Publications by authors named "Ick Dong Yoo"

A new sesquiterpene lactone dimer , together with five known compounds , was isolated from the flowers of . The structures of these compounds were established by extensive spectroscopic studies and chemical evidence. The inhibitory activities of these isolated compounds against human neutrophil elastase (HNE) were also evaluated in vitro; compounds and exhibited significant inhibitory effects against HNE activity, with IC values of 8.

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Clitocybin A, an isoindolinone from , was investigated to assess its anti-wrinkle properties, through reactive oxygen species (ROS)-scavenging and elastase inhibitory activities, procollagen synthesis, and matrix metalloproteinase-1 (MMP-1) expression, in human primary dermal fibroblast-neonatal (HDF-N) cells. Clitocybin A exhibited no significant cytotoxicity up to 10 ppm in HDF-N cells, with cell viability and cell proliferation activity greater than 94.6% and 91.

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Two new labdane diterpenes (1 and 2) were isolated from the fruiting bodies of Ramaria formosa. The structures of these compounds were established by extensive spectroscopic studies and chemical evidence. The inhibitory activity of compounds 1 and 2 against human neutrophil elastase (HNE) was evaluated in vitro.

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Two new sesquiterpene derivatives (1 and 2), ramarin A (1) and ramarin B (2), together with three known compounds (3-5) were isolated from the fruiting bodies of Ramaria formosa. The structures of the two sesquiterpenes were established by extensive spectroscopic studies and chemical evidence. The inhibitory activity of the isolated compounds (1-5) against human neutrophil elastase (HNE) was evaluated in vitro.

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The secondary metabolites illudins C2 (1) and C3 (2), obtained from the culture broth of Coprinus atramentarius, have been shown to possess antimicrobial activity. In the present study, we discovered novel biological activities of 1 and 2 in lipolysis of differentiated 3T3-L1 adipocytes and adipogenesis of 3T3-L1 preadipocytes. Compounds 1 and 2 exhibit a dose-dependent increase in glycerol release and thereby reduce intracellular lipid accumulation.

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During the course of screens to identify anti-melanogenic agents from natural resources, we found that the methanol extract of the dried flower of Inula britannica L. inhibited melanin synthesis in cultured melanoma cells stimulated with 3-isobutyl-1-methylxanthine (IBMX). A bioassay-guided isolation of the chloroform fraction of the I.

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In the continued search for melanogenesis inhibitors from microbial metabolites, we found that the culture broth of Clitocybe sp. MKACC 53267 inhibited melanogenesis in B16F10 melanoma cells. The active component was purified by solvent extraction, silica gel chromatography, Sephadex LH-20 column chromatography, and finally by preparative HPLC.

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Abnormal proliferation of vascular smooth muscle cells (VSMCs) plays an essential role in the pathogenesis of vascular diseases, such as atherosclerosis, hypertension, and restenosis. Clitocybin A, a novel isoindolinone, isolated from the culture broth of mushroom Clitocybe aurantiaca has been reported to possess free radical scavenging activity. However, the antiproliferative effects of clitocybin A on VSMCs are unknown.

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The increased proliferation of vascular smooth muscle cells (VSMCs) in the arterial wall is a critical pathogenic factor for vascular diseases such as atherosclerosis and restenosis after angioplasty. Clitocybin B was reported to have either a potent free radical scavenging effect or effects that were isolated from the culture broth of mushroom Clitocybe aurantiaca. The present study was designed to investigate the effects of clitocybin B on VSMC proliferation and its possible molecular mechanism.

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Rosmarinic acid, its analogues, and a phenolic compound were obtained from G. hederacea var. longituba.

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A new eudesmanolide, 1β,3β-dihydroxy-eudesman-11(13)-en-6α,12-olide (1) was isolated and identified from Taraxacum mongolicum, together with two known compounds, 1β,3β-dihydroxyeudesman-6α,12-olide (2) and loliolide (3). The structure of 1 was established by analysis of its physical and spectroscopic data. 1 was found to have an inhibitory activity on nitric oxide production with an IC(50) of 38.

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Three new sesquiterpene lactones, 1 α,10 β-epoxy-4-hydroxy-glechoma-5-en-olide (1), 1 β,10 α-epoxy-4,8-dihydroxy-glechoma-5-en-olide (2), and 1 β,10 α;4 α,5 β-diepoxy-8-methoxy-glechoman-8 α,12-olide (3), were isolated from the whole plant of Glechoma hederacea, together with four known sesquiterpene lactones. The structures of the three new sesquiterpene lactones were determined by spectroscopic evidence. Cytotoxic effects of the isolated compounds were examined against MDA-MB-231 (breast), HCT116 (colon), SW620 (colon), and DU145 (prostate) human cancer cell lines.

