• Bulletin of the Korean Chemical Society
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• v.32 no.1
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• pp.169-174
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• 2011

The synthesis of new pyrazolyl and cyclopropyl derivatives of purpurin-18 methyl ester and purpurin-18-N-butylimide 1a, 1b, 2a, 2b and 8 is described. The new compounds were characterized by NMR, UV-vis spectroscopy and mass spectrometry. UV-vis spectra of the new compounds showed long wavelength absorption of ranges 692 - 708 nm ($\lambda_{max}$). Photodynamic effects of the chlorin derivatives 1a, 1b, 2a and 2b were investigated by WST-1 assay in A549 cells, and showed good photodynamic activities with high photocytotoxicity and low cytotoxicity in the dark. In comparison between pyrazolyl and cyclopropyl derivatives, purpurin-18 methyl ester compounds 1a and 1b showed comparable photocytotoxicity result of the cell viabilities, otherwise, pyrazolyl derivative of purpurin-18-N-butylimide 2a showed better cell viabilities than those of cyclopropyl derivative 2b. And cyclopropyl derivative of purpurin-18-N-butylimide 2b showed higher dark cytotoxicity than that of others.

• Bulletin of the Korean Chemical Society
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• v.20 no.3
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• pp.355-361
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• 1999

To improve the volatility and stability of lead complexes, the principle of stabilization by saturating the metal coordination sphere by intramolecular coordination through a β-diketonates with an ethereal group has was tested. Several new lead complexes with alkoxyalkyl-substituted β-diketonates, Pb(R1C(O)CHC(O)(CH2)3OR2)2(Rl=t-Bu, Me, OMe, i-Pr, R2=Me, Et), or carboxylate, Pb(OC(O)(CH2)3OEt)2, were prepared by the reaction between Pb(OAc)2 and corresponding alkoxyalkyl-substituted β-diketonates, and they were found to have a viscous liquid phase. The nature of the head (β-diketonate or carboxylate) or tails and substituents of β-diketonates appeared not to be important for the formation of the liquid phase. It is worth mentioning that Pb(OAc)2, which has limited use due to its low solubility, was successfully adopted as a starting material for the preparation of new lead complexes. Easy hydrolysis, reaction with HCl, and 13C NMR spectra indicated that tail portions were not coordinated to the metal as a copper derivative, Cu(t-BuC(O)CHC(O)(CH2)3OMe)2. All these complexes were not volatile enough for the MOCVD experiments, but a methyl derivative, Pb(MeC(O)CHC(O)(CH2)3OEt)2, showed some sublimation. The methoxy derivative, Pb(MeOC(O)CHC(O)(CH2)3OEt)2, was thermally unstable due to possible equilibrium between species coordinating with a keto oxygen atom and an ethereal atom of a methoxy group, which was confirmed by IR and 13C NMR spectra.

• Journal of the Korean Society for Precision Engineering
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• v.18 no.1
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• pp.171-179
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• 2001

The purpose of this paper is the derivation and development of the new definitions and methods for the new estimation of robustness for the systems having structured uncertainties. This proposition adopts the theoretical analysis of the Lyapunov direct methods, that is, the sign properties of the Lyapunov function derivative integrated along finite intervals of time, in place of the original method of the sign properties of the time derivative of the Lyapunov function itself. This is the new sufficient criteria to relax the stability condition and is used to generate techniques for the robust design of control systems with structured perturbations. The systems considered are assumed to be nominally linear, with time-variant, nonlinear bounded perturbations. This new techniques demonstrate the improvement of robustness bounds from the numerical results.

• Bulletin of the Korean Mathematical Society
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• v.47 no.6
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• pp.1171-1180
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• 2010

In this paper we obtain some new characterizations for weighted Bergman spaces in the unit ball of $\mathbb{C}^n$.

• Toxicological Research
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• v.13 no.4
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• pp.423-433
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• 1997

The acute and subacute toxicity of water soluble dimethyl dimethoxy biphenylate derivative (new DDB), hepatitis therapeutics, were investigated in SD rats. In the acute toxicity study, body weights and clinical signs were observed for 7 days after the intravenous injection of new DDB at doses of 140, 182, 236, 307 and 400 mg/kg(r=1.3). Death. Severe convulsion, tremor and decrease motor activity were observed in almost treated groups (except the 140 mg/kg treated group). Changes of body weight in treated groups were not significantly different from control group. Autopsy of survived animals revealed no abnormal gross findings related to new DDB. As a results, the $LD_{50}$ values of new DDB were 244.1 mg/kg for male and 232.5 mg/kg for female. In subacute toxicity study, body weights and clinical signs were observed after intravenous injection of new DDB at doses of 57, 75 and 100 mg/kg/day for 28 days. Death, decrease motor activity and tremor were observed above 75 mg/kg treated groups. Statistically significant changes were observed in hematological and biochemical parameters of new DDB-treated groups; however, these changes were within normal range and had no relationship with dosage. Several abnormal findings were observed in microscopic examination of tissue; however, these findings were not caused by new DDB but environmental factor. The no toxic dose level of new DDB were estimated to be 57 mg/kg/day in this study.

