Structure determination of new bioactive secondary metabolites from Streptomyces, Actinomdaura, and Deinococcus bacteria

학위논문 (박사)-- 서울대학교 대학원 : 약학대학 약학과, 2018. 8. 오동찬.1. Suncheonoside A-D, benzothioate glycoside from marine-derived Streptomyces sp. A marine-derived Streptomyces strain, SSC21, was isolated from the sediment of Suncheon Bay, Republic of Korea. Chemical analysis of the bacterial strain resulted in the isolation of four new metabolites, suncheonosides A-D (1-4), each bearing a sulfur atom. The planar structures of the suncheonosides were identified as hexa-substituted benzothioate glycosides by combined spectroscopic analyses. Analysis of the configuration of the sugar moieties based on ROESY NMR correlations, 1-bond 1H-13C coupling constant analysis, and chemical derivatizations elucidated that the suncheonosides incorporate only L-rhamnose. Suncheonosides A, B, and D promoted adiponectin production in a concentration-dependent manner during adipogenesis in human mesenchymal stem cells, suggesting anti-diabetic potential. 2. JS8 A and B, novel bacterial flavonoid, from Streptomyces sp. associated with white grub Protaetia brevitarsis seulensis. Investigation of secondary metabolites of bacteria associated with eukaryotic hosts has become a promising approach to discover novel bioactive compounds. In search for new bioactive chemotypes, I have been focusing on secondary metabolites of bacterial strains associated in the gut of a white grub of Protaetia brevitarsis seulensis. The secondary metabolite profiles of the 80 actinobacterial strains isolated from the gut of a P. brevitarsis grub were chemically analyzed by LC/MS. This chemical analysis led to the discovery of two new flavonoid-like compounds, which are dominantly found in plants but really uncommon as bacterial metabolites. The epimeric compounds JS8A and B (6-7) were purified by HPLC using a chiral column (a polysaccharide-based immobilizing cellulose to silica gel). Their structures were determined mainly by spectroscopic analysis of NMR and mass data. The absolute configurations were established by time-controlled acetylation followed by the application of the modified Moshers method using MTPA. Moreover, the comparative full genome analysis of the strain JS8 and the producer (CNB-689) of actionflavoside, will be discussed along with their structures. 3. Actinomadurol, an antibacterial norditerpenoid from a rare actinomycete, Actinomadura sp. KC-191 A new secondary metabolite, actinomadurol (13), was isolated along with the known compound JBIR-65 (14) from a rare actinomycete, Actinomadura strain KC 191. The structure of 13 was established as a rare member of the bacterial C-19 norditerpenoid class by NMR data and ECD calculations. The absolute configuration of 14, which was previously reported without stereochemical analysis, was determined by using the modified Moshers method and ECD calculations. Actinomadurol (13) exhibited potent antibacterial activity against pathogenic strains, such as Staphylococcus aureus, Kocuria rhizophila and Proteus hauseri (MIC = 0.39 ~ 0.78 g/mL), whereas JBIR-65 (14) showed no antibacterial activity. 4. Deinococcucins A−D, aminoglycolipids from Deinococcus sp., a gut bacterium of the carpenter ant Camponotus japonicus. Four new aminoglycolipids, deinococcucins A-D (18-21), were discovered from a Deinococcus sp. strain isolated from the gut of queen carpenter ants, Camponotus japonicus. The structures of deinococcucins A-D were elucidated as a combination of N-acetyl glucosamine, 2,3-dihydroxypropanoic acid, and an alkyl amine with a C16 or C17 hydrocarbon chain primarily based on 1D and 2D nuclear magnetic resonance (NMR) and mass spectroscopic data. The exact location of the olefinic double bond in deinococcucins C-D (20-21) was assigned based on the liquid chromatography-mass spectroscopy (LC/MS) data obtained after olefin metathesis. The absolute configurations of the N-acetyl glucosamine and 2,3-dihydroxy moieties were determined through gas chromatography-mass spectroscopy (GC/MS) analysis of authentic samples and phenylglycine methyl ester (PGME)-derivatized products, respectively. Deinococcucins A and C displayed significant induction of quinone reductase in murine Hepa-1c1c7 cells.I. Introduction 1 II. Studies on the secondary metabolites from Streptomyces, Actinomadura, and Deinococcus bacteria 8 1. Suncheonoside A-D, benzothioate glycoside from marine-derived Streptomyces sp 9 1.1. Results and discussion 10 1.2. Experimental section 23 2. JS8 A and B, novel bacterial flavonoid, from Streptomyces sp. associated with white grub Protaetia brevitarsis seulensis 30 2.1. Results and discussion 31 2.2. Experimental section 37 3. Actinomadurol, an antibacterial norditerpenoid from a rare actinomycete, Actinomadura sp. KC- 191 45 3.1. Results and discussion 46 3.2. Experimental section 55 4. Deinococcucins AD, aminoglycolipids from Deinococcus sp., a gut bacterium of the carpenter ant Camponotus japonicus 63 4.1. Results and discussion 64 4.2. Experimental section 73 Ⅲ. Conclusion 82 References 86 Appendix A: NMR spectroscopic data 94 Appendix B: Supporting information 127 Abstract in Korean 136 Publication List 142 Permissions for republication of the published paper in thesis 144Docto

