• Molecules and Cells
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• 제25권2호
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• pp.247-252
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• 2008

There are several branch points in the flavonoid synthesis pathway starting from chalcone. Among them, the hydroxylation of flavanone is a key step leading to flavonol and anthocyanin. The flavanone 3-${\beta}$-hydroxylase (GmF3H) gene was cloned from soybean (Glycine max cultivar Sinpaldal) and shown to convert eriodictyol and naringenin into taxifolin and dihydrokaempferol, respectively. The major flavonoids in this soybean cultivar were found by LC-MS/MS to be kamepferol O-triglycosides and O-diglycosides. Expression of GmF3H and flavonol synthase (GmFLS) was induced by ultraviolet-B (UV-B) irradiation and their expression stimulated accumulation of kaempferol glycones. Thus, GmF3H and GmFLS appear to be key enzymes in the biosynthesis of the UV-protectant, kaempferol.

• 한국식품과학회지
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• 제46권4호
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• pp.511-515
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• 2014

각종 염증성 질환 및 패혈증으로 인한 치명적인 저혈압을 예방치료하는 약물 개발을 위한 기초 연구로서 유도성 NOS (inducible nitric oxide synthase, iNOS) 에 의한 NO의 과다 생성을 저해하는 성분을 천연물로부터 찾아내고자 본 연구를 수행하였다. NO 생성 저해활성의 검정은 대식세포주인 RAW 264.7 세포를 LPS로 활성화한 후, 유도되는 iNOS에 의해 생성되는 NO를 Griess 시약을 이용해 $NO_2{^-}$의 형태로 정량하였다. 또한 Western blot 실험 및 RT-PCR 실험을 시행하여 iNOS의 mRNA의 발현 및 단백 합성에 대한 영향을 조사하였다. 고량강(Alpinia officinarum Hance, Zingiberaceae)의 메탄올 추출물로부터 극성에 따른 용매 분획을 시행하여 활성성분을 분리하고 분광학적 분석법을 이용하여 분리한 단일성분이 flavonol 구조인 3,5,7-trihydroxy-2-phenylchromen-4-one (galangin, GLG)임을 확인하였다. 작용기전을 알아보기 위해, Western blot 및 RT-PCR 실험결과, 분리한 flavonol 성분(GLG)의 NO 생성저해 활성은 iNOS mRNA발현을 저해하여 iNOS 효소 단백질의 생성이 억제됨에 기인하는 것으로 확인하였다. 따라서, 고량강 추출물로부터 분리한 flavonol 화합물(GLG)이 iNOS 발현의 억제를 통해 다량의 NO 생산을 저해함으로써, 고량강(Alpinia officinarum)의 NO 과량생성과 관련된 염증성 질환에 대한 응용 가능성이 클 것으로 기대된다.

• Plant Biotechnology Reports
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• 제5권1호
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• pp.79-88
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• 2011

Vitis vinifera cv. Koshu is a traditional grape cultivar that has been grown for centuries in Japan. The Koshu grape has pink-colored skin and Koshu wines have slight astringency. We demonstrated for the first time the characterization of hydroxycinnamic acids, flavan-3-ols, and flavonoids in Koshu grape using high-performance liquid chromatography and liquid chromatography-mass spectrometry. The gross weight of phenolic compounds excluding anthocyanins and proanthocyanidins in Koshu grape at harvest was higher than those in Sauvignon Blanc, Chardonnay, and Merlot grapes. In addition, hydroxycinnamic acid and monomeric flavonol contents in Koshu grape were also higher than those in the other grape cultivars. Transcription analysis of cinnamic acid 4-hydroxylase, p-coumarate 3-hydroxylase, caffeate methyltransferase, and flavonol synthase genes indicated high accumulation of hydroxycinnamic acids and flavonols in Koshu grape skin compared with the other cultivars. These findings obtained by chemical and molecular approaches partially explained the phenolic characteristics and the peculiar astringency of Koshu grape.

• Journal of Microbiology and Biotechnology
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• 제20권9호
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• pp.1295-1299
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• 2010

Recently, recombinant Streptomyces venezuelae has been established as a heterologous host for microbial production of flavanones and stilbenes, a class of plant-specific polyketides. In the present work, we expanded the applicability of the S. venezuelae system to the production of more diverse plant polyketides including flavones and flavonols. A plasmid with the synthetic codon-optimized flavone synthase I gene from Petroselium crispum was introduced to S. venezuelae DHS2001 bearing a deletion of the native pikromycin polyketide synthase gene, and the resulting strain generated flavones from exogenously fed flavanones. In addition, a recombinant S. venezuelae mutant expressing a codon-optimized flavanone $3{\beta}$-hydroxylase gene from Citrus siensis and a flavonol synthase gene from Citrus unshius also successfully produced flavonols.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 추계학술대회
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• pp.248-248
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• 2017

• Journal of Microbiology and Biotechnology
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• 제30권2호
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• pp.163-171
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• 2020

Brugmansia arborea L. (Solanaceae), commonly known as "angel's trumpet," is widely grown in North America, Africa, Australia, and Asia. It has been mainly used for ornamental purposes as well as analgesic, anti-rheumatic, vulnerary, decongestant, and anti-spasmodic materials. B. arborea is also reported to show anti-cholinergic activity, for which many alkaloids were reported to be principally responsible. However, to the best of our knowledge, a phytochemical study of B. arborea flowers has not yet been performed. Four flavonol glycosides (1-4) and one dihydroflavanol (5) were for the first time isolated from B. arborea flowers in this study. The flavonoids showed significant antioxidant capacities, suppressed nitric oxide production in lipopolysaccharide (LPS)-treated RAW 264.7 cells, and reduced inducible nitric oxide synthase (iNOS) and cyclooxygenase (COX-2) protein production increased by LPS treatment. The contents of compounds 1-4 in n-BuOH fraction were determined to be 3.8 ± 0.9%, 2.2 ± 0.5%, 20.3 ± 1.1%, and 2.3 ± 0.4%, respectively, and that of compound 5 in EtOAc fraction was determined to be 12.7 ± 0.7%, by HPLC experiment. These results suggest that flavonol glycosides (1-4) and dihydroflavanol (5) can serve as index components of B. arborea flowers in standardizing anti-inflammatory materials.

• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.3-8
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• 2005

Torenia hybridacv. Summerwave Blue and Violet mainly produce delphinidin. Down regulation of their flavonoid 3'-hydroxylase and flavonoid 3',5'-hydroxylase (F3'5'H) genes and over expression of rose or pelargonium dihydroflavonol 4-reductase (DFR) cDNA yielded pelargonidin-based bright pink flowers. Nierembergia cv. Fairybells lack pink color as they produced only delphinidin and flavonols. Pelargonidin-based pink flowers were achieved by down regulation of F3'5'H and flavonol synthase genes and over expressing rose DFR cDNA. Introduction of petunia F3'5'H and DFR cDNAs into white carnations deficient in DFR activity produced violet carnations, which arc now commercialized in the USA, Canada, Australia, Europe and Japan. Introduction of pansy F3'5'H and iris DFR cDNAs and down regulation of rose DFR gene produced rose flowers which accumulates delphinidin imparting novel violet color.

• Journal of Applied Biological Chemistry
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• 제64권3호
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• pp.309-316
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• 2021

Trifolin (kaempferol 3-O-galactoside)는 플라보놀 그룹에 속하는 물질로 아토피, 항균, 폐암에 효과가 있는 것으로 알려져 있다. Trifolin은 다양한 식물에서 추출하여 사용하고 있지만 추출 과정이 복잡하고, 수율이 낮으며, 추출을 위한 바이오매스를 얻는데 계절적 어려움이 있다. 생물전환은 저렴한 화합물에서 고부가가치 화학물질을 생산할 수 있는 대체 수단으로 이용된다. 본 연구에서는 naringenin으로부터 trifolin을 생합성하기 위해 3개의 유전자(PeFLS 및 OsUGE-PhUGT)를 각각의 대장균에 도입한 BL-FLS균주와 BL-UGTE균주를 이용하여 공조배양시스템을 개발하였다. Naringenin으로부터 trifolin을 생합성하기 위해 세포의 밀도, 생물전환 온도, 재조합 단백질 유도의 적정 IPTG농도 및 시간, 기질 공급 농도 등의 최적화를 실시하였다. 최적화된 공동 배양 발효 시스템을 통해 67.3 mg/L의 trifolin을 성공적으로 생합성 하였다.

• Archives of Pharmacal Research
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• 제28권3호
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• pp.297-304
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• 2005

Naturally occurring flavonoids are known to modulate various inflammatory and immune processes. Based on structural property, in this study, molecular mechanism of flavonoids in modulating nitric oxide (NO) production and its signaling pathway were investigated using lipopolysaccharide (LPS)-activated RAW264.7 cells. Although flavonol-typed flavonoids (kaempferol and quercetin) more potently scavenged reactivity of nitric oxide ($\cdot$NO) as well as peroxynitrite (ONOO$\kappa$) than isoflavones (genistein and genistin), kaempferol, quercetin and genistein showed a little difference in inhibition of both inducible NO synthase expression and NO production, with IC$_{50}$ values of 13.9, 20.1 and 26.8 $\mu$M. However, there was a striking pattern related to structural feature in modulation of LPS-mediated signaling pathways. Thus, flavonols only inhibited transcription factor AP-1 activation, whereas isoflavones suppressed the DNA binding activation of NF-$\kappa$B and C/EBP$\beta$. Therefore, these data suggest that structural feature may be linked to decide drugs target molecule in LPS-mediated signaling pathways, rather than its potency.

• Molecules and Cells
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• 제26권6호
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• pp.536-547
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• 2008

Anthocyanidin synthase (ANS, leucoanthocyanidin oxygenase), a 2-oxoglutarate iron-dependent oxygenase, catalyzed the penultimate step in the biosynthesis of the anthocyanin class of flavonoids, from the colorless leucoanthocyanidins to the colored anthocyanidins. The full-length cDNA and genomic DNA sequences of ANS gene (designated as GbANS) were isolated from Ginkgo biloba for the first time. The full-length cDNA of GbANS contained a 1062-bp open reading frame (ORF) encoding a 354-amino-acid protein. The genomic DNA analysis showed that GbANS gene had three exons and two introns. The deduced GbANS protein showed high identities to other plant ANSs. The conserved amino acids (H-X-D) ligating ferrous iron and residues (R-X-S) participating in 2-oxoglutarate binding were found in GbANS at the similar positions like other ANSs. Southern blot analysis indicated that GbANS belonged to a multi-gene family. The expression analysis by real-time PCR showed that GbANS expressed in a tissue-specific manner in G. biloba. GbANS was also found to be up-regulated by all of the six tested abiotic stresses, UV-B, abscisic acid, sucrose, salicylic acid, cold and ethylene, consistent with the promoter region analysis of GbANS. The recombinant protein was successfully expressed in E. coli strain with pET-28a vector. The in vitro enzyme activity assay by HPLC indicated that recombinant GbANS protein could catalyze the formation the cyanidin from leucocyanidin and conversion of dihydroquercetin to quercetin, suggesting GbANS is a bifunctional enzyme within the anthocyanidin and flavonol biosynthetic pathway.