• Journal of the Korean Chemical Society
• /
• v.56 no.4
• /
• pp.464-467
• /
• 2012

A novel chitosan derivative with double quaternary ammonium salt-2-pyridine-acetyl-N-trimethyl chitosan chloride (PATMCS) was synthesized and the antioxidant activity of PATMCS against hydroxyl radicals was assessed. The results indicated that PATMCS had potent hydroxyl scavenging activity. The $IC_{50}$ of PATMCS was 0.13 mg/mL. PATMCS showed 100% scavenging effect at a dose of 0.8 mg/mL which markedly better than that of N-trimethyl chitosan chloride (TMCS). It was confirmed that quaternary chitosan derivatives showed potent antioxidant activity. PATMCS has double quaternary ammonium salt structure in the molecules. Therefore, the antioxidant activity of PATMCS was better than TMCS. The above results are theoretically fundamental for further development and making use of chitosan resources to prepare new antioxidants.

• Journal of the Korean Chemical Society
• /
• v.57 no.4
• /
• pp.455-460
• /
• 2013

A novel and simple method for the synthesis of 2-amino-4H-pyran-3,4,5-tricarboxylate derivative and the evaluation of their antibacterial activity against Pseudomonas syringae, Xanthomonas citi and Pectobacterium carotovorum are reported. The structure of the isolated compounds has been determined by means of $^1H/^{13}C$ NMR and FT-IR Spectroscopy. The reaction of alkyl isocyanides with acetylenic esters in the presence of dimethyl acetone-1,3-dicarboxylate in the present of $BF_3.SiO_2$ at ambient temperature. Some of the compound showed significant inhibition to growth of bacteria.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.1
• /
• pp.34-35
• /
• 2005

• Journal of Microbiology and Biotechnology
• /
• v.14 no.2
• /
• pp.422-425
• /
• 2004

To discover a potent strain against wheat leaf rust, soil samples collected from Ilgamho, Seoul, Korea were tested in vivo and a strain belonging to Streptomyces sp. was found to show good antifungal activity when fermented in a broth. The identification of the strain was carried out based on 16S rDNA analysis, and the active compound was separated from the fermented broth. Even though its structure was not determined completely, the authors report the results obtained so far indicate that the fermented broth of the strain showed activity against wheat leaf rust. Therefore, we propose that this may be a potential novel strain showing antifangal activity against Puccinia recondita.

• 한국정보디스플레이학회:학술대회논문집
• /
• 2000.01a
• /
• pp.211-212
• /
• 2000

Organic electroluminescent devices (OELDs) have received a great deal of attention due to their potential application as full-color displays. Europium complexes are known as excellent red light-emitting materials for OELDs since they show intense photoluminescence at around 612 nm with a narrow spectral bandwidth. In this study, a novel europium complex, $Eu(TTA)_3(TPPO)$ was synthesized and its photoluminescent and electroluminescent characteristics were investigated with a device structure of ITO/TPD/$Eu(TTA)_3(TPPO)$/ $Alq_3$/Al, where sharp emission at the wavelength of 615 nm has been observed. Details on the electrical properties of these structures was also discussed.

• Journal of the Korean Chemical Society
• /
• v.58 no.1
• /
• pp.33-38
• /
• 2014

In the course of work on new pharmacologically active antimicrobial agents, we have reported the synthesis of a new class of structurally novel derivatives, incorporating two bioactive structures, a benzothiazole and thiazolidin-4-one, to yield a class of compounds having interesting antimicrobial properties. The antimicrobial properties of the synthesized compounds were investigated against bacteria (Staphylococcus aureus and Escherchia coli) and fungi (Candida albicans and Aspergillus niger) using serial plate dilution method. The structure of the synthesized compounds have been established by elemental analysis and spectroscopic data.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.6
• /
• pp.1515-1518
• /
• 2010

Regio- and diastereoselective 1,3-dipolar cycloaddition reactions of nitrones {(Z)-${\alpha}$-phenyl-N-methylnitrone (1a) and (Z)-${\alpha}$-propyl-N-butylnitrone (1b)} with electron-deficient perfluoro-2-methyl-2-pentene (2) lead to novel isoxazolidines {5-fluoro-5-pentafluoroethyl-4,4-bis-trifluoromethyl-2-methyl-3-phenyl-isoxazolidine (3a) and 2-butyl-5-fluoro-5-pentafluoroethyl-4,4-bis-trifluoromethyl-3-propyl-isoxazolidines (3b) respectively} as major constituents. These derivatives were characterized by IR, $^1H$ and $^{19}F$ NMR, GC-MS and NOE measurements, and the absolute structure of 3a was confirmed by X-ray crystallography.

• Proceedings of the KIEE Conference
• /
• 2000.07c
• /
• pp.1742-1744
• /
• 2000

Organic materials have been considered for the fabrication of practical electroluminescent(EL) devices because a large number of organic materials are known to have extremely high fluorescence quantum efficiencies in the visible spectrum. In this study, electroluminescent devices are constructed using novel organic materials PRL-401, PRL-403 as the emitting elements. The devices have a triple-layer structure of organic thin films, prepared by vacuum vapor deposition. Greenish yellow electroluminescent emission is observed. The maximum luminances are over 1000 $cd/m^2$ and the turn-on voltages are about 13 V.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.4
• /
• pp.793-797
• /
• 2010

A series of 2-aminothiazoles derivatives have been synthesized and tested for in vitro antibacterial activity on different microorganisms. Syntheses have been carried out following simple methodology in excellent isolated yields. The structure and purity of the original compounds were confirmed by IR, NMR, Mass spectroscopy, and elemental analysis. All compounds were tested for antibacterial activity against S. aureus, S. pyogenes, E. coli, P. aeruginosa, S. typhi and V. parahaemolyticus. These preliminary results indicate that some of compounds are exhibiting good activity.

• Bulletin of the Korean Chemical Society
• /
• v.20 no.1
• /
• pp.65-68
• /
• 1999

Novel mononuclear group 13 metal complexes with the formula (R2M){NC5H4C(CH3)NNC(S)NH(C6H5)} (M=Al, R=iC4H9 (1); M=Ga, R=iC4H9 (2); M=Al, R=CH2SiMe3 (3); M=Ga, R=CH2SiMe3 (4)) result when 2-acetyl pyridine 4-phenyl-thiosemicarbazone ligand is mixed with trialkyl aluminum or trialkylgallium. These compounds 1-4 are characterized by microanalysis, NMR (1H, 13C) spectroscopy, mass spectra, and singlecrystal X-ray diffraction. X-ray single-crystal diffraction analysis reveals that 1 is mononuclear metal compound with coordination number of 5 and N, N, S-coordination mode.