years. Covalent organic nanotubes (CONs) can be prepared by stacking building blocks, such as macrocycles, through covalent linkages. However, because of the mismatched covalent connections, controllable synthesis of the discrete CONs with clear structures, such as sidewall and chirality, is a challenging target. In this work, by coupling two pillar[5]arenes through dynamic covalent bonds, thermodynamically stable discrete CONs with 5-fold symmetry are successfully prepared. Three different chiral CONs are separated, including homo-CONs, consisting of two enantiomers (pR, pR and pS, pS), and hetero-CON, consisting of the meso form (pR, pS). These CONs show negative allosteric binding affinities toward guest molecules, which are not observed in individual pillar[5]arenes

A novel transient receptor potential C3/C6 selective activator induces the cellular uptake of antisense oligonucleotides

Kohashi H., Nagata R., Tamenori Y., et al. A novel transient receptor potential C3/C6 selective activator induces the cellular uptake of antisense oligonucleotides. Nucleic Acids Research 52, 4784 (2024); https://doi.org/10.1093/nar/gkae245.Antisense oligonucleotide (ASO) therapy is a novel therapeutic approach in which ASO specifically binds target mRNA, resulting in mRNA degradation; however, cellular uptake of ASOs remains critically low, warranting improvement. Transient receptor potential canonical (TRPC) channels regulate Ca2+ influx and are activated upon stimulation by phospholipase C-generated diacylglycerol. Herein, we report that a novel TRPC3/C6/C7 activator, L687, can induce cellular ASO uptake. L687-induced ASO uptake was enhanced in a dose- and incubation-time-dependent manner. L687 enhanced the knockdown activity of various ASOs both in vitro and in vivo. Notably, suppression of TRPC3/C6 by specific siRNAs reduced ASO uptake in A549 cells. Application of BAPTA-AM, a Ca2+ chelator, and SKF96365, a TRPC3/C6 inhibitor, suppressed Ca2+ influx via TRPC3/C6, resulting in reduced ASO uptake, thereby suggesting that Ca2+ influx via TRPC3/C6 is critical for L687-mediated increased ASO uptake. L687 also induced dextran uptake, indicating that L687 increased endocytosis. Adding ASO to L687 resulted in endosome accumulation; however, the endosomal membrane disruptor UNC7938 facilitated endosomal escape and enhanced knockdown activity. We discovered a new function for TRPC activators regarding ASO trafficking in target cells. Our findings provide an opportunity to formulate an innovative drug delivery system for the therapeutic development of ASO

Real-time chirality transfer monitoring from statistically random to discrete homochiral nanotubes

Real time monitoring of chirality transfer processes is necessary to better understand their kinetic properties. Herein, we monitor an ideal chirality transfer process from a statistically random distribution to a diastereomerically pure assembly in real time. The chirality transfer is based on discrete trimeric tubular assemblies of planar chiral pillar[5]arenes, achieving the construction of diastereomerically pure trimers of pillar[5]arenes through synergistic effect of ion pairing between a racemic rim-differentiated pillar[5]arene pentaacid bearing five benzoic acids on one rim and five alkyl chains on the other, and an optically resolved pillar[5]arene decaamine bearing ten amines. When the decaamine is mixed with the pentaacid, the decaamine is sandwiched by two pentaacids through ten ion pairs, initially producing a statistically random mixture of a homochiral trimer and two heterochiral trimers. The heterochiral trimers gradually dissociate and reassemble into the homochiral trimers after unit flipping of the pentaacid, leading to chirality transfer from the decaamine and producing diastereomerically pure trimers

Photochemistry and spectroscopy of molecules at surfaces: Insights from ab initio molecular dynamics

Resumen del trabajo presentado al 2nd CECAM Workshop: "Challenges in reaction dynamics of gas-­surface interactions and methodological advances in dissipative and non­adiabatic processes", celebrado en Toulouse (France) del 27 al 30 de septiembre de 2021.Peer reviewe

Synthesis and luminescent properties of pyrenylvinylene-substituted tripylborane

A novel luminescent compound, bis((E)-2-pyren-1-yl-vinyl)-2, 4, 6-triisopropylphenylborane (3) was synthesized by hydroboration reaction and was fully characterized. The obtained compound was further investigated by single-crystal X-ray diffraction analysis and DFT calculations. The extended structure tells us their herringbone structures with closely faced pairs of the molecules. Comparing the photoluminescent spectra between solution-state and solid state, the spectrum of the solid state of the compound 3 exhibited dramatically red-shifted fluorescent emission. This change also supports the efficient π-stacking behavior of the compound 3

シンキ ケイコウセイ ホウソ ガンユウ コウブンシ ノ ゴウセイ

京都大学0048新制・課程博士博士(工学)甲第13845号工博第2949号新制||工||1435(附属図書館)UT51-2008-C761京都大学大学院工学研究科高分子化学専攻(主査)教授 中條 善樹, 教授 赤木 和夫, 教授 杉野目 道紀学位規則第4条第1項該当Doctor of EngineeringKyoto UniversityDA

Synthesis and luminescent properties of pyrenylvinylene-substituted tripylborane

A novel luminescent compound, bis((E)-2-pyren-1-yl-vinyl)-2, 4, 6-triisopropylphenylborane (3) was synthesized by hydroboration reaction and was fully characterized. The obtained compound was further investigated by single-crystal X-ray diffraction analysis and DFT calculations. The extended structure tells us their herringbone structures with closely faced pairs of the molecules. Comparing the photoluminescent spectra between solution-state and solid state, the spectrum of the solid state of the compound 3 exhibited dramatically red-shifted fluorescent emission. This change also supports the efficient π-stacking behavior of the compound 3