A Study on Beowulf as Christian English Liturature

Christian literature embodying biblical truth into a form of literatures has had a valuable position by securing a great number of works in the Western history, and there are many Christian literatures in modern Korea. Given the fact that there is no department on Christian literature in prestigious universities in Korea, nevertheless, it is necessary to take action to boost the status of Christian literature in Korea. As the circumstance has still existed, many Christian literatures were not analyzed in a point of view of Christianity. The purpose of this thesis, hence, is to analyze Beowulf which is the first Christian English literature with the scope of Christianity, systematizing fundamental theories and history on Christian literature and looking out tasks for it, presenting structuralism designed by Mary Douglas’ anthropological theory and a root of narrative theory as a suitable method of criticism on Christian literature. Christian literature is not a fanatical dogma for faith, a form in literature, and apologetic literature like communism literature but dealing with themes and materials of literature with the scope of Christianity. Thus, ideal Christian literature is to embody the truth of the Bible in order to guide people who indulge sinful behavior to a right way. Considering that Beowulf is the first Christian English literature, we can straightforwardly notice that the work is a literature like the Old Testament to Anglo-Saxon. In the work Christian thought is able to be found widely. On the other hand, Beowulf is a hero poem. A composer of the poem represents not only value system on Christianity but also heroism with weapon, in particular, sword. About as word the composer reveal his intent by compounding words. In Beowulf the sword play a pivotal role in examining identity of warriors and awakening the responsibility of revenge. The last but not least, Beowulf is a men-centered hero poem but the work exposes the roles of women such as Wealh theow, Hygd, Hildeburh, Freawaru, and even themother of Grendel. It was highly hard for them to play a significant role in deciding something essential, but Wealhtheow is exceptionally portrayed in a positive aspect in the work. To be sure, in order to examine these topics thoroughly a couple of methods such as literature survey, inter disciplinary research, historical-systematic approach are used. I enthusiastically hope that this thesis will play an important role in Korea Church that is going through difficulty time by making a contribution to the vitalization of Christian literature in Korea.;기독교 문학은 서구의 문학 역사의 대부분을 차지하며 한국 문학계에도 일부 영향을 주고 있다. 기독교 문학이란 기독교적 관점에서 인생을 묘사하고 삶의 의미를 찾는 문학이라고 할 수 있다. 기독교적 관점이란 희망의 해석학을 가지고, 인간의 인생사와 인류의 역사를 조망하는 것이다. 그리하여 기독교 문학은 선과 악 사이에서 방황하는 인간의 모습을 그리며, 인간 내면의 악과 세상의 악을 매우 심도 있게 묘사하게 된다. 그러면서 동시에 절망의 한 가운데서 피어나는 새 인간과 새 세상의 희망을 제시한다. 단순히 인간의 이성적 능력을 신뢰하는 인문주의 문학과 달리 세상의 악을 현실주의적으로 봄으로써, 기독교적 죄의식을 충분히 반영한 문학이라야 기독교 문학이라고 할 수 있다. 그러나 그 죄의식은 비관주의로 가지 않고 인간과 세상에 대한 긍정으로 가야 한다. 죄의 깊이를 발견하면서 동시에 희망을 말하는 역설이 기독교 문학의 깊이를 더해 준다고 할 수 있을 것이다. 꼭 호교적인 것이 아니더라도 그러한 기독교적 인간관과 세계관이 충분히 반영된 것은 기독교 문학이라 할 수 있을 것이다. 『베오울프』는 최초의 영문학 작품으로서, 이교 신화에서 기독교 문학으로 넘어가는 경계지점을 보여준다는 점에서 중요하다. 하나님을 찬양하고, 카인의 후예를 지적하는 등 그 소재가 기독교적인 모습을 보여주고 있을 뿐 아니라, 특별히 베오울프가 최후에 싸우는 용은 베오울프 내면의 악을 암시하고 있다는 점에서 주목할 만하다. 이는 결국 최후의 적은 인간 내면의 탐심과 교만임을 말해주는 것으로서, 베오울프를 통해 시인은 인간의 약함과 죄의 깊이를 드러내면서 하나님의 은총을 구한다. 결국 자기 자신과 싸우는 베오울프의 모습은 이교적 영웅으로부터 기독교적 영웅으로 전환되는 의식의 변화를 문학적으로 보여준다. 베오울프 연구는 앞으로 한국 문학에 적용되어, 진정한 의미에서 기독교 문학 비평이론을 정립하는데 유용할 것으로 보인다.I. 서론 1 A. 연구목적 3 B. 연구방법 4 C. 연구범위 5 II. 기독교 문학의 본질과 역사 7 A. 기독교 문학의 정의 7 B. 문학의 도덕성 문제와 기독교 문학 15 C. 기독교 문학의 역사 18 III. 기독교 문학으로서의베오울프 27 A. 최초의 기독교 영문학 27 B. 이교 신화에서 기독교 문학으로 34 1. 이교 신화적 요소: 영웅주의와 칼 35 2. 기독교 문학으로의 전환 44 C.『베오울프』의 내면 가치의 변화 48 IV. 결론 60 참고문헌 70 Abstract 7

