• Journal of the Korean Ceramic Society
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• v.48 no.5
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• pp.412-417
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• 2011

Formation and characterization of hydroxyapatite-based porous ceramics derived from polymer pyroysis were investigated. Polymer based process is chosen for preparing porous hydroxyapatite-based ceramics having a high mechanical strength. The hydroxyapatite-based porous ceramic was prepared by a self-blowing process of a polymethylsiloxane with filler and pyrolyzed at above $1000^{\circ}C$. Biphasic material consisted of hydroxyapatite and CaO has been prepared by solid state reaction from calcium hydroxide($Ca(OH)_2$) and calcium hydrogen phosphate dihydrate($CaHPO_4{\cdot}2H_2O$) as a filler material. The influence of filler content on mechanical properties was evaluated. The change of crystalline phase, microstructure and mechanical properties were investigated and discussed.

• Analytical Science and Technology
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• v.34 no.4
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• pp.153-159
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• 2021

In this study, we describe the development of a new high-performance liquid chromatography (HPLC) method for the simultaneous analysis of six bioactive compounds (including gallic acid, epicatechin 3-gallate, quercitrin, afzelin, quercetin, and kaempferol) from Orostachys japonicus. The extraction method was investigated and optimization of the extraction time (min), solvent composition (%), and solvent to material ratio were conducted. As a result, 30 min extraction with 50% methanol and 40:1 mL/g of solvent: material ratio achieved the highest extraction efficiency with a yield of 3.32 mg/g. Furthermore, the developed HPLC method was validated and the correlation coefficient (R) values were within the satisfactory range of 0.9995-0.9999 over the linearity range of 1.53-417 ㎍/mL. The limit of detection and limit of quantification for the six active components were between 0.03-0.08 ㎍/mL and 0.08-0.26 ㎍/mL, respectively. With these newly optimized and developed methods, four batches of O. japonicus were analyzed to confirm the high extraction efficiency of the method and the feasibility of an application.

• Journal of Marine Bioscience and Biotechnology
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• v.15 no.1
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• pp.24-32
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• 2023

The Laminaria japonica Aresch (Sea tangle) belongs to the brown algae and has a long history as a food material in Asia, including Korea. Recent studies have found that the fermented Sea tangle extract (FST) inhibited the differentiation of osteoclasts and protected osteoblasts from oxidative damage. This study aims to explore the possibility that FST can induce the differentiation of osteoblasts and identify the responsible mechanism. According to our results, FST induced differentiation into osteogenic cells in the presence of osteoblastic MC3T3-E1 cells under non-toxic conditions.. This finding was confirmed by phalloidin staining, increased alkaline phosphatase activity, and calcium deposition. Additionally, it was found that this process was achieved by increasing the expression of key factors involved in osteoblast differentiation, such as runt-related transcription factor-2, osterix, β-catenin, and bone morphogenetic protein-2. Moreover, FST increased autophagy, which may contribute to the maintenance of the bone formation homeostasis, and is associated with the activation of the phosphatidylinositol 3-kinase/Akt and mitogen-activated protein kinase signaling pathways. Although further research about the bioactive substances contained in FST and the tests of their efficacy are required, the results of this study indicate that FST has incredible applicability as a functional material for maintaining the bone homeostasis.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.spc1
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• pp.103-106
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• 2006

Anthocyanins are water-soluble glycosides and acylglycosides of anthocyanidins, having different color variations due to its substitution patterns. Anthocyanins, present in various fruits, vegetables and crops as natural colorant, have been well characterized for its bioactive properties, anti-oxidant, anti-cancer, anti-proliferative and anti-inflammatory properties. During extraction and purification, the factors, such as pH, temperature, oxygen, light, enzymes, nucleophilic agents, sugar derivatives and co-pigments, have affected on anthocyanin stability. For this reason, the extraction method should be thoroughly checked for the qualitative/quantitative analysis of anthocyanin in particular plant material. To identify the optimum extraction method of cyanidin-3-glucoside, major anthocyanin of dark purple-colored grains, Oryza sativa cv. Heugjinjubyeo, Phaselous vulgaris, Phynchosia gngularis, Sesamum indium, Rhynchosia nulubilis and Lablab purpureus, reversed-phase HPLC analysis using solvent system of acetonitrile, methanol and water were accomplished.

