16 results on '"Tae-Gyu Nam"'
Search Results
2. Quantification of 21 free amino acids in traditional and nontraditional soybean pastes
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Sanghee Lee, Dongwon Seo, Tae Gyu Nam, Dan-Bi Kim, Sun-Young Kim, and Miyoung Yoo
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Detection limit ,chemistry.chemical_classification ,Chromatography ,Chemistry ,General Chemical Engineering ,010401 analytical chemistry ,04 agricultural and veterinary sciences ,Glutamic acid ,Repeatability ,Free amino ,040401 food science ,01 natural sciences ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,Amino acid ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Composition (visual arts) ,Safety, Risk, Reliability and Quality ,Derivatization ,Histidine ,Food Science - Abstract
The amino acid concentration of soybean products is important for nutritional and health benefits along with desirable sensory characteristics, but these properties could be affected by the origin of raw ingredients, processing method, and storage. Here, we aimed to evaluate the compositional characteristics of free amino acids in soybean paste and identify potential differences between those generated by traditional and nontraditional manufacturing processes. We developed and validated a high-performance liquid chromatography-diode array detection (HPLC-DAD) method involving sample derivatization to analyze 21 free amino acids in soybean pastes. All amino acid compounds were separated within 45 min using a C18 column (250 mm × 4.6 mm, 3 μm). Validation of the optimized 21 free amino acid analysis method showed good linearity (R2 > 0.993), accuracy (≥ 80%), intra- (≤10.63%) and inter-day (≤ 11.58%) repeatability, and limit of quantification (0.025–1.91 µg/g). The levels of 21 free amino acids in nontraditional and traditional soybean pastes detected based upon the optimized method were total amino acid detection levels at 55.3–150.9 (average 92.7) and 49.6–143.4 (average 86.8) mg/kg, respectively. Moreover, we confirmed that the composition ratios of glutamic acid, histidine, and sacrosine were higher in nontraditional soybean paste manufacturing methods (p
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- 2021
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3. Optimization and validation for quantification for allulose of jelly candies using response surface methodology
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Dan-Bi Kim, Tae Gyu Nam, Young Sung Jung, Soonok Sa, Miyoung Yoo, and Hye Jung Kim
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Detection limit ,Accuracy and precision ,Materials science ,Chromatography ,Jelly (food) ,010401 analytical chemistry ,Extraction (chemistry) ,Linearity ,04 agricultural and veterinary sciences ,040401 food science ,01 natural sciences ,High-performance liquid chromatography ,0104 chemical sciences ,0404 agricultural biotechnology ,Original Article ,Extraction methods ,Response surface methodology ,Food Science - Abstract
A simple, rapid and reliable extraction method for allulose content in jelly were optimized using response surface methodology. The extraction method was selected based on preliminary experiments, with a three-factor, three-level central complex design including 20 experimental runs to optimize the extraction parameters. The optimum extraction factors predicted were temperature of 66 °C, solvent of 74% (v/v) ethanol, and extraction time of 24 min under shaking water bath extraction. The measured parameters were in accordance with the predicted values. The developed analytical method was validated with regard to linearity, accuracy and precision presenting recovery level from 90.79 to 95.18% and detection limits varying from 0.53 to 1.62 mg/mL. Finally, the method will be potentially applicable to a commercial jelly food using optimum extraction. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13197-020-04773-z) contains supplementary material, which is available to authorized users.
