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맥엽 및 항산화 조성물의 생리 기능적 특성에 관한 연구 : 아질산염 소거능을 중심으로 Study on the Nitrite Scavenging Effect
이성희,홍이진,박형근,주상섭,김경탁 한국응용생명화학회 2003 Applied Biological Chemistry (Appl Biol Chem) Vol.46 No.4
맥엽과 이를 이용한 항산화 조성물을 제조하여 이에 존재하는 nitrite scavenging 효과와 이에 따른 발암원으로 부터의 보호 효과를 조사한 결과는 다음과 같다. 맥엽과 항산화 조성물 모두 수층에 비하여 메탄올층에서 아질산염 소거능이 2배 이상 높게 나타나 M-BL50의 0.01㎎/㎖ 농도에서 약 64.3%, M-AM 0.01㎎/㎖의 처리군이 이보다 약간 높은 68.3% 정도로 나타내었다. 마우스 단핵구 기원인 RAW 264.7(macrophage, mouse)에 맥엽과 항산화 조성물의 수층과 메탄올층을 처리하고 세포 생존율을 측정한 결과 수층 처리군에 비해 메탄올층 처리군에서 모두 세포 생존율이 더 낮게 측정되었으며 모든 시료에서 농도의존적으로 세포 증식이 억제되었다. 특히, M-AM을 처리한 군의 경우 모든 농도에서 가장 낮은 세포 생존율을 나타내어 항산화물 첨가에 의해 세포 증식 억제 효과가 상승됨을 알 수 있었으며, IC_(50) 수치 또한 메탄올층과 A-AM 시료 처리군에서 현저히 낮은 수치를 나타내었다. 또한 세포 내 아질산염 소거능을 측정한 결과 역시 마찬가지로 맥엽 입자 크기에 따른 차이는 나타나지 않았으며 수층 처리군에 비해 메탄올층 처리군과 항산화물을 첨가한 군에서 모두 높은 소거능을 나타내어 맥엽 및 기타 항산화물을 섭취함으로써 체내에서의 니트로사민 생성을 억제시킬 수 있을 것으로 예상된다. This study was conducted to estimate the biofunctional characteristics, namely nitrite scavenging effect of barley leaves (BL) and their mixture (AM) with other antioxidants. Aqueous or methanol extracts were obtained from BL and AM. Aqueous and methanol extracts from barley leaves had relatively higher nitrite scavenging effects and its activities and contents increased in a concentration-dependent manner. The activities and contents of methanol extracts obtained from BL and AM were higher than those of aqueous extracts. Especially, AM containing BL and other antioxidant mixture had the highest activities and contents increased in a concentration-dependent manner. BL or AM were added to macrophage cells of RAW 264.7 Survival rates of the cells treated with BL and AM were measured to be different. IC_(50) value decreased in a concentration-dependent manner by the addition of aqueous or methanol extracts from BL and AM. Especially, methanol extracts of AM had the highest nitrite scavenging effects. Thus, BL and AM may have protective effect against carcinogen and immune ability against reactive molecules through NO (nitric oxide) signal pathway. From the above results, barley leaves appear to contain natural anticancer and immune-related agents and may have potentiality to be used as functional food ingredients.
아시아티코사이드로부터 메칠 2β, 3β-에폭시-23-히드록시우르스-12-엔-28-오애이트의 합성 및 이의 환원적 에폭시환 개열반응
주상섭,임두연,서성기,남태규,박형근,김희두,김창민,이민희,백형근,이민정,정영훈 성균관대학교 약학연구소 1998 成均藥硏論文集 Vol.10 No.1
Steroidal 2β, 3β-epoxy compound was prepared from asiaticoside via six steps and reduced regioselectively with lithium aluminum hydride. Epoxide ring opening furnished 9 as a sole product at reflux condition through axial hydride attack at C-3.
