• Communications of the Korean Mathematical Society
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• v.23 no.2
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• pp.161-167
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• 2008

A ring R is called an $I_0$-ring if each left ideal not contained in the Jacobson radical J(R) contains a non-zero idempotent. If, in addition, idempotents can be lifted modulo J(R), R is called an I-ring or a potent ring. We study whether these properties are inherited by some related rings. Also, we investigate the structure of potent rings.

• Natural Product Sciences
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• v.5 no.2
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• pp.104-106
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• 1999

The chloroform fraction of the aqueous extract of the fresh leaves of Vitex negundo by bioactivity guided isolation yielded a pure compound, rotundial (1) which has shown potent mosquito repellent activity. Using spectral data (UV, IR, $^1H\;&\;^{13}C$ NMR and MS) its structure has been elucidated.

• Archives of Pharmacal Research
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• v.25 no.2
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• pp.151-153
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• 2002

Three pseudoguaianolide type sesquiterpenes, bigelovin(1), 2,3-dihydroaromaticin (2), and ergolide (3) were isolated as inhibitory constituents against inducible nitric oxide synthase (iNOS) from the flowers of Inula britannica var. chinensis. Bigelovin (1) exhibited a highly potent inhibitory activity on lipopolysaccharide (LPS)-induced iNOS in murine macrophage RAW 264.7 cells with an $IC_{50}$ value of 0.46 mM, which is about 8 times more potent than the known selective inhibitor of iNOS, $L-N^6-(1-iminoethyl)Iysine{\;}(IC_{50}{\;}3.49{\;}{\mu}M)$. 2,3-Dihydroaromaticin (2) and ergolide (3) also exhibited potent inhibitory activities on LPS-induced iNOS with $IC_{50}$ values of 1.05 and $0.69{\;}{\mu}M$, respectively.

• YAKHAK HOEJI
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• v.29 no.5
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• pp.253-259
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• 1985

In order to search a more active and safer compound, piperine derivatives with substituents in piperidine residue were synthesized and evaluated on CNS depressant activity. N-Piperoyl-2-methylpiperidine (I) and N-piperoyl-3-methylpiperidine (II) were potent in strychnine-induced convulsion. Compound I and N-piperoyl-3-hydroxypiperidine (IX) exhibited a potent inhibitory effect againt pentetrazoleinduced convulsion and a significant prolongation effect of hexobarbital-induced sleeping time. The hydroxy derivatives were more toxic than the methyl derivatives.

• Bulletin of the Korean Chemical Society
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• v.33 no.8
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• pp.2741-2747
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• 2012

A new series of 2,5-disubstituted-1,3,4-thiadiazoles 6a-i was synthesized by overnight stirring various 1,4-disubstituted thiosemicarbazides 5a-i in polyphosphoric acid followed by neutralization. The structures of newly synthesized compounds 5a-i and 6a-i were characterized by IR, $^1H$ and $^{13}C$ NMR, elemental analysis and mass spectrometric studies. All the synthesized compounds were evaluated for their urease and acetylcholine esterase inhibition activities. Thiosemicarbazides 5a-i are found to possess excellent potential for urease inhibition, more than the standard drug. Thiosemicarbazides 5a-i are more potent urease inhibitor than their cyclic analogues thiadiazoles 6a-i. Almost all of the compounds are excellent inhibitors of acetylcholine esterase. The inhibition of acetylcholine esterase of compounds 5a, 5c, 5d, 5g, 5i, 6e, 6f, 6g, and 6i is much more than that of standard drug.

• Applied Biological Chemistry
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• v.50 no.3
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• pp.178-186
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• 2007

42 compounds such as ester, sulfonyl ester, phosphoyl ester and ether derivatives of 4-isopropylphenol (I) and 2-isopropylphenol (II) were synthesized. These derivatives were identified by IR, GC/MS and $^{1}H-NMR$ spectra. Their in vitro antifungal activities were tested against 10 plant pathogenic fungi. Among them, several compounds showed potent in vitro antifungal activity. The selected compounds showing potent in vitro antifungal activity were tested for their in vivo antifungal acitvities against 5 plant diseases such as rice blast, rice sheath blast, cucumber anthracnose, cucumber gray mold and tomato late blight. As a result, 2-isopropylphenyl piperonyloate (II-7a) showed a potent in vivo antifungal activity against cucumber anthracnose and tomato late blight, 4-isopropylphenyl 4-methoxybenzenesulfonate (I-6b) effectively inhibited the development of rice blast.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.17 no.2
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• pp.12-30
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• 2004