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- 2020
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4. Synthesis and anti-endoplasmic reticulum stress activity of N-substituted-2-arylcarbonylhydrazinecarbothioamides
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Wheesahng Yun, Jin-Mo Ku, Sang Won Park, J. H. Lee, Tae-gyu Nam, Dong Hwan Kim, Hoon Choi, Kyoung Pyo Seon, Kwiwan Jeong, Seoul Jang, and Jung-mi Hyun
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010405 organic chemistry ,Endoplasmic reticulum ,Organic Chemistry ,Inflammation ,01 natural sciences ,0104 chemical sciences ,Cell biology ,Palmitic acid ,Blot ,010404 medicinal & biomolecular chemistry ,chemistry.chemical_compound ,chemistry ,Apoptosis ,medicine ,Unfolded protein response ,Phosphorylation ,General Pharmacology, Toxicology and Pharmaceutics ,medicine.symptom ,Chemical chaperone - Abstract
Misfolded or unfolded proteins are accumulated in lumen of endoplasmic reticulum (ER) in ER stress condition. It has been implicated in many pathological conditions such as Alzheimer’s disease, diabetic retinopathy, atherosclerosis, β-cell apoptosis and lung inflammation. We found a series of N-substituted-2-arylcarbonylhydrazinecarbothioamides to potently decrease ER stress signal, showing up to almost 300-fold better activity than 1-hydroxynaphthoic acid and tauro-ursodesoxycholic acid, positive controls, respectively. Structure−activity relationship (SAR) study showed that 2-arylcarbonyl moiety is critical for the activity of the hydrazinecarbothioamide analogues and side chains tethering on thioamide moiety were relatively insensitive to the activity. Some analogues were found to consistently exert the potency under more physiologically relevant condition where ER stress was induced by palmitic acid. ER stress markers such as CHOP and phosphorylated eIF2α and PERK were accordingly decreased in western blotting upon treatment of compound 4h. Potential ER stress inhibitory activity and novel structures could provide a novel platform for new chemical chaperone and therapy for protein misfolding diseases.
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- 2019
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5. Extraction conditions for Rosa gallica petal extracts with anti-skin aging activities
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Pomjoo Lee, Eun Ju Shin, Ah-Ram Han, Tae-gyu Nam, Sungyoung Lee, Myung-Hee Lee, Tae-Gyu Lim, Kwang Min Lee, and Young-Ran Song
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0106 biological sciences ,chemistry.chemical_classification ,Ethanol ,integumentary system ,fungi ,Extraction (chemistry) ,Flavonoid ,Skin whitening ,04 agricultural and veterinary sciences ,040401 food science ,01 natural sciences ,Applied Microbiology and Biotechnology ,Skin Aging ,Melanin ,chemistry.chemical_compound ,0404 agricultural biotechnology ,chemistry ,010608 biotechnology ,medicine ,Petal ,Food science ,medicine.symptom ,Wrinkle ,Food Science ,Biotechnology - Abstract
The anti-skin inflammatory activities of rose petal extracts have been described in our previous study. Because skin inflammation is closely linked to skin aging, our study investigated the effects of Rosa gallica petals on skin aging-related activities such as skin whitening and anti-wrinkle properties. Each sample was prepared via extraction using different ethanol ratios with the objective of evaluationg optimal extraction conditions for industrial application. Aqueous 50% (v/v) EtOH extract of R. gallica petal significantly suppressed tyrosinase activity, melanin production, and solar UV-induced matrix metalloproteinase-1, a hall mark of wrinkle formation. In addition, the aqueous 50% (v/v) EtOH extract showed the highest antioxidative effect and had highest flavonoid contents, consistent with the reported anti-aging effects. Overall, our findings suggest that R. gallica petals extracts exhibit anti-aging effects. Furthermore, 50% EtOH extraction, in particular, was optimal for the highest anti-aging, and anti-oxidative effects as well as to obtain the highest flavonoid content.
