• Proceedings of the Korean Journal of Food and Nutrition Conference
• /
• 1997.06b
• /
• pp.13-14
• /
• 1997

영지의 약리효과는 triterpenoid계의 저분자와 polysaccharide인 고분자로 대별할 수 있다. 저분자 물질은 항염증작용, 항알러지작용, 간암세포 성장 억제작용, 혈압 강하작용, 혈소판 응집저해작용 등이 있으며, 고분자 물질은 혈압강하작용, 정혈작용, 고지혈증 개선작용, 혈당 강하작용, 면역 증강작용 및 항종양작용 등이 있는 것으로 알려졌다. 현재까지의 영지에 관한 연구는 주로 자실체에 대한 연구가 주류를 이루고 있으며 이들의 산지, 환경조건, 채집시기 및 실험자들에 따라 약리 효과 등에 많은 차이가 있다. 이들에 대한 효과가 영지의 대표적 약리효과라고 언급하기엔 부족한 점이 많으므로 약리효과가 우수하고 일관성이 있는 영지 유래 다당류를 얻기 위한 방법으로서는 균사체의 대량배양법 및 분리방법이 확립 되어야만 한다. 본 연구에서는 새로운 항암활성 다당류의 개발을 위해 국내 자생 영지를 채집하여 검색 및 계통적 분류를 행하였으며 분리된 균주의 최적 액체배양 조건, 다당류 분리 조건, 다당류의 물리화학적 특성 및 약리활성 등에 관한 연구를 실시하였다. 그 중 약리활성이 우수한 G- lucidum IY009 균주를 선발 하였다. 구조적 특징과 종양 면역 활성과의 관계 규명을 위해, G- lucidum IY009 배양균사체로부터 다당류를 T-AS, U-AS, M-AS, S 및 H로 분획 하였다. 추출조건에 따른 다당류 GLG의 수율은 열수 추출 분획이 2.98g/l로 가장 높았으며, U-AS및 T-AS에서 각각 2.32g/l, 2.07g/l이었다. GLG의 특성을 조사하기 위하여 수용성과 비수용성으로 분리한 결과 수용성 분획은 비수용성 분획보다 높은 당 함량을 나타냈으며, T-AS는 70.3%의 당과 7.8%의 단백질로 구성 되었다. GLG 대부분의 분획들은 60~93%의 glucose로 구성된 다당류 이었으며, 주로 $\beta$-glucose로 구성된 다당류 이었다. 아미노산은 Asp 및 Glu의 산성 아미노산과 Ala, Leu 등의 함량이 높게 나타났으며, 비알칼리 추출물에서 Ser과 Thr의 함량이 높게 나타났다. 다당류 T-AS는 평균 분자량이 2,000 kD와 12kD에서 주 peak를 나타냈으며, 수용성 분획의 평균 분자량은 12kD이고 비수용성 분획은 36~2,000 kD의 평균 분자량 분포를 갖는 것으로 나타났다. IR과 NMR 분석 결과 890 cm-1에서 흡수 peak를 나타내어 $\beta$-(1,3)0glucan과 $\beta$-(1,6)-glucan의 구조를 갖는 다당류로 확인 되었다. T-AS 분획은 C:H:O:N의 함량비가 38.9:5.7:49.6:1.84%이며, 이 물질의 융점은 163 $^{\circ}C$로 연한 갈색을 나타낸다. 분리된 GLG의 항암활성 기전 규명을 위해, in vivo 항암실험, 항보체 활성능, 항체 생성능, serum protein 분비능, 대식세포의 탐식능과 활성능 및 세포간 물질 분비 등의 상관관계를 조사하였다. 다당류 GLG 분획물들 가운데 항보체의 활성이 높았던 분획은 sarcome 180에 대한 항암 활성이 높게 나타났다. 다당류 T-AS의 보체 활성화 기작은 classical과 alternative complement pathway의 양 경로를 통해 활성화 되었다. T-AS 분획은 mouse내의 특정 혈청단백을 증가시켰으며, 항체 생성능의 증가가 관찰되어 effect T 세포의 활성화가 나타나고 있음을 알 수 있었다. T-AS는 생체내 투여시에 대식세포의 탐식능이 증진되었으며, 대식세포 기능 저해제에 의한 대식세포의 기능 저해 현상이 회복되었다. 이와 같은 결과들로부터, T-AS의 항암 활성은 활성화된 보체 성분 및 당 수용체들이 존재하는 대식세포의 개입을 시사한다.

