Inhibitory Effects of Hydrogels on the Adhesion,Germination, and Development of Zoospores Originating from Laminaria angustata

The inhibition of germination and development of zoospores originating from Laminaria angustata originated on various kinds of hydrogels is studied. The effects of the water content of the gel (the degree of swelling), the electrical nature (neutral, positive charge, negative charge), the charge density, the counterions of hydrogels on the inhibition of zoospore germination and development of gametophytes are phenomenologically investigated. Among the gels investigated, poly(acrylic acid) (PAA) gel showed a dramatic inhibition to germination, and might serve as a novel, environmentally safe inhibitor of zoospore adhesion.     

Development and application of a latent hydrosilylation catalyst. IX. Control of the catalytic activity of a platinum catalyst by polymers bearing amine moieties

A new thermal‐latent hydrosilylation catalyst consisting of H₂PtCl₆ and polymers bearing amine moieties is described. In the presence of aminated polymers, the catalytic activity of H₂PtCl₆ was suppressed remarkably in the model reaction of triethylsilane with trimethylvinylsilane, whose effect was remarkably higher in comparison with monomeric amines. On heating, however, sufficient catalytic activity was attained where the activation temperature was dependent on the amine content in the polymer and polymer structure. Furthermore, this catalyst system was applied to the curing process of silicone resin to confirm the thermal‐latent character of the catalyst. © 2000 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 38: 804–809, 2000     

Mechanochemical Tuning of the Binaphthyl Conformation at the Air–Water Interface

Gradual and reversible tuning of the torsion angle of an amphiphilic chiral binaphthyl, from ?90° to ?80°, was achieved by application of a mechanical force to its molecular monolayer at the air–water interface. This 2D interface was an ideal location for mechanochemistry for molecular tuning and its experimental and theoretical analysis, since this lowered dimension enables high orientation of molecules and large variation in the area. A small mechanical energy (<1 kcal mol^?1) was applied to the monolayer, causing a large variation (>50 %) in the area of the monolayer and modification of binaphthyl conformation. Single‐molecule simulations revealed that mechanical energy was converted proportionally to torsional energy. Molecular dynamics simulations of the monolayer indicated that the global average torsion angle of a monolayer was gradually shifted.     

KNI-272, a highly selective and potent peptidic HIV protease inhibitor

Kynostatin {KNI-272; systematic name: 3-[3-benzyl-2-hydroxy-9-(isoquinolin-5-yl­oxy)-6-methyl­sulfanyl­methyl-5,8-dioxo-4,7-di­aza­nonanoyl]-N-tert-butyl-1,3-thia­zolane-4-carbox­amide}, a highly selective and potent HIV protease inhibitor containing allo­phenyl­norstatin [(2S,3S)-3-amino-2-hydroxy-4-phenyl­butyric acid], has been crystallized as the hydrate, C₃₃H₄₁N₅O₆S₂·0.803H₂O, from aqueous hexyl­ene glycol. The observed disorder of the phenyl group in the structure is related to the mode of hydration. The backbone conformation of the mol­ecule is twisted and the overall conformation of the free inhibitor is similar to that observed in its complex with HIV protease.     

Controlled assembly of DNA nanostructures on silanized silicon and mica surfaces for future molecular devices

In order to establish key technology for future molecular devices, we have explored the assembly behaviour of λ-deoxyribonucleic acid (DNA) molecules adsorbed on silanized mica and silanized oxide silicon surfaces by using atomic force microscopy (AFM). AFM experiments show that λ-DNA molecules can be hardly adsorbed on untreated mica and oxidized silicon surfaces, but can be strongly adsorbed onto aminosilanized mica and oxidized silicon surfaces. Importantly, DNA molecules can be assembled into linear DNA alignment, and can also self-assemble into various network structures on the silanized surfaces. Our experimental observations have demonstrated the feasibility of assembling DNA-based nanostructures by varying surface chemistry of substrates, and offer useful clues in constructing DNA-based nanodevices for nanoelectronics and biomolecular computation as well as quantum computation.     

Nano Trek Beyond: Driving Nanocars/Molecular Machines at Interfaces

In 2016, the Nobel Prize in Chemistry was awarded for pioneering work on molecular machines. Half a year later, in Toulouse, the first molecular car race, a “nanocar race”, was held by using the tip of a scanning tunneling microscope as an electrical remote control. In this Focus Review, we discuss the current state‐of‐the‐art in research on molecular machines at interfaces. In the first section, we briefly explain the science behind the nanocar race, followed by a selection of recent examples of controlling molecules on surfaces. Finally, motion synchronization and the functions of molecular machines at liquid interfaces are discussed. This new concept of molecular tuning at interfaces is also introduced as a method for the continuous modification and optimization of molecular structure for target functions.     

Circularly Polarized Luminescence of Chiral Pt(pppb)Cl (pppbH=1‐pyridyl‐3‐(4,5‐pinenopyridyl)benzene) Aggregate in the Excited State

We prepared enantiomers of chiral Pt^II complexes, Pt(pppb)Cl and Pt(pppb)CN (pppbH=1‐pyridyl‐3‐(4,5‐pinenopyridyl)benzene), and measured their CPL (circularly polarized luminescence) spectra for excimer and trimer emission. The contribution of the pinene moiety to CPL was considerably low for the π–π* emission of the monomer but large for MMLCT (metal‐metal‐to‐ligand charge‐transfer) of the excimer and trimer which had a helical structure induced in a face‐to‐face stacking fashion. The trimer CPL for (+)‐Pt(pppb)Cl was larger in intensity than that of excimer CPL; on the other hand, that for (+)‐Pt(pppb)CN was opposite in sign compared with that of excimer CPL. We conclude that differences in the excited‐state structure of the aggregate between Pt(pppb)Cl and Pt(pppb)CN account for the variation in the CPL spectra. By the aid of TD‐DFT calculations it was predicted that the dihedral angle θ(Cl‐Pt‐Pt‐Cl) was 50–60° or 110–140° for Pt(pppb)Cl aggregates and 160° for Pt(pppb)CN aggregates.     

Ueber die Fällung des Eisenhydroxyd-Sols durch verschiedene Elektrolyte

Ohne Zusammenfassung     

Biomimetic reductive amination under the continuous-flow reaction conditions

This study present a full account of continuous-flow reaction conditions for biomimetic reductive amination of fluorinated carbonyl compounds to corresponding amines and amino acids of biomedical importance. We demonstrate that simple silica-adsorbed DBU can be used as efficient catalysts for on-column 1,3-proton shift reaction, a key transformation in the biomimetic reductive amination process. This new on-column process features operationally convenient conditions, higher chemical yields, enantioselectivity and purity of the corresponding products as compared with traditional in-flask reactions. Moreover the removal of base-catalyst, the most delicate problem of the in-flask reactions, is not an issue in the on-column process, as the silica-adsorbed DBU or polymer-bound guanidine remains on the column and can be reused. This feature renders the overall process substantially more economical and synthetically efficient, in particular, for large-scale synthesis of the corresponding fluorinated amines and amino acids target.