• 한국생물물리학회:학술대회논문집
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• 한국생물물리학회 2003년도 정기총회 및 학술발표회
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• pp.42-42
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• 2003

Large-conductance $Ca^{2+}$-activated potassium channels ($BK_{Ca}$ are a widely distributed and play key roles in various cell functions. In nerve cells, $BK_{Ca}$ channels shorten the duration of action potentials and block $Ca^{2+}$ entry thereby repolarizing excitable cells after excitation. $BK_{Ca}$ channel opening has been postulated to confer neuroprotection during stroke, and has attracted attention as a means for therapeutic intervention in asthma, hypertension, convulsions, and traumatic brain injury. Several natural and synthetic compounds including a steroid hormone, $\beta$-estradiol, have been identified as the activators of $BK_{Ca}$ channels. Based on the structural features of the previously reported activators of $BK_{Ca}$ channels, we designed several lead compounds, synthesized chemically, and tested their functional activity on cloned $BK_{Ca}$ channels. The $\alpha$ subunit of rat $BK_{Ca}$ channel was expressed alone or with different $\beta$ subunits in Xenopus oocytes and the effects of the compounds were tested electrophysiological means. One of the lead compounds affected the activity of the $\alpha$ subunit of $BK_{Ca}$ channel in a $\beta$ subunit-specific manner. While the activity of B $K_{ca}$ channel $\alpha$ subunit was Potentiated, the channel composed of $\alpha$ and $\beta$1 subunits were inhibited by this compound. We are currently investigating the mechanism of the $\beta$ subunit-dependent effects and planning to localize the receptor site of the lead compound.f the lead compound.

• 한국식품저장유통학회지
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• 제7권4호
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• pp.366-372
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• 2000

SDE 방법으로 추출한 블랙올림피아, 캠벨, 델라웨어의 향기성분을 분석하여 각각 77종, 72종, 74종의 휘발성 향기성분을 분리.동정하였다. 블랙올림피아의 주요향기성분으로 (E)-2-hexenal(20.36%), diethylacetal(18.03%), hexanal, ethyl acetate가 다량 함유되어 있었다. 캠벨에서는 에스터류로써 30.81%를 나타낸 ethyl acetate가 가장 높은 함량을 보였으며, ethyl (E,E)-2,4-decadienoate와 ethyl butanoate가 각각 7.96%, 2.59%를 차지하였고, 알코올류와 알데이드류는 주로 $C_{6}$ 화합물이 다량 함유되었다. 델라웨어에서는 블랙올림피아나 켐벨과는 달리 알코올류가 높은 함량을 나타내었으며, 주요 성분은 (E)-2-hexenal (21.07%)과 (E)-2-hexen-1-ol(19.43%) 이었다. 세 종류의 품종에서 공통적으로 hexanal, (E)-2-hexenal, hexanol, (E)-2-hexen-1-ol, ethyal acetate 둥이 다량 동정되어 $C_{6}$-화합물이 포도의 주된 향기성분으로 확인되었으나 테르펜올류는 델라웨어에서만 미량으로 검출되었다. 품종별 휘발성 향기성분의 총함량으로 블랙올림피아, 캠벨, 델라웨어에서 각각 13.7 mg/kg, 48.5 mg/kg,15.3 mg/kg이 정량분석 되었다.

• Journal of Microbiology and Biotechnology
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• 제30권9호
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• pp.1436-1442
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• 2020

Amylosucrase (ASase, E.C. 2.4.1.4) is capable of efficient glucose transfer from sucrose, acting as the sole donor molecule, to various functional acceptor compounds, such as polyphenols and flavonoids. An ASase variant from Deinococcus geothermalis, in which the 226^th alanine is replaced with asparagine (DgAS-A226N), shows increased polymerization activity due to changes in the flexibility of the loop near the active site. In this study, we further investigated how the mutation modulates the enzymatic activity of DgAS using molecular dynamics and docking simulations to evaluate interactions between the enzyme and phenolic compounds. The computational analysis revealed that the A226N mutation could induce and stabilize structural changes near the substrate-binding site to increase glucose transfer efficiency to phenolic compounds. Kinetic parameters of DgAS-A226N and WT DgAS were determined with sucrose and 4-methylumbelliferone (MU) as donor and acceptor molecules, respectively. The k_cat/K_m value of DgAS-A226N with MU (6.352 mM^-1min^-1) was significantly higher than that of DgAS (5.296 mM^-1min^-1). The enzymatic activity was tested with a small phenolic compound, hydroquinone, and there was a 1.4-fold increase in α-arbutin production. From the results of the study, it was concluded that DgAS-A226N has improved acceptor specificity toward small phenolic compounds by way of stabilizing the active conformation of these compounds.

