• Natural Product Sciences
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• 제7권4호
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• pp.107-109
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• 2001

To investigate anti-diabetic component from the node of lotus rhizome (Nelumbo nucifera; Nymphaeaceae), activity guided isolation was conducted. One amino acid was isolated from active fraction of the aqueous methanolic extract. The structure of this compound was identified as tryptophan (1) by the analysis of spectroscopic evidences and comparisons with the data of authentic samples. Tryptophan reduced the blood glucose level significantly in glucose-fed hyperglycemic mice compared with glucose-treated group and exhibited 44.3% of activity compared with tolbutamide,.

• Archives of Pharmacal Research
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• 제28권2호
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• pp.169-171
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• 2005

The methanolic extract of the aerial parts of Persicaria thunbergii was found to show inhibitory activity on Farnesyl Protein Transferase (FPTase). Bioassay-guided fractionation of the methanolic extract resulted in the isolation of isorhamnetin, as an inhibitor on FPTase. This compound inhibited FPTase activity in a dose-dependent manner, and the $IC_{50}$ value of isorhamnetin was $37.5\;{\mu}M$.

• Archives of Pharmacal Research
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• 제29권1호
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• pp.64-66
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• 2006

The methanolic extract of the aerial parts of Centipeda minima was found to show inhibitory activity on farnesyl protein transferase (FPTase). Bioassay-guided fractionation of the methanolic extract resulted in the isolation of 6-O-angeloylprenolin, as an inhibitor on FPTase. This compound inhibited FPTase activity in a dose-dependent manner, and the $IC_{50}$ value of 6-O-angeloylprenolin was 18.8 ${\mu}M$.

• 약학회지
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• 제44권2호
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• pp.119-127
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• 2000

This paper describes isolation and elucidation structure of the components from leaves and evaluate the radical scavenging activity on DPPH radical for antioxidant effect. Bioassay guided fractionation of MeOH extract afforded active EtOAc and BuOH factions. The most active EtOAc fraction was repeatedly chrormatographed over silica and Sephadex LH-20 to afford six flavonoid compounds. Studies on the antioxidant activity of these constituents showed that quercetin was the most active of these compounds. Luteolin and kaempherol are also active, These results suggested that the antioxidant activity of leaves of Angelica gigas may be due to flavonoid components. All the compounds were identified by spectroscopic methods and are the first report from leaves of Angelica gigas.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.1
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• pp.266.1-266.1
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• 2003

Fruits of Hovenia dulcis T. (Rhamnaceae) was called ‘jiguja’ in oriental medicine which has been used for diuresis, remove of hangover and leaves has been used for detoxified the alcohol. In order to investigate the efficacy of antioxidative activity from leaves of Hovenia dulcis, the activity guided fraction and isolation of physiologically active substance were performed. Its 20％, 40％, 60％, 80％, 100％ MeOH, H2O, Acetone fractions were examined antioxidative activity by DPPH method and TBARS assay. (omitted)

• 동의생리병리학회지
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• 제17권5호
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• pp.1235-1242
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• 2003

This study was performed for the investigation of vasodilatory effects of Crataegus pinnatifida Bunge and for isolation and structure determination of the constituent from the active fraction. The fruits of this herbal drug were extracted with 80% methanol, then fractioned successively with methylene chloride, ethylacetate and n-butanol. Among the fractions, ethyl acetate fraction exhibited the most effective vascular relaxation against phenylephrine-induced arterial contraction. In order to isolate the active constituent by activity-guided fractionation, this fraction was chromatographed on silica gel to yield seven subfractions. Among the subfractions, the active one showing the most potent vascular relaxation activity was further separated by prep. HPLC with reversed phase Microsorb C-18 column using 1 % acetic acid and methanol gradient solvent system to afford one pure compound, which revealed a potent vasodilatory effect. Instrumental analyses (NMR and mass spectrometry) of the isolated constituent indicated this compound to be (-)-epicatechin. The vasodilatory action mechanism of this compound should be further investigated.

• 생약학회지
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• 제35권4호통권139호
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• pp.364-367
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• 2004

Cordyceps militaris (CM) has been used as antidiabetics, anticancer, endocrine and sexual functions enhancement in the traditional medicine. Water soluble fractions of CM showed cytotoxic activities on the three kinds of human cancer cell lines, stomachic adenocarcinoma(SNU-1), colorectal adenocarcinoma (SNU-C4), and hepatocellular carcinoma(SNH-354). Cytotoxic activity guided isolation and identification of active fractions afforded cordycepin as an active component.

• 생약학회지
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• 제26권4호
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• pp.323-326
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• 1995

Through bioassay-guided separation of the chemical constituents from the heartwood of Dalbergia odorifera, an 2'-O-methoxyisoliquiritigenin(1) was isolated as cytotoxic principle. 1 showed potent cytotoxic activity against the three kinds of human cancer cell lines (A-549, SK-MEL-2 and SK-OV-3) with similar activity to 5-Fluorouracil.

• Preventive Nutrition and Food Science
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• 제7권2호
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• pp.119-122
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• 2002

Oryza sativa cv. Mihyangbyo is one of several recently developed varieties of rice; characterized by high levels of aromatic components, which may increase its sensory and nutritional properties. In conjunction with our continuing investigation of bioactive components of improved grain varieties, a quinolone alkaloid was isolated from the n-butanol soluble fraction of the aleurone layer of Oryza sativa cv. Mihyangbyo (Gramineae) through activity-guided fractionation and isolation. The compound exhibited moderate antineoplastic activity in a human leukemia cell line (U937) with an $IC_{50}$/ value of 118.1 ug/mL, based on the MTT(3-[4, 5]dimethylthiazol-2-yl]-2, 5-diphenyltetrazolium bromide) cell proliferation assay. The chemical structure of the functional compound was determined, based on physical and spectroscopic characteristics.

• 한국응용약물학회:학술대회논문집
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• 한국응용약물학회 1998년도 Proceedings of UNESCO-internetwork Cooperative Regional Seminar and Workshop on Bioassay Guided Isolation of Bioactive Substances from Natural Products and Microbial Products
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• pp.104-107
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• 1998

The studies for antithrombotic substances from medicinal plants in my laboratory were started from the studies on PAF-antagonistic substances from Korean medicinal plants. The screening studies of PAF-receptor binding antagonistic activity were conducted on the extracts of 300 Korean medicinal plants, 37 tropical medicinal plants, 20 mushrooms, and 30 vegetables. From the results of screening studies, it was possible to select two Korean medicinal plants, i.e. 1) the leaf of Biota orientalis and 2) the seed of Arctium lappa, and two tropical medicinal plants, i.e. 3) the rhizome of Alpinia officinarum and 4) the leaf of Ardisia crispa as the candidates for the activity guided isolation of PAF-antagonistic substances.