• Natural Product Sciences
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• 제19권1호
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• pp.8-14
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• 2013

The inhibitory effect and the structure-activity relationships of luteolin and its related derivatives isolated from Taraxacum mongolicum against MAO activities were investigated. The activity-guided isolation of extract from Taraxacum mongolicum led to the isolation of three flavonoids, luteolin, diosmetin, and luteolin-7-glucoside, a polyphenol, chlorogenic acid, a tyrosine and a uridine. The inhibitory activities of luteolin and its related derivatives against MAOs activities are dependent on their molecular structures. The presence of the phenolic hydroxy group at para-position is the active site for MAO-A inhibition as well as of MAO-B. The methoxy group has no potential on MAO-A inhibition. An additional phenolic hydroxy group at the ortho-position alleviates about 4-fold MAO-A inhibitory activity of phenolic hydroxy group at para-position. A carboxylic group seems to be critical for DBH inhibition and has no effects on MAO.

• 대한화학회지
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• 제67권3호
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• pp.181-190
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• 2023

Melanoma is a malignant skin tumor caused by damage to melanocytes that can spread to other organs. Hence, various studies have been conducted on preventing the spread of melanoma. Flavonoid-structured substances such as apigenin and galanzin are effective therapeutic agents for inhibiting the proliferation and metastasis of melanoma. In this study, luteolin, quercetin, and their respective derivatives were synthesized. These compounds inhibited cell proliferation of B16 melanoma cells. These results confirmed that the derivatives of quercetin and luteolin may be useful as therapeutic agents to prevent melanoma metastasis.

• 생약학회지
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• 제48권4호
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• pp.285-288
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• 2017

A lignan and four flavonoid derivatives were isolated from the aerial parts of Panicum dichotomiflorum Michaux (Gramineae) through repeated column chromatography. Their chemical structures were identified as (-)-pinoresinol (1), tricin (2), luteolin (3), luteolin-4'-O-${\beta}$-D-glucopyranosde (4) and luteolin-7-O-${\beta}$-D-glucopyranosde (5), respectively, by spectroscopic analysis. These compounds were isolated for the first time from this plant.

• Journal of Applied Biological Chemistry
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• 제51권2호
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• pp.57-60
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• 2008

Eight compounds, including 2 flavones, luteolin (1) and apigenin (2), 2 flavonols, kaempferol (3) and quercetin (4), and 4 flavonoid glucosides, luteolin-7-O-${\beta}$-D-glucoside (5), apigetrin (6), astragalin (7), and isoquercitrin (8), isolated from the whole herb of Sonchus oleraceus L. were analyzed on the basis of chemical and spectroscopic evidence. This was the first time to report compounds 3, 4, 6, 7 and 8 from the Sonchus oleraceus L. The antioxidant activities of the isolated flavonoids and their glucoside derivatives were evaluated by DPPH free radical-scavenging assay, showing that compounds 1, 3, 4 and 8 exhibited stronger antioxidant activities compared with ${\alpha}$, tocopherol and curcumin. Flavonoids containing more hydroxyl groups exhibited better antioxidant activities. The antioxidant activity of flavonols was superior to their corresponding flavones, and that of aglycone are more potent than their glucoside derivatives.

• Natural Product Sciences
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• 제17권4호
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• pp.367-371
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• 2011

Effects of the extract and fractions from Parasenecio pseudotaimingasa on rat lens aldose reductase (AR) inhibition have been investigated. Among them, the n-BuOH fraction was exhibited good inhibitory potencies ($IC_{50}$ value 1.42 ${\mu}g/ml$). Phytochemical constituents were isolated from the n-BuOH fraction by open column chromatography. Their structures were elucidated as luteolin-7-O-rutinoside (1) and luteolin-7-Oglucoside (2) on the basis of spectroscopic analysis. Compounds 1 and 2 exhibited strong AR inhibitory activity, with $IC_{50}$ values of 2.37 and 1.05 ${\mu}M$, respectively. This is the first report on the isolation of compounds 1 and 2 from P. pseudotaimingasa. These results suggest that P. pseudotaimingasa could be a useful material in the development of a novel AR inhibitory agent against diabetic complications.

