Methylelaiophylin의 항균활성

이동선,이상한,우주형,이진만,서영배,홍순덕,Lee, Dong-Sun,Lee, Sang-Han,WOO, Ju-Hyung,Lee, Jin-Man,Seu, Young-Bae,Hong, Soon-Duck 한국생명과학회 1997 생명과학회지 Vol.7 No.3

Methylelaiophylin은 gram양성균에 대하여 광범위한 항균활성을 보이며, 특히Bacillus subtilis에서 superoxide redicals을 발생하여 항균활성을 나타낸다. B. subtilis에 대한 항균활성은 wild type strain보다 mutant strain인 rec$^{-}$에 대하여 더민감하며, 이러한 항균력은 항산화제인 dithiothreito에 의하여 현저히 감소되었다. 또한 항균력은 세포내 RNA합성보다 DN합성에 효과적으로 작용하였다. 이러한 결과들은 methylelaiophylin의 항균활성이 세포내에서 발생한 활성산소에 의하여 기인한 것임을 나타낸다. Methylelaiophylin generated superoxide radicals in Bacillus subtilis and showed antibacterial activity against a broad range of gram positive bacteria. The inhibition of DNA synthesis was more sensitive than one of RNA synthesis. A recombination-deficient mutant strain of B. subtilis was 2-fold more sensitive than a wild strain, and this sensitivity was reduced in the presence of an antioxidant, dithiothreitol. Methylelaiophylin generated superoxide radicals in B. subtilis lysates, and this suggests that the antibacterial activity of methylelaiophylin is related to the generation of active oxygen species in the cells.

Farmesy-Protein Transferase의 저해제 Dihydrotanshinone l.

이동선,이상한,하상철,김종국,서영배,홍순덕,Lee, Dong-Sun,Lee, Sang-Han,Ha, Sang-Chul,Kim, Jong-Guk,Seu, Young-Bae,Hong, Soon-Duck 한국생명과학회 1998 생명과학회지 Vol.8 No.2

Farmesy-Protein Transferase의 저해제는 Ras단백질의 발암활성을 차잔하는 항암제의 후보로서 알려져있다. 우리는 최근에 topoisomerase I에 대하여 저해활성을 갖는 dihydrotanshinone I을 약용식물인 Salvia miltorhiza Bunge(Danshen)으로부터 분리하였다. Dihydrotanshinone Iml 작용기작의 해석을 위한 시도에서 farmesy-Protein Transferase에 대한 저해능($IC_{50}$치= 15ug/ml)을 관찰하였으며, 이것은 유용한 항암제로서의 가능성을 제시한 결과로 본다. An inhibitor of farnesy-protein transferae is known to be a fgood candidate for antitumor agent that block the oncogenic activity of Ras protein . We recently isolated and characterized dihydrotanshinone I from Salvia miltiorrhiza Bunge (Danshen), an oriental herb, which has an inhibitory activity of toposimerase I to some cancer cell lines. In order to examine the molecular mechanism of dihydrotanshinone I, we studied the farmesy-Protein Transferase activity by dihydrotanshinone I. As a result, we found that result, we found that dihydrotanshinone I showed inhibitory effect on farnesyl-protein transferase with $IC_{50}$ value of 15 ug/ml. This result suggest that dihydrotanshinone I may be an useful anticancer agent with the inhibitory activity of farnesyl-protein transferase.

계면중합에 의한 폴리우레아 마이크로캡슐의 제조 -이소시아네이트의 종류에 따른 마이크로캡슐의 생성수율과 열적특성-

이동선,조창기,Lee, Dong-Sun,Cho, Chang-Gi 한국섬유공학회 2002 한국섬유공학회지 Vol.39 No.5

In this study, a series of polyurea microcapsules were prepared by interfacial polyconden-sation using various isocyanates as the oil soluble monomer and diethylenetriamine as the water soluble monomer. Nonionic surfactant, NP-10, was used as an emulsifier. The yields of microcapsules from aliphatic isocyanates were higher than those of microcapsules from aromatic isocyanates due to the flexibility of the aliphatic chains. Polyurea microcapsules obtained from aliphatic isocyanates were stable well above 25$0^{\circ}C$ and showed better thermal stability compared to those obtained from aromatic analogs.