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- 2019
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6. Analytical method validation for terbutryn using gas chromatography/ion trap, gas chromatography/mass selective detector, and liquid chromatography/triple quadrupole mass spectrometers
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Seung-Hyun Kim, Hyun-Wook Choi, Kwang Geun Lee, Hae Won Jang, Jangho Lee, and Tae Gyu Nam
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Detection limit ,Chromatography ,Chemistry ,010401 analytical chemistry ,Detector ,Relative standard deviation ,010501 environmental sciences ,Mass spectrometry ,01 natural sciences ,Applied Microbiology and Biotechnology ,Article ,0104 chemical sciences ,Triple quadrupole mass spectrometer ,Ion trap ,Gas chromatography ,Quantitative analysis (chemistry) ,0105 earth and related environmental sciences ,Food Science ,Biotechnology - Abstract
Analytical methods including solvent extraction followed by gas chromatography/ion-trap (GC/IT) with scan and MS/MS mode, a GC/mass selective detector (GC/MSD), and liquid chromatography/triple quadrupole mass spectrometers (LC/MS/MS) were optimized to identify and quantify terbutryn. The spike recovery was 96.5% using GC/IT with scan mode and 103.5% with MS/MS mode, 90.3% by GC/MSD, and 92.5% by LC/MS/MS. The limit of detection (LOD) was 0.0015 mg/kg by GC/IT with scan, 0.026 mg/kg with MS/MS mode, 0.015 mg/kg with GC/MSD, and 0.026 mg/kg by LC/MS/MS. Of the four methods, GC/IT with scan mode was determined to be the most sensitive (with LOD: 0.0015 mg/kg and limit of quantitation (LOQ): 0.0047 mg/kg), rapid (retention time: 9.6 min) and the most precise method (relative standard deviation: 17%) for the quantification of terbutryn. GC/IT with scan mode proved to be the more sensitive analytical method for terbutryn than other methods in this study, showing better accuracy and rapid analysis.
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- 2018
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7. Flavonoid accumulation in common buckwheat (Fagopyrum esculentum) sprout tissues in response to light
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Tae Gyu Nam, You Jin Lim, and Seok Hyun Eom
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0106 biological sciences ,chemistry.chemical_classification ,Orientin ,biology ,Isoorientin ,010401 analytical chemistry ,Flavonoid ,food and beverages ,Plant Science ,Horticulture ,biology.organism_classification ,01 natural sciences ,0104 chemical sciences ,chemistry.chemical_compound ,Rutin ,Flavonols ,Flavonoid biosynthesis ,chemistry ,Seedling ,Fagopyrum ,010606 plant biology & botany ,Biotechnology - Abstract
The content and accumulation patterns of flavonoids in response to light were investigated in common buckwheat (Fagopyrum esculentum) sprouts over the course of 9 days. Buckwheat sprouts were grown under fluorescent (FL), red (RL), and blue (BL) light sources, as well as in darkness, and their extracts were analyzed. Sprout elongation and chlorophyll content were high in the presence of red light. The contents of the major buckwheat sprout flavonoids, orientin, isoorientin, vetexin, isovetexin, and rutin all peaked 5 days after germination under all four growth conditions, then gradually decreased. Sprouting cotyledons accumulated around 1.5-fold more orientin, isoorientin, quercetin-3-O-robinobioside, and rutin in the presence of red light, including from the RL and FL light sources, than in blue light alone. The C-glycosyl flavones, orientin, isoorientin, vetexin, and isovetexin, were not detected in the stem tissues of the hypocotyls, but C-glycosyl flavonols, such as quercetin-3-O-robinobioside and rutin, were present, and were twice as abundant under BL and FL than in the RL and darkness conditions. In the root tissues, a small amount of C-glycosyl flavonols was detected after BL exposure only; however, the other flavonoids were not detected at all. These results indicated that red light induces flavonoid biosynthesis in the cotyledons of buckwheat seedlings, but blue light has a greater effect on the accumulation of C-glycosyl flavonols in other seedling tissues.
