Kentaro Tanaka

We have recently reported the first artificial nucleoside for alternative DNA base pairing through metal complexation (J. Org. Chem. 1999, 64, 5002-5003). In this context, we have accomplished a Ag(I)-mediated base pair or a base triplet in a double- or triple-stranded DNA, respectively, by introducing a pair of pyridine nucleobases in the middle of the sequence. As a result, the incorporated Ag(I) complex significantly stabilized the DNA duplex and triplex. This strategy would be expanded to th

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTSynthesis of a Novel Nucleoside for Alternative DNA Base Pairing through Metal ComplexationKentaro Tanaka and Mitsuhiko ShionoyaView Author Information Institute for Molecular Science, Okazaki National Research Institutes, Myodaiji, Okazaki 444-8585, Japan Cite this: J. Org. Chem. 1999, 64, 14, 5002–5003Publication Date (Web):June 17, 1999Publication History Received22 February 1999Published online17 June 1999Published inissue 1 July 1999https://

Columnar liquid crystals composed of a giant macrocyclic mesogen were prepared. The giant macrocyclic mesogen has a square hollow with a 2.5 nm diagonal, which was bounded by diindolo[3,2-b:2',3'-h]carbazole (diindolocarbazole) moieties as the edges and bis(salicylidene)-o-phenylenediamine (salphen) moieties as the corners. The shape and size of the macrocycle were directly observed by scanning tunneling microscopy (STM). Each side of the bright square in the STM image corresponds to a diindoloc

A μ-oxo-dinuclear iron complex of a supramolecular porphyrin-phthalocyanine conjugate was synthesized and its catalytic electrochemical oxygen reduction properties were investigated. In the conjugate, porphyrin and phthalocyanine units were connected to form a cofacial dimeric structure through a flexible fourfold rotaxane linkage, which was advantageous for accommodating small substrates between the iron centers. The conjugate showed efficient catalytic properties, at more positive potentials t

Abstract Besides the biological importance of DNA as storage of genetic information, DNA is a smart molecule to assemble functional units since it is possible to use sequences of nucleobases to encode molecularly assembled systems in a predetermined fashion over a wide range in size. This review highlights recent advance in precise control of molecular assembly on DNA templates directed towards functionalized materials.

An efficient strategy for the specific recognition of ellipsoidal fullerenes uses molecular containers with well-designed three-dimensional (3D) nanospaces. We describe the synthesis of a supramolecular double-decker cage composed of shape-persistent metallomacrocycles and pillar ligands. A discrete 3D nanospace was built within the molecular framework of the shape-persistent-macrocycle/bidentate-pillar molecule. The single-crystal structure of the supramolecular cage reveals a uniquely shaped i

A new series of shape-persistent imine-bridged macrocycles were synthesized based on dynamic covalent chemistry. The macrocycles had an alternating sequence of dibenzothiophene and N,N'-bis(salicylidene)-ethylenediamine (salen) tethering branched alkyl chains. The macrocycles and tetranuclear metallomacrocycles bearing long and branched alkyl chains exhibited thermotropic columnar liquid-crystalline phases over a wide temperature range and the metallomacrocycles greatly depended on the character

In a thin elongated current sheet, it is likely that more than one X-line forms and thus multiple magnetic islands are produced. The islands are then subject to merging. By simulating such a case with a two-dimensional full-particle code, we show that a merger forming a large island produces the most energetic electron population in the system. By setting the lateral extent of the simulation box to be as large as ∼100 ion inertial lengths, we introduce many (16) small islands in the initial thin

Since magnesium concentration (Mg/Ca) in biogenic calcite is considered to reflect water temperature during precipitation, the magnesium-to‑calcium ratio has been examined as a proxy for water temperature in paleoclimate research, although factors other than temperature may also influence Mg/Ca in biogenic calcite, thereby introducing a potential bias in the relationship between Mg/Ca and temperature observed in inorganic systems. To better understand factors controlling Mg incorporation into th

1. The effect of erythromycin on polyadenylic acid (poly A) directed polylysine synthesis was examined in cell-free extracts from E. coliK-12. 2. The inhibition by erythromycin of 14C-lysine incorporation into trichloroacetic acid-tungstate (W-TCA) insoluble materials was dependent on the amount of ribosomes in the system. 3. Changes in amount of 105,000×gsupernatant fraction and E. colitransfer RNA (tRNA) showed no influence on the inhibition of 14C-lysine incorporation by erythromycin. 4. Pape

Magnetopause reconnection would be characterized by the density jump across the current sheet, the flow shear across the boundary, and nonzero guide field. While effects of each of these elements have been studied, the effects arising from the combination of these are still unexplored. Two-dimensional full-particle simulations show that the combination of shear flow and/or guide field with density asymmetry induces the sliding motion of the<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"