• 생약학회지
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• 제27권2호
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• pp.136-141
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• 1996

We have previously reported the isolation of nine hydrolisable tannins and five flavonoids from the aerial parts of Euphorbia ebracteolata. Further investigation about the same plant has led to the isolation of 5-O-caffeoyl quinic acid, kaempferol $3-O-(2'-O-galloyl-{\beta}-_D-glucoside)$ and euphorbin A.

• 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.

• 생약학회지
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• 제27권2호
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• pp.142-145
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• 1996

We have previously reported the isolation of seven hydrolyzable tannins and nine flavonoids from Euphorbia pekinensis Ruprecht. Further investigation about the same plant has led to the isolation of kaempferol, quercetin, kaempferol $3-O-(2'-O-galloyl-{\beta}-_D-glucoside)$, quercetin 3-O-(2'-O-galloylrutinoside), ellagic acid and acetonyl geraniin. These compounds were isolated from this plant for the first time.

• 생약학회지
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• 제27권3호
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• pp.238-245
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• 1996

The activity guided fractionation of $CH_2Cl_2$ soluble part of Platycarya strobilacea leaves(Juglandaceae) has led to the isolation of eight active principles, identified as 5-hydroxy-2-methoxy-1,4-naphthoquinone(1), ursolic acid(2), gallic acid(3), 4,8-dihydroxynaphthalene $1-O-{\beta}-_D-glucoside(4)$, eriodictyol(5), quercetin $3-O-(2'-O-galloyl)-{\beta}-_D-glucoside(6)$. quercetin $3-O-(2'-O-galloyl)-{\beta}-_D-galactoside(7)$ and quercetin $3-O-{\alpha}-_L-rhamnoside(8)$ by the means of chemical and spectral evidence, respectively.

• 생약학회지
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• 제30권3호
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• pp.295-300
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• 1999

Seven compounds were isolated from the n-BuOH extract of the dried stem barks of Rhus javanica L. On the basis of physico-chemical, spectroscopic evidences and comparison with authentic samples, the compounds $1{\sim}7$ were identified as gallic acid (1), methyl gallate (2), scopoletin (3), scopolin (4), $1,\;2,\;3,\;4,\;6-penta-O-galloyl-{\beta}-D-glucose$ (5), orcinol (6) and $orcinol-{\beta}-D-glucoside$ (7). Among these compounds, scopolin, $orcinol-{\beta}-D-glucoside$ were isolated from this plant for the first time.

• 생약학회지
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• 제23권3호
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• pp.126-131
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• 1992

Four flavonoids were isolated from the aerial parts of Euphorbia ebracteolata. On the basis of chemical and spectroscopic evidence, the structures of these compounds were established as $quercetin-3-O-{\beta}-D-glucoside$(isoquercitrin)(I), quercetin-3-O-rutinoside(rutin)(II), kaempferol-3-O-rutinoside(III) and $quercetin-3-O-(2'-O-galloyl)-{\beta}-D-glucoside$(IV) which was the main flavonoidal component in this plant. The isolation of flavonoids from E. ebracteolata is the first example.

• 생약학회지
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• 제24권4호
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• pp.319-321
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• 1993

A tannin compound has been isolated from the underground part of Rosa rugosa Thunb. and its structure has been established to be methyl gallate $3-O-{\beta}-D-(6'-O-galloyl)-glucopyranoside(1)$ on the basis of chemical and spectroscopic evidences. This compound was the first example in this plant.

• 한국식품과학회지
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• 제45권6호
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• pp.777-784
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• 2013

본 연구는 항산화 활성이 뛰어난 작두콩의 메탄올 추출물을 대상으로 극성차를 이용한 용매분획을 행하여 n-hexane층, $CHCl_3$층, EtOAc층, butanol층, 그리고 $H_2O$층을 얻었다. 그중 활성이 가장 높은 EtOAc층을 대상으로 silica gel column chromatography 및 HPLC를 행하여 4종의 활성 화합물을 분리하고, MS 및 NMR분석을 통하여 구조해석을 행하였다. 그 결과 화합물 1-4는 methyl 3,4,5-trihydroxybenzoate (methyl gallate, 화합물 1), 3,4,5-trihydroxybenzoic acid (gallic acid, 화합물 2), 1,6-di-O-galloyl ${\beta}$-$\small{D}$-glucopyranoside (화합물 3), 그리고 1,4,6-tri-O-galloyl ${\beta}$-$\small{D}$-glucopyranoside (화합물 4)로 각각 동정되었다. 그리고 분리 화합물들의 DPPH radical-scavenging 활성은 화합물 4>화합물 3>화합물 2>화합물 1 순으로 평가되었다. 또 분리된 양을 기준으로 하였을 때, 화합물 1과 2는 작두콩 중에 다른 화합물들에 비해 다량으로 존재해있을 것으로 시사되었으며, 이들 화합물이 작두콩의 항산화 활성에 상당부분 기여하고 있는 것으로 판단되었다. 또한 화합물 4는 본 연구를 통해 작두콩으로부터는 처음 분리 동정되었다.

• 생약학회지
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• 제30권4호
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• pp.397-403
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• 1999

Tyrosinase plays an important role in the process of melanin polymer biosynthesis. Therefore, the enzyme inhibitors have been of great concern as cosmetics to have skin-whitening effects on the local hyperpigmentation. During the search for new inhibitory compounds on melanin polymer biosynthesis from natural sources, MeOH extracts of 589 higher plants were tested for the inhibitory effect on tyrosinase activity by the muschroom tyrosinase assay in vitro. Among plants tested, the leaves of Cercis chinensis exhibited potent inhibitory effect on mushroom tyrosinase activity. Subsequently seven active compounds were isolated from the ethyl acetate soluble part of acetone extract of the leaves of C. chinensis by the activity guided fractionation monitoring the inhibitory effect on tyrosinase activity. Their chemical structures were identified as $kaempferol-3-0-{\alpha}-L-rhamnoside$, quercitrin, $myricetin-3-0-{\alpha}-L-rhamnoside$, myricetin-3-0-(2'-O-galloyl)- ${\alpha}$ -L-rhamopyranoside (desmanthin), (-)-epicatechin-3-0-gallate, (-)-epigallocatechin-3-0-gallate, and methyl gallate on the basis of the speculation of spectral data and chemical reaction. Among the flavonol rhamnosides, myricetin-3-0-(2'-O-galloyl)- -L-rhamnoside(desmanthin) showed most potent inhibitory effect on tyrosinase activity and the structure of B-ring in flavonol moiety was related to the activity. (-)-Epigallocatechin-3-O-gallate having pyrogallol group in flavan-3-ol moiety exhibited more potent inhibitory effect than (-)-epicatechin-3-0-gallate having catechol group in flavan-3-ol moiety on mushroom tyrosinase activity.