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- 2018
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8. Identification of Sphingosine 1-Phosphate Receptor Subtype 1 (S1P1) as a Pathogenic Factor in Transient Focal Cerebral Ischemia
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Chi-Ho Lee, Jerold Chun, Sang Yeul Lee, Hee Jun Cho, Bhakta Prasad Gaire, Ji Woong Choi, Tae-gyu Nam, and Arjun Sapkota
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0301 basic medicine ,Gene knockdown ,Microglia ,Sphingosine ,Neuroscience (miscellaneous) ,Ischemia ,Brain damage ,Pharmacology ,Biology ,medicine.disease ,Neuroprotection ,03 medical and health sciences ,Cellular and Molecular Neuroscience ,chemistry.chemical_compound ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,Neurology ,chemistry ,Downregulation and upregulation ,Neurotrophic factors ,medicine ,medicine.symptom ,Neuroscience ,030217 neurology & neurosurgery - Abstract
Medically relevant roles of receptor-mediated sphingosine 1-phosphate (S1P) signaling have become a successful or promising target for multiple sclerosis or cerebral ischemia. Animal-based proof-of-concept validation for the latter is particularly through the neuroprotective efficacy of FTY720, a non-selective S1P receptor modulator, presumably via activation of S1P1. In spite of a clear link between S1P signaling and cerebral ischemia, it remains unknown whether the role of S1P1 is pathogenic or neuroprotective. Here, we investigated the involvement of S1P1 along with its role in cerebral ischemia using a transient middle cerebral artery occlusion ("tMCAO") model. Brain damage following tMCAO, as assessed by brain infarction, neurological deficit score, and neural cell death, was reduced by oral administration of AUY954, a selective S1P1 modulator as a functional antagonist, in a therapeutic paradigm, indicating that S1P1 is a pathogenic mediator rather than a neuroprotective mediator. This pathogenic role of S1P1 in cerebral ischemia was reaffirmed because tMCAO-induced brain damage was reduced by genetic knockdown with an intracerebroventricular microinjection of S1P1 shRNA lentivirus into the brain. Genetic knockdown of S1P1 or AUY954 exposure reduced microglial activation, as assessed by reduction in the number of activated microglia and reversed morphology from amoeboid to ramified, and microglial proliferation in ischemic brain. Its role in microglial activation was recapitulated in lipopolysaccharide-stimulated primary mouse microglia, in which the mRNA expression level of TNF-α and IL-1β, well-known markers for microglial activation, was reduced in microglia transfected with S1P1 siRNA. These data suggest that the pathogenic role of S1P1 is associated with microglial activation in ischemic brain. Additionally, the pathogenic role of S1P1 in cerebral ischemia appears to be associated with the blood-brain barrier disruption and brain-derived neurotrophic factor (BDNF) downregulation. Overall, findings from the current study clearly identify S1P1 signaling as a pathogenic factor in transient focal cerebral ischemia, further implicating S1P1 antagonists including functional antagonists as plausible therapeutic agents for human stroke.
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- 2017
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9. Evaluation of pH differential and HPLC methods expressed as cyanidin-3-glucoside equivalent for measuring the total anthocyanin contents of berries
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Sang Gil Lee, Sung I. Koo, Dae-Ok Kim, Terrence M. Vance, Ock K. Chun, and Tae Gyu Nam
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Chromatography ,Chemistry ,General Chemical Engineering ,010401 analytical chemistry ,04 agricultural and veterinary sciences ,040401 food science ,01 natural sciences ,High-performance liquid chromatography ,Industrial and Manufacturing Engineering ,0104 chemical sciences ,Blowing a raspberry ,chemistry.chemical_compound ,0404 agricultural biotechnology ,Cyanidin-3-glucoside ,Anthocyanin ,Safety, Risk, Reliability and Quality ,Hplc method ,Food Science - Abstract
The present study evaluated the accuracy of pH differential (PD) method and HPLC method expressed as cyanidin-3-glucoside equivalent (CGE) for measuring total anthocyanin (TA) contents of five berries. Major anthocyanins of blueberry, blackberry, black currant, raspberry, and cranberry were analyzed with quantitative HPLC (q-HPLC) method using individual anthocyanin standards and used as a standard reference of comparison. PD method and HPLC method showed similar trend, although absolute amounts of TA differed in blueberry and cranberry. However, data showed that the TA of black currant and raspberry expressed as CGE considerably deviated from those obtained by q-HPLC. This discrepancy was due to underestimating TA of these two berries which contain disaccharides as major glycones, when expressed as CGE. On the other hand, when expressed as their major anthocyanin equivalents, TA of these two berries showed better approximate values with those by q-HPLC method. In addition, this finding was confirmed by Bland–Altman analysis. Our findings demonstrated that the type of glycone in berries is a critical factor to cause discrepancy between TA as CGE and actual TA and should be considered for measuring TA contents.
