• 생약학회지
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• 제30권3호
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• pp.280-283
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• 1999

Using the bioassay-guided fractionation and isolation technique, two $PLC{\gamma}1$ inhibitors were isolated from the sarcotestas of Ginkgo biloba (Ginkgoaceae). The structures of these compounds were identified as (3R)-(-)-8-hydroxy-3-(6'-pentadecenyl)3,4-dihydroisocoumarin (1) and 3-heptadecen-2-one (2) by UV, IR, MS, $^1H-NMR$, $^{13}C-NMR$ and $^1H-^{13}C\;COSY$. Isolate compounds 1 and 2 have not been reported previously from the sarcotestas of G. biloba and Ginkgoaceae, respectively. In addtion, these compounds showed significant $PLC{\gamma}1$ inhibitory effects with the $IC_{50}$ of the 9.7 (1) and $25.6\;{\mu}M\;(2)$.

• Journal of Plant Biology
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• 제38권2호
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• pp.181-193
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• 1995

Cuticle micromorphology of four families of Korean gymnosperms, Cycadaceae, Ginkgoaceae, Taxaceae, and Cephalotaxaceae, were studied with scanning electron microscopy. The outer and inner features of abaxial and adaxial cuticles were described in details; the absent or present of Florin ring, orifice, trichome, and plug and their shape, the shape and periclinal and anticlinal wall sculpture of epidermal cells, the shape of cuticular flange of epidermal cell, guard cell, and subsidiary cell, the number of stomatal bands and rows, and stomatal apparatus including the shape of polar extension, number of subsidiary cells, the sculpture of guard cell and subsidiary cell. Most of these features have not been sufficiently substantiated by the previous reprots. Furthermore, all the species investigated showed distinctive cuticle morphology with morphological and taxonomical informations.

• Archives of Pharmacal Research
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• 제13권2호
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• pp.207-210
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• 1990

The position of interglycosidic linkages of two acylated flavonol glucorhamnosides from Ginkgo biloba leaves was unambiguously determined as 1 $\longrightarrow$ 2 linkages rather than 1 $\longrightarrow$ 4 ones on the basis of spectroscopic and chemical evidence.

• 생약학회지
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• 제21권2호
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• pp.148-152
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• 1990

Seven flavonol glycosides from the EtOAc fraction of Ginkgo biloba leaves were identified by high performance liquid chromatography. Separation by reversed phase chromatography on $Lichrosorb^{\circledR}$ RP-18 column was achieved by isocratic elution. The content of the major acylated flavonol glycoside, kaempferol 3-0-[$6'-O-{p}-coumaroyl-{\beta}-_D-glucosyl(1{\rightarrow}2)-{\alpha}-_L-rhamnoside$] was about 8.0% and 0.55% for EtOAc fraction and MeOH extract, respectively.

• 생약학회지
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• 제21권2호
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• pp.111-120
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• 1990

Five biflavones and sevenflavonolglycosideswereisolatedfromtheleaves of Ginkgo biloba. They were sciadopitysin(1), ginkgetin(2), isoginkgetin(3), bilobetin(4), amentoflavone(5), kaempferol 3-O-[$6'-O-{\rho}-coumaroyl-{\beta}-_D-glucopyranosyl(1{\rightarrow}2)-{\alpha}-_Lrhamnopyranoside$](6), quercetin 3-O-[$6'-O-{\rho}-coumaroyl-{\beta}-_D-glucopyranosyl(1{\rightarrow}2)-{\alpha}-_Lrhamnopyranoside$](8), rutinosides of kaempferol(7), isorhamnetin(9), quercetin(10), laricitrin(11), and kaempferol 3-O-($2',6'-{\alpha}-_L-dirhamnopyranosyl-{\beta}-_{D}-glucopyranoside$)(12). The structures were established by spectroscopic and chemical methods.

