Geum-Sook Hwang

Chungnam National University, Daiden, Daejeon, South Korea

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Publications (78)269.85 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Discovery of biomarkers in peripheral blood is a crucial step toward the early diagnosis and repetitive monitoring of treatment response for Alzheimer's disease (AD). Metabolomics is a promising technology that can identify unbiased biomarkers. To explore potential blood biomarkers for AD via metabolic profiling with high-resolution magic angle spinning nuclear magnetic resonance techniques, we identified changes in peripheral blood metabolomic profiles in response to amyloid-β (Aβ)-induced neuroinflammation and co-treatment with gallate, a phytochemical known to have anti-neuroinflammatory properties. Alzheimer's-like (AL) model mice were produced by intracerebroventricular infusion of Aβ and compared with normal control mice with infusion of vehicle. AL mice were treated with either gallate (treated AL mice) or vehicle (untreated AL mice). Metabolomic analyses of both whole blood and plasma showed a clear separation between untreated AL mice and the other two groups, with levels of several metabolites involved in energy metabolism, including pyruvate and creatine, being significantly reduced in untreated AL mice compared with control and treated AL mice. Gallate treatment suppressed Aβ-induced overproduction of the inflammatory cytokine tumor necrosis factor-α in the hippocampus and normalized plasma levels of the affected metabolites. These results suggest that plasma levels of several metabolites could be indicative of both brain pathology and therapeutic responses, supporting the possibility of a close relationship between central neuroinflammation and systemic metabolic disturbance. These findings also suggest the potential of NMR-based metabolomics as a method to identify novel plasma biomarkers for AD, which could be confirmed by future translational research with human patients.
    Journal of Alzheimer's disease: JAD 06/2014; · 4.17 Impact Factor
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    ABSTRACT: Leachate, generated by the decomposition of animal carcasses, presents many environmental, sanitary, and food safety hazards. However, research on the characteristics of leachate is lacking. In this study, we performed biochemical profiling of leachate from two animal species (pig and cattle) in two soil types (sandy loam and sandy soil) using (1)H-NMR-based profiling, followed by multivariate data analysis. The leachate was collected from a well-controlled artificial burial site over a 31-week period. Principal components analysis (PCA) of the NMR data showed similar patterns between species and soil types. Organic components, including organic acids and phenols, predominated, and their levels increased with time. The methylamine level in leachate from pig carcasses 18 weeks following burial was significantly higher than that from cattle carcasses; leachate from cattle carcasses in sandy soil 1 week after burial contained unique components (specifically ethanol, formate, alanine, N-methylation, and taurine), in contrast with those from sandy loam soil. This study suggests that a NMR-based profiling approach is useful to characterize the organic components in leachate from animal carcasses over time.
    Environmental Science and Pollution Research 05/2014; · 2.62 Impact Factor
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    ABSTRACT: For nuclear magnetic resonance (NMR)-based protein structure determinations, the random coil chemical shifts are very important because the secondary and tertiary protein structure predictions become possible by examining deviations of measured chemical shifts from those reference chemical shift values. In addition, neighboring residue effects on chemical shifts and J-coupling constants are crucial in understanding the nature of conformational propensities exhibited by unfolded or intrinsically disordered proteins. We recently reported the 1D NMR results for a complete set of terminally blocked dipeptides (Oh KI, Jung YS, Hwang GS, Cho M. J Biomol NMR 2012;53:25-41), but the NMR resonance assignments were not possible so that the average chemical shifts and J-coupling constants were only considered. In the present work, to thoroughly investigate the neighboring residue effects and random coil chemical shifts we extend the previous studies with 2D NMR, and measured all the (3) JHNHα values and H(α) and H(N) chemical shifts of the same set of terminally blocked dipeptides that are free from structural effects like secondary structure, hydrogen-bond, long-range backbone, and side-chain interactions. In particular, the preceding and following residue effects on amino-acid backbone conformational propensities are revealed and directly compared with previous works on either short peptides or empirical chemical shift database. Chirality 00:000-000, 2014. © 2014 Wiley Periodicals, Inc.