• Korean Journal of Food Science and Technology
• /
• v.29 no.6
• /
• pp.1105-1112
• /
• 1997

By sequential degradation using partial acid hydrolysis of a weakly acidic polysaccharide (GL-4IIb2'), two acidic oligosaccharide fragments, PA-2' and PA-1-III were isolated and their structures were characterized. PA-2' consisted of almost equal proportion of a rhamnose (Rha) and an unusual sugar, 3-deoxy-D-manno-2-octurosonic acid (Kdo). When permethylated oligosaccharide-alditol derived from PA-2' was analyzed by GC-MS, the peak gave the fragment ions at m/z 189 $(bA_1,\;6-deoxyhexose)$ and at m/z 308 $(aJ_2,\;alditol\;from\;Kdo)$. The peak also gave the characteristic ion at m/z 162 but it did not give the fragment ion at m/z 177, suggesting that Kdo is substituted at C5 but not at C4. Methylation analysis also indicated that PA-2' was composed mainly of terminal Rhap and 5-substituted Kdo. When the reduced product from PA-2' was analyzed by $^1H-NMR$, it gave a signal at 5.09 ppm due to an anomeric proton of ${\alpha}-L-Rha$. These results indicated that PA-2' mainly contained ${\alpha}-L-Rhap-(1{\rightarrow}5)-Kdo$. On the other hand, PA-1-III mainly comprised Rha and Kdo in addition to small proportions of arabinose (Ara) and 3-deoxy-D-lyxo-2-heptulosaric acid (Dha). MS analysis of permethylated oligosaccharide-alditols from PA-1-III suggested that the major peak 1P was $Rhap-(1{\rightarrow}5)-Kdo$ whereas the minor peaks 2P and 3P possessed $Araf-(1{\rightarrow}5)-Dha$ unit and these peaks were produced as epimers during reduction of carbonyl groups in Dha.

• Investigative Magnetic Resonance Imaging
• /
• v.8 no.2
• /
• pp.94-99
• /
• 2004

Purpose : To investigate the signal enhancement ratio by NOE effect on in vivo $^{31}P$ MRS in human heart muscle and liver. we also evaluated the enhancement ratios of different phosphorus metabolites, which are important in 31P MRS for each organ. Materials and Methods : Ten normal subjects (M:F = 8:2, age range = 24-32 yrs) were included for in vivo $^{31}P$ MRS measurements on a 1.5 T whole-body MRI/MRS system using $^1H-^{31}P$ dual tuned surface coil. Two-dimensional Chemical Shift Imaging (2D CSI) pulse sequence for $^{31}P$ MRS was employed in all $^{31}P$ MRS measurements. First, $^{31}P$ MRS performed without NOE effect and then the same 2D CSI data acquisitions were repeated with NOE effect. After postprocessing the MRS raw data in the time domain, the signal enhancements in percent were estimated from the major metabolites. Results : The calculated NOE enhancement for liver $^{31}P$ MRS were $\alpha-ATP\;(7\%),\;\beta-ATP\;(9\%),\;\gamma-ATP\;(17\%),\;Pi\;(1\%),\;PDE\;(19\%)$ and $PME\;(31\%)$. Because there is no creatine kinase activity in liver, PCr signal is absent. For cardiac $^{31}P$ MRS, whole body coil gave better scout images and thus better localization than surface coil. In $^{31}P$cardiac multi-voxel spectra, DPG signal increased from left to right according to the amount of blood included. The calculated enhancement for cardiac $^{31}P$ MRS were : $\alpha-ATP\;(12\%),\;\beta-ATP\;(19\%),\;\gamma-ATP\;(30\%),\;PCr\;(34\%),\;Pi\;(20\%),\;(PDE)\;(51\%),\;and\;DPG\;(72\%)$. Conclusion : Our results revealed that the NOE effect was more pronounced in heart muscle than in liver with different coupling to 1H spin system and thus different heteronuclear cross-relaxation.

• Journal of KIISE:Information Networking
• /
• v.32 no.3
• /
• pp.279-290
• /
• 2005

Recently, as the serious damage caused by DDoS attacks increases, the rapid detection and the proper response mechanisms are urgent. However, existing security mechanisms do not effectively defend against these attacks, or the defense capability of some mechanisms is only limited to specific DDoS attacks. In this paper, we propose a detection architecture against DDoS attack using data mining technology that can classify the latest types of DDoS attack, and can detect the modification of existing attacks as well as the novel attacks. This architecture consists of a Misuse Detection Module modeling to classify the existing attacks, and an Anomaly Detection Module modeling to detect the novel attacks. And it utilizes the off-line generated models in order to detect the DDoS attack using the real-time traffic. We gathered the NetFlow data generated at an access router of our network in order to model the real network traffic and test it. The NetFlow provides the useful flow-based statistical information without tremendous preprocessing. Also, we mounted the well-known DDoS attack tools to gather the attack traffic. And then, our experimental results show that our approach can provide the outstanding performance against existing attacks, and provide the possibility of detection against the novel attack.

