• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.205-205
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• 1994

동물, 곤충, 해조류 등으로 부터 얻어진 독소는 해로운 것으로 알려져 있지만 의학적으로 유용한 화합물을 내포하고 있다. 본 연구는 이러한 점에 착안하여 독사, 또는 곤충의 독 30여종을 대상으로 위암 세포인 SNU-1에 대해서 MTT assay에 의한 세포 독성 시험을 실시하였다. 이 중 세포 독성 활성이 가장 놓은 코브라 계통인 Ophiphagus hannah의 독으로 부터 세포 독성 물질의 정제를 시도하였다. HPLC-GPC와 HPLC-lEX 또는 RP-HPLC를 이용하여 정제하였고 각 분획들을 암세포주에 대해서 시험하였다. TSK-2000SW로 부터 2개의 분획을 얻어 분획 I에서 $IC_{50}$/ 의 값이 0.5 - 3 $\mu\textrm{g}$/ml의 범위 내에서 확인되었다. 분자량이 작은 분획 II에서는 세포독성이 작게 나타났지만 농축하여 성분 분석을 시도하였다. 분획 I을 RP-HPLC를 이용하여 TFA와 acetonitrile의 linear gradient에 의해 더욱 분리를 하였고, phopholipase $A_2$ 활성의 가능성도 측정하였다. 분획 II는 Mono S 칼람을 이용하여 ammonium acetate농도에 따른 pH gradient에 의한 분리를 시도하여 순도를 SDS-PAGE에 의해서 확인하였다. 각각의 크로마토그리피로 부터 얻은 분획에 대해서 세포 독성을 실시중에 있으며 성질도 동정중에 있다.

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2243-2248
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• 2011

Carbon-based solid acid catalyst was found to be highly efficient, eco-friendly and recyclable heterogeneous catalyst for the multicomponent reaction of dimedone, aromatic aldehydes, and a nitrogen source (ammonium acetate or aromatic amines) under solvent-free conditions, giving rise to 1,8-dioxodecahydroacridines in high yields. The present methodology offers several advantages, such as a simple procedure with an easy work-up, short reaction times, high yields, and the absence of any volatile and hazardous organic solvents.

• Archives of Pharmacal Research
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• v.21 no.2
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• pp.217-222
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• 1998

A stereospecific HPLC method has been developed for the resolution of the enantiomers of salbutamol in human urine. After solid-phase extraction and derivatization with 2,3,4,6-tetra-O-acetyl-$\beta$-D-glucopyranosyl isothiocyanate, the diastereomeric derivatives were resolved (Rs=1.83) on $5{\mu}m$ octadecylsilan column using 35% acetonitrile in 0.05M ammonium acetate buffer (pH=6) as a mobile phase with electrochemical detection. The diastereomeric derivatives were formed within 30 min. The detection limit of each enantiomer was 20 ng/ml (S/N=3).

• Journal of the Korean institute of surface engineering
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• v.29 no.6
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• pp.709-713
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• 1996

Mechanical solderless chip packaging with small gold bumps or metal balls has increased in the electronic devices. The preparation of conductive particles (5~7 $\mu\textrm{m}$ diamiter) by electroless nickel plating have been investigated. Generally, batch type electroless plating is applied to provide conductivity on the nonconductors. Since the surface areas of particles are much larger than the bulk substrate, accordingly the electroless plating bath becomes unstable. Thus, we applied the continuous dropping method for the preparation of conductive particles. The uniform coverage of deposited nickel on the particles was obtained by using ammonium acetate as a complexing agent, and surface coverage is further improved without coagulation of particles by the surface active agent treatment before enter the plating bath.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.10 no.1
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• pp.49-74
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• 1984