• Bulletin of the Korean Chemical Society
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• 제29권8호
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• pp.1549-1553
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• 2008

A molecular imprinted polymer (MIP) using (+)catechin ((+)C) as a template and acrylamide (AM) as a functional monomer was prepared. Acetonitrile was used as the porogen with ethylene glycol dimethacrylate (EGDMA) as the crosslinker and 2,2'-azobis(isobutyronitrile) (AIBN) as the initiator. The adsorption isotherms in the MIP were measured and the parameters of the equilibrium isotherms were estimated by linear and nonlinear regression analyses. The linear equation for original concentration and adsorpted concentrations was then expressed, and the adsorption equilibrium data were correlated into Langmuir, Freundlich, quadratic, and Langmuir Extension isotherm models. The mixture compounds of (+)C and epicatechin (EC) show competitive adsorption on specific binding sites of the (+)catechin-MIP. The adsorption concentrations of (+)C, epicatechin (EC), epicatechin gallate (ECG), and epigallocatechin gallate (EGCG), on the (+)catechin-molecular imprinted polymer were compared. Through the analysis, the (+)catechin-molecular imprinted polymer showed higher adsorption ability than blank polymer which was synthesized molecular imprinted polymer without (+)catechin. Furthermore, the competitive Langmuir isotherms were applied to the mixture compounds of (+)C and EC.

• 한국작물학회지
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• 제48권
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• pp.41-48
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• 2003

The number of natural products obtained from plants has now reached over 100,000 and new chemical compounds are being discovered ever year. Medicinal and Aromatic plants and their extracts have been used for centuries to relieve pain, aid healing, kill bacteria and insects are important as the antifungal and anti-herbivore agents with further compounds being involved in the symbiotic associations. Although their functions in plants have not been fully established, it is Known that some substances have growth regulatory properties while others are involved in pollination and seed dispersal. The complex nature of these chemicals are usually produced in various types of secretory structures which is an important character of a plant family and also influenced and controlled by genetic and ecological factors. Detailed anatomical description of these structures ave relevant to the market value of the plants, the verification of authenticity of a given species and for the detection of substitution or adulteration. Volatile oils are used for their therapeutic action for flavoring of lemon, in perfumery of rose or as starting materials for the synthesis of other compounds of turpentine. For therapeutic purposes they are administered as inhalations of eucalyptus oil, peppermint oil, as gargles and mouthwashes of thymol and transdermally many essential oils including those of lavender, etc. With these current trend for using volatile components in essential oil will be increasing in the future in Korea and in the world as well.

• The Plant Pathology Journal
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• 제27권4호
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• pp.349-353
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• 2011

The ascomycete fungus Fusarium graminearum is an important plant pathogen responsible for Fusarium head blight in small grains and ear rot on maize. This fungus also produces the estrogenic metabolite, zearalenone (ZEA) that causes estrogenic disorders in humans and animals. Previously, we developed a conditional gene expression system for this fungus using a ZEA-inducible promoter (Pzear). In the present study, four other estrogenic compounds, including ${\beta}$-estradiol, estriol, estrone, and secoisolariciresinol, were screened as possible substitutes for ZEA in this system. Among them, ${\beta}$-estradiol was able to successfully induce the expression of a gene controlled by Pzear, while estrone was only able to partially induce its expression but the other two compounds were not effective. In combination, these results demonstrate that ${\beta}$-estradiol can replace ZEA in this conditional gene expression system, thereby eliminating the need to use the more expensive reagent, ZEA, and facilitating high-throughput functional analyses of F. graminearum in future studies.