• Food Science and Biotechnology
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• 제16권1호
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• pp.71-77
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• 2007

The antioxidant properties of twelve phenolic compounds, including matairesinol 4'-O-$\beta$-D-glucoside, 8'-hydroxyarctigenin 4'-O-$\beta$-D-glucoside, matairesinol, 8'-hydroxyarctigenin, N-feruloylserotonin 5-O-$\beta$-D-glucoside, N-(p-coumaroyl)-serotonin-5-O-$\beta$-D-glucoside, N-feruloylserotonin, N-(p-coumaroyl)serotonin, luteolin 7-O-$\beta$-D-glucoside, luteolin, acacetin 7-O-$\beta$-glucuronide, and acacetin, isolated from defatted safflower (Carthamus tinctorius L.) seeds were evaluated with regard to the DPPH, superoxide and hydroxyl radicals. Additionally, levels of phenolic compounds were determined by HPLC in two cultivars of safflower seeds. Among them, four serotonin derivatives showed potent DPPH ($IC_{50}=10.83-21.75\;{\mu}M$) and hydroxyl ($IC_{50}=75.93-374.63\;{\mu}M$) radical scavenging activities, and their activities were significantly stronger than that of ${\alpha}-tocopherol$. Four flavonoids ($IC_{50}=170.65-275.83\;{\mu}M$) and four lignans ($IC_{50}=114.22-406.10\;{\mu}M$) exhibited significant superoxide and hydroxyl radical scavenging activities, respectively, whereas these compounds contained less activity toward the DPPH and hydroxyl radicals than serotonin derivatives. The levels of serotonin derivatives, lignans and flavonoids in safflower seeds of two cultivars ranged from 49.30 to 260.40, 3.72 to 158.90, and 11.72 to 214.97 mg% (dry base), respectively. Of the two cultivars, 'Cheongsu' had somewthat higher concentrations of phenolic compounds than 'Uisan'. These results suggest that phenolic compounds in safflower seeds may playa role as protective phytochemical antioxidants against reactive oxygen-mediated pathological diseases.

• 한국식생활문화학회지
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• 제9권2호
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• pp.131-136
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• 1994

한국산 씀바귀(Lactuca dentata Makino)의 ethylacetate 추출물에서 6 종류의 flavonoid 성분이 TLC에 의해서 검출 되었으며, 이들은 극성에 따라서 A에서 F가지 명명되었다. 그들 중 주성분으로 생각되는 물질 E를 column chromatography을 이용하여 분리정제 하였다. 물질 E의 녹는 점은 $249.5^{\circ}C-251^{\circ}C$ 로 나타났으며, 그 구조를 밝히기 위하여, 물질 E와 이를 가수분해한 genin에 대한 여러가지 shift reagent에서 UV와 IR분석을 하고 또한 물질 E와 그의 acetyl 유도체에 대한 NMR 분석을 하였으며 물질 E에 결합된 당은 TLC에 의하여 확인하였다. 이와같은 분석 결과에서 물질 E는 luteolin 모핵에 glucose가 결합된 $luteolin-7-0-{\beta}-D-glucoside$로서 확인되었다.

• 식물분류학회지
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• 제41권1호
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• pp.10-15
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• 2011

본 연구에서는 한국산 닭의덩굴속 호장근절 분류군들을 대상으로 개체군 수준에서 flavonoid 분석을 수행하여, 본 절 분류군에서 나타나는 형태변이 양상을 화학적 측면에서 파악하고, 이를 토대로 한반도에 분포하는 본 절 분류군들의 실체 및 한계를 정확히 파악하고자 하였다. 그 결과, 한국산 본 절 3분류군 15개체군의 잎으로부터 19종류의 서로 다른 flavonoid compound가 분리, 동정되었으며, 이들은 flavonol인 quercetin 및 kaempferol 3-O-glycoside들과 flavone인 apigenin및 luteolin C-glycoside들이었다. 이들 compound들 중 한국산 본 절 식물에 분포하는 주요 flavonoid compound는 quercetin 3-O-galactoside 와 quercetin 3-O-glucoside이었다. 본 절 한국산 분류군들은 그 flavonoid 조성에 의해 뚜렷이 구분되는 것으로 밝혀졌으며, 이러한 결과는 기존의 외부 형태학적 연구 결과와 전반적으로 일치하였다. 한편, 잡종으로 추정되는 논산 개체군의 flavonoid 조성은 F. japonica var. japonica, F. forbesii 및 F. sachalinensis와 일부 compound를 공유하는 것으로 나타났다. Fallopia japonica var. japonica의 경우, 염색체수 배수화에 따른 flavonoid 조성의 정성적 차이는 발견할 수 없었으나, 지리적 변이가 일부 나타나는 것으로 밝혀졌다.