(The) effects of GaAlAs laser irradiation on osteoblast and osteosarcoma cell proliferation and differentiation in vitro

학위논문(석사) --서울대학교 대학원 :치의학과,2009.2.Maste

Development of Design Technologies for Harbor Structures Based on Open-cell Caissons

한국해양과학기술

Development of Design Technologies for Harbor Structures Based on Open-cell Caissons

한국해양과학기술

환경친화적 항만관리를 위한 지침서 작성

목차 제1장 서 론 1.1. 연구 배경 및 목적 1.1.1. 연구 배경 1.1.2. 연구 목적 1.2. 연구 범위 및 방법 제2장 Working Group 공동연구 2.1. 컨테이너터미널의 효율적 개발을 위한 하역능력 연구 2.1.1. 연구 개요 2.1.2. 동북아 3국의 컨테이너 터미널 하역능력 산정 방식 2.1.3. 해외 주요 항만의 하역능력 2.1.4. 소결 2.1.5. 향후 계획 2.2. 환경 친화적 항만관리 지침 작성 연구 2.2.1. 공동연구 내용 2.2.2. 환경관리 기준 제3장 지원 실적 3.1. 제18차 동북아 항만국장회의의 워킹그룹 회의 3.1.1. 개최 목적 3.1.2. 주요 내용 3.1.3. 지원 내용 3.2. 제18차 동북아 항만국장 회의 3.2.1. 회의 개요 3.2.2. 워킹그룹 회의 3.2.3 제18차 동북아 항만국장회의 3.2.4. 제18차 동북아 항만심포지엄 부록 1. 한중일 컨테이너 터미널 하역능력 국제워크숍 1.1 워크숍 개요 및 일정 1.2 발표자료 부록 2. 환경 친화적 항만관리를 위한 지침서 작성 실무자 회의 2.1 실무자 회의 개요 및 일정 2.2. 발표 자료 부록 3. 제18차 동북아 항만국장회의 3.1 회의 개요 및 일정 3.2 발표 자료한국해양수산개발

Development of Countermeasure Technologies for National Ocean Disasters and Calamities

한국해양과학기술