• Journal of Microbiology and Biotechnology
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• v.18 no.10
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• pp.1729-1734
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• 2008

Chitosan, a cationic polysaccharide, has been widely used as a dietary supplement and in a variety of pharmacological and biomedical applications. The antifungal activity and mechanism of action of low molecular weight water-soluble chitosan (LMWS-chitosan) were studied in fungal cells and vesicles containing various compositions of fungal lipids. LMWS-chitosan showed strong antifungal activity against various pathogenic yeasts and hyphae-forming fungi but no hemolytic activity or cytotoxicity against mammalian cells. The degree of calcein leakage was assessed on the basis of lipid composition (PC/CH; 10:1, w/w). Our result showing that LMWS-chitosan interacts with liposomes demonstrated that chitosan induces leakage from zwitterionic lipid vesicles. Confocal microscopy revealed that LMWS-chitosan was located in the plasma membrane. Finally, scanning electron microscopy revealed that LMWS-chitosan causes significant morphological changes on fungal surfaces. Its potent antibiotic activity suggests that LMWS-chitosan is an excellent candidate as a lead compound for the development of novel anti-infective agents.

• 보존과학연구
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• s.29
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• pp.125-136
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• 2008

To investigate bioactive materials for development of natural conservative agent on organic cultural heritage, methanol extracts from 17 medicinal plants were screened for antifungal and insecticidal activity against 6 wood rot fungi and adult of Lasioderma serricorne. Antifungal activity of extracts was tested by using paper disc soaking method against wood-rot fungi. Among these extracts, the most significant antimicrobial activity was observed from the extract of Coptis japonica at 5 mg/disc against all wood rot fungi tested. The insecticidal activity of extracts was examined by topical application against L. serricorne adults. The extracts from Asarum sieboldii gave 83.3 % mortality at $25{\mu}g/adult$ for 24hr. From these result, the methanol extract from C. japonica and A. sieboldii described could be useful for conservation of organic cultural heritage against biological deterioration by wood rot fungi and L. serricorne.

• Journal of Microbiology and Biotechnology
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• v.12 no.5
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• pp.854-857
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• 2002

Bioassay-directed chromatographic fractionation of a methylene chloride extract of Ailanthus altisshima indicated the presence of 20(S), 24(R), epoxy-25-hydroxydammarane-3-one (compound 1, ocotillone) which was isolated from this plant, for the first time. Antimicrobial activity of compound 1 was measured by inhibition of bacterial and fungal cells growth and by a hemolytic assay with human erythrocytes, respectively. The results revealed that compound 1 had potent antibacterial activity against Cram-negative bacteria, P. aeruginosa and S. typhimurium, that were without hemolytic activity, whereas it had weak antimicrobial activity against Gram-positive bacteria and fungi. These results demonstrated that the compound 1 has more antibacterial activity against 6ram-negative bacteria, which have no hemolytic activity, than Gram-positive bacteria and fungi. This is the first report on the biological activities of the compound 1.

• Archives of Pharmacal Research
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• v.20 no.2
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• pp.138-143
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• 1997

5-Aryl-2,3-dihydroimidazo[2,1-a]isoquinolines were reported to have strong antitumor activity and one of the derivatives such as $5-[4^{l}$ -(piperidinomethyl)phenyl]-2,3-dihydroimidazo[2,1-a] isoquinoline (1, SDZ 62-434) was found to be more effective than the clinical cytostatic agent edelfosine (2) in in vitro and in vivo assays. Currently SDZ 62-434 is in clinical trials in Europe. The structure-activity relationship studies of SDZ 62-434 showed that compounds with substitution on ring A were less active than the lead compound. Ring B in SDZ 62-434 was essential for the activity because compounds without B ring had no antitumor activity. Among the 3-arylisoquinolin-1-one derivatives, $3-[4^{I}$-(piperidinomethyl)phenyl] substituted analog had no antitumor activity but simple phenyl substituted compound, such as 4, showed the most potent antitumor activity in various human tumor cell lines.

• Archives of Pharmacal Research
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• v.19 no.3
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• pp.246-247
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• 1996

In the previous reports (Park et al., 1991, and 1993), we described the synthesis and analgesic effects of various homovanillic amides as analogs of capsaicin. In the study, we tried to enhance the analgesic actvity of capsaicin by structural modification. Our study has been performed in three directions. First, the amide bond of capsaicin was transposed. Second, a phenyl ring was introduced to replace a double bond of capsaicin. Finally, aminoethylation was performed on 4-hydroxy group of capsaicin to improve oral bioavailability. These studies have led to N-(3-phenylpropyl)homovanillic amide 2 which has high analgesic activity. Our continuing efforts in this area have focused on the introduction of various substituents on the phenyl ring of 2 as well as their pharmacological studies. We report herein the synthesis of homovanillic amide derivatives and their analgesic activity.