    Chirality 01/2014; · 1.72 Impact Factor
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    ABSTRACT: Chronic kidney disease (CKD) is characterized by the gradual loss of the kidney function to excrete wastes and fluids from the blood. (1)H NMR-based metabolomics was exploited to investigate the altered metabolic pattern in rats with CKD induced by surgical reduction of the renal mass (i.e., 5/6 nephrectomy (5/6 Nx)), particularly for identifying specific metabolic biomarkers associated with early of CKD. Plasma metabolite profiling was performed in CKD rats (at 4- or 8-weeks after 5/6 Nx) compared to sham-operated rats. Principle components analysis (PCA), partial least squares-discriminant analysis (PLS-DA) and orthogonal partial least squares-discriminant analysis (OPLS-DA) score plots showed a significant separation between the groups. The resulting metabolic profiles demonstrated significantly increased plasma levels of organic anions, including citrate, β-hydroxybutyrate, lactate, acetate, acetoacetate, and formate in CKD. Moreover, levels of alanine, glutamine, and glutamate were significantly higher. These changes were likely to be associated with complicated metabolic acidosis in CKD for counteracting systemic metabolic acidosis or increased protein catabolism from muscle. In contrast, levels of VLDL/LDL (CH2)n and N-acetylglycoproteins were decreased. Taken together, the observed changes of plasma metabolite profiles in CKD rats provide insights into the disturbed metabolism in early phase of CKD, in particular for the altered metabolism of acid-base and/or amino acids.
    PLoS ONE 01/2014; 9(1):e85445. · 3.73 Impact Factor
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    ABSTRACT: ICP-MS and 1H NMR are commonly used to determine the geographical origin of food and crops. In this study, data from multielemental analysis performed by ICP-AES/ICP-MS and metabolomic data obtained from 1H NMR were integrated to improve the reliability of determining the geographical origin of medicinal herbs. Astragalus membranaceus and Paeonia albiflora with different origins in Korea and China were analysed by 1H NMR and ICP-AES/ICP-MS, and an integrated multivariate analysis was performed to characterise the differences between their origins. Four classification methods were applied: linear discriminant analysis (LDA), k-nearest neighbour classification (KNN), support vector machines (SVM), and partial least squares-discriminant analysis (PLS-DA). Results were compared using leave-one-out cross-validation and external validation. The integration of multielemental and metabolomic data was more suitable for determining geographical origin than the use of each individual data set alone. The integration of the two analytical techniques allowed diverse environmental factors such as climate and geology, to be considered. Our study suggests that an appropriate integration of different types of analytical data is useful for determining the geographical origin of food and crops with a high degree of reliability.
    Food Chemistry. 01/2014; 161:168–175.
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    ABSTRACT: Curcuma, a genus of rhizomatous herbaceous species, has been used as a spice, traditional medicine, and natural dye. In this study, the metabolite profile of Curcuma extracts was determined using gas chromatography-time of flight mass spectrometry (GC/TOF MS) and ultrahigh-performance liquid chromatography-quadrupole time-of-flight mass spectrometry (UPLC/Q-TOF MS) to characterize differences between Curcuma aromatica and Curcuma longa grown on the Jeju-do or Jin-do islands, South Korea. Previous studies have performed primary metabolite profiling of Curcuma species grown in different regions using NMR-based metabolomics. This study focused on profiling of secondary metabolites from the hexane extract of Curcuma species. Principal component analysis (PCA) and partial least-squares discriminant analysis (PLS-DA) plots showed significant differences between the C. aromatica and C. longa metabolite profiles, whereas geographical location had little effect. A t-test was performed to identify statistically significant metabolites, such as terpenoids. Additionally, targeted profiling using UPLC/Q-TOF MS showed that the concentration of curcuminoids differed depending on the plant origin. Based on these results, a combination of GC- and LC-MS allowed us to analyze curcuminoids and terpenoids, the typical bioactive compounds of Curcuma, which can be used to discriminate Curcuma samples according to species or geographical origin.
    Molecules (Basel, Switzerland). 01/2014; 19(7):9535-9551.
