• Proceedings of the Ginseng society Conference
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• 1990.06a
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• pp.49-57
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• 1990

It has been well known that extended exposure to reactive oxygens causes severe damage to susceptible biomolecules. In this study, the effects of flavonoids including trifling and kaempferol from Ginseng leaves on single oxygen induced photohemolysis of erythrocytes and free radical scavenging activities were investigated . Each flavonoid aglycone (5-50UM) such as kaempferol, quercetin or baicalein exhibited a high protective effect against the photohemolysis. They protected the cells by scavenging 102 and free radicals. Although the free radical scavenging activities of the flavonoid glycosides were not much lower than those of their corresponding aglycones, their insolubility into lipid bilayers of membrane made them less effective in preventing the photohemolysis induced by 1O2. The 102 and free radical scavenging activities of flavonoids were estimated by the decomposition of the flavonoid by 1O2 and the bleaching of free radicals by the flavonoid, respectively. The solubilization of the flavonoid into micelle or erythrocytes was deduced from spectrophotometric and microscopic observations. The cooperation of L-ascorbic acid and a flavonoid, and a possible involvement of lipoxygenase or cyclooxygenase in the photohemolysis mechanism were discussed. Keywords Panax ginseng C.A Meyer, ginseng leaves, flavonoids, singe1 oxygen, Photohemolysis.

• Food Science and Preservation
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• v.6 no.1
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• pp.121-135
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• 1999

Effective synthetic antioxidants such as butylated hydroxyanisole(BHA) and butylated hydroxytoluene(BHT) have been widely used in the food industry, but they are suspected to be toxic and carcinogenic effects. Therefore, the development of safely available natural antioxidants such as ascorbic acid, ${\alpha}$-tocopherol, ${\beta}$-carotene, flavonoids and selenium is essential. In particular, flavonoids, 2-phenyl-benzo-${\alpha}$-pyrones, are polyphenolic compounds that occur ubiquitously in food of plant origin. flavonoids occur in foods generally as O-glycosides with sugars bound usually at the C\ulcorner position. And variations in their heterocyclic ring gibes rise to flavones, flavonols, flavanones, flavanols, catechins, anthocyanidins, chalcone and isoflavones. Vegetables, fruits, and beverages are the main dietary sources of the flavonols, primarily as quercetin, kaempferol, and myricetin and the corresponding flavones, apigenin and luteolin. These flavonoids have biological activity such as antioxidant, anti-inflammatory, antithrombotic, antimutagenic, anticarcimogenic antiallergic and antimicrobial activity effects in vitro and in vivo. Flavonoids posses strong antioxidant activities acting as oxygen radicals scavenger, metal chelators and enzyme inhibitor. The antioxidant activity of flavonoids is determined by their molecular structure and more specially, by the position and degree of hydroxylation of the ring structure. All flavonoids with the 3`, 4`-dihydroxy(ortho-dihydroxy) posses marked antioxidant activity. And antioxidant activity increases with the number of hydroxyl groups substituted on the A-and B-rings. There is as yet no certainty about the effect of the presence of a double bond between C\ulcorner and C\ulcorner on the antioxidant activity of flavonoids.

• Journal of Ginseng Research
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• v.14 no.2
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• pp.191-199
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• 1990

It has been well known that extended exposure to reactive oxygens causes severe damage to susceptible biomolecules. In this study, the effects of flavonoids including trifolin and kaempferol from Ginseng leaves on singlet oxygen induced photohemolysis of erythrocytes and free radical scavenging activities were investigated. Each flavonoid aglycone (5-50$\mu$M) such as kaempferol, quercetin or baicalein exhibited a high protective effect against the photohemolysis. They protected the cells by scavenging $^1O_2$ and free radicals Although the free radical scavenging activities of the flavonoid glycosides were not much lower than those of their corresponding aglycones, their insolubility into lipid bilayers of membrane made them less effective in preventing the photohemolysis induced by $^1O_2$. The $^1O_2$ and free radical scavenging activities of flavonoids were estimated by the decomposition of the flavonoid by $^1O_2$ and the bleaching of free radicals by the flavonoid, respectively. The solubilization of the flavonoid into micells or erythrocytes was deduced from spectrophotometric and microscopic observations. The cooperation of L-ascorbic acid and a flavonoid, and a possible involvement of lipoxygenase or cyclooxygenase in the photohemolysis mechanism were discussed.