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- 2016
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10. Amelioration of Experimental autoimmune encephalomyelitis and DSS induced colitis by NTG-A-009 through the inhibition of Th1 and Th17 cells differentiation
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Tae-gyu Nam, Sabita Neupane, Byeong-Seon Jeong, Maheshwor Timilshina, Sang Won Park, Jae-Hoon Chang, Sang Yeul Lee, Liyuan Jiang, Suman Acharya, Dong-Young Choi, and Jung-Ae Kim
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0301 basic medicine ,Encephalomyelitis, Autoimmune, Experimental ,Encephalomyelitis ,T cell ,lcsh:Medicine ,Aminopyridines ,Inflammation ,Article ,Mice ,03 medical and health sciences ,medicine ,Animals ,Colitis ,lcsh:Science ,Multidisciplinary ,Chemistry ,lcsh:R ,Experimental autoimmune encephalomyelitis ,Cell Differentiation ,Th1 Cells ,medicine.disease ,Acquired immune system ,In vitro ,030104 developmental biology ,medicine.anatomical_structure ,Cancer research ,Th17 Cells ,lcsh:Q ,medicine.symptom ,Signal transduction ,Signal Transduction - Abstract
CD4+ T cells are the central for the mammalian adaptive immune system. Naïve CD4+ T cells mainly differentiate in to pro-inflammatory Th1, Th2 and Th17 cells upon antigenic stimulation. IFN-γ secreting Th1 cells and IL-17 secreting Th17 cells are found to play key roles in autoimmune diseases like multiple sclerosis (MS) and ulcerative colitis (UC). In this study we found NTG-A-009, 6-aminopyridin-3-ol, has great inhibitory effect on in vitro differentiation of Th1 and Th17 cells without affecting regulatory T cells. Moreover, NTG-A-009 had no effect on CD4+ T cell proliferation and viability. In vivo treatment has shown that NTG-A-009 has ameliorated experimental autoimmune encephalomyelitis (EAE) and dextran sulfate sodium (DSS) induced colitis through the inhibition of Th1 and Th17 cells differentiation. Mechanistically, NTG-A-009 suppressed Th1 and Th17 cells differentiation via the modulation of JAK/STAT signaling pathway. Thus, our data demonstrated that NTG-A-009 ameliorated inflammation through the inhibition of Th1 and Th17 cells generation making it a potential therapeutic candidate for the treatment of inflammatory diseases.
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- 2018
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11. Contribution of Anthocyanin Composition to Total Antioxidant Capacity of Berries
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Dae-Ok Kim, Sung I. Koo, Ock K. Chun, Tae Gyu Nam, Terrence M. Vance, and Sang Gil Lee
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Antioxidant ,medicine.medical_treatment ,Blueberry Plants ,fungi ,Cyanidin ,food and beverages ,Berry ,Malvidin ,Antioxidants ,Anthocyanins ,carbohydrates (lipids) ,stomatognathic diseases ,chemistry.chemical_compound ,Ribes ,chemistry ,Chemistry (miscellaneous) ,Fruit ,Anthocyanin ,medicine ,Composition (visual arts) ,Food science ,Delphinidin ,Rubus ,Food Science ,Anthocyanidin - Abstract
The present study aimed to evaluate the contribution of anthocyanin composition to the total antioxidant capacity (TAC) of berries having different anthocyanin composition; blackberry, black currant, and blueberry. Blackberry demonstrated the highest TAC, while it had the lowest total anthocyanin content among the three berries in both of the phenolic extract and anthocyanin fractions. On the other hand, black currant had the highest total anthocyanin content, but the lowest TAC. Cyanidin-3-O-glucoside (cya-3-glc) accounted for 94% of blackberry anthocyanins, and as one of the strongest antioxidants present in these three berries, it substantially contributed to the TAC of blackberry anthocyanin fraction (96.0%). Delphinidin-3-O-rutinoside and cyanidin-3-O-rutinoside in black currant had lower antioxidant capacities compared with delphinin-3-O-glucoside and cya-3-glc, resulting in its lowest TAC among berry anthocyanin fractions examined. Malvidin derivatives, major anthocyanins of blueberry, had considerably lower antioxidant capacity than other anthocyanidin derivatives, such as cyanidin or delphinidin, resulting in lower TAC of blueberry compared with blackberry. Our findings indicate that anthocyanin composition as well as the antioxidant capacity of individual anthocyanins contributes to the TAC of berries rich in distinct anthocyanins.