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    ABSTRACT: A metabolomic analysis was performed to examine the post-harvest processing of Astragalus membranaceus roots with focus on the peeling procedure using 1H-NMR and UPLC-MS analyses. Principal component analysis (PCA) score plots from the 1H NMR and UPLC-MS data showed clear separation between peeled and unpeeled Astragalus roots. Peeled roots exhibited significant losses of several primary metabolites, including acetate, alanine, arginine, caprate, fumarate, glutamate, histidine, N-acetylaspatate, malate, proline, sucrose, trigonelline, and valine. In contrast, the peeled roots contained higher levels of asparagine, aspartate, and xylose, which are xylem-related compounds, and formate, which is produced in response to wound stress incurred during the post-harvest processing. In addition, the levels of isoflavonoids and astragalosides were significantly reduced in peeled Astragalus root. These results demonstrate that metabolite profiling based on a combination of 1H NMR and UPLC-MS analyses can be used to evaluate peeling procedures used in the post-harvest processing of herbal medicines.
    Journal of Agricultural and Food Chemistry 09/2013; · 2.91 Impact Factor
  • Sung Il Lee, Geum-Sook Hwang, Do Hyun Ryu
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    ABSTRACT: Chiral oxazaborolidinium ion catalyzed Csp2-H functionalization of enones using diazoacetate has been developed. Various β-substituted cyclic enones are synthesized with high yield (up to 99%) and high to excellent enantioselectivity (up to 99%). The synthetic utility of this reaction was demonstrated by formal syn-thesis of (+)-epijuvabione.
    Journal of the American Chemical Society 05/2013; · 10.68 Impact Factor
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    ABSTRACT: OBJECTIVE: We examined the association of cardiac hypertrophy or fibrosis with the phospholipid fatty acid (FA) composition of heart and kidney in hypertensive rats. DESIGN AND METHODS: Eight-week-old spontaneously hypertensive rats (SHRs) (n=8) and Wistar Kyoto rats (WKYs, n=8) as a normotensive control, were fed ad libitum for 6 weeks with regular AIN-76 diet. Phospholipid FA compositions in the left ventricle and kidney were measured and histological analyses were performed. RESULTS: Compared with WKYs, SHRs had lower proportions of γ-linolenic acid, α-linolenic acid, eicosadienoic acid, eicosatrienoic acid, dihomo-γ-linoleic acid, docosadienoic acid and nervonic acid in heart, and stearic acid (SA), γ-linolenic acid, and eicosapentaenoic acid (EPA) in kidney. After adjusting for food intake, SHRs still maintained higher proportions of SA, and total saturated FAs in the heart and a lower proportion of eicosapentaenoic acid in the kidney. Additionally, compared with WKYs, SHRs showed larger cardiomyocyte diameters in the left ventricles, indicating cardiac hypertrophy and interstitial fibrosis. Cardiomyocyte diameters also positively correlated with cardiac SA (r=0.550, p<0.05) and negatively with kidney EPA (r=-0.575, p<0.05). CONCLUSION: Tissue FA compositions were associated with cardiac hypertrophy in a hypertensive setting, implicating the pathogenic role of tissue FAs in hypertension and related complications.
    Clinical biochemistry 04/2013; · 2.02 Impact Factor
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    ABSTRACT: Cabbage (Brassica rapa ssp. pekinensis) is one of the most popular foods in Asia and is widely cultivated in many countries for the production of lightly fermented vegetables. In this study, metabolomic analysis was performed to distinguish two cultivars of cabbage grown in different geographical areas, Korea and China, using (1)H NMR spectroscopy coupled with multivariate statistical analysis. Principal component analysis (PCA) showed clear discrimination between extracts of cabbage grown in Korea and China for two different cultivars (Chunmyeong and Chunjung). The major biochemicals (metabolites) that contributed to discrimination between cabbages grown in the two regions were 4-aminobutyrate (GABA), acetate, asparagine, leucine, isoleucine, O-phosphocholine, phenylacetate, phenylalanine, succinate, sucrose, tyrosine, and valine. These results suggest that the levels of the major metabolites that differ significantly between cabbages grown in these two areas were influenced by environmental factors such as climate and geology. Our study demonstrates that (1)H NMR based on metabolomics, coupled with multivariate statistics, can be applied to identify the regions of cultivation of various cabbage cultivars.
