• 한국식물학회:학술대회논문집
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• 한국식물학회 1998년도 The 12th Symposium on Plant Biotechnology Vol.12
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• pp.79-82
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• 1998

White and blue/white varieties of Torenia hybrida cv. Summerwave (SWB) were successfully obtained from the blue variety of by cosuppressing gene expression of two of the enzymes involved in anthocyanin biosynthesis; chalcone synthase (CHS) and dihydroflavonol 4-reductase (DFR). Such molecular brceding is the only precise and efficient way to widen the flower color variation of SWB due to its male and female sterility. Flower color and the degree of suppression varies depending on the transgenic lines. The dorsal and ventral petal lobes and corolla tube consistently lose anthocyanins prior to lateral petal lobes. A pink variety was also obtained by cosuppressing the flavonoid 3`5`-hydroxylase (F3`5`H) gene. Yellow torenia was obtained from T-33, an in-house cultivar that contained both carotenoids and anthocyanins, by blockage of anthocyanin biosynthesis with cosuppressing CHS or DFR genes.

• 한국육종학회지
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• 제40권4호
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• pp.422-429
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• 2008

본 실험에서 Lilium longiflorum과 11품종에 대한 biochemical, enzymology 등의 분석방법을 적용하여, 화색생합성조절유전자 chalcone synthase(CHS), flavanone 3-hydroxylase(FHT)의 활성을 분석한 결과는 다음과 같다. 1. Flavonoid의 기본골격형성을 위한 첫 효소인 CHS가 malonyl-CoA와 p-coumaroyl-CoA 기질을 촉매하여 naringenin(NAR) 산물을 생성하였고, caffeoyl-CoA와 p-coumaroyl-CoA 기질에는 eridictiol(ERI)를 생성하지 않아, 백합의 CHS는 기질특이성을 나타냈다. 2. L. longiflorum에서 FHT 효소는 NAR를 기질로써 사용하여, dihydrokaempferol(DHK) 산물을 생성하였고, 그 외 11백합품종에서도 FHT 효소의 뚜렷한 활성이 확인되었다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권15호
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• pp.6317-6325
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• 2015

Ginkgo biloba extract (GBE) is a popular phytomedicine and has been used for disorders of the central nervous system, cardiovascular, renal, respiratory, and circulatory diseases. Although GBE is a complex mixture of over 300 compounds, its major components are 24% flavonoids and 6% terpene lactones. In this study, we tested the inhibitory effects of the three major flavonoids (kaempferol, quercetin, and isorhamnetin) from GBE, independently and as mixtures, on aromatase activity using JEG-3 cells (human placental cells) and recombinant proteins (human placental microsome). In both systems, kaempferol showed the strongest inhibitory effects among the three flavonoids; the flavanoid mixtures exerted increased inhibitory effects. The results of exon I.1-driven luciferase reporter gene assays supported the increased inhibitory effects of flavonoid mixtures, accompanied by suppression of estrogen biosynthesis. In the RT-PCR analysis, decreased patterns of aromatase promoter I.1 mRNA expressions were observed, which were similar to the aromatase inhibition patterns of flavonoids and their mixtures. The present study demonstrated that three flavonoids synergistically inhibit estrogen biosynthesis through aromatase inhibition, decrease CYP19 mRNA, and induce transcriptional suppression. Our results support the usefulness of flavonoids in adjuvant therapy for breast cancer by reducing estrogen levels with reduced adverse effects due to estrogen depletion.

• Journal of Applied Biological Chemistry
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• 제62권1호
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• pp.1-6
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• 2019

Flavonoid인 isokaempferide는 간 보호, 항균, 항증식성, 항염 등 다양한 생리활성을 가지는 것을 보고 되고 있으며 Amburana cearensis와 Cirsium rivulare (Jacq.)과 같은 식물에서 추출하여 사용한다. 생물전환은 비교적 값이 싼 물질로부터 고부가가치 물질을 얻기 위한 방법으로 유용물질의 식물추출법을 대체할 수 있는 방법이다. Naringenin으로부터 isokaempferide를 생합성 하기 위해 대장균에 포플러에서 분리한 PFLS와 벼에서 분리한 ROMT-9 유전자를 도입하였다. 이 균주를 이용하여 naringenin으로부터 isokaempferide의 생합성 수율(9.8 mg/L)은 낮았다. Isokaempferide의 생합성 수율을 높이기 위해 S-adenosylmethionine (SAM) 생합성 경로의 transcriptional regulator인 MetJ를 제거함으로써 methyl donor로 사용되는 SAM을 증가시켰다. SAM생합성 대사를 조절한 대장균을 이용하여 생물전환 균주의 최적 세포밀도 및 최적의 기질공급 농도를 결정하였다. 최적화된 조건을 이용하여 isokaempferide의 생합성은 87 mg/L까지 증가하였다.

