• Journal of Power Electronics
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• v.17 no.6
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• pp.1553-1562
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• 2017

For the purpose of enhancing the performance of the shunt active power filter (APF), this paper presents a novel Fast Weighted Compound Control (FWCC) strategy based on the synchronous frame. In this control strategy, the proposed new repetitive controller can work faster and more stably by reducing the internal model cycle and introducing a damping coefficient. In addition, the harmonic detector can be removed to simplify the structure of the APF owing to the improvements. Furthermore, a proportional-integral (PI) controller is added to work in parallel with the repetitive controller by using a weighted ratio. Then, a convergence speed analysis and design algorithm are given in detail. Simulation and experimental results show that the harmonic distortion is reduced from 2.91% to 1.89%. In addition, the content for each of the characteristic harmonic orders has decreased by more than three times.

• Journal of the Korean Magnetic Resonance Society
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• v.22 no.4
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• pp.144-148
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• 2018

Catalytic enzyme Pyrazinamidase (PncA) from Mycobacterium tuberculosis can hydrolyze substrate pyrazinamide (PZA) to pyrazoic acid (POA) as active form of compound. Using NMR spectroscopy, pH-dependent catalytic properties were monitored including metal binding mode during converting PZA to POA. There seems to be a conformational change through zinc binding in active site from the perturbation of peak intensities in series of 2D HSQC spectra the conformation changes through zinc binding.

• Journal of Microbiology and Biotechnology
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• v.30 no.4
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• pp.552-560
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• 2020

Human carbonic anhydrase (CA) isozyme II has been used as protein target for disorder treatment including glaucoma. Current clinically used sulfonamide-based CA inhibitors can induce side effects, and so alternatives are required. This study aimed to investigate a natural CA inhibitor from Murraya paniculata. The previously developed yeast-based assay was used to screen 14 compounds isolated from M. paniculata and identified by NMR analysis for anti-human CA isozyme II (hCAII) activity. Cytotoxicity of the compounds was also tested using the same yeast-based assay but in a different cultivation condition. Two flavonoid candidate compounds, 5, 6, 7, 8, 3', 4', 5'-heptamethoxyflavone (4) and 3, 5, 7, 8, 3', 4', 5'-heptamethoxyflavone (9), showed potent inhibitory activity against hCAII with a minimal effective concentration of 10.8 and 21.5 μM, respectively, while they both exhibited no cytotoxic effect, even at the highest concentration tested (170 μM). The results from an in vitro esterase assay of the two candidates confirmed their hCAII inhibitory activity with IC₅₀ values of 24.0 and 34.3 μM, respectively. To investigate the potential inhibition mechanism of compound 4, in silico molecular docking was performed using the FlexX and SwissDock software. This revealed that compound 4 coordinated with the Zn²⁺ ion in the hCAII active site through its methoxy oxygen at a distance of 1.60 Å (FlexX) or 2.29 Å (SwissDock). The interaction energy of compound 4 with hCAII was -13.36 kcal/mol. Thus, compound 4 is a potent novel flavonoid-based hCAII inhibitor and may be useful for further anti-CAII design and development.

• Archives of Pharmacal Research
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• v.27 no.12
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• pp.1220-1225
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• 2004

The overproduction of nitric oxide (NO) by inducible nitric oxide synthase (iNOS) is known to be responsible for vasodilation and hypotension observed in septic shock and inflammation. Inhibitors of iNOS, thus, may be useful candidates for the treatment of inflammatory diseases accompanied by overproduction of NO. In the course of screening oriental anti-inflammatory herbs for the inhibitory activity of NO synthesis, a crude methanolic extract of Curcuma zedoaria exhibited significant activity. The activity-guided fractionation and repetitive chromatographic procedures with the EtOAc soluble fraction allowed us to isolate three active compounds. They were identified as 1,7-bis (4-hydroxyphenyl)-1,4,6-heptatrien-3-one (1), procurcumenol (2) and epiprocurcumenol (3) by spectral data analyses. Their concentrations for the 50% inhibition of NO production $(IC_{50})$ in lipopolysaccharide (LPS)-activated macrophages were 8, 75, 77 ${\mu}M$, respectively. Compound 1 showed the most potent inhibitory activity for NO production in LPS-activated macrophages, while the epimeric isomers, compound 2 and 3 showed weak and similar potency. Inhibition of NO synthesis by compound 1 was very weak when activated macrophages were treated with 1 after iNOS induction. In the immunoblot analysis, compound 1 suppressed the expression of iNOS in a dose-dependent manner. In summary, 1,7-bis (4-hydroxyphenyl)-1,4,6-heptatrien-3-one from Curcuma zedoaria inhibited NO production in LPS-activated macrophages through suppression of iNOS expression. These results imply that the traditional use of C. zedoaria rhizome as anti-inflammatory drug may be explained at least in part, by inhibition of NO production.