• Applied Biological Chemistry
• /
• v.43 no.1
• /
• pp.72-77
• /
• 2000

The repeated silica gel colum chromatographies of EtOAc fraction, showing anticonvulsant activity, obtained from MeOH extracts of Schizandra chinensis B. fruits led to isolation of a sesquiterpenoid, four lignans and a sterol glycoside. Their chemical structures were determined to be chamigrenal, gomisin A, gomisin H, gomisin N. schizandrin and daucosterol. Among them, schizandrin and daucosterol inhibited GABA degrative enzymes, succinic semialdehyde dehydrogenase and succinic semialdehyde reductase, respectively. It is postulated that the schizandrin and daucosterol are able to elevate the neurotransmitter GABA levels in central nervous system by inhibitory action on GABA degrative enzymes and act as anticonvulsant drugs.

• Journal of Pharmaceutical Investigation
• /
• v.39 no.6
• /
• pp.393-400
• /
• 2009

PHEA (hydroxyethyl-aspartamide)-mPEG (methoy-polyethyleneglycol)-$C_{16}$ (hexadecylamine)-ED (ethylenediamine) was prepared as a drug delivery carrier. The structure and molecular weight of polymers were characterized by $^1H$-NMR and gel permeation chromatography. Micelle size and shape were measured by electro-photometer light scattering and transmission electron microscope. The mean diameter of micelles was 23 nm in aqueous solution. To evaluate the potential of these polymeric micelles as a drug carrier, PSI-mPEG-$C_{16}$-ED was conjugated with Cy5.5 for Near-Infrared Fluorescent (NIRF) based optical imaging. PSI-mPEG-$C_{16}$-ED-Cy5.5 was injected intravenously into mice (n=5) and in vivo NIRF imaging was performed during 48 h after injection. The biodistribution study at 24 h after injection showed the longcirculation property of PSI-mPEG-$C_{16}$-ED-Cy5.5. Therefore, PSI-mPEG-$C_{16}$-ED micelles could be a promising drug carrier and imaging agent.

• Journal of the Korean Society of Safety
• /
• v.26 no.4
• /
• pp.47-58
• /
• 2011

Halogen free intumescent flame retardants(IFRS), such as the mixture of melamine phosphate(MP) and char forming agents(pentaerythritol(PER), di-pentaerythritol(DiPER), tris(2-hydroxyethyl) isocyanurate(THEIC)), were prepared and characterized. Polypropylene(PP)/$IFR_S$ composites were also prepared in the presence of ethylene diamine phosphate(EDAP) as a synergist and used into flame retardant PP powder coatings. Thermoplastic PP powder coatings at 20 wt% flame retardant loading were manufactured by extruded and then mechanical cryogenic crushed to bring them in fine powder form. These intumescent flame retardant powder coatings($IFRPC_S$) were applied on mild steel surface for the purpose of protection and decorative. It is a process in which a $IFRPC_S$ particles coming in contact with the preheated mild steel surface melt and form a thin coating layer. The obtained MP flame retardant was analyzed by utilizing FTIR, solid-state $^{31}P$ NMR, ICP, EA and PSA. The mechanical properties as tensile strength, melt flow index(MFI) and the thermal property as TGA/DTA and the fire safety characteristics as limiting oxygen index(LOI), UL94 test, SEM were used to investigate the effect of $IFRPC_S$. The experimental results show that the presence of $IFR_S$ considerably enhanced the fire retardant performances as evidenced by the increase of LOI values 17.3 vol% and 32.6 vol% for original PP and $IFRPC_S$-3(PP/MP-DiPER/EDAP), respectively, and a reduction in total flaming combustion time(under 15 sec) in UL94 test of $IFRPC_S$. The prepared $IFRPC_S$-3 have good comprehensive properties with fire retardancy 3.2 mm UL94 V-0 level, LOI value 32.6%, tensile strength $247.3kg/cm^2$, surface roughness Ra $0.78{\mu}m$, showing a better application prospect. Through $IFRPC_S$-2(PP/MP-PER/EDAP) and $IFRPC_S$-3 a better flame retardancy than that of the $IFRPC_S$-1(PP/MP/EDAP) was investigated which was responsible for the formed more dense and compact char layer, improved synergy effect of MP and PER/DiPER.

