• BMB Reports
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• v.46 no.1
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• pp.59-64
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• 2013

Signal transducer and activator of transcription 3 (STAT3) and telomerase are considered attractive targets for anticancer therapy. The in vitro anticancer activity of the gold(I) compound auranofin was investigated using MDA-MB 231 human breast cancer cells, in which STAT3 is constitutively active. In cell culture, auranofin inhibited growth in a dose-dependent manner, and N-acetyl-L-cysteine (NAC), a scavenger of reactive oxygen species (ROS), markedly blocked the effect of auranofin. Incorporation of 5-bromo-2'-deoxyuridine into DNA and anchorage-independent cell growth on soft agar were decreased by auranofin treatment. STAT3 phosphorylation and telomerase activity were also attenuated in cells exposed to auranofin, but NAC pretreatment restored STAT3 phosphorylation and telomerase activity in these cells. These findings indicate that auranofin exerts in vitro antitumor effects in MDA-MB 231 cells and its activity involves inhibition of STAT3 and telomerase. Thus, auranofin shows potential as a novel anticancer drug that targets STAT3 and telomerase.

• Preventive Nutrition and Food Science
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• v.7 no.2
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• pp.215-218
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• 2002

A methanol extract of Physalis angulata exhibited in vitro antibarterial activity against oral pathogens such including Streptococcus mutans and Porphyromonas gingivalis. The methanol extract of Physalis angulata was further fractionated with ethyl acetate, n-butanol and water, in which the ethyl acetate fraction exclusively showed antibacterial activity. An active antibacterial compound from the ethyl acetate fraction was purified to a single compound using silica gel column chromatography and identified as oleanolic acid by $^{13}$ C-NMR, $^1$H-NMR and EI-MS. MIC of oleanolic acid against S. mutants and p. gingivalis were determined to be 50 and 25 ug/mL, respectively. The Antibacterial activity of oleanolic acid from Physalis angulata suggested that it has potential as an anticarcinogenic and antiperiodontic ingredients in various foods and oral care products.

• Fisheries and Aquatic Sciences
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• v.14 no.4
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• pp.251-256
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• 2011

We screened for antibacterial substances against methicillin-resistant Staphylococcus aureus (MRSA). Methanolic extract of Eisenia bicyclis exhibited anti-MRSA activity according to a disk diffusion assay. To identify the active compound(s), the methanolic extract was further fractionated using hexane, dichloromethane, ethyl acetate, and n-butanol. The ethyl acetate-soluble fraction showed both the greatest anti-MRSA activity and the highest polyphenol content. The minimum inhibitory concentrations of the ethyl acetate fraction ranged from 32 to 64 ${\mu}g$ per mL against methicillin-susceptible S. aureus and MRSA strains. High-performance liquid chromatography analysis revealed that both the methanolic extract and the ethyl acetate soluble fraction contained sizeable quantities of dieckol, which is a known anti-MRSA compound. Thus, these data strongly suggest that the anti-MRSA activity of E. bicyclis may be mediated by phlorotannins such as dieckol.

• Bulletin of the Korean Chemical Society
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• v.26 no.1
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• pp.57-62
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• 2005

The potentiometric responses for various anions are investigated with membrane electrode (membrane 1) based on 1,3-diethyl-1,3-dihydroxy-1,3-bis(2-dimethylaminomethyl ferrocenyl) disiloxane. The nitrate ion-selective electrode based on compound 1 gave a good Nernstian response of 58.18 mV per decade for nitrate with the detection limit of −e5.66 of log [NO3−e]. Compound 1 has all those functional groups and the other two compounds have less functional group of ferrocenyl or ferrocenyl and hydroxide, respectively. Even though, potentiometric response to anions was excellent at pH 5, the selectivity pattern for all three membrane electrode based on series of disiloxane is almost like Hofmeister sequence at pH 5. However, the membrane electrode 1-3 exhibited very different response to anions at pH 7. In this pH, NH2 is not protonated and ionophore may act as neutral carrier. Hydrogen bond may enhance the responsibility to hydrogen acceptors and intramolecular electro-active site may increase the permeability of analyte to ionophore in membrane.

• Korean Journal of Pharmacognosy
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• v.26 no.2
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• pp.130-138
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• 1995

Phytochemical study on the aerial parts of Solanum lyratum (Solanaceae) was carried out. On the basis of phytochemical and spectroscopic evidences, compound I was identified as mixtures of hexadecanoic acid methyl ester, 2,6,10,15-tetramethyl heptadecane, tricosane, tetracosane, pentacosane, docosanoic acid methyl ester, docosane, tricosanoic acid methyl ester, 8-hexyl pentadecane, tetracosanoic acid methyl ester, pentatriacontane, hexatriacontane, eicosane, hexacosane, hentriacontane and stigmasta-5,23-dien $3-{\beta}-ol$, and compound II, III, IV and V were identified as hexacosanoic acid methyl ester, ${\beta}-sitosterol-{\beta}-{_D}-glucoside$, $3-O-{\alpha}-{_L}-rhamnopyranosyl-(1->2)-{\beta}-{_D}-glucuronopyranosyl$ diosgenin and $3-O-{\alpha}-{_L}-rhamnopyranosyl-(1->6)-{\beta}-{_D}-glucopyranosyl$ quercetin (rutin), respectively. Rutin was identified as one of the active principles having antioxidative effect from S. lyratum.