• Archives of Pharmacal Research
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• v.29 no.12
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• pp.1086-1090
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• 2006

The chromatographic separation of the MeOH extract from the twigs of Acer tegmentosum led to the isolation of ten phenolic compounds. The structures of these compounds were determined using spectroscopic methods as 3,7,3',4'-tetramethyl-quercetin (1), 5,3'-dihydroxy-3,7,4'-trimethoxy flavone (2), 2,6-dimethoxy-p-hydroquinone (3), (-)-catechin (4), morin-3-O-${\alpha}$-L-lyxoside (5), p-hydroxy phenylethyl-O-${\beta}$-D-glucopyranoside (6), 3,5-dimethoxy-4-hydroxy phenyl-1-O-${\beta}$-D-glucoside (7), fraxin (8), 3,5-dimethoxy-benzyl alcohol 4-O-${\beta}$-D-glucopyranoside (9) and 4-(2,3-dihydroxy propyl)-2,6-dimethoxy phenyl ${\beta}$-D-glucopyranoside (10). The compounds were examined for their cytotoxic activity against five cancer cell lines. Compound 3 exhibited good cytotoxic activity against five human cancer cell lines with $ED_{50}$ values ranging from $1.32\;to\;3.85\;{\mu}M$.

• Korean Journal of Plant Resources
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• v.24 no.4
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• pp.461-471
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• 2011

This study was carried out to establish an in vitro culture method of callus having a high antioxidant activity from Ginkgo biloba L. Leaf explants were cultured on Murashige and Skoog's medium supplemented with various growth regulators. The explants were incubated in the dark or 3,000 lux cool-white light. Methanol extracts from incubated callus were evaluated for scavenging activity of the free radicals using DPPH. The best callus growth rate was achieved in MS medium combined with 10 ${\mu}M$ NAA and 5 ${\mu}M$ kinetin in the light condition. Total antioxidant activity of cell aggregates in suspension culture [MS medium supplemented with 10 ${\mu}M$ NAA in the light] was up to 80% of ascorbic acid. By means of HPLC analysis, quantification of the quercetin dehydrate and keamperol profiles from suspension callus was compared. Contents of quercetin dehydrate and keamperol from leaf extracts were 0.07 and 2.24 ${\mu}g/20{\mu}l$, and those from callus 0.56 and 0.18 ${\mu}g/20{\mu}l$, respectively.

• Korean Journal of Food Science and Technology
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• v.53 no.1
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• pp.40-45
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• 2021

Prior studies of physiologically active substances in grapes have focused only on the fruit, pericarp, and branches, as well as the pulp and seeds. The present study assessed the changes in quercetin-3-O-glucuronide (Q3OG) and flavonol glycoside content using grape leaves from Vitis labruscana B. and V. coignetiae at different growth stages and provided basic data for quality control. Content analysis showed that both varieties differed in Q3OG and flavonol glycoside content by growth stage, and the components were found to be high in the order of fruit, maturation, and coloration. Also, Vitis labruscana B. has a better vascular relaxation effect than Vitis coignetiae. These results suggest that in the use of grape leaves as a functional raw material, Q3OG and flavonol glycosides can be used as indicator components. In addition, if raw materials for each growth stage are mixed in a particular ratio, it will be a way to manage the specific efficacy and content of indicator components.

• Applied Biological Chemistry
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• v.51 no.4
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• pp.309-315
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• 2008

The methanol extract from the aerial parts of Aceriphyllum rossii was fractionated into ethyl acetate, n-BuOH and $H_2O$ layers through solvent fractionation. Repeated silica gel column chromatography of EtOAc and n-BuOH layers afforded five flavonol glycosides. They were identified as astragalin (1), kaempferol 3-O-${\alpha}$-L-rhamnopyranosyl (1${\rightarrow}$6)-${\beta}$-D-glucopyranoside (2), rutin (3), kaempferol 3-O-${\alpha}$-L-rhamnopyranosyl (1${\rightarrow}$4)-${\alpha}$-L-rhamnopyranosyl 1${\rightarrow}$6)-${\beta}$-D-glucopyranoside (4), and quercetin 3-O-${\alpha}$-L-rhamnopyranosyl (1${\rightarrow}$4)-${\alpha}$-L-rhamnopyranosyl (1${\rightarrow}$6)-${\beta}$-D-glucopyranoside (5) on the basis of spectroscopic data. All of them showed an inhibition in farnesyl protein tranferase (FPTase) activity, and rutin (3) inhibited the growth of rat H-ras cell and the cell migration of human umbilical vein endothelial cells (HUVECs).

