Biomedical subjects

Takuya Kubo

Publications and source records attributed to Takuya Kubo.

23 records · Page 2Linked to original sources

PubMed2003

On-column concentration of bisphenol A with one-step removal of humic acids in water.

An efficient extraction method for bisphenol A from environmental water including contaminants was developed using surface selective localization of functional group, on a polymeric separation device. The polymer utilized in this study was prepared through a kind of molecular imprinting technique, namely fragment imprinting effect utilizing a pseudo-template molecule (p-tert.-butylphenol) instead of bisphenol A. The concentration of bisphenol A onto the polymer device prepared, up to 1000 times concentration from environmental water including contaminants (humic acids), was achieved very easily with interesting exclusion effect for humic acids. The results obtained in this study suggest that molecular imprinting with the pseudo-template molecule is quite an effective way for selective concentration of the diluted target molecule from other contaminants including similar functional group with the target molecule.

Benzhydryl Compounds↗

PubMed2003

A possible purification method of DNAs' fragments from humic matters in soil extracts using novel stimulus responsive polymer adsorbent.

Novel stimulus responsive, uniformly sized polymer-based adsorbent was prepared for a possible purification method of DNAs from humic matters in soil extracts. The prepared polymer adsorbent has a pair of anion exchangeable and cation exchangeable polymeric selectors, which are reversibly responded by the changes of column temperature as well as pH of mobile phase. At pH 5, DNAs and humic matters were completely adsorbed on the polymer adsorbent at room temperature, while up to 90% of the adsorbed DNAs were released and recovered at 70 degrees C with no release of adsorbed humic matters. Cleaning up of the polymer adsorbent could be performed by washing the adsorbed humic matters with alkaline mobile phase (pH 9) to recover those and realize repeatable use of the adsorbent.

Adsorption↗

PubMed2002

Novel surface modification of polymer-based separation media controlling separation selectivity, retentivity and generation of electroosmotic flow.

Uniformly sized packing materials based on synthetic polymer particles for high-performance liquid chromatography (HPLC) and capillary electrochromatography (CEC) have been prepared from polymerization mixtures containing methacrylic acid (MAA) as a functional monomer and by using a novel surface modification method. This "dispersion method" affords effectively modified separation media. Both the amount of MAA utilized in the preparation and reaction time affect the selectivity of chromatographic separation in both the HPLC and the CEC mode and electroosmotic flow. This detailed study revealed that the dispersion method effectively modified internal surface of macroporous separation media and, based on the amount of MAA introduced, exclusion mechanism for the separation of certain solutes could be observed.

Chromatography, High Pressure Liquid↗

PubMed2002

Spiroidesin, a novel lipopeptide from the cyanobacterium Anabaena spiroides that inhibits cell growth of the cyanobacterium Microcystis aeruginosa.

Spiroidesin (1), a novel D-amino acid-containing linear lipopeptide, was isolated from waterblooms of the cyanobacterium Anabaena spiroides. The structure was identified by 2D NMR and chemical degradation analyses. Spiroidesin inhibited cell growth of the toxic cyanobacterium Microcystis aeruginosa (IC(50), 1.6 x 10(-6) M).

Anabaena↗

PubMed2002

Selective surface modification technique for improvement of chromatographic separation selectivity for sugar derivatives.

Highly cross-linked macroporous polymers were prepared utilizing ethylene dimethacrylate as a cross-linking agent, in the presence or absence of methyl-alpha-D-glucoside as a kind of template molecule with methacrylic acid as a functional monomer. After the preparation of the polymers, we applied a high temperature to the cross-linked polymers to study the changes of adsorption properties of the polymers for sugar derivatives including the template molecule utilized. Interestingly, the heat treatment up to 250 degrees C afforded improvement of relative adsorption affinity for several sugar derivatives including the template molecule, while heat treatment up to 150 degrees C did not afford those improvements. The detailed studies including polymers prepared using acrylic acid as a functional monomer instead of methacrylic acid prove that temperatures higher than the Tg temperature of the polymer derived from a functional monomer such as methacrylic acid and higher than the melting point (mp) of the sugar template are necessary to afford the observed improvement of relative affinity based on the surface modification effects through the heat treatment to cross-linked polymers.

Carbohydrates↗