• Transactions of the Korean hydrogen and new energy society
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• v.14 no.1
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• pp.1-7
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• 2003

In this study, activity changes of $Ni/Ce-ZrO_2$ catalyst for steam reforming reaction in the various steam treatment condition were investigated and BET, XRD and XPS analysis were introduced to characterize the catalyst before and after treatment. Activity test showed that $Ni/Ce-ZrO_2$ catalyst had good activity after reduction in steam reforming reaction but deactivated rapidly after steam treatment at high temperature. Activities of deactivated catalyst by steam was recovered to die previous activity level after reduction using hydrogen rich gas. It was observed that catalytic activity was preserved after repeated steam treatment, too. It showed that change of catalytic activity due to steam treatment is perfectly reversible. From the BET, XRD and XPS analysis, deactivation of $Ni/Ce-ZrO_2$ catalyst was due to the transition from Ni, that is activity site for steam reforming reaction, to $NiAl_2O_4$ in steam treatment at high temperature.

• Proceedings of the Korean Society of Crop Science Conference
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• 2002.05a
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• pp.77-81
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• 2002

The scope of the research is investigation of immune-modulating activities of A. rugosa (Baechohyang) extract was preformed through the screening active constituents using in vitro assays and evaluating anti-inflammatory activity and anti-atherosclerotic activity of the extract and active compound (tilianin) in vivo. In addition, various functional foods using the extract and whole plant was developed. The extract showed strong anti-inflammatory activity in carrageenan-induced acute edema mouse model and anti-atherogenic lesion activity in LDLR (low density lipoprotein receptor) deficient mouse model. These activities were thought to be resulted from modulation activity of several pathways of inflammation process. Among the main constituents of Baechohyang, polyunsaturated fatty acids (PUFA), Phytosterols, oleanolic acid and rosmarinic acid showed anticomplement activity, and PUFA, acacetin and tilianin newly showed potent ICAM-1 expression inhibition activity. The processes of extraction, mixing ratio of additives and storage conditions were established for drinks, granule tea, leaf tea, mixed tea and furigake.

• YAKHAK HOEJI
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• v.16 no.3
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• pp.121-128
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• 1972

Alcohol extracts of 70 Korean medicinal plants have been tested for their biological activity. Most of the extracts had slight activity only. Some extracts had more pronounced activity. The results are tabulated.

• Preventive Nutrition and Food Science
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• v.16 no.4
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• pp.370-375
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• 2011

The antioxidative activity and the polyphenolic composition were examined in four different cultivars of apple (Malus domestica), 'Fuji', 'Tsugaru', 'Hongro' and 'Kogetsu', and their parts (peel, core, pulp and juice). The total phenolics, flavonoids and anthocyanins differed among the tested cultivars and parts. Peel parts had the highest total phenolics and anthocyanin content. Contributions of those phenolics to total antioxidative activity were determined using 1,1-diphenyl-2-picrylhydrazyl (DPPH) and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging assays, and the linoleic acid oxidation assay. Concentration of phenolics contributes significantly to the total antioxidative activity of apples. Clearly, apple peels, especially from Hongros and Kogetsus, possess high levels of phenolic compounds and antioxidants. Therefore, apple peels may potentially function as a value-added ingredient.

• BMB Reports
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• v.32 no.6
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• pp.561-566
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• 1999

CA(1-8)-ME(1-12) [CA-ME], composed of cecropin A(1-8) and melittin(1-12), is a synthetic antimicrobial peptide having potent antibacterial and antitumor activities with minimal hemolytic activity. In order to investigate the effects of the flexible hinge sequence, Gly-Ile-Gly, of CA-ME on antibiotic activity, CA-ME and three analogues, CA-ME1, CA-ME2, and CA-ME3, were synthesized. The Gly-Ile-Gly sequence of Ca-ME was deleted in CA-ME1 and replaced with Pro and Gly-Pro-Gly in CA-ME2 and CA-ME3, respectively. CA-ME1 and CA-ME3 showed a significant decrease in antitumor activity and phospholipid vesicle-disrupting ability. However, CA-ME2 showed similar antitumor and vesicle-disrupting activities, as compared with CA-ME. These results suggest that the flexibility or ${\beta}$-turn induced by Gly-Ile-Gly or Pro in the central part of CA-ME may be important in the electrostatic interaction of the N-terminus cationic ${\alpha}$-helical region with the cell membrane surface and the hydrophobic interaction of the C-terminus amphipathic ${\alpha}$-helical region with the hydrophobic acyl chains in the cell membrane. CA-ME3 exhibited lower antitumor and vesicle-disrupting activities than CA-ME and CA-ME2. This result suggests that the excessive ${\beta}$-turn structure caused by the Gly-Pro-Gly sequence in CA-ME3 seems to interrupt ion channel/pore formation in the lipid bilayer. We concluded that the appropriate flexibility or bilayer. We concluded that the appropriate flexibility or ${\beta}$-turn structure provided by the central hinge is responsible for the effective antibiotic activity of the antimicrobial peptides with the helix-hinge-helix structure.