• 대한한의학방제학회지
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• 제18권2호
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• pp.241-249
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• 2010

The Geranium nepalense has been used traditionally for treatment of various diseases. However, the molecular studies on the effect of Geranium nepalense have not been carried out. In the present study, Quercetin, quercitrin, and afzelin were isolated from the methanol extract of Geranium nepalense were tested for their anti-inflammatory effect. The anti-inflammatory effect of the compounds was studied in lipopolysaccharide(lps)-treated mouse macrophage cells, RAW 264.7. RAW 264.7 cells were pre-incubated with isolated compounds(0, 5, 10, 20, 40, $50\;{\mu}g/ml$) for 4h and treated with $1\;{\mu}g/ml$ lps for 18h, and then the anti-inflammatory effects of compounds were determined. The results are as follows: Quercetin at various concentration inhibited the viability of Raw 264.7 from 7% to 45%, quercitrin from 25% to 80%, and afzelin from 13% to 52%. Isolated compounds showed a significant decrease in iNOS (inducible nitric oxide synthase) and COX-2 (cyclooxygenase-2). These results suggest that these compounds can be used as stable anti-inflammatory materials.

• 약학회지
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• 제40권2호
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• pp.170-176
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• 1996

A chemical examination of the aerial parts of Euphorbia pekinensis $R_{UPRECHT}$. (Euphorbiaceae) has led to the isolation of seven hydrolyzable tannins and ten fl avonoid glycosides. The former ones have been identified as gallic acid, methylgallate, 3-O-galloyl shikimic acid, 1,3,4,6-tetra-O-galloyl-${\beta}-_D$-glucose, 1,2,3,4,6-penta-O-galloyl-${\beta}-_D$-glucose, corilagin, geraniin and the latter ones as isoquercitrin, quercitrin, astragalin, afzelin, prunin, rutin, kaempferol-3-O-rutinoside, quercetin-3-O-(2"-O-galloyl)-${\beta}-_D$-glucoside and quercetin-3-O-(2"-O-galloyl)-${\alpha}-_L$-rhamnoside on the basis of chemical and spectroscopic evidence.

• 한국산림과학회지
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• 제96권4호
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• pp.408-413
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• 2007

굴피나무 수피를 채취하여 건조시킨 후 분말로 제조하여 95% EtOH로 추출하고 여기서 얻어진 EtOH 조추출물의 하나는 헥산(n-hexane), 디클로로메탄($CH_2Cl_2$)으로, 또 하나는 석유에테르(petroleumether), 디에틸에테르($Et_2O$) 및 에틸아세테이트(EtOAc)를 사용하여 순차적으로 분획하였다. 이중 디클로로메탄($CH_2Cl_2$) 가용부(6.0 g)는 EtOH-$CHCl_3$ (7:3, v/v)를 용출용매로 한 Sephadex LH-20 칼럼($72.0{\times}5.0cm$)을 사용한 칼럼크로마토그래피를 실시하였다. 또한 디에틸에테르($Et_2O$) 가용부는 $CHCl_3$-MeOH (9:3, v/v)을 용출용매로 한 silica gel 칼럼($42.0{\times}3.5cm$)을 사용하여 칼럼크로마토그래피를 실시하였다. 단리된 화합물들은 TLC로 확인한 후 $^1H$-, $^{13}C$-NMR, HMBC 등의 스펙트럼을 사용하여 화학구조를 규명하였고 EI-MS로써 분자량을 측정하였다. 추출물로부터 3, 3', 4', 5, 7-pentahydroxyflavone (quercetin), 3, 3', 4', 5, 5', 7-hexahydroxyflavone (myricetin), flavonoids 배당체인 kaempferol-3-O-${\alpha}$-L-rhamnopyranoside (afzelin), quercetin-3-O-${\alpha}$-L-rhamnopyranoside (quercitrin), myricetin-3-O-${\alpha}$-L-rhamnopyranoside (myricitrin)등을 단리할 수 있었다.