    Food Chemistry 04/2013; 137(1-4):68-75. · 3.33 Impact Factor
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    ABSTRACT: The first example of the boron Lewis acid catalyzed Csp2-H functionalization of cyclic enones was achieved using diazoacetates. The insertion of the carbon atom of diazoacetates utilizes BF3•Et2O or a newly designed oxazaborolidinium ion as a catalyst to afford β-functionalized cyclic enones from simple cyclic enones in a single step and high yields. The reaction mechanism was investigated with deuterium labeled 2-cyclohexen-1-one.
    Organic Letters 03/2013; · 6.14 Impact Factor
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    ABSTRACT: Despite the numerous metabolic studies on obesity, gender bias in obesity has rarely been investigated. Here, we report the metabolomic analysis of obesity by using leptin-deficient ob/ob mice based on the gender. Metabolomic analyses of urine and serum from ob/ob mice compared with those from C57BL/6J lean mice, based on the (1)H NMR spectroscopy in combination with multivariate statistical analysis, revealed clear metabolic differences between obese and lean mice. We also identified 48 urine and 22 serum metabolites that were statistically significantly altered in obese mice compared to lean controls. These metabolites are involved in amino acid metabolism (leucine, alanine, ariginine, lysine, and methionine), tricarbocylic acid cycle and glucose metabolism (pyruvate, citrate, glycolate, acetoacetate, and acetone), lipid metabolism (cholesterol and carnitine), creatine metabolism (creatine and creatinine), and gut-microbiome-derived metabolism (choline, TMAO, hippurate, p-cresol, isobutyrate, 2-hydroxyisobutyrate, methylamine, and trigonelline). Notably, our metabolomic studies showed distinct gender variations. The obese male mice metabolism was specifically associated with insulin signaling, whereas the obese female mice metabolism was associated with lipid metabolism. Taken together, our study identifies the biomarker signature for obesity in ob/ob mice and provides biochemical insights into the metabolic alteration in obesity based on gender.
    PLoS ONE 01/2013; 8(10):e75998. · 3.73 Impact Factor
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    ABSTRACT: Acinetobacter baumannii is an aerobic and gram-negative pathogenic bacterium that is resistant to most antibiotics. Recently, A. baumannii 1656-2 exhibited the ability to form biofilms under clinical conditions. In this study, global metabolite profiling of both planktonic and biofilm forms of A. baumannii 1656-2 was performed using high-resolution nuclear magnetic resonance (NMR) spectroscopy and multivariate statistical analysis to investigate the metabolic patterns leading to biofilm formation. Principal components analysis (PCA) and orthogonal partial least-squares discriminant analysis (OPLS-DA) score plots showed a distinct separation between planktonic and biofilm cells. Metabolites including acetates, pyruvate, succinate, UDP-glucose, AMP, glutamate, and lysine were increasingly involved in the energy metabolism of biofilm formation. In particular, the ratio of N-acetyl-D-glucosamine (GlcNAc) to D-glucosamine (GlcNH2) was significantly higher during biofilm formation than under the planktonic condition. This study demonstrates that NMR-based global metabolite profiling of bacterial cells can provide valuable insight into the metabolic changes in multidrug resistant and biofilm-forming bacteria such as A. baumannii 1656-2.
    PLoS ONE 01/2013; 8(3):e57730. · 3.73 Impact Factor
  • Sung Il Lee, Jin Hee Jang, Geum-Sook Hwang, Do Hyun Ryu
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    ABSTRACT: A simple and efficient method for the asymmetric synthesis of alpha-alkylidene-beta-hydroxy-gamma-butyrolactones and related natural products was developed based on the catalytic asymmetric tandem Michael-aldol reaction and simple transformations. The synthetic utility of this method was illustrated by the facile synthesis of trisubstituted gamma-butyrolactone natural products.