This study was carried out to investigate the effects of SMG on the in vitro and in vivo inflammatory reactions. In experiment I, in vitro tests, ethanol extract of SMG showed potent radical scavenging activity tested by DPPH(I,1-diphenyl-2-picryl-hyrazyl) method and inhibited the lipopolysaccharide-induced gene expressions of interleukin-1${\beta}$, interleukin-6 and tumor necrosis factor-${\alpha}$ (above 50$\%$ at a concentration of 50㎍／㎖) by the macrophage RAW 246.7 cells. Among the herbal ingredients of SMG, ethanol extracts of Scutellaria baicalensis, Paeonia lactiflora, Glycyrrhiza glabra showed potent radical scavenging activity. And Glycyrrhiza glabra and Scutellaria baicalensis showed potent inhibitory activity of nitric oxide production. Especially, ethanol extract of Scutellaria baicalensis inhibited the gene expression of IL-1${\beta}$, IL-6 and TNF-${\alpha}$. In cyclooxygenase-2 assay, Scutellaria baicalensis and Glycyrrhiza glabra showed the potent inhibition of prostaglandin E2 generation. In experiment 2, in vivo tests, SMG showed inhibitory effects on vascular permeability (28.7$\%$) and leukocyte migration (11.5$\%$). These results mean that SMG has a anti-inflammatory effects by it's inhibitory effects of leukocyte migration and vascular permeability as well as it's inhibitory effects of lipopolysaccharide-induced gene expression of IL-1${\beta}$, IL-6 and TNF-${\alpha}$, and radical scavenging activity. Therefore, I expect that SMG may be used as a effective drug for treatment on inflammation.

• Biomolecules & Therapeutics
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• v.9 no.3
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• pp.183-187
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• 2001

Nitric oxide (NO) produced in large amounts by the inducible nitric oxide synthase (iNOS) is known to be responsible for the vasodilation and hypotension observed in septic shock and inflammation. The inhibitors of iNOS, thus, may be useful candidate for the treatment of inflammatory diseases accompanied by the overproduction of NO. We prepared alcoholic extracts of Chinese medicinal plants and screened their inhibitory activity against NO production in lipopolysaccharide (LPS)-activated macrophages. Among the 80 kinds of extracts of herbal drugs, 15 extracts showed potent inhibitory activity of NO production above 80% at the concentration o$50\mu\textrm{g}/ml$. These potent extracts showed dose dependent inhibition of NO production of LPS-activated macrophages at the concentration of 50, 30,$10\mu\textrm{g}/ml$. Especially, Rhus chinensis, Senecio scandens and Wikstroemia indica showed most potent inhibition above 50% at the concentration of $10\mu\textrm{g}/ml$. These plants are promising candidates for the study of the activity-guided purification of active compounds and would be useful for the treatment of inflammatory diseases and endotoxemia accompanying the overproduction of NO.

• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2487-2490
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• 2013

SA51, a medium potency inhibitor of protein tyrosine phosphatase 1B (PTP1B), was identified to be a potent inhibitor of $I{\kappa}B$ kinase ${\beta}$ ($IKK{\beta}$). Consistent with this, SA51 prevented lipopolysaccharide (LPS)-induced breakdown of $I{\kappa}B{\alpha}$ in macrophages. The effects of SA51 in mice were compared with those of structurally related compounds, SA18 and SA32, which were previously reported as inhibitors of both enzymes - less potent against $IKK{\beta}$ but more potent against PTP1B compared to SA51. SA51 improved glucose tolerance and lipid parameters in mice, consistent with the results reported for $IKK{\beta}^{+/-}$ mice. In contrast, SA18 and SA32 showed anti-obesity effects without anti-diabetic effects. Collectively, the effects of SA51 could be due largely to the inhibition of $IKK{\beta}$, whereas SA18 and SA32 may be more likely to inhibit PTP1B, consistent with their relative in vitro inhibitory effects.

• International Journal of Oral Biology
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• v.34 no.4
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• pp.215-222
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• 2009

Medial vestibular nucleus (MVN) neurons are involved in the reflex control of the head and eyes, and in the recovery of vestibular function after the formation of peripheral vestibular lesions. In our present study, whole cell patch clamp recordings were carried out on MVN neurons in brainstem slices from neonatal rats to investigate the actions of a group I metabotropic glutamate receptor (mGluR) agonist upon synaptic transmission and ionic currents. Application of the mGluR I agonist (S)-3,5- dihydroxyphenylglycine (DHPG) increased the frequency of miniature inhibitory postsynaptic currents (mIPSCs) but had no effect upon amplitude distributions. To then identify which of mGluR subtypes is responsible for the actions of DHPG in the MVN, we employed two novel subtype selective antagonists. (S)-(+)-$\alpha$-amino-a-methylbenzeneacetic acid (LY367385) is a potent competitive antagonist that is selective for mGluR1, whereas 2-methyl-6-(phenylethynyl)-pyridine (MPEP) is a potent noncompetitive antagonist of mGluR5. Both LY367385 and MPEP antagonized the DHPG-induced increase of mIPSCs, with the former being more potent. DHPG was also found to induce an inward current, which can be enhanced under depolarized conditions. This DHPG-induced current was reduced by both LY367385 and MPEP. The DHPG-induced inward current was also suppressed by the PLC blocker U-73122, the $IP_3$ receptor antagonist 2-APB, and following the depletion of the intracellular $Ca^{2+}$ pool by thapsigargin. These data suggest that the DHPG-induced inward current may be mainly regulated by the intracellular $Ca^{2+}$ store via the PLC-$IP_3$ pathway. In conclusion, mGluR I, via pre- and postsynaptic actions, may modulate the excitability of the MVN neurons.