A Study on Network Planning and Optimization Strategy for Network Scalability

이동선,Lee, Dong-Sun The Korean Institute of Communications and Informa 2007 韓國通信學會論文誌 Vol.32 No.6a

현재의 전송네트워크용량을 향상시킬때 중요하게 고려해야 할것중의 하나가 네트워크 scalability 이다. 새로운 풀 메쉬의 링 확장 방법 및 플래닝 툴을 제안하였다. 3$\sim$15 노드의 확장링에서 본 툴을 사용하여 SNR이 증진되는 것을 입증하였다. 노드의 출력신호 및 광 SNR이 제안된 NPOT에 의해 -16dBm/10dB 에서 +005dBm/21dB 로 증진되었다. One of the major issues that has to be carefully considered when upgrading current transport network capacity, is network scalability. A novel full-meshed connected ring expansion methodology and planning tool have been proposed. A 3 to 15 node expansion ring has been studied by demonstrating a dramatic system SNR improvement when the proposed planning tool was used. The results are that node output signal and optical SNR have been improved from -16dBm/10dB to +005dBm/21dB by NPOT.

방선균주 7489가 생산하는 DNA Topoisomerase I 저해제에 관한 연구

이동선,하상철,이상용,김종국,홍순덕,Lee, Dong-Sun,Ha, Sang-Chul,Lee, Sang-Yong,Kim, Jong-Guk,Hong, Soon-Duck 한국미생물 · 생명공학회 1996 한국미생물·생명공학회지 Vol.24 No.1

During the screening of inhibitor of DNA topoisomerase I from microbial secondary metabolites, Streptomyces melanosporofaciens 7489 which was capable of producing high level of inhibitor was selected from soil. The active compound (7489-1) was purified from the culture broth by solvent extraction, silica gel column chromatography and HPLC. The inhibitor was identified as dibutyl phthalate by spectroscopic methods of UV, $^{1}H$-NMR, $^{13}C$-NMR, DEPT and EI-MS. 7489-1 showed a strong inhibitory activity against topoisomerase I with 10 ${\mu}$M of $IC_{50}$ value.

이온 이동도 분석법의 원리와 응용에 관한 고찰

이동선,Lee, Dong-Sun 한국분석과학회 2001 분석과학 Vol.14 No.1

Inhibition of $\alpha$-Glucosidase Activity by Quercetin

이동선,김종국,이상한,Lee, Dong-Sun,Kim, Jong-Guk,Lee, Sang-Han The Korean Society for Microbiology and Biotechnol 2006 한국미생물·생명공학회지 Vol.34 No.4

Quercetin is a flavonoid molecule that is known to tie in various sources of natural products such as vegetables and fruits. It has been proven that quercetin plays a crucial role in the prevention of colon cancer as well as homeostasis as radical scavenger in human body. It is also well-known that glycosidases, including $\alpha$-glucosidase, are involved in a variety of degenerative metabolic disorders. In the course of screening useful $\alpha$-glucosidase inhibitors, we screened out quercetin as a $\alpha$-glucosidase inhibitor from chemical libraries. Quercetin was shown to be a reversible, slow-binding, and noncompetitive inhibitor of yeast a-glucosidase with a K$_i$ value of $6.3\times10^{-8}$ M when it was included with an enzyme mixture. Together, these results show that quercetin has potential in treating disorders including diabetes, although the further mechanistic study is needed. Quercetin은 flavonoid 계통의 물질로서 자연계에서 채소나 과일에 매우 흔하다. 또한 인체에서는 radical scavenger로서 신체항상성 뿐만 아니라 직장암의 예방에도 중요한 역할을 한다. Glucosidase를 포함한 glycosidase는 많은 종류의 대사성 질환에 관련이 있다. 유용한 $\alpha$-glucosidase 저해제를 스크리닝 하던 중 chemical library로부터 quercetin을 선별하였다. Quercetin은 $\alpha$-glucosidase에 가역적으로, 느리게 결합하며, 비경쟁적인 저해제인데, $6.3\times10^{-8}$ M의 Ki값을 가진다. 이러한 결과는 비록 기전 연구가 더 필요하지만, quercetin이 당뇨병과 같은 퇴행성 질환을 치료할 수 있다는 잠재성을 보여주는 것이다.