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Chemical structure of fomitellan A, a polysaccharide with a mitogenic effect isolated from the fruiting bodies of Fomitella fraxinea, has been assigned as a mannofucogalactan with a repeating unit of penta-saccharide, which was composed of a (1 →6)-linked D-galactopyranosyl backbone having a C-2 position substituted with disaccharide units of 3-O-D-mannopyranosyl-L-fucopyranosyl residue. The (1)H and (13)C NMR signals of fomitellan A have been completely assigned by extensive NMR experiments.

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Titanium is biocompatible with bodily tissues. However, the formation of ROS on the titanium surfaces might have negative response of the activity of the surroundings cells. Terrein was isolated from Penicullium sp.

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We report the synthesis of a novel series of highly potent melanin inhibitors which were obtained through structural modification of an anticancer compound S-(+)-decursinol. The in vitro inhibitory potencies of the newly synthesized compounds were evaluated against α-MSH induced melanin production in B16 murine melanoma cells. Among the compounds evaluated, compounds 2, 3, 6b, 7a, 7b, 8a and 8b emerged as highly potent inhibitors of melanin production.

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In an ongoing investigation of compounds from natural products that exhibit anti-aging properties, hydroxyhibiscone A (1), a new furanosesquiterpenoid, together with hibiscone D (2), was isolated from the root bark of Hibiscus syriacus. Utilizing UV, IR, NMR, and MS spectroscopic analyses, these chemical structures were revealed. Compounds 1 and 2 were found to possess significant anti-aging properties on the human neutrophil elastase (HNE) assay, exhibiting HNE inhibitory activities with IC50 values of 5.

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Several lanostane triterpenes [butyl ganoderate A (1), butyl ganoderate B (2), butyl lucidenate N (3), and butyl lucidenate A (4)] bearing a butyl ester side chain from the fruiting bodies of Ganoderma lucidum exhibited considerable inhibitory effects on adipogenesis in 3T3-L1 cells. The inhibitory mechanism of 1 and 3 on adipogenesis in 3T3-L1 cells was investigated; we found that the mRNA and protein expression levels of SREBP-1c were reduced by treatment with 1 and 3 versus the untreated control. Furthermore, compounds 1 and 3 suppressed the mRNA expression levels of FAS and ACC.

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In this study, the decursin derivative dihydropyranocoumarin D2 (1) was selected for its effects on melanogenesis using a spontaneously immortalized mouse melanocyte cell line (Mel-Ab). The results showed that 1 effectively inhibited melanin synthesis in a concentration-dependent manner, but that it did not inhibit tyrosinase in a cell-free system. In addition, the changes in ERK, Akt, and microphthalmia-associated transcription factor (MITF) in response to treatment with 1 were assessed.

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Two acetylated megastigmane glycosides, matenosides A (1) and B (2), have been isolated from the MeOH extract of Ilex paraguariensis leaves, and their structures were elucidated on the basis of spectroscopic analysis. Compounds 1 and 2 exhibited human neutrophil elastase (HNE) inhibitory activity with IC(50) values of 50.4 muM and 11.

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Four compounds were isolated from the broth culture of Volvariella bombycina and they were identified as ergosta-4,6,8(14),22-tetraene-3-one (1), ergosterol peroxide (2), indole-3-carboxaldehyde (3) and indazole (4) by interpretation of spectroscopic data. Among them, compound 2 exhibited melanogenesis inhibitory effect in cultured B16 mouse melanoma cells.

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Bioassay-guided fractionation of the culture broth of Aspergillus sp. FN070449 (KCTC 26428) using a DPPH (2,2-diphenyl-1-picrylhydrazyl) assay led to the isolation of two compounds: reticulone (1) and reticulol (2). Their chemical structures were elucidated on the basis of UV, IR, NMR, and MS spectroscopic analysis.

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Five iridoid glycosides were isolated from the MeOH extract of Hedyotis diffusa, and their structures were elucidated as E-6-O-p-methoxycinnamoyl scandoside methyl ester (1), Z-6-O-p-methoxycinnamoyl scandoside methyl ester (2), E-6-O-p-feruloyl scandoside methyl ester (3), E-6-O-p-coumaroyl scandoside methyl ester (4), and Z-6-O-p-coumaroyl scandoside methyl ester (5) by interpretation of their spectroscopic data. All the isolated compounds were evaluated for human neutrophil elastase inhibitory effect, and compound 1 showed potent activity with an IC(50) value of 18.0muM.

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