• Natural Product Sciences
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• v.16 no.4
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• pp.239-244
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• 2010

Protein tyrosine phosphatase 1B (PTP1B), a negative regulator of insulin signaling, has served as a potential drug target for the treatment of type 2 diabetes. The MeOH extracts of twenty-nine medicinal plants, traditionally used in Vietnam as anti-diabetes agents, were investigated for PTP1B inhibitory activity in vitro. The results indicated that, most materials showed moderate to strong inhibitory activity with $IC_{50}$ values ranging from $3.4\;{\mu}g/mL$ to $35.1\;{\mu}g/mL$; meanwhile, eleven extracts (37.9%) could demonstrate PTP1B activity with $IC_{50}$ values less than $15.5\;{\mu}g/mL$; sixteen extracts (55.2%) could demonstrate PTP1B activity with $IC_{50}$ values ranging from $15.5\;{\mu}g/mL$ to $35.1\;{\mu}g/mL$. The study may provide a proof, at least in a part, for the ethno-medical use in diabetes disease of these plants.

• The Korean Journal of Food And Nutrition
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• v.6 no.1
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• pp.16-24
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• 1993

The "Namul" is a Korean common vegetable food composed of edible young leaves and soft stalks of wild plants or cultivating vegetables and treated with traditional condiments. It has been widely used as not only a regular diet but seasonal foods or special ceremonial foods. In this thesis, the kinds of edible plants for namul were philologically approached by books published in Korea from Koryo to Chosun dynasty. The first historical record about cultivated vegetable as food in Korea was a garlic and a gourd in $\ulcorner$Samkuksaki$\lrcorner$. According to numerous records, edible wild plants might have played an important part as food resources, since they have variable edible portions as famine relief foods. Four kinds of namul were first introduced in Koryo age, but in Chosun dynasty over eighty kinds were recorded. The root of ballonflower and white radish were most commonly used for raw namul and bamboo shoot and squash for boils ones. Most kinds of namul were introduced in $\ulcorner$Zeungtosanrimkwungiae$\lrcorner$ and $\ulcorner$Limwonsiprwukji$\lrcorner$ influenced by pragmatism in later half period of Chosun. The chronic state of famine in later half period of Chosun caused to introduce various edible wild vegetables, and had greatly influenced on the Korean people to acquire vegetarian food habits and to favor salty taste. It seems to need a further study on recent nutritional problems including dietary fiber.ary fiber.

• Preventive Nutrition and Food Science
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• v.7 no.2
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• pp.123-127
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• 2002

Ninety nine extracts from Korean plants were screened for their inhibitory activities on human immunodeficiency virus (HIV) type 1 pretense by an HPLC method. The pretense inhibitory activities were determined by incubating the extracts in reaction mixtures containing pretense and substrate (His-Lys-Ala-Arg-Val-Leu-(p-NO$_2$- Phe)-Glu-Ala-Nle-Ser-NH$_2$) to perform proteolytic cleavage reactions. Of the extracts tested, the water extracts of Viburnum awabuki (stem and leaves) and Distylium racemosum (leaves) had the highest pretense inhibitory activities at a concentration of 100ug/mL. Activity-guided fractionation, revealed that the n-butanol fraction of the V. awabuki extract and the ethyl acetate fraction from the D. racemosum extract had the greatest inhibitory activity on HIV-1 pretense.

• The Korean Journal of Food And Nutrition
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• v.15 no.4
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• pp.300-306
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• 2002

141 methanol extracts from 125 plant species which populate in Korea were screened for antimicrobial activity against various food-borne pathogens and food spoilage microorganisms. Those plants were selected from 3 different plant groups: traditional herbs, edible plants and flowers. The methanol extracts were tested by using the disk diffusion assay against five bacteria: Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Enterobacter aerogenes, Escherichia coli. From the evaluation of the inhibition zone diameter of microbial growth, the most significant antimicrobial activity against Bacillus subtilis, Staphylococcus auresus, Pseudomonas aeruginosa, Enterobacter aerogenes, Escherichia coli was observed from the extract of Schizandra chinensis (Turcz.) Baill., Rheum officinale Baill., Schizandra chinensis (Turcz.) Baill., Koelreuteria paniculata Lax and Crataegus pinnatifida Bunge, respectively. The extract from many plants - Koelreuteria paniculata Lax, Chaenomeles sinensis Koehne, Scutellaria bacicalensis Georgi, Castanea crenata Sieb. et Zucc., Rosa centifolia L., Allium fistulosum L. var. giganteum Makino, Crataegus pinnatifida Bunge, Schizandra chinensis (Turcz.) Baill., Lonicera japonica - showed antimicrobial activity all four tested bacteria.

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.97.1-97.1
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• 2007

See Full Text

• Proceedings of the Korean Nutrition Society Conference
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• 2003.05a
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• pp.264.2-264.2
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• 2003

• Proceedings of the Korean Society of Food Science and Nutrition Conference
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• 2000.11a
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• pp.158-158
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• 2000

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.4
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• pp.672-672
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• 1994

• Food Science of Animal Resources
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• v.37 no.4
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• pp.502-510
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• 2017

This study investigated bacterial growth-inhibitory effect of 69 therapeutic herbal plants extracts on 9 bacterial strains using a disc diffusion assay. Especially, the antimicrobial activity of Psoraleae semen, which showed different activity on pathogenic Gram-positive and Gram-negative bacteria, was evaluated by MIC (minimal inhibition concentration) and biofilm formation assay. The effect of Psoraleae semen extract on bacterial cell membranes was examined by measurement of protein leakage (optical density at 280 nm) and scanning electron microscope (SEM). No clear zone was formed on discs containing Gram-negative bacteria, but Gram-positive bacteria exhibited clear zones. The MICs of Psoraleae semen extract were $8{\mu}g/mL$ for Streptococcus mutans, and $16{\mu}g/mL$ for Enterococci and Staphylococcus aureus. In addition, biofilm formation was inhibited at concentration $8-16{\mu}g/mL$. Protein leakage values and SEM images revealed that cell membranes of Gram-positive bacteria were impaired following exposure to the extract. Further, the extract inhibited the growth of Listeria monocytogenes in sausages. These results indicate that Psoraleae semen extract could be utilized as a natural antimicrobial agent against Gram-positive bacteria.

• Korean Journal of Pharmacognosy
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• v.24 no.4
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• pp.299-303
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• 1993

The antioxidant activity of methanol extracts of plants and marine algae was tested by using 1,1-diphenyl-2-picrylhydrazyl(DPPH). Five plant extracts(Prunus davidiana, Eriobotrya japonica, Artemisia iwayomogi, Stirodella tolyrrhiza and Ulmus davidiana) and two algae (Ecklonia stolonifera and Symphycoladia latiuscula) were found to be the most effective in DPPH radical scavenging activity. The methanol extract obtained from the stems of Prunus davidiana was fractionated with several solvents. The ethylacetate soluble fraction exhibiting the strongest antioxidant activity was further purified by repeated silica gel and Sephadex LH-20 column chromatography. Antioxidant flavonoids and flavonoid glycosides were isolated and the most active ones was identified as (+)-catechin by MS, $^1H-NMR$ and $^{13}C-NMR$. Its antioxidant activity was higher than that oil vitamin C.