• 약학회지
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• 제43권3호
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• pp.334-341
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• 1999

Thyroid peroxidase is a biochemical target protein for the antithyroid drugs. Ethanol extracts from one hundred and thirty seven natural products were screened for the inhibition of thyroid peroxidase activity. Thyroid peroxidase was purified from porcine thyroids, and the inhibition of peroxidase activity was evaluated using guaiacol oxidation (C-C coupling) assay. Twenty one natural products expressed a remarkable inhibition (>50%) of peroxidase activity at $330{\mu\textrm{g}}$ solid weight/m. The 50% inhibitory concentration ($IC_{50}$) of 70% ethanol extract from six potent natural products ranged from 3.1 to $31.2{\;}{\mu\textrm{g}}$ solid weight/m, in contrast to the range ($0.33~0.54{\;}{\mu\textrm{g}}/ml$) of $IC_{50}$ values fro catechin and epigallocatechin gallate as positive controls. Noteworthy, the extract of Camellia taliensis showed irreversible inhibition of the enzyme. It is suggested that extract from some natural products such as Camellia taliensis, Rheum undulatum or Euphorbia perinensis, exhibiting a potent inhibition of peroxidase activity, may be developed as sources of potent antithyroid agents.

• Journal of Microbiology and Biotechnology
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• 제9권4호
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• pp.525-528
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• 1999

Mutagenic activities of extracts from the filtrate of the cultured broth (PI-I), mycelia (pI-II), and the fruiting bodies (PI-III) of Phellinus igniarius were examined by Ames/Salmonella tests. No mutagenic activity was found in Salmonella typhimurium strains TA98 and TA100, either with or without S9 activation. In contrast, PI-I, PI-II, and PI-III showed inhibitory effects on the mutagenic activities by the directly-acting mutagens, 4-nitro-ο-phenylenediamine(NPD) and sodium azide ($NaN_3$), and also by the indirectly-acting mutagens, 2-aminofluorene (2-AF) and benzo[a]pyrene (B[a]P). These results suggest that P. igniarius possesses some antimutagenic activity and may contain some chemopreventive agents.

• Archives of Pharmacal Research
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• 제23권5호
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• pp.477-481
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• 2000

The cytotoxicity of crude insect drugs was measured using HeLa cells originating from human cervix and uterine cancer. using the dye uptake assay in order to find potential anticancer agents. Three kinds of extracts (buffer, methanol and ethylacetate) were prepared from 26 insects and used as raw materials for the activity assay. Among these, the buffer extracts from Tabanus, Mylabris and Huechys showed a potent anticancer activity, and those from Catharsius, Red ant, Scorpion, Tabanus and Vespae Nidus showed a strong L-amino acid oxidase (AAO) activity as well as cytotoxicity. In contrast, buffer extracts from Gryllotalpa orientalis and Apriona germari larvae showed greater/more rapid Hela cell growth than that of other insects.

• Bulletin of the Korean Chemical Society
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• 제32권3호
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• pp.1022-1026
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• 2011

The syntheses of DTPA-bis(amide) conjugates of phosphonated cyclohexane moieties (5a-d) and their Gd(III) complexes of the type $[Gd(L)(H_2O)]{\cdot}nH_2O$ (6a-d; L = 5a-d) are described. All new compounds have been characterized by microanalysis and spectroscopic techniques. High $r_1$ relaxivities of aqueous solutions of 6a-d are observed to be in the range of $10.7-18.3\;mM^{-1}sec^{-1}$, which compare much better than that of $Omniscan^{(R)}$ ($r_1=3.90\;mM^{-1}sec^{-1}$).

• Bulletin of the Korean Chemical Society
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• 제30권6호
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• pp.1305-1308
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• 2009

The experimental particle samples included ($Mn_{0.1}Fe_{0.9}$)O-$Fe_2O_3$ and FeO-($Gd_{0.1}Fe_{0.9}$)$_2O_3$ with $Mn^{2+}\;and\;Gd^{3+}$ substitutions in inverse spinel $Fe_3O_4$. A lecithin surfactant was adsorbed onto the magnetic particles by ultrasonication. The samples prepared showed excellent dispersibility at the mean size of 13 nm; their saturation magnetization values were 63 emu/g for the bare and Mn-substituted magnetites, and 56 emu/g for the Gd-substituted magnetite. The crystal structure of the substituted magnetites was very similar to that of the bare magnetite, due to a small amount of 0.1 mole fraction substituted in synthesizing the magnetite. The magnetite fluids, according to T2-weighted MR images, effectively diminished the signal intensity in the liver and spleen of Sprague-Dawley rats.

