Eisuke Kanao

We study the isotope effect by liquid chromatography (LC) with a variety of separation media under reversed and normal phase conditions using the protiated and/or deuterated compounds as the solutes. Results of reversed phase LC (RPLC) suggested that the protiated compounds were more hydrophobic than that of deuterated compounds due to the isotope effect based on the hydrogen bonding between hydrogen atoms of isotopologues and hydroxy groups in the mobile phase. The importance of the hydrogen bo

The halogen-π (X-π) interaction is an intermolecular interaction between the electron-poor region of bonded halogen atoms and aromatic rings. We report an experimental evaluation of the halogen-π (X-π) interaction using liquid chromatography with carbon-material coated columns providing strong π interactions in the normal phase mode. A C₇₀-fullerene (C70)-coated column showed higher retentions for halogenated benzenes as the number of halogen substitutions increased as a result of X-π

Extracellular vesicles (EVs) are lipid bilayer vesicles that enclose various biomolecules. EVs hold promise as sensitive biomarkers to detect and monitor various diseases. However, they have heterogeneous molecular compositions. The compositions of EVs from identical donor cells obtained using the same purification methods may differ, which is a significant obstacle for elucidating objective biological functions. Herein, the potential of a novel lectin-based affinity chromatography (LAC) method

Convex-concave π conjugated surfaces in hemispherical bucky bowl such as corannulene (Crn) have shown increasing utility in constructing self-assembled new functional materials owing to its unique π electrons and strong dipole. Here, we investigate these specific molecular recognitions on Crn by developing new silica-monolithic capillary columns modified with Crn and evaluating their performance in the separation of different aromatic compounds by liquid chromatography (LC). We synthesized two C

Abstract In the recent decades, separation technologies have been significantly furthered by the development of a variety of new separation media. Especially, carbon-based nanomaterials (CNMs), including graphene, carbon nanotubes, and fullerenes, have been applied for effective separations and sensitive detections in recent years. Here, the fundamental preparation protocols of new separation media consisting of CNMs and a great number of their applications summarize the fundamental preparation

We report hydrogen/deuterium (H/D) isotope effects based on weak intermolecular interactions with polar functional groups and aromatic rings in liquid chromatography (LC). Various LC experiments with different aromatic analytes, separation media, and nonpolar mobile phases were conducted under normal phase LC conditions, where the hydrophobic interaction was completely suppressed. The separation media that had polar functional groups, such as silanol groups, allowed for higher separation efficie

Halogen bonding is a highly directional interaction and a potential tool in functional material design through self-assembly. Herein, we describe two fundamental supramolecular strategies to synthesize molecularly imprinted polymers (MIPs) with halogen bonding-based molecular recognition sites. In the first method, the size of the σ-hole was increased by aromatic fluorine substitution of the template molecule, enhancing the halogen bonding in the supramolecule. The second method involved sandwic

In this report, C70-fullerene (C70), which has aspheric structure and greater π electrons compared to C60-fullerene (C60), was effectively immobilized onto the surface of a silica-monolithic capillary, and then the retention characteristics for polycyclic aromatic hydrocarbons (PAHs) due to π-π interaction were evaluated in liquid chromatography (LC). For the immobilization of C70, a C70 derivative via thermal reactive agent, perfluorophenylazide (PFPA) and N-hydroxysuccinimide (NHS) was synthes

We developed a novel purification medium of extracellular vesicles (EVs) by constructing a spongy-like monolithic polymer kneaded with TiO₂ microparticles (TiO₂-hybridized spongy monolith, TiO₂-SPM). TiO₂-SPM was applied in a solid-phase extraction format and enabled simple, rapid, and highly efficient purification of EVs. This is due to the high permeability caused by the continuous large flow-through pores of the monolithic skeleton (median pore size

In mass spectrometry-based proteomics, loss-minimized peptide purification techniques play a key role in improving sensitivity and coverage. We have developed a desalting tip column packed with thermoplastic polymer-coated chromatographic particles, named ChocoTip, to achieve high recoveries in peptide purification by pipet-tip-based LC with centrifugation (tipLC). ChocoTip identified more than twice as many peptides from 20 ng of tryptic peptides from Hela cell lysate compared to a typical Stag

We developed molecularly imprinted polymers (MIPs) with a poly(ethylene glycol) (PEG)-based cross-linker and boronic acids in functional monomers, which selectively form a complex with a diol structure for selective removal of lactones from a coffee beverage. We synthesized a boronic acid monomer, 1-allylpyridinium-3-boronic acid, which has lower pKa and stronger binding strength to saccharides than commonly used boronic acids. Then, we prepared the MIPs with the monomer and succeeded in selecti

This review highlights the growing impact of StageTips (Stop and Go Extraction Tips), a pipette tip-based LC column in MS-based proteomics. By packing standard pipette tips with reversed-phase, ion-exchange, or metal oxide materials, StageTips enable efficient peptide desalting, fractionation, selective enrichment, and in-tip reactions with minimal sample loss. Recent improvements, including new resin designs and integrated workflows, have further expanded the applications to phosphoproteomics,

π interactions have recently received considerable attentions due to principal factor governing molecular recognitions and self-assemble abilities, as accumulated in the database on proximate arrangements in structures of biological systems and organic functional materials. Therefore, further deep understanding and control of π interactions will greatly facilitate the development of new functional materials. Despite the importance of π interactions, they are still challenging to study because π

Herein, we explore the hidden molecular recognition abilities of ZnO nanowires uniformly grown on the inner surface of an open tubular fused silica capillary <i>via</i> liquid chromatography. Chromatographic evaluation revealed that ZnO nanowires showed a stronger intermolecular interaction with phenylphosphoric acid than any other monosubstituted benzene. Furthermore, ZnO nanowires specifically recognized the phosphate groups present in nucleotides even in the aqueous mobile phase, and the inte

Biomembrane coating technologies have been developed to equip synthetic nanomaterials with natural biointerfaces. We report a one-step method for nondestructively coating the biomembranes of "living" cells onto nanoparticle surfaces. By using simple centrifugation, nanoparticles pass through a concentrated layer of living cells. This process mimics exosome release via endocytosis and exocytosis, preserving the membrane integrity of the source cells. The resulting silica nanoparticles were effici