Highly Enantioselective Total Synthesis of (+)-Isonitramine
Park, Yohan,Lee, Young Ju,Hong, Suckchang,Lee, Myungmo,Park, Hyeung-geun American Chemical Society 2012 Organic letters Vol.14 No.3
<P>A new efficient enantioselective synthetic method of (+)-isonitramine is reported. (+)-Isonitramine was obtained in 12 steps (98% ee and 43% overall yield) from δ-valerolactam <I>via</I> enantioselective phase-transfer catalytic alkylation, Dieckman condensation, and diastereoselective reduction as key steps.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/orlef7/2012/orlef7.2012.14.issue-3/ol2033042/production/images/medium/ol-2011-033042_0007.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/ol2033042'>ACS Electronic Supporting Info</A></P>
Conjugation of Ginsenoside Rg3 with Gold Nanoparticles
Park, You-Mie,Im, A-Rang,Joo, Eun-Ji,Lee, Ji-Hye,Park, Hyeung-Geun,Kang, Young-Hwa,Linhardt, Robert J.,Kim, Yeong-Shik Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.1
Ginsenoside Rg3 was reported to have important biological activities. We demonstrate conjugation and quantification procedures of ginsenoside Rg3 to gold nanoparticles for future biological and medical applications. Ginsenoside Rg3 was conjugated to spherical gold nanoparticles using a bifunctional heptaethylene glycol linker. The sulfhydryl group of heptaethylene glycol was adsorbed onto gold nanoparticles, and carboxylic acid end of heptaethylene glycol was bonded through a hydroxyl group of Rg3 via ester bond formation. The conjugation of Rg3 was characterized with various spectroscopic techniques, high resolution-transmission electron microscopy, and using Rg3 monoclonal antibody. The Rg3- functionalized gold nanoparticles were $4.7{\pm}1.0$ nm in diameter with a surface charge of -4.12 mV. The total number of Rg3 molecules conjugated to a 3.6 mL solution of gold nanoparticle was determined to be $9.5{\times}10^{14}$ corresponding to ~6 molecules of Rg3/gold nanoparticle. These results suggest that ginsenoside Rg3 is successfully conjugated to gold nanoparticles via heptaethylene glycol linker. The quantification was performed by using Rg3 monoclonal antibody without interference of gold's intrinsic color.
Implant system의 매몰조건과 소환온도에 대한 조사
박근형,Park, Geun-Hyeung 대한치과기공학회 2001 대한치과기공학회지 Vol.23 No.1
This study was investigated on effect of implant system about investment condition and burn out temperature. Posterior bridges were fabricated by using plastic sleeve and gold sylinder. The results were as follows; In plastic sleeve test and fitting cast copings. the phosphate bonded investment showed better gypsum bonded investment. The pure special liquid showed better margin fitness compared with mixed liquid (special liquid + distilled water). In gold cylinder test. the good burn out temperature of Ceramic PFG and Crown Gold was evaluated $0^{\circ}C$ to $820^{\circ}C$ and was decreased on $780^{\circ}C$ for 30 minutes. $0^{\circ}C$ to $750^{\circ}C$ and was decreased on $650^{\circ}C$ for 30 minutes.
Zhao, Long-Xuan,Park, Hyeung-Geun,Jew, Sang-Sup,Lee, Mi-Kyeong,Kim, Young-Choong,Thapa, Pritam,Karki, Radha,Jahng, Yurng-Dong,Jeong, Byeong-Seon,Lee, Eung-Seok Korean Chemical Society 2007 Bulletin of the Korean Chemical Society Vol.28 No.6
For the development of novel hepatoprotective agents, C11, C28, C2,3,23 or C2,23,28 functional groups on asiatic acid were modified, and their hepatoprotective effects were evaluated. Most of the prepared compounds displayed potent hepatoprotective activities against CCl4- and galactosamine (GaIN)-induced hepatotoxicity. Especially, compounds 16 and 20 showed the most significant hepatoprotective effects against GaIN-induced hepatotoxicity (54.2% and 46.4% protection at 50 mM, respectively).
Practical Hofmann Rearrangement
Jew, Sang-Sup,Park, Hyeung-Geun,Kang, Myoung-hee,Lee, Tae-hee,Cho, Youn-sang The Pharmaceutical Society of Korea 1992 Archives of Pharmacal Research Vol.15 No.4
Hofmann rearrangement of a series of primary aliphatic and aromatic carboxamides 1a-1m with HgO-NBS (or dibromantin)R'OH-DMF gives corresponding carbamates 2a-2m in excellent yields.
ChemInform Abstract: Cinchona-Based Phase-Transfer Catalysts for Asymmetric Synthesis
Jew, Sang-sup,Park, Hyeung-geun WILEY-VCH Verlag 2010 Chem Inform Vol.41 No.11
<P>ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.</P>