• 한국식품저장유통학회지
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• 제18권1호
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• pp.53-58
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• 2011

신선한 울릉도 민들레 뿌리를 70% ethanol로 침지 추출하여 얻어진 추출물을n-hexane, EtOAc, n-BuOH로 순차용매 분획하였다. 이중 상대적으로 높은 pancreatic lipase 저해활성을 나타낸 EtOAc 분획에 대해 Toyopearl 및 $C_{18}$겔을 활용한 column chromatography를 수행하여 5종의 페놀성 화합물을 분리하였다. 각 화합물의 화학구조는 NMR 스펙트럼 데이터 해석 및 표품과의 HPLC 직접 비교를 통하여 3,5-di-O-caffeoylquinic acid, chicoric acid, caffeic acid, protocatechuic aldehyde, luteolin 으로 동정하였다. 이들 화합물중 3,5-di-O-caffeoylquinic acid 는 $IC_{50}$ 값이 $65.1\;{\pm}0.7\; {\mu}M$로 가장 강한 효능을 나타내었으며, 다음으로 tartaric acid의 수산기에 2분자의 caffeic acid가 결합한 chicoric acid 의 IC50 값이 $126.3{\pm}2.3{\mu}M$의 저해능을 나타내었다. 민들레 뿌리의 EtOAc 가용부에에 존재하는 caffeic acid 유도체가 pancreatic lipase 저해활성 물질임을 확인하였으며, 이들 활성은 caffeic acid가 결합한 quinic acid 및 tatrtaric acid 등의 구성화합물에 따라 다름이 시사되었다. 향후 이들 활성물질의 활성 기작에 대한 연구가 필요하며 본 연구결과는 보다 우수한 pancreatic lipase 저해능을 가지는 새로운 선도화합물 발굴을 위한 기초자료로 이용될 수 있을 뿐만 아니라 울릉도에 자생하는 민들레 뿌리의 식물 화학적 성분에 대한 기초자료로 이용될 수 있을 것으로 사료된다.

• Archives of Pharmacal Research
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• 제29권8호
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• pp.617-623
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• 2006

In our ongoing search for bioactive compounds originating from the endemic species in Korea, we found that the hexane and EtOAc fractions of the MeOH extract from the root of Dystaenia takeshimana (Nakai) Kitagawa (Umbelliferae) showed cyclooxygenase-2 (COX-2) and 5- lipoxygenase (5-LOX) dual inhibitory activity by assessing their effects on the production of prostaglandin $D_2\;(PGD_2)$ and leukotriene $C_4\;(LTC_4)$ in mouse bone marrow-derived mast cells. By activity-guided fractionation, five coumarins, viz. psoralen (2), xanthotoxin (3), scopoletin (4), umbelliferone (5), and (+)-marmesin (6), together with ${\beta}-sitosterol$ (1), were isolated from the hexane fraction, and two phenethyl alcohol derivatives, viz. 2-methoxy-2-(4'-hydroxyphenyl)ethanol (7) and 2-hydroxy-2-(4'-hydroxyphenyl)ethanol (8), three flavonoids, viz. apigenin (9), luteolin (10), and cynaroside (11), as well as daucosterol (12) were isolated from the EtOAc fraction using silica gel column chromatography. In addition, D-mannitol (13) was isolated from the BuOH fraction by recrystallization. Two of the coumarins, scopoletin (4) and (+)- marmesin (6), the two phenethyl alcohol derivatives (7, 8) and the three flavonoids (9-11) were isolated for the first time from this plant. Among the compounds isolated from this plant, the five coumarins as well as the three flavonoids showed COX-2/5-LOX dual inhibitory activity. These results suggest that the anti-inflammatory activity of D. takeshimana might in part occur via the inhibition of the generation of eicosanoids.