• Journal of Microbiology and Biotechnology
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• v.22 no.6
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• pp.872-881
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• 2012

The inhibitory effect of the Klebsiella pneumoniae ATCC 13883 strain caused by the hexane extract of Halimeda discoidea (Nor Afifah et al., 2010) was further evaluated by means of the microscopy view and its growth curves. The morphological changes of the K. pneumoniae ATCC 13883 cells were observed under the scanning electron microscope (SEM) and transmission electron microscope (TEM) after they were treated at minimum inhibitory concentration (MIC; 0.50 mg/ml) (Nor Afifah et al., 2010) for 12, 24, and 36 h. The results showed the severity of the morphological deteriorations experienced by the treated cells. The killing curve assay was performed for 48 h at three different extract concentrations (1/2 MIC, MIC, and 2 MIC). An increase in the extract concentration of up to 2 MIC value did significantly reduce the number of cells by approximately 1.9 $log_{10}$, as compared with the control. Identification of the potential compounds of the extract responsible for the antibacterial activity was carried out through the gas chromatography-mass spectrum (GC-MS) analysis of the active subfraction, and the compound E-15-heptadecenal was identified and suggested as the most potential antibacterial compound of this extract. The subsequent cellular degenerations showed by the data might well explain the inhibitory mechanisms of the suggested antibacterial compound. All of these inhibitory effects have further proven the presence of an antibacterial compound within H. discoidea that can inhibit the growth of K. pneumoniae ATCC 13883.

• Journal of Pharmacopuncture
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• v.19 no.3
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• pp.239-245
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• 2016

Objectives: This study was conducted to clarify the effects of agarwood on histamine release from mast cells in rats and on the scratching behaviors in mice. Methods: Histamine release from rat mast cells induced by compound 48/80 or concanavalin A (Con A) and compound 48/80-induced scratching behavior in mice were examined to investigate the effects of agarwood. The hyaluronidase activity and the 3',5'-cyclic adenosine monophosphate (cAMP) levels in mast cells were examined to investigate the mechanisms for the inhibition of histamine release. The correlation between the inhibitory effects of agarwood on histamine release and the content of its typical ingredients, a 2-(2-phenylethyl)chromone derivatives, was analyzed using thin-layer chromatography. Results: Agarwood showed an inhibitory effect on mast-cell histamine release induced by compound 48/80 or Con A without any effect on hyaluronidase activity; this effect involves an increase in the cAMP levels in mast cells. Oral administration of agarwood showed an inhibitory effect on compound 48/80-induced scratching behavior in mice. The inhibitory effects of agarwood on histamine release were quite different, depending on the area where the agarwood was produced, its quality, and its market price. No correlation was found between the inhibitory effects of agarwood on histamine release and the typical ingredients of agarwood, which are 2-(2-phenylethyl)chromone derivatives. Conclusion: These results show that agarwood inhibits histamine release from mast cells partially through an increase in the cAMP levels in cells. We suggest that some active ingredients of agarwood must be effective on oral intake and that agarwood can be used to treat patients with a number of conditions, including urticaria, atopic dermatitis, and bronchial asthma, in which an increase in histamine release occurs. Differences in the pharmacological effects of this crude drug among markets may provide important information for the quality control of this herbal medicine.

• Journal of Animal Reproduction and Biotechnology
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• v.38 no.3
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• pp.167-176
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• 2023

Background: A breast cancer is the second leading cause of cancer death in women worldwide and among different types of breast cancers, triple-negative breast cancer (TNBC) has a poor prognosis. Methods: We investigated the potential of ginsenoside compound K (CK), an active ingredient in the bio-transformed ginsenoside, to be used as a therapeutic ingredient by examining the effects of CK on cell proliferation, apoptosis, and cancer-related gene expressions in breast cancer cells. Results: From the results of treating MCF-7, an ER and PR-positive breast cancer cells, and MDA-MB-231 (TNBC) with CK at a concentration of 0-100 µM, the half maximal inhibitory concentration (IC₅₀) values for each cell were 52.17 µM and 29.88 µM, respectively. And also, it was confirmed that cell migration was inhibited above the IC50 concentration. In addition, fluorescence analysis of Apoptosis/Necrosis showed that CK induced apoptosis rather than necrosis of breast cancer cells. Through qPCR, it was confirmed that the expression of genes related to apoptosis and cell cycle arrest was increased in CK-treated breast cancer cells, and it acted more effectively on TNBC. However, the expression of genes related to tumor invasion and metastasis is also increased, so it is necessary to consider the timing of application of CK as a potential therapeutic anticancer compound. Conclusions: CK showed a stronger inhibitory effect in TNBC with poor prognosis but considering the high tumor invasion and metastasis-related gene expression, the timing of application of CK should be considered.

