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Solid-Phase Synthesis of 1,3,7,8-Tetrasubstituted Xanthine Derivatives on Traceless Solid Support
Lee, Doohyun,Lee, Seungyeon,Liu, Kwang-Hyeon,Bae, Jong-Sup,Baek, Dong Jae,Lee, Taeho American Chemical Society 2016 ACS Combinatorial Science Vol.18 No.1
<P>Traceless solid-phase synthesis of 1,3,7,8-tetrasubstituted xanthine (1,3,7,8-tetrasubstituted 1H-purine-2,6(3H,7H)-dione) derivatives has been developed. The solid-phase synthetic route began on a solid supported N'-cyano-N-substituted carbamimidothioate, which was prepared from cyanamide, isothiocyanate, and Merrifield resin. After N-alkylation of carbamimidothioate resin with ethyl 2-bromoacetate, an imidazole ring is introduced by Thorpe-Ziegler-type cyclization. The resulting imidazole resin is converted to 1,3,7-trisubstituted xanthine resin using sequential reactions, such as Lewis acid-catalyzed urea formation, pyrimidine ring cyclization, and N-alkylation. After oxidation of sulfides to sulfones, traceless cleavage with amine or thiol nucleophiles afforded the desired 1,3,7,8-tetrasubstituted xanthines in good purities and overall yields (eight-steps; 36 examples). This efficient solid-phase synthesis enables the incorporation of four diversity points into the preparation of the 1,3,7,8-tetrasubstituted xanthines.</P>
Lee, Wonhwa,Lee, Doohyun,Lee, Yuri,Lee, Taeho,Song, Kyung-Sik,Yang, Eun-Ju,Bae, Jong-Sup American Chemical Society and American Society of 2018 Journal of natural products Vol.81 No.5
<P>Only a few isoflavones have been isolated from plants of the genus <I>Abronia</I>. The biological properties of compounds isolated from <I>Abronia</I> species have not been well established, and their antisepsis effects have not been reported yet. In the present study, a new <I>C</I>-methylcoumarinochromone, was isolated from <I>Abronia nana</I> suspension cultures. Its structure was deduced as 9,11-dihydroxy-10-methylcoumarinochromone (boeravinone Y, <B>1</B>) by spectroscopic data analysis and verified by chemical synthesis. The potential inhibitory effects of <B>1</B> against high mobility group box 1 (HMGB1)-mediated septic responses were investigated. Results showed that <B>1</B> effectively inhibited lipopolysaccharide-induced release of HMGB1 and suppressed HMGB1-mediated septic responses, in terms of reduction of hyperpermeability, leukocyte adhesion and migration, and cell adhesion molecule expression. In addition, <B>1</B> increased the phagocytic activity of macrophages and exhibited bacterial clearance effects in the peritoneal fluid and blood of mice with cecal ligation and puncture-induced sepsis. Collectively, these results suggested that <B>1</B> might have potential therapeutic activity against various severe vascular inflammatory diseases <I>via</I> inhibition of the HMGB1 signaling pathway.</P> [FIG OMISSION]</BR>
Lee, Gee-Hyung,Lee, Seong Jin,Jeong, Dae Young,Kim, Ha-Young,Lee, Doohyun,Lee, Taeho,Hwang, Jong-Yeon,Park, Woo Kyu,Kong, Jae-Yang,Cho, Heeyeong,Gong, Young-Dae Korean Chemical Society 2014 Bulletin of the Korean Chemical Society Vol.35 No.8
Novel 2,6-difuctionalized 2H-benzopyrans were synthesized and evaluated for a sphingosylphosphorylcholine(SPC) inhibitor. The synthetic 2H-benzopyrans 1c and 3a showed high potency in SPC-induced cell proliferation assay ($IC_{50}$ < 20 nM). Neither hERG $K^+$ channel binding (> $10{\mu}M$) nor CYP inhibitions (> $10{\mu}M$) were observed. Also, the simple structure-activity relationship (SAR) results were obtained from analysis of 2H-benzopyran derivatives 1-3 and the anti-SPC effect of 2H-benzopyran 1c was confirmed by a HUVEC tube formation assay.
