• Proceedings of the Korean Society for Bioinformatics Conference
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• 2005.09a
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• pp.139-143
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• 2005

Cytochrome P450 14${\alpha}$-sterol demethylase enzyme (CYP51) is the target a of azole type antifungals. The azole blocks the ergosterol synthesis and thereby inhibits fungal growth. A three-dimensional (3D) homology model of CYP51 from Candida albicans was constructed based on the X-ray crystal structure of CYP51 from Mycobacterium tuberculosis. Using this model, the binding modes for the substrate (24-methylene-24, 25-dihydrolanosterol) and the known inhibitors (fluconazole, voriconazole, oxiconazole, miconazole) were predicted from docking. Virtual screening was performed employing Structure Based Focusing (SBF). In this procedure, the pharmacophore models for database search were generated from the protein-ligands interactions each other. The initial structure-based virtual screening selected 15 compounds from a commercial available 3D database of approximately 50,000 molecule library, Being evaluated by a cell-based assay, 5 compounds were further identified as the potent inhibitors of Candida albicans CYP51 (CACYP51) with low minimal inhibitory concentration (MIC) range. BMD-09-01${\sim}$BMD-09-04 MIC range was 0.5 ${\mu}$g/ml and BMD-09-05 was 1 ${\mu}$g/ml. These new inhibitors provide a basis for some non-azole antifungal rational design of new, and more efficacious antifungal agents.

• Natural Product Sciences
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• v.13 no.3
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• pp.190-194
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• 2007

Two new flavonoid compounds, 8,8'-bisbaicalein 1 and baicalein-7-O-caffeate 2 along with six known flavonoids, baicalein, chrysin, scutellarein, 6-hydroxyluteolin, 6-methoxyluteolin and baicalein-7-Oglucoside and ${\beta}-sitosterol$ have been isolated from the stem-bark of Oroxylum indicum (Bignoniaceae) and identified on the basis of spectroscopic and chemical studies. 6-Hydroxyluteolin and 6-methoxyluteolin are reported for the first time from this plant.

• Natural Product Sciences
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• v.23 no.3
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• pp.208-212
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• 2017

A new sesquiterpenoid, 11-hydroxy-valenc-1(10),3(4)-dien-2-one (3), two chemically synthesized but first isolate from nature, $3-oxocedran-8{\beta}-ol$ (1) and valenc-1(10),3(4),11(12)-trien-2-one (2) along with four known compounds, sugiol (4), (+)-nootkatone (5), 11-hydroxy-valenc-1(10)-en-2-one (6), and clovandiol (7), were isolated from the heartwood of Juniperus chinensis. All chemical structures were elucidated using extensive spectroscopic analysis including 1D and 2D NMR spectroscopy. Valenc-1(10),3(4),11(12)-trien-2-one (2) exhibited significant inhibitory activity against butyrylcholinesterase with an $IC_{50}$ value of $68.45{\mu}M$.

• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.65-70
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• 2011

Coumarins are ubiquitous in plant kingdom and have been used as antitumor, antifungals, anticoagulants, insecticides. Chalcones are also widespread in plant kingdom and have been known to possess diverse biological activities; antibacterial, antifungal, antitumor and anti-inflammatory, etc. As they are considered as important natural products, numerous synthetic approaches have been reported up to the present. We devise a new selective method of preparing dihydrocoumarins and chalcones from aryl cinnamates by the selection of reagents. Dihydrocoumarin derivatives were prepared selectively by using intramolecular cyclization catalyzed by p-toluene sulfonic acid. Also, chalcones were prepared by Fries-rearrangement catalyzed by $TiCl_4$. This method can be used for preparing various coumarin & chalcone compounds.

• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.52-58
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• 2010

Human histamine H1 receptor (HHR1) is a G protein-coupled receptor and a primary target for antiallergic therapy. Here, the ligand-based three-dimensional pharmacophore models were built from a set of known HHR1 inverse agonists using HypoGen module of CATALYST software. All ten generated pharmacophore models consist of five essential features: hydrogen bond acceptor, ring aromatic, positive ionizable and two hydrophobic functions. Best model had a correlation coefficient of 0.854 for training set compounds and it was validated with an external test set with a high correlation value of 0.925. Using this model Maybridge database containing 60,000 compounds was screened for potential leads. A rigorous screening for drug-like compounds unveiled RH01692 and SPB00834, two novel molecules for HHR1 with good CATALYST fit and estimated activity values. The new lead molecules were docked into the active site of constructed HHR1 homology model based on recently crystallized squid rhodopsin as template. Both the hit compounds were found to have critical interactions with Glu177, Phe432 and other important amino acids. The interpretations of this study may effectively be deployed in designing of novel HHR1 inverse agonists.