• Journal of Applied Biological Chemistry
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• 제59권1호
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• pp.19-23
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• 2016

A phenol substance was extracted from Pinus koraiensis Siebold et Zucc leaf extracts and its biological efficacy was measured. The highest content of the phenol substance contained in Pinus koraiensis Siebold et Zucc leaves was 13.5 mg/g, which was obtained when it was extracted with 80% ethanol. At a concentration of 200 mg/mL, the phenolic substances extracted with 80% ethanol and water showed antimicrobial activities against Helicobacter pylori, producing clear zones of 10 and 12 mm diameter, respectively. Pinus koraiensis Siebold et Zucc. leaf extracts were separated using a Sephadex LH-20 column and 4 fractions were obtained (fractions A-D). Fractions C and D showed the greatest inhibitory activity against Helicobacter pylori producing 10.1 and 12.3 mm clear zones, respectively. These two fractions were purified using a Sephadex LH-20 and MCI-gel column ($H_2O{\rightarrow}100%$ ethanol). Purified compounds A and B were identified as syringic acid and compound C was identified as p-coumaric acid based on $^1H$-nuclear magnetic resonance (NMR), $^{13}C$-NMR, and fast atom bombardment mass spectrometry spectra. When two or more purified compounds were mixed, a synergistic effect of anti-Helicobacter pylori activity was evident. This result indicates that extracts of Pinus koraiensis Siebold et Zucc leaves could be considered a functional food because of their high antimicrobial properties.

• 분석과학
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• 제12권6호
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• pp.478-483
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• 1999

Alum, PAC, PACS의 알루미늄 응집제에서 유기화합물의 응집효율을 조사하였다. pH에 따른 응집효율은 pH 6~7에서 가장 크며, 중성의 pH에서 응집효율은 PACS, PAC, alum의 순서로 감소하였다. 분자량이 큰 유기물은 모든 응집제에 대해 좋은 응집율을 보였으나 작은 분자들은 응집되지 않았다. 반면에 분자량이 작은 유기물 중에서 인접한 위치에 2개 이상의 COOH와 OH의 작용기를 가진 분자들은 10~80%의 응집효율을 보였다.

• Preventive Nutrition and Food Science
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• 제7권4호
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• pp.405-410
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• 2002

Rice wine was prepared with medicinal plants or plant extracts to obtain a value added nutritious alcoholic tonics. Powders of ten medicinal plants (PTM) or aqueous extracts prepared from them (ATM) were added during the initial stage of fermentation. Aroma compounds of rice wine (control) and wines containing PTM or ATM were isolated by liquid-liquid continuous solvent extraction (LLCSE) and analyzed by gas chromatography-olfactometry and aroma extract dilution analysis (AEDA). Desirable aroma compounds: acetaldehyde (sweet, ethereal), benzaldehyde (sweet, fragrant), ethyl acetate (sweet) and ethyl octanoate (sweet, ethanolic) had the highest log$_3$-flavor dilution (FD) factors in ATM. Results of sensory evaluation demonstrated that intensities of undesirable aroma attributes, such as koji and yeasty notes in control, and raw medicinal herb notes in PTM, were lowest in wine with ATM. Wines made with ATM had the most attractive aroma attributes among the three different traditional Korean medicinal wines.

• 한국식품조리과학회지
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• 제22권3호통권93호
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• pp.402-417
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• 2006

Research interest on functional food and phytochemicals has mainly focused on their health effects, mechanism of action and structure-activity relationship for the development of nutraceuticals. Considering the intake of phytochemicals via the normal diet, further information is required on changes in food functionality or individual phytochemicals that occur during the cooking or processing of foods, in order to increase the intake of these bioactive compounds, because many of the unit-operating procedures involved in cooking or food processing may result in physicochemical changes of food constituents. This study reviews the changes of selected phytochemicals, i.e. flavonoids, organosulfur compounds and carotenoids, or food functionality by major cooking or processing procedures such as heating, fermentation, and pH changes. In general, heating has a negative effect on food functionality, although in some cases, mild heating increases bioactive phytochemical contents. Some phytochemicals, including anthocyanins and catechins, are stabilized in lower pH conditions. The structures of phytochemicals, including isoflavones and catechins, are changed by fermentation. The loss of bioactive compounds may be decreased by recently developed cooking or processing methods such as microwave cooking or use of high hydrostatic pressure. However, the effects of cooking and processing procedures on food functionality and phytochemicals are so diverse and dependent on test conditions that further research efforts are needed to form accurate conclusions on the effects of cooking and processing of foods.