• 생약학회지
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• 제37권3호
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• pp.177-183
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• 2006

Six compounds were isolated from EtOAc soluble fraction of the leaves of Rhododenderon schlipenbachii. On the basis of spectral data, they were identified as quercetin (1), juglanin (2), avicularin (3), quercitrin (4), afzelin (5), and hirsutrin (6), respectively.

• Natural Product Sciences
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• 제7권1호
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• pp.23-26
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• 2001

Five flavonoids and one aromatic acid were isolated from the leaves of Zanthoxylum piperitum. The structures of compounds were elucidated as quercetin, afzelin, quercitrin, hyperoside, hesperidin and protocatechuic acid on the basis of spectral evidence.

• Natural Product Sciences
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• 제5권2호
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• pp.80-84
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• 1999

Peroxynitrite is a cytotoxic intermediate produced by the reaction between the superoxide anion radical and nitric oxide. Flavonoids (afzelin, quercitrin and quercetin 3-O-sambubioside), and chlorogenic acid and its methyl ester obtained from leaves of loquat (Eriobotrya japonica) have recently been shown to scavenge 1,1-diphenyl-2-picrylhydrazyl radical and to inhibit lipid peroxidation in mouse liver homogenate. The aim of this study is to investigate the inhibitory effects of the above components on peroxynitrite produced stimulated by 3-morpholinosydnonimine (SIN-1) to produce superoxide anion radical and nitric oxide at the same time. In addition, the present study tests whether or not the components directly scavenge peroxynitrite itself. The results showed that the components with the aromatic ortho-dihydroxyl groups (catechol) were more potent inhibitors of peroxynitrite formation by SIN-1. In particular, the methyl ester form of chlorogenic acid showed the most potent inhibition. At $5\;{\mu}M$ concentration, the order of minimizing peroxynitrite formation were : methyl chlorogenic acid > quercitrin > quercetin 3-O-sambubioside > chlorogenic acid > afzelin. Authentic peroxynitrite was directly scavenged by the components in a manner similar to peroxynitrite formation by SIN-1. In particular, when compared with penicillamine as a positive control, methyl chlorogenate was as effective in inhibiting peroxynitrite formation and approximately 2 times more effective in scavenging an authentic peroxynitrite. These results demonstrate therefore, that components extracted from the leaves of Eriobotrya japonica effectively scavenged peroxynitrite.

• Journal of the Korean Wood Science and Technology
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• 제34권6호
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• pp.72-80
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• 2006

일본잎갈나무 낙엽(8.5 kg)을 채취하여 95% 에탄올 용액으로 추출하고 농축한 후 분획깔때기로 헥산, 메틸렌클로라이드, 에틸아세테이트 및 수용성으로 순차 추출하여 동결건조하였다. 에틸아세테이트용성과 수용성 분획에 대하여 칼럼크로마토그래피를 실시하였고, 충진물질로는 Sephadex LH-20을, 용리용매로는 메탄올 수용액 및 에탄올-헥산 혼합용액을 사용하였다. 단리된 화합물들은 TLC로 확인한 후 NMR 스펙트럼을 사용하여 구조규명을 하였고 FAB-MS와 EI-MS 스펙트럼으로 분자량을 측정하여 7개의 flavonoid 화합물인 (+)-catechin, (-)-epicatechin, 2"-O-rhamnosylvitexin, juglanin, afzelin, laricitrin-3-O-${\beta}$-D-glucopyranoside 및 isoquercitrin과 neolignan 화합물인 cedrusin을 단리하였다.