• Natural Product Sciences
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• v.26 no.2
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• pp.176-181
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• 2020

Two new compounds, 3-methyl-but-2-en-1-yl-1-O-β-xylopyranosyl-(1"→2')-O-β-glucopyranoside (1) and 1-O-β-glucopyranosyl-6-hydroxy-2-methyl-hep-2-enoic acid (2), along with sixteen known terpenoids were isolated from the peels of Citrus unshiu Markov. Their structures were elucidated based on extensive NMR analyses (¹H NMR, ¹³C NMR, DEPT, COSY, HMQC, and HMBC) and high-resolution mass spectrometry. In addition, all isolates (1 - 18) were tested their effects on nitric oxide (NO) production in RAW264.7 cells. Limonin (15) showed to inhibit LPS-induced NO production in a concentration-dependent manner without cytotoxicity.

• Natural Product Sciences
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• v.5 no.3
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• pp.124-126
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• 1999

A new natural product $stigmast-5-en-3-O-{\beta}-D-glucopyranoside$ tetraacetate (1) along with known compounds $stigmast-5-en-3-O-{\beta}-D-glucopyranoside$ (2), stigmast-5-en-3-yl-cetate (3) and ${\beta}-sitosterol$ (4) have been isolated from the stems of Cuscuta reflexa. Their structures were elucidated on the basis of chemical and spectroscopic evidence.

• Archives of Pharmacal Research
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• v.29 no.2
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• pp.131-134
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• 2006

A new compound 2 and two known guaiane-type sesquiterpenoids were isolated from the methylene chloride-soluble fraction of the methanolic extract of the fruits of Torilis japonica (Umbelliferae) through repeated silica gel and Sephadex LH-20 column chromatography. Their chemical structures were elucidated as torilin (1), 11-acetoxy-8-angeloyloxy-$1{\beta}$-hydroxy-4-guaien-3-one ($1{\beta}$-hydroxytorilin, 2), and 11-acetoxy-8-angeloyloxy-$1{\alpha}$-hydroxy-4-guaien-3-one ($1{\alpha}$-hydroxytorilin, 3) by spectroscopic analysis. Compounds 1-3 exhibited cytotoxicity against human A549, SK-OV-3, SK-MEL-2, and HCT15 tumor cells.

• Journal of Microbiology and Biotechnology
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• v.16 no.4
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• pp.637-638
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• 2006

Bioassay-guided fractionation of an organic extract of the culture broth from an unidentified marine-derived fungus led to the isolation of a new metabolite, N-[2-(4-hydroxyphenyl) acetyl]formamide (1), along with four known polyketides, 4-hydroxyphenyl acetamide (2), 4-hydroxyphenyl acetic acid (3), 3,4-dihydroxyphenyl acetic acid (4), and N-[2-(4-hydroxyphenyl)ethenyl]formamide (5). The structures of 1-5 were elucidated by spectral data analyses. Among them, compounds 1, 4, and 5 exhibited significant radical scavenging activity against 1, 1-diphenyl-2-picrylhydrazyl (DPPH) with $IC_{50}$ values of 8.4, 11.9, and $0.2{\mu}M$, respectively.

• Natural Product Sciences
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• v.4 no.4
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• pp.215-220
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• 1998

A new flavonol $3,5-di-O-KSO_3$:kaempferol 7,4'-dimethyl ether $3,5-O-KSO_3$, was isolated and identified from the flowers of Tamarix amplexicaulis. The known compounds quercetin $3-mono-O-KSO_3$, kaempferol 4'-methyl ether $3-mono-O-KSO_3$, kaempferol 7,4'-dimethyl ether $3-O-KSO_3$, quercetin 7,4'-dimethyl ether $3-mono-O-KSO_3$, kaempferol 3-O-glucuronide and quercetin 3-O-glucuronide were also separated and identified. Structures were established by conventional methods, including electrophoretic analysis, and confirmed by negative FAB-MS, $^1H-\;and\;^{13}C-NMR$.