Seiichi Nishizawa

ADVERTISEMENT RETURN TO ISSUEPREVCommunicationNEXTFluorescence Sensing of Anions via Intramolecular Excimer Formation in a Pyrophosphate-Induced Self-Assembly of a Pyrene-Functionalized Guanidinium ReceptorSeiichi Nishizawa, Yuichi Kato, and Norio TeramaeView Author Information Department of Chemistry, Graduate School of Science Tohoku University, Aoba-ku, Sendai 980-8578, Japan Cite this: J. Am. Chem. Soc. 1999, 121, 40, 9463–9464Publication Date (Web):September 24, 1999Publication History Rece

S. Nishizawa, H. Kaneda, T. Uchida and N. Teramae, J. Chem. Soc., Perkin Trans. 2, 1998, 2325 DOI: 10.1039/A805075I

Finding flavins: A new class of DNA-duplex aptamers that bind to riboflavin by utilizing an abasic (AP) site has been developed (see model). An optimized duplex shows high selectivity for riboflavin over flavin mononucleotide and flavin adenine dinucleotide. Such riboflavin–duplex interactions are discussed as a basis for the further development of AP-site-based DNA aptamers.

Thiourea-based hydrogen-bond forming ionophore 2, alpha,alpha'-bis(N'-p-nitrophenylthioureylene)-m-xylene, is synthesized and investigated by using ion transfer polarography for the facilitated transfers of H2PO4-, HPO42- and Cl- across the nitrobenzene-water interface. Bis-thiourea 2 has a significant ability to assist H2PO4- transfer across the interface whereas its counterpart, N-(p-nitrophenyl)-N'-propylthiourea (ionophore 3), cannot facilitate the transfer of this hydrophilic anion. The H2P

RNA-binding small probes with deep-red emission are promising for RNA analysis in biological media without suffering from background fluorescence. Here benzo[<i>c</i>,<i>d</i>]indole-quinoline (BIQ), an asymmetric monomethine cyanine analogue, was newly developed as a novel RNA-selective probe with light-up signaling ability in the deep-red spectral range. BIQ features a significant light-up response (105-fold) with an emission maximum at 657 nm as well as improved photostability over the commer

A convenient conversion is described of thiourea-based receptors to fluorescent isothiouronium-based photoinduced electron transfer (PET) sensors for oxoanion sensing. Naphthalene- or anthracene-functionalized mono-isothiouroniums are synthesized from the corresponding thioureas, in which the fluorophore is connected to the sulfur atom of the thiourea moiety by a methylene or an ethylene spacer. Even though all of the isothiouroniums with a methylene spacer readily decompose in MeOH upon excitat

A series of triplex-forming peptide nucleic acid (TFP) probes carrying a thiazole orange (TO) base surrogate through an alkyl linker was synthesized, and the interactions between these so-called tFIT probes and purine-rich sequences within double-stranded RNA (dsRNA) were examined. We found that the TO base surrogate linker significantly affected both the binding affinity and the fluorescence response upon triplex formation with the target dsRNA. Among the probes examined, the TO base surrogate

Red-emissive fluorescent probes have been developed by integration of quinoline blue or thiazole red as the base surrogate into triplex-forming PNAs, allowing selective sensing of a sequence of double-stranded RNA.

A new class of flourescent PET (photoinduced electron transfer) sensors for alkali metal cations, 1 shows a significant change of the monomer to the exciplex emissions upon complexation, allowing emission ratio sensing of alkali metal cations.

Kinetics and thermodynamics of triplex formation between 9-mer homopyrimidine PNA (H₂N-Lys-TCTCCTCCC-CONH₂) and double-stranded RNA (dsRNA, 5'-AGAGGAGGG-3'/3'-UCUCCUCCC-5') at acidic pH were studied by means of a stopped-flow technique and isothermal titration calorimetry (ITC). These results revealed the following main findings: (i) the stable PNA-dsRNA triplex formation mostly originated from the large association rate constant (k_on), which was dominated by bot