• Korean Journal of Food Science and Technology
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• v.37 no.1
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• pp.78-83
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• 2005

Recently, much attention has been focused on plant antioxidants, because they are expected to protect against oxidative damage, possibly preserving biological functions of cells. Antioxidant compounds were isolated from Angelica keiskei through extraction with 80% EtOH, and fractionations were carried out sequentially with n-hexane, chloroform, ethyl acetate, n-butanol, and water. Two active compounds were isolated from ethyl acetate fraction by silica gel column chromatography, and were identified as isoquercitrin ($quercetin-3-O-{\beta}-D-glucose$) and hyperoside ($quercetin-3-O-{\beta}-D-glucose$). Isoquercitrin and hyperoside showed strong antioxidative potency, as revealed by evaluation of their ABTS, DPPH, OH, and $H_{2}O_{2}$ radical-scavenging activities, and ex vivo DNA damage-protecting effects.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2022.09a
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• pp.25-25
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• 2022

피부 노화는 피부와 피부 지지층 등의 광범위한 퇴행 과정을 말한다. 피부 노화의 원인은 흡연, 공해, 스트레스 등이 있지만, 그 중에서도 자외선(ultra violet, UV) 조사가 가장 큰 요인으로 꼽힌다. 반복적인 자외선 조사에 의해 진행되는 피부노화를 광노화라고 하며 그 가장 큰 특징으로는 콜라겐 섬유와 엘라스틴의 감소로 야기되는 주름을 들 수 있다. 본 연구에서는 제주에서 채집한 바위수국의 추출물 및 분획물의 항산화 및 자외선으로 인한 피부노화 예방(anti-photoaging) 효능을 확인하고, 활성물질을 분리하여 광노화 예방 효능과 그 메커니즘을 확인하였다. 실험에 사용된 바위수국은 범의귀과의 덩굴성 식물로 바위면이나 나무줄기 등에 붙어서 자라며, 한국(제주, 울릉도)과 일본에 분포한다. 바위수국 추출물과 분획물에서 총 페놀 함량. 총 플라보이드 함량, DPPH 및 ABTS 라디칼소거 활성의 항산화 실험 결과, 부탄올과 에틸아세테이트 분획층에서 강력한 항산화 활성이 관찰되었다. 또한 UVA를 조사한 인간 진피 섬유아세포 (human dermal fibroblast, HDF)데 대한 콜라겐 분해효소인 matrix metalloproteinase-1(MMP-1) 생성 억제 활성을 확인한 결과, 부탄올 분획층이 세포 생장 저해 없이 가장 우수한 효능이 확인되었다. 따라서 부탄올 분획층에서 주요 성분 분리 실험을 수행하여 총 4개의 화합물을 분리하였다; Chlorogenic acid (1), Quercetin-3-O-glucosyl-(1-2)-rhamnoside (2), Quercetin-3-O-xylosyl-(1-2)-rhamnoside (3), Quercitrin (4). 분리한 4개의 물질의 MMP-1 생성 억제 활성을 비교한 결과 화합물 2가 세포독성 없이 MMP-1 생성 억제 효능이 우수하였고, 이후 화합물 2의 광노화 예방 효능과 그 메커니즘을 확인하였다. 화합물 2는 MMP-1의 생성을 억제할 뿐만 아니라 procollagen type I의 생성을 증가시켰으며, MMP-1 생성에 관여하는 mitogen-activated protein kinase (MAPK)/activator protein-1 (AP-1) 신호전달경로를 하향 조절하며, 콜라겐 생성과 관련된 Transforming growth factor-β (TGF-β)/Smad 신호전달경로를 상향 조절하여 UVA에 의한 광노화 예방에 효능을 나타내었다. 이러한 결과들을 바탕으로, 바위수국은 항노화(anti-aging) 기능성 화장품 및 이너뷰티 기능성 식품 소재로 개발이 가능할 것으로 기대된다.

• Molecules and Cells
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• v.25 no.3
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• pp.368-375
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• 2008

Approximately 120 UDP-glycosyltransferases (UGTs), which are classified into 14 distinct groups (A to N), have been annotated in the Arabidopsis genome. UGTs catalyze the transfer of sugars to various acceptor molecules including flavonoids. Previously, UGT71C1 was shown to glycosylate the 3-OH of hydroxycinnamates and flavonoids in vitro. Such secondary metabolites are known to play important roles in plant growth and development. To help define the role of UGT71C1 in planta, we investigated its expression patterns, and isolated and characterized a loss-of-function mutation in the UGT71C1 gene (named ugt71c1-1). Our analyses by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR), microarray data mining, and histochemical detection of GUS activity driven by the UGT71C1 promoter region, revealed the tissue-specific expression patterns of UGT71C1 with highest expression in roots. Interestingly, upon treatment with methyl viologen (MV, paraquat), ugt71c1-1 plants displayed enhanced resistance to oxidative stress, and ROS scavenging activity was higher than normal. Metabolite profiling revealed that the levels of two major glycosides of quercetin and kaempferol were reduced in ugt71c1-1 plants. In addition, when exposed to MV-induced oxidative stress, eight representative ROS response genes were expressed at lower levels in ugt71c1-1 plants, indicating that ugt71c1-1 probably has higher non-enzymatic antioxidant activity. Taken together, our results indicate that ugt71c1-1 has increased resistance to oxidative stress, suggesting that UGT71C1 plays a role in some glycosylation pathways affecting secondary metabolites such as flavonoids in response to oxidative stress.