• Journal of Ginseng Research
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• v.35 no.3
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• pp.368-374
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• 2011

American ginseng (Panax quinquefolius L.) is grown in some regions of the USA and Canada and marketed for its health promoting attributes. While cultivation of this plant species has taken place in North America for over 100 years, there are many challenges that need to be addressed. In this article, the current production method used by growers is described and the challenges and opportunities for research on this valuable plant are discussed. These include studies on pharmacological activity, genetic diversity within the species, genetic improvement of currently grown plants, molecular characterization of gene expression, and management of diseases affecting plant productivity. The current research developments in these areas are reviewed and areas requiring further work are summarized. Additional research should shed light on the nature of the bioactive compounds and their clinical effects, and the molecular basis of active ingredient biosynthesis, and provide more uniform genetic material as well as improved plant growth, and potentially reduce losses due to pathogens.

• Preventive Nutrition and Food Science
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• v.14 no.1
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• pp.49-53
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• 2009

Antioxidative activities of major pentacyclic terpenoids from the semi-fermented tea of Camellia sinensis L. were investigated. The free radical scavenging activities of triterpenoids $1{\sim}3$ were examined with of DPPH and superoxide anion radical scavenging activity. The $IC_{50}$ of compounds 1 and 2 for DPPH radical scavenging activities were 23.1 and $37.2{\mu}g/mL$ respectively, and for superoxide anion radical scavenging activities were 37.2 and $35.2{\mu}g/mL$, respectively. According to this result, compounds 1 or 2 in semi-fermented tea could be the candidates for bioactive material having antioxidant activity.

• Journal of Microbiology and Biotechnology
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• v.29 no.12
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• pp.1873-1881
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• 2019

The innate immune response serves as a first-line-of-defense mechanism for a host against viral infection. Viruses must therefore subvert this anti-viral response in order to establish an efficient life cycle. In line with this fact, Kaposi's sarcoma-associated herpesvirus (KSHV) encodes numerous genes that function as immunomodulatory proteins to antagonize the host immune system. One such mechanism through which KSHV evades the host immunity is by encoding a viral homolog of cellular interferon (IFN) regulatory factors (IRFs), known as vIRFs. Herein, we summarize recent advances in the study of the immunomodulatory strategies of KSHV vIRFs and their effects on KSHV-associated pathogenesis.

• Microbiology and Biotechnology Letters
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• v.24 no.2
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• pp.213-216
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• 1996

Optically active carboxylic acid, D-(-)-$\beta$-hydroxyisobutyric acid {(D)-(-)-HIBA} is a useful chiral starting material for the preparation of enantiomerically pure bioactive compounds which have a chiral methyl carbon center in the molecule such as captopril, $\alpha$-tocopherol, erythromycin A, muscone and so on. (S)-3-Acetoxy-2-methylpropanol can be used as the precursor of (D)-(-)-HIBA, that is, chemical oxidation of the hydroxyl group and subsequent hydrolysis of acyl group in (S)-3-acetoxy-2-methylpropanol affords D-(-)-$\beta$-hydroxyisobutyric acid. (S)-3-Acetoxy-2-methyl-propanol was prepared by lipase-catalyzed asymmetric hydrolysis. In the enzymatic hydrolysis system, lipase AY (Candida rugosa) provided the expected (S)-3-acetoxy-2-methylpropanol in 60% e.e. of the enantiomeric purity under the phosphate buffer and organic co-solvent system.

• Proceedings of the KSLP Conference
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• 2017.04a
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• pp.87-87
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• 2017

• Korean Journal of Pharmacognosy
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• v.28 no.2
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• pp.65-71
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• 1997

This study was carried out to purify and to characterize various bioactive material acemannan from Aloe vera. Purified acemannan was mannose (67%) and acetyl group (23%), and the rest of glucose was galactose that consists of long chain polydispered beta-(1, 4) linked mannan polymers. The sugar and acetyl group in the molecule were linked by molar ratio of 3 : 1. This polysaccharide from Aloe vera may provide functional flood and potential drug source with antiviral and immunomodulating properties.