• Bulletin of the Korean Chemical Society
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• 제30권7호
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• pp.1445-1451
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• 2009

New benzotriazoles (5-8) or dibenzodiazepine derivatives (11-18) were synthesized starting from 3-[(2-amino- 4,5-disubstitutedphenyl)amino]-5,5-disubstitutedcyclohex-2-enones (1-4) through internal coupling of their diazonium salts or internal Mannich reaction in the presence of aromatic aldehydes. Pharmacological evaluation of benzotriazole and dibenzodiazepine derivatives for their clozapine-like properties revealed that dibenzodiazepine 11 bearing 4-bromophenyl group exhibited the same antipsychotic activity as the reference drug clozapine while the activity of benzotriazole 7 was 25% lesser than that of clozapine. Moreover, compounds 7 and 11 did not show significant CNS depressant activity as well as no or slight neurotoxicity on contrast to clozapine when tested in mice using forced swim, rotarod and horizontal screen tests.

• Tuberculosis and Respiratory Diseases
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• 제58권6호
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• pp.543-553
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• 2005

Radiological analysis of chest lesions detected on chest radiographs or CT scans begins with their classification into parenchymal, pleural, or extrapleural lesions according to their presumed origin. The mediastinum is divided anatomically into the anterior, middle, and posterior mediastinal compartments, and localizing a mediastinal mass to one of these divisions can facilitate their differential diagnosis. A differential diagnosis of a mediastinal mass is usually based on a number of findings, including its location; the structure from which it is arising; whether it is single, multifocal (involving several different areas or lymph node groups), or diffuse; its size and shape; its attenuation (fatty, fluid, soft-tissue, or a combination of these); the presence of calcification along with its characteristics and amount; and its opacification following the administration of contrast agents.

• Macromolecular Research
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• 제9권6호
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• pp.332-338
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• 2001

Waterborne polyurethane as a new polymer electrolyte was synthesized by using relatively hydrophilic polyols. The morphology of polyurethane was changed as it was dispersed in water. In contrast to polyurethane ionomer, waterborne polyurethane did not form an ionic cluster but produced a binary system composed of hydrophilic and hydrophobic groups. In the colloidal system, the former and the latter existed at outward and inward, respectively. Waterborne polyurethane was prepared from poly(ethylene glycol) (PEG) /poly(propylene glycol) (PPG) copolymer, 4,4'-diphenylmethane diisocyanate(MDI), ethylene diamine as a chain extender, and three ionization agents, 1,3-propane sultone, sodium hydride and lithium hydroxide. PEG/PPG copolymer was used for suppressing the crystallinity of PEG and N-H bond was ionized for increasing the electrochemical stability of polyurethane. Low molecular weight poly(ethylene glycol) and poly(ethylene glycol dimethyl ether) (PEGDME) were used as plasticizers. DSC, FT-IR and $^1$H-NMR of the waterborne polyurethane were measured. Also, the ionic conductivity of solid polymer electrolytes based on waterborne polyurethane and various concentrations of low molecular weight poly(ethylene glycol) or PEGDME were measured by AC impedance.

• Ocean and Polar Research
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• 제43권3호
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• pp.165-178
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• 2021

Gadolinium (Gd), one of a rare earth element (REE), has been widely used worldwide since the 1980s, as a resource material for contrast agents injected into examiners of magnetic resonance imaging (MRI) test. The organic complexed form of Gd shows an extremely stable behavior in natural environment (water), so is known that the artificial Gd from medical uses is not removed from the waste water treatment plant (WWTP) and eventually introduced into the ocean through the estuary. Since the 1990s, some previous studies have often been conducted on Gd anomalies in natural water and their effects an artificial origin from land or metropolitan areas, but little research has been potential impacts on the ocean water. In this paper, we review and introduce recent studies related to Gd anomaly in natural water and related marine effects, and also propose the future research directions.

• 대한약학회:학술대회논문집
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• 대한약학회 2003년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2-2
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• pp.178.1-178.1
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• 2003

6-Arylthio-/6-arylamino-4,7-dioxobenzothiazoles were synthesized and tested for in vitro antifungal activity against Candida species and Aspergillus niger. 6-Arylamino-4,7-dioxobenzothiazoles showed, in general, more potent antifungal activity than 6-arylthio-4,7-dioxobenzothiazoles. The 6-arylamino-substituted compounds exhibited the greatest activity. In contrast, 6-arylthio-, 2-/5-methyl-or 5-methoxy-moieties of compounds did not improve their antifungal activity significantly. The results of this study suggest that 6-arylamino-4,7-dioxobenzothiazoles would be potent antifungal agents