• 한국자원식물학회지
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• 제6권1호
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• pp.45-51
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• 1993

Many plants collected at Japan, China, Korea, Imdonesia and South America were applied to antitumor and / or cytotoxic screening tests against Sarcoma 180 ascites in mice and / or V-79, KB, P388 cultured cells. On the course of these screening tests, alcoholic extracts of Forsythia viridissima (Oleaceae), Eurycoma longifolia(Simaroubaceae), Rubia cordifolia and R. akane(Rubiaceae), Cissampelos pareira and Abuta concolor (Menispermaceae), Nardostachys chinensis (Valerianacese), Mansoa alliaceae (Bignoniaceae), Casearia sylvestris (Flacourtiacear), Maytenus ilicifolia (Celastraceae), Hedychium coronarium (Zingiberaceae), Croton palanostigma(Euphorbiaceae), Cocculus trilobus(Menispermaceae), Ginkgo biloba(Ginkgoaceae), Alpinia galanga and Cucculus zanthorrhiza(Zingiberaceae), Evodia rutaecarpa(Rutaceae), and Periploca sepium(Asclepiadaceae) showed significant activity and their active principles were clarified. In this paper, a few antitumor substances in above plants are introduced.

• Journal of Plant Biology
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• 제35권4호
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• pp.339-358
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• 1992

한국산 나자식물 6개과에서 대표적인 1종씩을 선정하여 수피의 특징을 형태 및 해부학적으로 조사하고 기재하였다. 수피를 인위적으로 조직단위로 간주할 경우 수피의 색, 두께, 내수피와 외수피의 두께, 확장조직의 유무 및 발달정도, 조피내 주피의 층우와 주피의 층수와 주피의 구성요소들의 두께, 2기 사부지역 각 구성요소들의 배열양상과 점유면적 비율 등은 종류에 따라 차이를 보였다. 또한 보강세포의 형태와 사세포의 사역 등도 앞으로 상세한 조사가 수행될 경우 비교형태학적 연구에 매우 가치있는 정보를 제공할 것으로 생각되었다.

• 생약학회지
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• 제26권1호
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• pp.23-26
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• 1995

6-Hydroxykynurenic acid and ginkgolide B together with flavonol glycosides and biflavonoids were isolated from the yellow leaves of Ginkgo biloba and identified by means of spectroscopic methods. The correctness of $H{\"{o}}lzl's$ ${13}^C-NMR$ assignments for 6-hydroxykynurenic acid was confirmed by HMQC and HMBC techniques. Based on our present findings, it may be considered that the yellow Ginkgo leaves may contribute to be a source of high medicinal values.

• 생약학회지
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• 제24권1호
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• pp.47-53
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• 1993

The seasonal variations of the major six flavonol glycosides(kaempferol 2,6-dirhamnosyl glucoside, quercetin 3-O-rutinoside, kaempferol 3-O-rutinoside, isorhamnetin 3-O-rutinoside, quercetin 3-O-coumaroyl glucorhamnoside and kaempferol 3-O-coumaroyl glucorhamnoside) in Ginkgo biloba leaves were investigated. The contents were determined by HPLC on reversed phase $C_{18}$ column. This result showed that the percentage of six flavonol glycosides decreased during the season from 1.57% in May to 0.39% in November. The content of each flavonol glycoside indicated a similar tendency to decrease. However, the contents of rutinosides of kaempferol, quercetin and isorhamnetin fluctuated markedly than those of coumaroyl glucorhamnosides of kaempferol and quercetin and kaempferol 2,6-dirhamnosyl glucoside.

• 생약학회지
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• 제24권1호
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• pp.54-57
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• 1993

The seasonal variations of five biflavones from Ginkgo biloba leaves from May to November were investigated by a reversed phase HPLC method. The total amount of biflavones was increased with time to reach its maximum in yellow autumnal leaves. Each biflavone showed a similar tendency. It increased rapidly about 3.1-fold from May to June and thereafter gradually increased about 2.5-fold. The ratio of each biflavone content to the total amount of biflavones was in the order of as follows: isoginkgetin>sciadopitysin>bilobetin>ginkgetin>amentoflavone.