    The Journal of Organic Chemistry 12/2012; · 4.56 Impact Factor
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    ABSTRACT: Curcuma is used to treat skin diseases and colic inflammatory disorders, and in insect repellants and antimicrobial and antidiabetic medications. Two Curcuma species (C. aromatica and C. longa) grown in Jeju-do and Jin-do were used in this study. Methanolic extracts were analyzed by (1)H NMR spectroscopy, and metabolite profiling coupled with multivariate analysis was applied to characterize the differences between species or origin. PCA analysis showed significantly greater differences between species than origins, and the metabolites responsible for the differences were identified. The concentrations of sugars (glucose, fructose, and sucrose) and essential oils (eucalyptol, curdione, and germacrone) were significantly different between the two species. However, the samples from Jeju-do and Jin-do were different mainly in their concentrations of organic acids (fumarate, succinate, acetate, and formate) and sugars. This study demonstrates that NMR-based metabolomics is an efficient method for fingerprinting and determining differences between Curcuma species or those grown in different regions.
    The Analyst 10/2012; · 4.23 Impact Factor
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    ABSTRACT: OBJECTIVE: While data on the relationship between fatty acid (FA) composition and the risk for total stroke have accumulated, the association between FA composition and the risk for intracranial atherosclerotic stenosis (ICAS) has never been studied. We compared plasma phospholipid FA composition between non-stroke control and ischemic stroke in Korean population, to discern the FA that distinguishes ICAS from total ischemic stroke patients. METHODS: Non-stroke controls (n = 215) and stroke patients (no cerebral atherosclerotic stenosis, NCAS: n = 144 and ICAS: n = 104) were finally included in the analysis. Plasma phospholipid FA compositions were analyzed. RESULTS: Age, coexistence of hypertension/diabetes were significantly different among the groups. Phospholipid FA compositions were significantly different between non-stroke control and ischemic stroke patients, and interestingly, between NCAS and ICAS in stroke patients. Pattern analysis showed that docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), the ω3-polyunsaturated FAs were important FAs in distinguishing NCAS and ICAS in strokes. Particularly, the risk of ICAS was inversely associated with levels of DHA contents in phospholipids (OR: 0.590, 95% CI: 0.350-0.993, p < 0.05), indicating that the risk may be increased at lower levels of DHA contents. CONCLUSION: DHA and EPA are important FAs for distinguishing NCAS and ICAS in strokes. Additionally, the risk of ICAS was inversely associated with the levels of phospholipid DHA, which indicates that sufficient amounts of DHA in plasma or in diet may reduce the risk of ICAS.
    Atherosclerosis 09/2012; · 3.71 Impact Factor
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    ABSTRACT: Kimchi is a well-known traditional Korean food. Its geographical origins can be determined by its biochemical composition. This study identified the biochemical compositions of kimchi extracts from Korea and China by (1)H nuclear magnetic resonance (NMR) spectroscopy followed by multivariate data analysis. Principal component analyses (PCA) clearly discriminated between extracts prepared in the two countries. The identified metabolites, including amino acids, organic acids, sugars, and ethanol, contributed to discriminating the geographical origin of kimchi extracts. Furthermore, differences in composition by origin were predicted with high accuracy in external validation models. These results establish biochemical profiles for kimchi extracts, and indicate that metabolomics can be used in the discrimination of food origins.
    Bioscience Biotechnology and Biochemistry 09/2012; 76(9):1752-7. · 1.27 Impact Factor
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    ABSTRACT: OBJECTIVES: To test the hypothesis that urinary metabolites characterizing heart failure (HF) are associated with the magnitude of echocardiographic measurements and ultimately the severity of HF. DESIGN/METHODS: Patients with systolic HF (n=46) and control subjects (n=32) participated in this study. Patients with type 2 diabetes mellitus were excluded. Echocardiographic measurements were performed, and selected urinary metabolites were quantified. RESULTS: Urinary levels of acetate (p<0.05), acetone (p<0.01), cytosine (p<0.001), methylmalonate (p<0.001), and phenylacetylglycine (p<0.01) were significantly higher, while 1-methylnicotinamide (p<0.05) were significantly lower in HF patients than in controls. There were significant differences in E/E' (p<0.05), urinary levels of acetate (p<0.005), acetoacetate (p<0.05), acetone (p<0.05) and ketones (p<0.01) according to the New York Heart Association (NYHA) classification in HF patients. Multiple linear regression analysis revealed that urinary ketones were found to be independent factors for both left ventricular ejection fraction and E/E' after adjusting for confounders. CONCLUSION: Our results showed that urinary levels of ketone bodies are associated with the magnitude of echocardiographic parameters.