• Natural Product Sciences
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• v.5 no.2
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• pp.93-96
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• 1999

A new ergosteryl myristate (1) and ergosterol (2) have been isolated from the organic extract of the mycelium of unidentified marine algicolous fungus, isolate MF001. The structure of a new compound was assigned on the basis of comprehensive spectroscopic analyses and chemical synthesis.

• Natural Product Sciences
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• v.26 no.4
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• pp.279-282
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• 2020

Chemical investigation of the methanol extract of Koordersiodendron pinnatum Merr. leaves resulted a new naphthalene derivative, (Z)-4-(tetradec-3-enyl)naphthalene-1,2,7-triol (1), together with three known compounds, ��-sitosterol (2), 20-epibryonolic acid (3), and scopoletin (4). The structure of the new compound was elucidated based on spectroscopic evidence. The isolated compounds (1-4) were tested their cytotoxic activities against the P-388 murine leukemia cell line and compound 1 has highest activity with IC50 1.94 μM.

• The Journal of Korean Medicine
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• v.23 no.2
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• pp.39-56
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• 2002

Objective : The aim of this study is to investigate the inhibitory effect of lnjinchunggantang-derivative on acute and sub-acute hepatic fibrosis induced by $CCl_4$, and to compare the efficiency of lnjinchunggantang-derivative, Salviae Radix and Scirpi Tuber.Zeloariae Rhizoma on acute and sub-acute hepatic fibrosis induced by $CCl_4$. Method : Western blotting for collagen type N, quantitative RT-PCR and gross & histological findings on liver tissue (Hematoxylin & Eosin stain, Reticulin stain, Masson-Trichrome stain) were studied. Results : In the study on collagen type N expression, lnjinchunggantangcderivative, Scirpi Tuber.Zeloariae Rhizoma and Salviae Radix showed inhibitory effect in western blotting. In quantitative RT-PCR assay, lnjinchunggantang-derivative showed inhibitory effect on collagen type N expression in acute hepatic fibrosis model, whereas lnjinchunggantang-derivative, Scirpi Tuber.Zeloariae Rhizoma and Salviae Radix showed inhibitory effect on collagen type N expression in sub-acute hepatic fibrosis model. In the gross findings of acute and sub-acute hepatic fibrosis models,lnjinchunggantang-derivative, Salviae Radix and Scirpi Tuber. Zeloariae Rhizoma showed inhibitory effect on hepatic fibrosis in the order. In the histological findings of acute and sub-acute hepatic fibrosis models in Hematoxylin & Eosin, Reticulin and Masson-Trichrome staining, the liver of $CCl_4$-only group showed atrophy and necrotic change with white nodules whereas that of $CCl_4$+ Injinchunggantang-derivative showed no significant histological change with well preservation of the tone of the tissue, and Scirpi Tuber. Zeloariae Rhizoma and Salviae Radix group showed minimal fibrotic changes. In the scoring system of the extent of the inhibition of the hepatic fibrosis, lnjinchunggantang-derivative group showed statistically significant inhibitory effect(p<0.05) whereas Scirpi Tuber.Zeloariae Rhizoma and Salviae Radix group showed no statistically significant effect in the acute hepatic fibrosis model. In the sub-acute hepatic fibrosis model, lnjinchunggantang-derivative, Scirpi Tuber.Zeloariae Rhizoma and Salviae Radix group showed statistically significant effect (p<0.01). Conclusion : These results show that lnjinchunggantang-derivative, Salviae Radix and Scirpi Tuber.Zeloariae Rhizoma have inhibitory effect in the order on hepatic fibrosis induced by $CCl_4$ by suppressing the expression of collagen type N, ultimately preventing liver cirrhosis. To obtain more credible results in this experiment, developement of a new experimental model more similar to human hepatic fibrosis is still needed.

• Journal of applied mathematics & informatics
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• v.6 no.3
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• pp.685-696
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• 1999

We present local and semilocal convergence results for New-ton's method in a Banach space setting. In particular using Lipschitz-type assumptions on the second Frechet-derivative we find results con-cerning the radius of convergence of Newton's method. Such results are useful in the context of predictor-corrector continuation procedures. Finally we provide numerical examples to show that our results can ap-ply where earlier ones using Lipschitz assumption on the first Frechet-derivative fail.

• Bulletin of the Korean Chemical Society
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• v.28 no.3
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• pp.471-473
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• 2007