• Herbal Formula Science
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• v.26 no.3
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• pp.237-250
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• 2018

Objectives : This study is a pharmacological network approach, aimed to identify the potential active compounds contained in Curcumae Radix, and their associated targets, to predict the various bio-reactions involved, and finally to establish the cornerstone for the deep-depth study of the representative mechanisms. Methods : The active compounds of Curcumae Radix have been identified using Traditional Chinese Medicine System Pharmacology Database and Analysis Platform. The UniProt database was used to collect each of information of all target proteins associated with the active compounds. To find the bio-metabolic processes associated with each target, the DAVID6.8 Gene Functional classifier tool was used. Compound-Target and Target-Pathway networks were analyzed via Cytoscape 3.40. Results : The target information from 32 potential active compounds of Curcumae Radix was collected through TCMSP analysis. The active compounds interact with 133 target genes engaging in total of 885 biological pathways. The most relevant pathway was the lipid-related metabolism, in which 3 representative active compounds were naringenin, oleic acid, and ${\beta}-sitosterol$. The mostly targeted proteins in the lipid pathway were ApoB, AKT1 and PPAR. Conclusions : The pharmacological network analysis is convenient approach to predict the overall metabolic mechanisms in medicinal herb research, which can reduce the processes of various experimental trial and error and provide key clues that can be used to validate and experimentally verify the core compounds.

• Herbal Formula Science
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• v.31 no.4
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• pp.295-313
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• 2023

Objectives : While treatments for cancer are advancing, the development of effective treatments for cancer metastasis, the main cause of cancer patient death, remains insufficient. Recent studies on Dichroae Radix have revealed that its active ingredients have the potential to inhibit cancer metastasis. This study aimed to investigate the cancer metastasis inhibitory effect of Dichroae Radix using network pharmacological analysis. Methods : The active compounds of Dichroae Radix have been identified using Traditional Chinese Medicine System Pharmacology Database and Analysis Platform. The UniProt database was used to collect each of information of all target proteins associated with the active compounds. To find the bio-metabolic processes associated with each target, the DAVID6.8 Gene Functional classifier tool was used. Compound-Target and Target-Pathway networks were analyzed via Cytoscape 3.40. Results : In total, 25 active compounds and their 62 non-redundant targets were selected through the TCMSP database and analysis platform. The target genes underwent gene ontology and pathway enrichment analysis. The gene list applied to the gene ontology analysis revealed associations with various biological processes, including signal transduction, chemical synaptic transmission, G-protein-coupled receptor signaling pathways, response to xenobiotic stimulus, and response to drugs, among others. A total of eleven genes, including HSP90AB1, CALM1, F2, AR, PAKACA, PTGS2, NOS2, RXRA, ESR1, ESR2, and NCOA1, were found to be associated with biological pathways related to cancer metastasis. Furthermore, nineteen of the active compounds from Dichroae Radix were confirmed to interact with these genes. Conclusions : The results provide valuable insights into the mechanism of action and molecular targets of Dichroae Radix. Notably, Berberine, the main active ingredient of Dichroae Radix, plays a significant role in degrading AR proteins in advanced prostate cancer. Further studies and validations can provide crucial data to advance cancer metastasis prevention and treatment strategies.

• Korean Journal of Acupuncture
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• v.24 no.4
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• pp.151-162
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• 2007

Objectives : The purpose of this study was to examine the anti-allergic effect in vivo, and to observe single toxicity in mice of Armeniacae Semen herbal acupuncture solution (ASHA). Methods : We investigated anti DNP IgE-mediated passive cutaneous anaphylaxis in rodents and compound 48/80-induced active systemic anaphylatic shock in mice after treatment at both BL13 with ASHA of 25 ${\mu}{\ell}$(mice) or 50 ${\mu}{\ell}$(rats) 3 times for 5 days. To ascertain safety and toxicity of ASHA, we examined single toxicity test. In single test, three groups were treated with different dosages of ASHA (ASHA250, ASHA500 and ASHA1000) according to on Korean Food and Drug Administration, respectively. We observed attentively motality, abnormal clinical sign, body weight change, and organ weight of mice after ASHA treatment. Results : ASHA inhibited passive cutaneous anaphylaxis and active systemic anaphylatic shock by oral administration. During toxicity experiment period, there was no difference in body weight change, and organ weight among different dose groups. Death were not found in single test i.p. group. (ASHA250, ASHA500 and ASHA1000). Several individuals of single test i.p. group were observed yellow brown discharge around anus in early period after administration. Conclusions : These results indicate that ASHA have inhibition effects on passive cutaneous anaphylaxis and active systemic anaphylatic shock, and suggest that has some toxicity in high dosage.