    Clinical biochemistry 08/2012; · 2.02 Impact Factor
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    ABSTRACT: Breaking kamp: A catalytic route toward chiral α-alkyl-β-ketoesters using the title reaction of α-alkyl diazoester with aldehydes has been developed. The reaction proceeds with high to excellent enantioselectivities and this methodology was applied to a concise two-step synthesis of the natural pheromone sitophilate.
    Angewandte Chemie International Edition 07/2012; 51(33):8322-5. · 13.73 Impact Factor
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    ABSTRACT: A metabolomics approach using proton nuclear magnetic resonance (NMR) was applied to investigate metabolic alterations following adriamycin (ADR) treatment for gastric adenocarcinoma. After BALB/c-nu/nu mice were implanted with human gastric adenocarcinoma, ADR (1 or 3 mg kg(-1) per day) was intraperitoneally administered for 5 days. Urine was collected on days 2 and 5 and analyzed by NMR. The levels of trimethylamine oxide (TMAO, ×0.3), hippurate (×0.3) and taurine (×0.6) decreased significantly (P < 0.05), whereas the levels of 3-indoxylsulfate (×12.6), trigonelline (×1.5), citrate (×2.5), trimethylamine (TMA, ×2.0) and 2-oxoglutarate (×2.3) increased significantly (P < 0.05) in the tumor model. After ADR treatment, TMAO, hippuarte and taurine were increased significantly on day 5 compared with those of the tumor model. The levels of 2-oxoglutarate, 3-indoxylsulfate, trigonelline, TMA and citrate, which increased in the tumor model, significantly decreased to those of normal control by ADR treatment. Furthermore, the ratio between TMA and TMAO was dramatically altered in both tumor and ADR-treated groups. Overall, metabolites such as TMAO, TMA, 3-indoxylsulfate, hippurate, trigonelline, citrate and 2-oxoglutarate related to the tricarboxylic acid (TCA) cycle might be considered as therapeutic targets to potentiate the efficacy of ADR. Thus, these results suggest that the metabolomics analysis of tumor response to ADR treatment may be applicable for demonstrating the efficacy of anticancer agent, ADR and treatment adaptation. Copyright © 2012 John Wiley & Sons, Ltd.
    Journal of Applied Toxicology 07/2012; · 2.60 Impact Factor

Publication Stats

404 Citations
269.85 Total Impact Points

Institutions

  • 2009–2014
    • Chungnam National University
      Daiden, Daejeon, South Korea
  • 2008–2014
    • Korea Basic Science Institute KBSI
      • Seoul Center
      Sŏul, Seoul, South Korea
  • 2013
    • Dong-A University
      • Department of Food Science and Nutrition
      Pusan, Busan, South Korea
  • 2007–2013
    • Sungkyunkwan University
      • Department of Chemistry
      Seoul, Seoul, South Korea
  • 2012
    • Ewha Womans University
      • Department of Neurology
      Seoul, Seoul, South Korea
    • Dankook University
      • College of Pharmacy
      Yŏng-dong, North Chungcheong, South Korea
  • 2010–2012
    • Kyungpook National University
      • • Department of Biochemistry and Cell Biology
      • • Department of Internal Medicine
      Daikyū, Daegu, South Korea
    • Seoul National University
      • College of Veterinary Medicine
      Seoul, Seoul, South Korea
    • Inje University
      • Department of Pharmaceutical Engineering
      Kimhae, South Gyeongsang, South Korea
  • 2008–2012
    • Korea University
      • Department of Chemistry
      Seoul, Seoul, South Korea
  • 2011
    • Gachon University
      Sŏngnam, Gyeonggi Province, South Korea
    • Korea Centers for Disease Control and Prevention
      Daiden, Daejeon, South Korea