• Bulletin of the Korean Chemical Society
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• v.35 no.6
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• pp.1605-1612
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• 2014

Copper(I)-catalyzed Huisgen cycloaddition of terminal alkynes with unmasked azidoamines derived from amino acids is described. The reported strategy provides a new entry to highly hindered ${\beta}$-amino 1,2,3-triazole derivatives bearing a gem-diaryl group, which are potentially valuable entities as molecular catalysts for asymmetric transformations.

• Bulletin of the Korean Chemical Society
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• v.27 no.11
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• pp.1795-1800
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• 2006

The convergent synthesis of symmetric PAMAM-like dendrimers from azide-functionalized poly(amido- amine) (PAMAM) dendrons and two different multi-alkynes was investigated. The stitching method was based on the click chemistry protocol, i.e., the copper-catalyzed cycloaddition reaction between an alkyne and an azide.

• Archives of Pharmacal Research
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• v.29 no.10
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• pp.826-833
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• 2006

Previously, we synthesized and evaluated several benzofuran derivatives containing heterocyclic ring substituents linked to the benzofuran nucleus at C-2 by a two- to four-atom spacer as potential anti-HIV-1, anticancer and antimicrobial agents. Among these derivatives, NSC 725612 and NSC 725716 exhibited interesting anti-HIV-1 activity. To further investigate the structure-activity relationship, we synthesized several new benzofuran derivatives derived from 2-acetylbenzofuran (2, 3a-c) and 2-bromoacetylbenzofuran (6; 7a,b; 8a,b). The compounds were designed to comprise the heterocyclic substituents directly linked to the benzofuran nucleus at C-2. Moreover, various related benzimidazoles derived from 2-acetylbenzimidazole and from 2-cyanomethylbenzimidazole (12a,b; 13a,b; 15; 16a,b) were also prepared as isosteres. The synthesized compounds were preliminarily evaluated for their in vitro anti-HIV-1, anticancer and antimicrobial activity. Compounds 2, 3a, 3b, and 12b showed weak anti-HIV-1 activity. Compound 6 exhibited mild activity against S. aureus, while compound 15 had mild activity towards S. aureus and C. albicans. However, no significant anticancer activity was observed with any of the tested compounds. From these results, we conclude that the presence of the spacer between the heterocyclic substituent and the benzofuran nucleus may be essential for the biological activity.

• Journal of the Korean Chemical Society
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• v.32 no.4
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• pp.301-310
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• 1988

Reaction rates for mononuclear heterocyclic rearrangement of N-(5-phenyl-1,2,4-oxadiazol-3-yl)-N'-arylformamidines into 3-acylamino-1-aryl-1,2,4-triazoles were determined spectrophotometrically in dioxane/water (50 : 50, v/v). There are two different reaction paths according to pH. One is pH-independent path, the other is pH-dependent one. In pH-independent path, the result of substituent effect by IYT equation show that N-H bond breaking as well as new N-N bond formation controls the reaction rate. In pH-dependent path, concave-upward Hammett plot was observed. It can be concluded that new N-N bond formation is more advanced than N-H bond breaking in transition state for electron-donating substituents, but N-H bond breaking is more advanced than new N-N bond formation for electron-withdrawing substituents.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2603-2608
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• 2012

A novel mononuclear supramolecule of copper(II) has been synthesized with Ippyt ligand (Ippyt=3-(4'-imidazole phenyl)-5-(pyrid-2''-yl)-1,2,4-triazole) (1). Compound 1, namely [$Cu(Ippyt)_2(H_2O)_2$], has been characterized by single-crystal X-ray diffraction, IR spectrum, elemental analysis and thermogravimetric analysis. Structure determination reveals that the elongated-octahedral geometry is formed in the vicinity of the copper (II) atom being coordinated by four nitrogen atoms from two Ippyt ligands occupying the equatorial position and two oxygen atoms from two coordinated water molecules in the axial position, which together form the $N_4O_2$ donor set. Hydrogen bonding interactions between nitrogen and oxygen atoms result in the set up of a supramolecular network architecture. Biological properties including antibacterial activity and superoxide dismutase (SOD) mimetic activity of compound 1 have been investigated by agar diffusion method and the modified Marklund method, respectively. The results indicate that compound 1 exhibits a stronger antibacterial efficiency than the parent ligand and it also has a certain radical-scavenging activity.

• The Korean Journal of Pesticide Science
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• v.16 no.1
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• pp.28-34
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• 2012

We analysed 149 samples of Korean traditional herbal tea materials. The 156 pesticides were analyzed by GC/ECD and NPD, detected pesticides were confirmed by GC-TOF/MS. Sample preparation was performed bv multi-residue analysis method of multiclass pesticides of the Korea Food Code. The residual pesticides were detected in 22 samples(14.8%), the highest detection frequency samples are lycium and jujube. Detected pesticides in Korean traditional herbal tea materials were chlorpyrifos (5 samples), chlorothalonil (3 samples), cypermethrin (3 samples), hexaconazol (3 samples) and cyhalothrin(3 samples). The pesticide types detected in Korean traditional herbal tea materials were organophosphorus(29.2%), pyrethroids(16.7%), organochlorines (12.5%) and triazoles(12.5%). The 5 samples(lycium, jujube, chrysanthemum, balloon-flower, milk vetch root) were detected pesticides below MRLs, 2 samples(cornus fruit, cnidium) were detected pesticides unnotificated MRLs.