• Journal of Microbiology and Biotechnology
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• 제34권5호
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• pp.1154-1163
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• 2024

Glucosylation is a well-known approach to improve the solubility, pharmacological, and biological properties of flavonoids, making flavonoid glucosides a target for large-scale biosynthesis. However, the low yield of products coupled with the requirement of expensive UDP-sugars limits the application of enzymatic systems for large-scale. C. glutamicum is a Gram-positive and generally regarded as safe (GRAS) bacteria frequently employed for the large-scale production of amino acids and biofuels. Due to the versatility of its cell factory system and its non-endotoxin producing properties, it has become an attractive system for the industrial-scale biosynthesis of alternate products. Here, we explored the cell factory of C. glutamicum for efficient glucosylation of flavonoids using apigenin as a model flavonoid, with the heterologous expression of a promiscuous glycosyltransferase, YdhE from Bacillus licheniformis and the endogenous overexpression of C. glutamicum genes galU1 encoding UDP-glucose pyrophosphorylase and pgm encoding phosphoglucomutase involved in the synthesis of UDP-glucose to create a C. glutamicum cell factory system capable of efficiently glucosylation apigenin with a high yield of glucosides production. Consequently, the production of various apigenin glucosides was controlled under different temperatures yielding almost 4.2 mM of APG1(apigenin-4'-O-β-glucoside) at 25℃, and 0.6 mM of APG2 (apigenin-7-O-β-glucoside), 1.7 mM of APG3 (apigenin-4',7-O-β-diglucoside) and 2.1 mM of APG4 (apigenin- 4',5-O-β-diglucoside) after 40 h of incubation with the supplementation of 5 mM of apigenin and 37℃. The cost-effective developed system could be used to modify a wide range of plant secondary metabolites with increased pharmacokinetic activities on a large scale without the use of expensive UDP-sugars.

• Molecules and Cells
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• 제25권2호
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• pp.312-316
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• 2008

Flavanone $3{\beta}$-hydroxylases (F3H) are key enzymes in the synthesis of flavonol and anthocyanin. In this study, three F3H cDNAs from Oryza sativa (OsF3H-1 ~3) were cloned by RT-PCR and expressed in E. coli as gluthatione S-transferase (GST) fusion proteins. The purified recombinant OsF3Hs used flavanone, naringenin and eriodictyol as substrates. The reaction products with naringen and eriodictyol were determined by nuclear magnetic resonance spectroscopy to be dihydrokaempferol and taxifolin, respectively. OsF3H-1 had the highest enzymatic activity whereas the overall expression of OsF3H-2 was highest in all tissues except seeds. Flavanone $3{\beta}$-hydroxylase could be a useful target for flavonoid metabolic engineering in rice.

• KSBB Journal
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• 제26권2호
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• pp.93-99
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• 2011

Glycosylation is a key mechanism in determining diversity of natural products, and influencing their bioactivities. This approach requires a core set of glycosyltransferase that synthesizes the diverse sugar structures observed in nature. Recently, the researchers have begun to alter the sugar moiety and glycosylation patterns of natural products both in vivo E. coli system and in vitro for their glycodiversification. This review highlights new glycosylation tools using microbialproduced deoxysugar and a flexible glycosyltransferase on natural plant-flavonoids to generate novel glycoforms with useful biological activity.

• 생약학회지
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• 제29권2호
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• pp.75-78
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• 1998

In the course of phytochemical studies for the aerial parts of Ajuga multiflora, one flavonoid and two iridoid glycosides were isolated and identified as apigenin (1), 8-O-acetylharpagide (2) and harpagide (3) on the basis of spectroscopic evidence.

• 한국약용작물학회:학술대회논문집
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• 한국약용작물학회 2010년도 심포지엄 및 추계학술발표회
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• pp.386-387
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• 2010

• 화훼연구
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• 제17권4호
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• pp.308-315
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• 2009

본 실험에서 Lilium longiflorum 과 11 나리품종에 대한 생화학적, 효소학적 방법을 적용하여, 화색생합성조절 유전자 flavonoid 3'hydroxylase(F3'H)와 dihydroflavonol 4-reductase(DFR)의 활성을 분석한 결과는 다음과 같다. L. longiflorum에서 F3'H가 dihydrokaempferol(DHK) 기질을 촉매하여 dihydroquercetin(DHQ) 산물을 생성하였고, 그 외 실험에 사용한 모든 8품종에서도 F3'H 활성이 확인되었다. 나리의 F3'H는 기질특이성이 있어 naringenin(NAR)에서는 eridictiol(ERI)를 생성하지 않았다. L. longiflorum에서 DFR은 DHQ를 기질로 사용하여, leucocyanidin(LCy) 산물을 생성하였고 'Montreux', 'Monte Negro', 'Star Gazer', 'Acapulco', 'Etude', 'Le Reve'품종에서도 DFR의 활성이 나타났다. 또한 'Siberia', 'Royal Race', 'Nove Cento', 'Elite', 'Cannes' 품종에서는 DFR의 활성이 나타나지 않았다. 나리의 DFR는 기질특이성이 있어 DHK에서는 leucopelargonidin(LPg)를 생성하지 않았다.