• Journal of Applied Biological Chemistry
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• 제56권4호
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• pp.213-217
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• 2013

Phytochemical studies on the leaves of Ailanthus altissima (Simaroubaceae) have not been reported previously. Thus, the authors isolated and identified secondary metabolites from A. altissima. Dried and powdered leaves were extracted with 80% aqueous methanol, and the concentrated extract was successively partitioned with ethyl acetate, n-butanol, and water. Four flavonoids were isolated from the ethyl acetate fraction through repeated silica gel and octadecyl silica gel column chromatography. Spectroscopic data including NMR, MS, and IR allowed for identification of the chemical structures as quercetin (1), afzelin (2), quercitrin (3), and isoquercitrin (4). This is the first report of the isolation of these compounds from A. altissima. The four isolated flavonoids 1-4 as well as solvent fractions (ethyl acetate, n-butanol, and water), were evaluated for DPPH radical scavenging activity.

• 농업과학연구
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• 제45권4호
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• pp.761-767
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• 2018

Degenerative diseases are commonly associated with excess free radicals. Acer okamotoanum, a plant endemic to Korea, is reported to have anti-oxidant, anti-cancer, and anti-viral activities. We previously isolated flavonoids from the ethyl acetate fraction of A. okamotoanum such as quercitrin (QU), isoquercitrin (IQ), and afzelin (AF). In the present study, the in vitro antioxidant activity of flavonoids such as QU, IQ, and AF isolated from the ethyl acetate fraction of A. okamotoanum were investigated by measuring the free radical scavenging activity including 1,1-diphenyl-2-picrylhydrazyl (DPPH), hydroxyl radical ($^{\cdot}OH$), and superoxide anion ($O_2{^-}$). The flavonoids (QU, IQ, and AF) concentration-dependently showed a DPPH radical scavenging activity. In particular, QU and IQ showed a higher DPPH radical scavenging activity than that of AF. In addition, the flavonoids (QU, IQ, and AF) at $10{\mu}g/mL$ showed over an 80% scavenging effect against $^{\cdot}OH$ radical production. Furthermore, the $O_2{^-}$ radical scavenging activity of the flavonoids, QU, IQ, and AF increased in a dose-dependent manner. Particularly, IQ exerted the strongest scavenging activities against $^{\cdot}OH$ and $O_2{^-}$ radicals among the other flavonoids. These results indicate that the flavonoids from A. okamotoanum, in particular IQ, would have a protective activity against oxidative stress induced by free radicals, and potentially be considered as a natural antioxidant agent.

• 농업과학연구
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• 제49권2호
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• pp.227-237
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• 2022

Amyloid beta (Aβ) is produced from an amyloid precursor protein by the activation of the amyloidogenic pathway, and it is widely known to cause Alzheimer's disease (AD). In this study, we investigated the neuroprotective effects of three flavonoids, quercitrin, isoquercitrin, and afzelin, from Acer okamotoanum against Aβ-induced neurotoxicity in SH-SY5Y neuronal cells. Aβ_25-35 treatments resulted in decreased cell viability and increased levels of nuclei condensation and fragmentation. However, an isoquercitrin treatment dose-dependently increased cell viability and decreased nuclei condensation and fragmentation levels. SH-SY5Y cells treated with Aβ_25-35 showed increased reactive oxygen species (ROS) production compared to that from cells not treated with Aβ_25-35. However, treatment with the three flavonoids significantly inhibited ROS production compared to an Aβ_25-35-treated control group, indicating that the three flavonoids blocked neuronal oxidative stress. For a closer examination of the neuroprotective mechanisms, we measured the expressions of the non-amyloidogenic pathway-related proteins of a disintegrin and metalloprotease 10 (ADAM10) and the tumor necrosis factor-α converting enzyme (TACE). An isoquercitrin treatment enhanced the expressions of ADAM10 compared to the control group. In addition, the three flavonoids activated the non-amyloidogenic pathway via the upregulation of TACE. In conclusion, we demonstrated neuroprotective effects of three flavonoids from A. okamotoanum, in particular isoquercitrin, on neurotoxicity by the regulation of the non-amyloidogenic pathway in Aβ_25-35-treated SH-SY5Y cells. Therefore, we suggest that flavonoids from A. okamotoanum may have some potential as therapeutics of AD.