Formation of spherulitic amyloid β aggregate by anionic liposomes.

Alzheimer's disease is the most common form of senile dementia. This neurodegenerative disorder is characterized by an amyloid deposition in senile plaques, composed primarily of fibrils of an aggregated peptide, amyloid β (Aβ). The modeling of a senile plaque formation on a model neuronal membrane under the physiological condition is an attractive issue.

Morphological changes in vesicles and release of an encapsulated compound triggered by a photoresponsive Malachite Green leuconitrile derivative.

Photoinduced morphological changes in phosphatidylcholine vesicles are triggered by a Malachite Green leuconitrile derivative dissolved in the lipidic membrane, and are observed at Malachite Green derivative/lipid ratios <5 mol %. This Malachite Green derivative is a photoresponsive compound that undergoes ionization to afford a positive charge on the molecule by UV irradiation. The Malachite Green derivative exhibits amphiphilicity when ionized photochemically, whereas it behaves as a lipophilic compound under dark conditions.

A bridged nucleic acid, 2',4'-BNA COC: synthesis of fully modified oligonucleotides bearing thymine, 5-methylcytosine, adenine and guanine 2',4'-BNA COC monomers and RNA-selective nucleic-acid recognition.

Recently, we synthesized pyrimidine derivatives of the 2'-O,4'-C-methylenoxymethylene-bridged nucleic-acid (2',4'-BNA(COC)) monomer, the sugar conformation of which is restricted in N-type conformation by a seven-membered bridged structure. Oligonucleotides (BNA(COC)) containing this monomer show high affinity with complementary single-stranded RNA and significant resistance to nuclease degradation. Here, BNA(COC) consisting of 2',4'-BNA(COC) monomers bearing all four bases, namely thymine, 5-methylcytosine, adenine and guanine was efficiently synthesized and properties of duplexes containing the 2',4'-BNA(COC) monomers were investigated by UV melting experiments and circular dichroism (CD) spectroscopy.

Novel bis(ethylenedithio)tetrathiafulvalene-based organic conductor with 1,1'-ferrocenedisulfonate.

A new bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF)-based salt with a ferrocenyl moiety, alpha' ''-(BEDT-TTF)(4)(Fe(C(5)H(4)SO(3))(2)).6H(2)O, has been prepared. The ferrocenyl part of this salt is neutral and diamagnetic, but the magnetic susceptibility is well modeled by a Curie-Weiss law with C = 0.

Synthesis of 2',4'-BNACOC bearing a purine nucleobase.

Recently, we have synthesized pyrimidine derivatives of 2',4'-BNA(COC) monomer, the sugar conformation of which was restricted in N-form by a seven-membered bridged structure. The oligonucleotides containing these monomers showed high affinity with complementary single-stranded RNA and significant resistance to nuclease degradation. For an application to antisense methodology, it is important to synthesize 2',4'-BNA(COC) monomers bearing a purine nucleobase.

Synthesis and properties of 2'-O,4'-C-methyleneoxymethylene bridged nucleic acid.

A novel bridged nucleic acid (BNA) analogue, 2'-O,4'-C-methyleneoxymethylene bridged nucleic acid (2',4'-BNA(COC)), was synthesized and incorporated into oligonucleotides. The 2',4'-BNA(COC) modified oligonucleotides showed high binding affinity with an RNA complement and significant enzymatic stability against snake venom phosphodiesterase.