Rheology of gels prepared with stearyl dimethyl benzyl ammonium hectorite (SDBAH) and various polar additives in n-butyl acetate was investigated by measuring the viscosity and rheogram. Including generally recognized polar additives, additional studies on the rheogram and viscosity were made with ether-type methyl cellosolve and carbitol, with dimethyl sulfoxide (DMSO) having sulfonyl group, and furthermore with above-mentioned polar additives containing small quantity of water, It was observed that molecular size, dipole moments and dielectric constants of polar additives had a great influence on viscosity increase and rheology of SDBAH gel, and the increase of SDBAH interlayer spacing was important factor in gel formation and viscosity change. It was also shown that thixotropy effect was increased with the increase of polar additive concentration, finally changed to rheopexy from thixotropy as the concentration of polar additives was increased more than about 40% of SDBAH weight. In addition thixotropy changed to rheopexy as the increase of shear rate. It was further found that the aqueous solutions of polar additives (water content, 5-25%) had more effects on rheology than additives without water, and particularly 95clo DMSO solution was the most effective. And the optimum concentration of polar additives showing maximum viscosity in the same SDBAH concentration system was examined.

• Bulletin of the Korean Chemical Society
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• v.31 no.11
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• pp.3180-3182
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• 2010

A simple facile 'one pot' synthesis of 2-amino-3-cyano-4,6-diarylpyridine derivatives via three component reaction of chalcone, malanonitrile and ammonium acetate under ultrasonic irradiation and grindstone technology. All the synthesized compounds have been characterized on the basis of their elemental analyses and spectral data (IR, $^1H$ NMR, $^{13}C$ NMR and Mass).

• Bulletin of the Korean Chemical Society
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• v.30 no.5
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• pp.1057-1060
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• 2009

Boric acid ($BO_3H_3$) is an inexpensive, efficient and mild catalyst for the synthesis of 2,4,5-triaryl-1H-imidazoles in excellent yields from the one-pot three-component condensation of benzil/benzoin, an aldehydes and ammonium acetate in aqueous media under ultrasound at room temperature. The remarkable advantages offered by this method are green catalyst, mild reaction conditions, simple procedures, much faster reactions and excellent yield of products.

• Bulletin of the Korean Chemical Society
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• v.33 no.7
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• pp.2140-2144
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• 2012

A polymer support immobilized acidic ionic liquid was prepared by copolymerization of 3-vinyl-1-(4-sulfonic acid)butylimidazolium hydrogen sulfate with styrene in the presence of benzoyl peroxide and its primary application as a solid acidic heterogeneous catalyst to the synthesis of Hantzsch 1,4-dihydropyridines through a one-pot three-component reaction of aromatic aldehydes, ethyl acetoacetate and ammonium acetate was investigated. The results showed that this heterogeneous catalyst has high catalytic activity and the desired products were obtained in good to high yields. Moreover, the catalyst was found to be reusable and a considerable catalytic activity still could be achieved after third run.

• Bulletin of the Korean Chemical Society
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• v.30 no.11
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• pp.2532-2534
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• 2009

A facile and efficient synthetic route has been developed for the polyhydroquinoline via four component reactions of aldehydes, dimedone, ethyl acetoacetate and ammonium acetate in the presence of catalytic amount of scolecite in ethanol at 70 ${^{\circ}C}$ through Hantzsch reaction. This method gives remarkable advantages such as simple work-up procedure, environmentally friendly, inexpensive, non-toxic and recyclable catalyst, shorter reaction time along with excellent yields.

• Bulletin of the Korean Chemical Society
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• v.34 no.5
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• pp.1508-1512
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• 2013

A simple and efficient synthesis of 2,4,5-trisubstituted imidazoles was achieved via a one-pot three-component cyclocondensation of benzil, aromatic aldehydes, and ammonium acetate in the presence of a catalytic amount of tetrabutylammonium hexatungstate $[TBA]_2[W_6O_{19}]$ as a heterogeneous catalyst under thermal solvent-free conditions. The key features of this methodology are operational simplicity, high yields, short reaction times, and a recyclable catalyst with a very easy work up.