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Ji Young Kwon

Publications and source records attributed to Ji Young Kwon.

6 recordsLinked to original sources
PubMed2005

A highly selective fluorescent chemosensor for Pb2+.

A new fluorescent sensor based on rhodamine B for Pb2+ was synthesized. The new fluorescent sensor showed an extreme selectivity for Pb2+ over other metal ions examined in acetonitrile. Upon the addition of Pb2+, an overall emission change of 100-fold was observed, and the selectivity was calculated to be 200 times that of Zn2+. The signal transduction occurs via of reversible CHEF (chelation-enhanced fluorescence) with this inherent quenching metal ion.

Journal Article↗
PubMed2004

A novel angiotensin I converting enzyme inhibitory peptide from Alaska pollack (Theragra chalcogramma) frame protein hydrolysate.

Alaska pollack frame protein, which is normally discarded as an industrial byproduct in the processing of fish in plants, was hydrolyzed with pepsin. This was fractionated into five major types of Alaska pollack frame protein hydrolysates (APH-I, 10-30 kDa; APH-II, 5-10 kDa; APH-III, 3-5 kDa; APH-IV, 1-3 kDa; and APH-V, below 1 kDa) using an ultrafiltration membrane bioreactor system. Angiotensin I converting enzyme (ACE) inhibitory activities of the fractionated hydrolysates were investigated, and the fraction that exhibited the highest ACE inhibitory activity was further purified using consecutive chromatographic methods on SP-Sephadex C-25 column, Sephadex G-25 column, and high-performance liquid chromatography (HPLC) on an octadecylsilane column. Finally, we purified a novel ACE inhibitory peptide with an IC50 value of 14.7 microM, and the sequence of the peptide was Phe-Gly-Ala-Ser-Thr-Arg-Gly-Ala. In addition, the ACE inhibition pattern of the peptide was found to be noncompetitive.

Amino Acid Sequence↗
PubMed2004

Fluorescent GTP-sensing in aqueous solution of physiological pH.

A new water-soluble imidazolium anthracene derivative not only differentiates two structurally similar compounds GTP and ATP but also acts as potential fluorescent chemosensors (as a quencher and an enhancer, respectively) for GTP and ATP in 100% aqueous solution (pH = 7.4, 10 mM HEPES).

Adenosine Triphosphate↗
PubMed2004

Unique hydrogen bonds between 9-anthracenyl hydrogen and anions.

Unique hydrogen bonds of the 9-H of anthracene moieties in hosts 1 and 2 with fluoride and pyrophosphate ions were observed on the basis of the (1)H NMR experiments. Furthermore, hosts 1 and 2 act as a colorimetric sensor and a fluorescent chemosensor for the recognition of fluoride ion, respectively.

Journal Article↗
PubMed2002

New fluorescent chemosensors for silver ion.

New fluorescent chemosensors, 1,8-bis(pyrazolylmethyl)anthracene and 9,10-bis(pyrazolylmethyl)anthracene, were synthesized. The 1,8-isomer showed selective fluorescent quenching effects with Ag(I) and Cu(II). On the other hand, the 9,10-isomer displayed a selective fluorescent quenching effect only with Ag(I). From the association constants obtained from fluorescent titrations and by extraction, we conclude that rigid immobilization of the ligands, 1,8-isomer, plays a more important role in the binding with Ag(I) than the additional pi-cation interaction offered by the 9,10-isomer.

Journal Article↗