반도체 패키지의 굽힘변형 측정을 위한 그림자 무아레의 감도향상 기법연구

이동선,주진원,Lee, Dong-Sun,Joo, Jin-Won 한국마이크로전자및패키징학회 2015 마이크로전자 및 패키징학회지 Vol.22 No.3

반도체 패키지는 여러 가지 다양한 재료로 구성되어 있으며, 제조시나 사용 환경에서 온도가 변하면 각 재료의 열팽창 계수의 차이로 인하여 굽힘변형이 발생하게 된다. 그림자 무아레 방법은 비접촉으로 전체 영역에 걸친 면외변위를 측정하는 광학적 방법이지만 측정 감도가 $50{\mu}m/fringe$ 이상이어서 반도체 패키지의 굽힘변형을 측정하기에는 적당하지 않은 면이 있었다. 본 논문에서는 그림자 무아레 시스템에 위상이동 기법을 적용하여 $12.5{\mu}m/fringe$의 향상된 감도를 갖는 측정장치를 구성하였다. 그림자 무아레 측정에서 나타나는 탈봇 현상을 고려하여 1/2 탈봇 영역에서 변형을 측정할 수 있도록 실험을 수행하였다. 위상이동에 의해 기록되는 4장의 그림자 무늬를 영상처리하여 감도가 4배 향상된 그림자 무늬를 얻어내었다. 본 논문에서 개발한 측정방법을 기존의 섬유강화 패키지 기판과 무섬유 패키지 기판에 적용하여 상온과 약 $100^{\circ}C$의 환경에서 발생하는 굽힘변형을 측정하였다. Electronic packages consist of various materials, and as temperature changes, warpage occurs because of the difference in coefficient of thermal expansion. Shadow $moir{\acute{e}}$ is non-contact, whole field measurement technique for out-of-plane displacement. However, the technique has low sensitivity above $50{\mu}m/fringe$, it is not adequate for the warpage measurement in some circumstance. In this paper, by applying phase shifting process to the traditional shadow $moir{\acute{e}}$, measurement system having enhanced sensitivity of $12.5{\mu}m/fringe$ is constructed. Considering Talbot effect, the measurement is carried out in the half Talbot area. Shadow fringe pattern having four times enhanced sensitivity is obtained by the image process with four shadow fringes. The measurement technique is applied to the fibered package substrate and coreless package substrate for measuring warpages at room temperature and at about $100^{\circ}C$.

The Performance Analysis for the New Architecture of DWDM Network

이동선,Lee, Dong-Sun The Korea Institute of Information and Commucation 2008 韓國通信學會論文誌 Vol.33 No.6B

Aggregate bandwidth required by the internet is expected to be explosively increased. To meet this anticipated need, an ultra high speed internet backbone transport network, capable of supporting up to a Tbps traffic capacity, is required. this thesis examines, through computer simulation and modeling, the technological requirements and assesses the performance analysis and feasibility for implementing ultra-high speed NGI backbone transport network fabric based on WDM technology. The study results are that C/L band EDFA spectral gains for ultra high speed DWDM have been improved from 2.61dB/1.5386dB to 0.03dB/0.096dB by proposed architecture.

계면중합에 의한 폴리우레아 마이크로캡슐의 제조 -분산상의 점도에 따른 마이크로캡슐의 크기 변화-

이동선,금창헌,조창기,Lee, Dong-Sun,Kum, Chang-Hun,Cho, Chang-Gi 한국섬유공학회 2007 한국섬유공학회지 Vol.44 No.5

Polyurea microcapsules were prepared by interfacial polycondensation using diisocyanates as the oil soluble monomers and diethylenetriamine as the water soluble monomer. NP-10, nonionic surfactant, was used as an emulsifier. Toluene was used as the diluent of the diisocyanates as well as the means to prepare microcapsule with empty shell. Number average particle size of the microcapsule showed a linear relationship with the viscosity of the dispersed oil phase. Polyurea microcapsule with thinner shell thickness showed good thermal stability well above $250^{\circ}C$ and showed same thermal stability compared to that with thicker shell thickness.