• Natural Product Sciences
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• v.23 no.4
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• pp.247-252
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• 2017

The methylglyoxal (MGO) trapping constituents from onion (Allium cepa L.) peels were investigated using pre-column incubation of MGO and crude extract followed by HPLC analysis. The peak areas of MGO trapping compounds decreased, and their chemical structures were identified by HPLC-ESI/MS. Among major constituents in outer scale of onion, 2-(3,4-dihydroxybenzoyl)-2,4,6-trihydroxy-3(2H)-benzofuranone (2) was more effective MGO scavenger than quercetin (6) and its 4'-glucoside, spiraeoside (3). After 1 h incubation, compound 2 trapped over 90% MGO at a concentration of 0.5 mM under physiological conditions, but compounds 3 and 6 scavenged 45%, 16% MGO, respectively. HPLC-ESI/MS showed that compound 2 trapped two molecules of MGO to form a di-MGO adduct and compounds 3 and 6 captured one molecule of MGO to form mono-MGO adducts, and the positions 6 and 8 of the A ring of flavonoids were major active sites for trapping MGO.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1998.11a
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• pp.135-135
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• 1998

To find an antagonist of Pythium ultimum, the causal agent of damping-off, numerous actinomycete strains were screened for in vitro inhibiting mycelial growth of the target fungus and producing bioactive metabolites. A strain identified as Streptomyces sp. G60655 was isolated and used for further antagonistic efficacy. The degree of antagonism between the fungus and G60655 was affected by the medium used. Furthermore, the preinoculation of the antagonist was found to be necessary to exhibit the maximum efficacy of antagonsim against the fungus. From the culture broth, a bioactive metabolite was detected and purified by solvent extraction, silica gel chromatography and preparative HPLC. The FAB-MS spectrum of the active compound showed a molecular ion peak at m/z 1101 (M + H)$\^$+/, suggesting the molecular weight of 1100. The UV absorptions at 242 and 323 nm indicated the presence of aromatic functions. The structure of this compound was identified as echinomycin, a depsipeptide antibiotic by spectroscopic studies including various NMR measurements. Echinomycin was inactive against several soil born fungi, but inhibited the mycelial growth of P. ultimum and its related oomycetous fungi.

• Journal of Microbiology
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• v.44 no.4
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• pp.432-438
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• 2006

Twelve actinomycete strains were isolated from Egyptian soil. The isolated actinomycete strains were then screened with regard to their potential to generate antibiotics. The most potent of the producer strains was selected and identified. The cultural and physiological characteristics of the strain identified. the strain as a member of the genus Streptomyces. The nucleotide sequence of the 16S rRNA gene (1.5kb) of the most potent strain evidenced a 99% similarity with Streptomyces spp. and S. aureofaciens 16S rRNA genes, and the isolated strain was ultimately identified as Streptomyces sp. MAR01. The extraction of the fermentation broth of this strain resulted in the isolation of one major compound, which was active in vitro against gram-positive, gram-negative representatives and Candida albicans. The chemical structure of this bioactive compound was elucidated based on the spectroscopic data obtained from the application of MS, IR, UV, $^1H$ NMR, $^{13}C$ NMR, and elemental analysis techniques. Via comparison to the reference data in the relevant literature and in the database search, this antibiotic, which had a molecular formula of $C_{19}H_{29}NO_2$ and a molecular weight of 303.44, was determined to differ from those produced by this genus as well as the available known antibiotics. Therefore, this antibiotic was designated Meroparamycin.

• Applied Chemistry for Engineering
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• v.17 no.6
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• pp.565-574
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• 2006

The trend towards the application of single enantiomers of chiral compounds is undoubtedly increasing. Among the various methods to obtain one single enantio-riched compound selectively, enantioselective catalysis is the most attractive method. Especially, it is important to increase the activity, selectivity and lifetime of usually expensive chiral catalysts with a minute quantity in the enantioselective synthesis. Immobilization of active homogeneous catalysts is a fashionable topic in asymmetric catalysis, providing the inherent advantage of easy separation and better handling properties. Many different ways have been investigated to improve the enantioselectivity of products and to recycle the catalysts. This review mainly focused on the present scope and limitations of different types of enantioselective heterogeneous catalysts.

• Archives of Pharmacal Research
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• v.28 no.10
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• pp.1147-1151
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• 2005

A new naturally occurring sterol, compound 5, and six known stigmasterols were isolated from fruits of Ailanthus altissima Swingle by repeated column chromatography and RP-HPLC. Their structures were identified as, 5${\alpha}$-stigmastane-3,6-dione (1), 3${\beta}$-hydroxystigmast-5-en-7-one (2), stigmast-5-ene-3${\beta}$, 7${\alpha}$-diol (3), 6${\alpha}$-hydroxystigmast-4-en-3-one (4), 5${\alpha}$-stigmastane-3${\beta}$, 6${\beta}$-diol (5), stigmast-4-ene-3${\beta}$, 6${\alpha}$-diol (6), stigmast-5-ene-3${\beta}$, 7${\alpha}$, 20$\xi$-triol (7) by spectral analysis and comparison with the published data. These compounds have not been reported from genus Ailanthus, whereas compound 7 was identified by NMR for the first time. In addition, the $95\%$ ethanol extract and compounds from the fruits of Ailanthus altissima SWINGLE were assayed for in vitro antimicrobial activity. The extract was potent active against the assayed bacteria while compounds 3 and 7 exhibited moderate activity.