• Journal of the Korean Chemical Society
• /
• v.34 no.2
• /
• pp.143-158
• /
• 1990

Metal complexes were prepared by reacting uranium (Ⅵ), thorium (Ⅳ) and rare earth metal (Ⅲ) ions including Nd (Ⅲ), Sm (Ⅲ) and Ho (Ⅲ) with macrocyclic ligands including five crown ethers, nine crownands and one cryptand ligands, and subjected to NMR studies in order to examine coordination sites of the ligands and compositions of the complexes formed. Among the marcocyclic ligands, crown ethers and crownand ligands have shown down-field shifts of the methylene protons of the lcigands by forming stable complexes with all the metal ions and the differences of chemical shifts were decreased as increasing of the cavity-size of crown ethers for the same metal ions and decreasing of the atomic number of the rare earth metals for the same ligands. It has been found that crownand 22 gave a stable complex with uranium(Ⅵ) ion by the coordination through both oxygen and nitrogen atoms of the ligand whereas no complex was formed with the rare earth metal(Ⅲ) ions, which on the other hand were found to form stable complexes with cryptand 221. The rest of the crowand ligands have also been found to form stable complexes with uranium(Ⅵ) ion by coordinating through all the oxygen and nitrogen atoms of the ligands whereas no complexes were formed with the rare earth metal(Ⅲ) ions. It has also been shown by 1H-NMR study that uranium(Ⅵ), thorium(Ⅳ) and rare earth metal(Ⅲ) ions formed 1:1 complexes with the macrocyclic ligands except for thorium(Ⅳ) complex of 12C4 in which the mole ratio of metal to ligand is 1:2. More stable metal complexes show larger changes in chemical shifts of the coordinated ligand protons. Finally, the rare earth metal(Ⅲ) complexes of 18C6 have shown ligand exchange reaction with the solvent molecules in acetylacetone solution, which was not observed for the uranium (Ⅵ) complexes.

• Bulletin of the Korean Chemical Society
• /
• v.31 no.5
• /
• pp.1314-1318
• /
• 2010

The $[Ru(tpy)_2]Cl_2$ (tpy:2,2':6',2"-terpyridine) complex was synthesized and its structure was confirmed by $^1H$-NMR and elemental analysis. Its binding mode toward DNA was compared with the well-known $[Ru(bpy)_3]Cl_2$ (bpy:2,2-bipyridyl), using isotropic absorption, linear dichroism(LD) spectroscopy, and an energy minimization study. Compared to $[Ru(bpy)_3]^{2+}$, the $[Ru(tpy)_2]^{2+}$ complex exhibited very little change in its absorption pattern, especially in the MLCT band, upon binding to DNA. Furthermore, upon DNA binding, both Ru(II) complexes induced a decrease in the LD magnitude in the DNA absorption region. The $[Ru(tpy)_2]^{2+}$ complex produced a strong positive LD signal in the ligand absorption region, which is in contrast with the $[Ru(bpy)_3]^{2+}$ complex. Observed spectral properties led to the conclusion that the interaction between the ligands and DNA bases is negligible for the $[Ru(tpy)_2]^{2+}$ complex, although it formed an adduct with DNA. This conclusion implies that both complexes bind to the surface of DNA, most likely to negatively charged phosphate groups via a simple electrostatic interaction, thereby orienting to exhibit the LD signal. The energy minimization calculation also supported this conclusion.

• Bulletin of the Korean Chemical Society
• /
• v.34 no.9
• /
• pp.2616-2622
• /
• 2013

A novel zwitterionic monomer 3-[(2-acrylamido)dimethylammonio]propanesulfonate (DMADAS) was designed and synthesized in this study. Then it was polymerized with acrylamide (AM) by free radical polymerization in 0.5 mol/L NaCl solution with ammonium persulfate ($(NH_4)_2S_2O_8$) and sodium sulfate ($NaHSO_3$) as initiator. The structure and composition of DMADAS and acrylamide-3-[(2-acrylamido)-dimethylammonio]propanesulfonate copolymer (P-AM-DMADAS) were characterized by FT-IR spectroscopy, $^1H$ NMR and elemental analyses. Isoelectric point (IEP) of P-AM-DMADAS was tested by nanoparticle size and potential analyzer. Solution properties of copolymer were studied by reduced viscosity. Antipolyelectrolyte behavior was observed and was found to be enhanced with increasing DMADAS content in copolymer. The results showed that the viscosity of P-AM-DMADAS is 5.472 dl/g in pure water. Electrolyte was added, which weakened the mutual attraction between sulfonic acid group and quaternary ammonium group. The conformation became loose, which led to the increase of reduced viscosity. The ability of monovalent and divalent cation influencing the viscosity of zwitterionic copolymer obeyed the following sequence: $Li^+$ < $Na^+$ < $K^+$, $Mg^{2+}$ < $Ca^{2+}$ < $Ba^{2+}$, and that of anion is in the order: $Cl^-$ < $Br^-$ < $I^-$, $CO{_3}^{2-}$ > $SO{_3}^{2-}{\approx}SO{_4}^{2-}$.