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Synthesis and Characterization of Epigallocatechin Gallate Fructosides by using Levansucrase
Levansucrase를 이용한 epigallocatechin gallate (EGCG)의 수친화성 유도체 제조 및 기능성 연구

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dc.contributor.advisor김도만-
dc.contributor.author김시나-
dc.date.accessioned2018-05-29T03:45:31Z-
dc.date.available2019-04-17-
dc.date.issued2018-02-
dc.identifier.other000000149812-
dc.identifier.urihttps://hdl.handle.net/10371/141684-
dc.description학위논문 (석사)-- 서울대학교 대학원 : 국제농업기술대학원 국제농업기술학과, 2018. 2. 김도만.-
dc.description.abstractLevansucrase is one of fructosyltransferases and synthesizes levan, composed of β-(2-6)-linked fructose residues, or inulin, composed of β-(2-1)-liked fructose residues. Levansucrase also catalyzes transfructosylation from sucrose to a variety of acceptors. In this study, I expressed of levansucrase from Leuconostoc mesenteroides 512 in E. coli. The optimum condition for levansucrase expression is 1 mM lactose, 25 µM ampicillin at 33°C. The levansucrase activity was 2.84 U/mg. The production of levansucrase was used to catalyze transfructosylation using sucrose as substrate and pigallocatechin gallate (EGCG), one of the most abundant catechin in green tea, as acceptors. The five novel epigallocatechin gallate fructosis were detected. When compare to EGCG, water solubility of 5'-EGCG-β-D-fructofuranosyl-β-2-6-fructofuranoside was increased 350 mM, which is 64-fold water solubility of EGCG. Also antioxidant activities of EGCG-F2 (SC50, 9.7 μM) are similar to EGCG (SC50, 7.6 μM), and EGCG-F1 (IC50, 173.6 μM) showed higher inhibitory activity against HMA than EGCG-F2 (IC50, 253 μM).-
dc.description.tableofcontentsIntroduction 1
Literature Review 3
Materials and methods 6
2.1.1 Expression of levansucrase M1Ft gene in E. coli 6
2.1.2 Optimization of lactose concentration for induction 6
2.1.3 Levansucrase hydrolytic activity assay 7
2.1.4 Fermentation of levansucrase 7
2.2 EGCG acceptor reaction 8
2.3 Optimization of acceptor reaction using response surface methodology (RSM) 8
2.4 Purification EGCG and EGCG-Fs10 10
2.5 Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis 12
2.6 Nuclear magnetic resonance (NMR) analysis 12
2.7 biological activity of EGCG and EGCG-Fs 12
2.7.1 water solubility analysis 12
2.7.2 Antioxidant activity 13
2.7.3 The human maltase intestinal maltase inhibition assay 14
2.7.4 Browning resistant effect of EGCG and EGCG-Fs 15
Results and discussions16
3.1 Levansucrase was expression in E.coli using lactose induction 16
3.2 Optimization of EGCG-Fs synthesis by RSM 19
3.3 Two novel EGCG-Fs derivatives were identified by NMR 26
3.4 Assessment of the biological activities of EGCG-Fs 32
3.4.1 Water solubility of EGCG and EGCG-Fs 32
3.4.2 Antioxidant activities of EGCG and EGCG-Fs as their concentration 34
3.4.3 Inhibition activity of EGCG and EGCG-Fs against human intestinal maltase (HMA) 36
3.4.4 The browning effect of EGCG and EGCG-Fs 38
Conclusion 40
References 41
Abstract in Korea 44
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dc.formatapplication/pdf-
dc.format.extent1470865 bytes-
dc.format.mediumapplication/pdf-
dc.language.isoen-
dc.publisher서울대학교 대학원-
dc.subjectantioxidant activities-
dc.subjectepigallocatechin gallate-
dc.subjectfructosylation-
dc.subjectlevansucrase.-
dc.subject.ddc631-
dc.titleSynthesis and Characterization of Epigallocatechin Gallate Fructosides by using Levansucrase-
dc.title.alternativeLevansucrase를 이용한 epigallocatechin gallate (EGCG)의 수친화성 유도체 제조 및 기능성 연구-
dc.typeThesis-
dc.contributor.AlternativeAuthorShina Jin-
dc.description.degreeMaster-
dc.contributor.affiliation국제농업기술대학원 국제농업기술학과-
dc.date.awarded2018-02-
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Graduate School of International Agricultural Technology (국제농업기술대학원)Dept. of International Agricultural Technology (국제농업기술학과)Theses (Master's Degree_국제농업기술학과)
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