Wu, Zhexue,Lee, Doohyun,Joo, Jeongmin,Shin, Jung-Hoon,Kang, Wonku,Oh, Sangtaek,Lee, Do Yup,Lee, Su-Jun,Yea, Sung Su,Lee, Hye Suk,Lee, Taeho,Liu, Kwang-Hyeon American Society for Microbiology 2013 Antimicrobial agents and chemotherapy Vol.57 No.11
<P>Albendazole and fenbendazole are broad-spectrum anthelmintics that undergo extensive metabolism to form hydroxyl and sulfoxide metabolites. Although CYP3A and flavin-containing monooxygenase have been implicated in sulfoxide metabolite formation, the enzymes responsible for hydroxyl metabolite formation have not been identified. In this study, we used human liver microsomes and recombinant cytochrome P450s (P450s) to characterize the enzymes involved in the formation of hydroxyalbendazole and hydroxyfenbendazole from albendazole and fenbendazole, respectively. Of the 10 recombinant P450s, CYP2J2 and/or CYP2C19 was the predominant enzyme catalyzing the hydroxylation of albendazole and fenbendazole. Albendazole hydroxylation to hydroxyalbendazole is primarily mediated by CYP2J2 (0.34 μl/min/pmol P450, which is a rate 3.9- and 8.1-fold higher than the rates for CYP2C19 and CYP2E1, respectively), whereas CYP2C19 and CYP2J2 contributed to the formation of hydroxyfenbendazole from fenbendazole (2.68 and 1.94 μl/min/pmol P450 for CYP2C19 and CYP2J2, respectively, which are rates 11.7- and 8.4-fold higher than the rate for CYP2D6). Correlation analysis between the known P450 enzyme activities and the rate of hydroxyalbendazole and hydroxyfenbendazole formation in samples from 14 human liver microsomes showed that albendazole hydroxylation correlates with CYP2J2 activity and fenbendazole hydroxylation correlates with CYP2C19 and CYP2J2 activities. These findings were supported by a P450 isoform-selective inhibition study in human liver microsomes. In conclusion, our data for the first time suggest that albendazole hydroxylation is primarily catalyzed by CYP2J2, whereas fenbendazole hydroxylation is preferentially catalyzed by CYP2C19 and CYP2J2. The present data will be useful in understanding the pharmacokinetics and drug interactions of albendazole and fenbendazole <I>in vivo</I>.</P>
Rational Design and Evaluation of a Branched-Chain-Containing Glycolipid Antigen That Binds to CD1d
Baek, Dong Jae,Lee, Yoon-Sook,Lim, Chaemin,Lee, Doohyun,Lee, Taeho,Lee, Jae-Young,Lee, Kyoo-A,Cho, Won-Jea,Kang, Chang-Yuil,Kim, Sanghee Wiley (John WileySons) 2010 Chemistry - An Asian Journal Vol.5 No.7
김지환 ( Doohyun Kim ),김두현 ( Jihwan Kim ),김진우 ( Jinwoo Kim ),고유준 ( Youjune Go ),이수원 ( Soowon Lee ),이정진 ( Jeongjin Lee ) 한국정보처리학회 2014 한국정보처리학회 학술대회논문집 Vol.21 No.2
본 연구에서는 유동인구 얼굴을 인식하기 위한 방법을 비교하고 유동인구 분석을 위한 얼굴 인식 알고리즘의 성능을 평가하는데 중점을 둔다. 현재 얼굴 인식 알고리즘의 종류는 매우 다양한데 건널목이라는 특정 공간을 제약하여 알고리즘들에 대한 평가와 분석을 통하여 앞으로 건널목 유동인구를 분석하기 위해 얼굴 인식 알고리즘을 사용하는 사용자에게 정보를 제공하고자 한다. 특히 Color Model 기반 얼굴 인식 알고리즘과 Haar-Like Feature 기반 얼굴 인식 알고리즘을 각각 이용하여 환경에 따른 성능을 비교 분석하고 그 평가를 한다.
이두현(Doohyun Lee),조진옥(Jinok Cho),이돈응(Donoung Lee) 한국HCI학회 2014 한국HCI학회 학술대회 Vol.2014 No.2
본 연구는 자연스러운 가야금 소리의 샘플링을 위한 최적의 방법을 찾고자 수행한 다양한 실험들과 그 결과를 측정, 분석, 평가한 내용을 담고 있다. 이는 한국 전통음악 콘텐츠의 제작과 그 데이터 구축을 위해 필요한 국악기 음원의 디지털화와, 이를 기반으로 하는 컴퓨터 소프트웨어 및 모바일 기기용 애플리케이션 개발을 위한 기초 연구이다. This study seeks to find solution to sample the most natural sound of Gayageum. Accordingly, various experiments have been performed in many different environments, and then the results have been analyzed and evaluated It is a basic study for building digital sound source library and eventually for developing software for personal computer and application for mobile device.