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- 2015
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12. Flavonoids from Fragaria ananassa calyx and their antioxidant capacities
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Hee-Cheol Kang, Nam-In Baek, Oh-Keun Kwon, Tae Gyu Nam, Yoon-Su Baek, Dae-Ok Kim, and Na-Young Song
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chemistry.chemical_classification ,ABTS ,Chromatography ,Oxygen radical absorbance capacity ,DPPH ,Organic Chemistry ,Flavonoid ,General Biochemistry, Genetics and Molecular Biology ,Calyx ,chemistry.chemical_compound ,chemistry ,Organic chemistry ,heterocyclic compounds ,Astragalin ,Kaempferol ,Quercetin - Abstract
The calyx of Fragaria ananassa (Rosaceae) has not been investigated for its chemical constituents and biological activity. This study focused on the isolation of active metabolites from the calyx of this plant. Compounds from F. ananassa calyx were extracted in 80 % aqueous MeOH and the concentrated extract was successively partitioned into EtOAc, n-BuOH, and H2O fractions. Repeated silica gel, octadecyl silica gel, and Sephadex LH-20 column chromatographies afforded six purified flavonoids. On the basis of spectroscopic methods, including 1H, 13C nuclear magnetic resonance spectrometry (NMR), DEPT, and 2D NMR (gCOSY, gHSQC, gHMBC), the flavonoids were identified as kaempferol (1), astragalin (2), quercetin (3), isoquercitrin (4), sexangularetin (5), and sinensin (6). All the flavonoids were isolated for the first time from the F. ananassa calyx in this study. The flavonoids were evaluated for radical-scavenging capacity 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid ammonium salt), 2,2-diphenyl-1-picrylhydrazyl, and oxygen radical absorbance capacity methods. In conclusion, quercetin (3) consistently showed the highest ABTS, DPPH, and ORAC radical-scavenging activities compared with the other isolated flavonoids.
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- 2015
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13. Additive antioxidant capacity of vitamin C and tocopherols in combination
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Sungbin Im, Dae-Ok Kim, Sang Gil Lee, Ock K. Chun, Young Jun Kim, and Tae Gyu Nam
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Vitamin ,Antioxidant ,ABTS ,Chromatography ,Vitamin C ,Vitamin E ,medicine.medical_treatment ,Radical ,food and beverages ,Ascorbic acid ,Applied Microbiology and Biotechnology ,chemistry.chemical_compound ,chemistry ,medicine ,lipids (amino acids, peptides, and proteins) ,heterocyclic compounds ,Tocopherol ,Food Science ,Biotechnology - Abstract
Vitamin C (ascorbic acid) and vitamin E (tocopherols) are water-soluble and fat-soluble essential nutrients, respectively, present ubiquitously in cellular membranes and plasma through dietary intake of fruits and vegetables. These vitamins act as antioxidants by virtue of their free hydroxyl groups. To quantitatively assess the vitamin C-tocopherol interaction in generating total antioxidant capacity, various binary mixtures of vitamin C and tocopherols (α, β, δ, and γ) were titrated with ABTS radicals. In this assay, the antioxidant capacity of tocopherols increased as follows: β-tocopherol
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- 2014
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14. 8-hydroxyarctigenin isolated from safflower sprouts inhibits melanogenesis of melan-a cells and light quality during the sprout growth determines the compound yield
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Dae-Ok Kim, Sun Mi Lee, Moon-Sik Chang, Tae Gyu Nam, Myeong-Hwa Kang, Jae Sung Hwang, Seok Hyun Eom, Uk-Sun Jung, and Jong Il Park
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Plant physiology ,Plant Science ,Horticulture ,Biology ,Fluorescence ,Melanin ,chemistry.chemical_compound ,Column chromatography ,chemistry ,Germination ,Bromide ,Botany ,Darkness ,Bioassay ,sense organs ,Food science ,Biotechnology - Abstract
Safflower sprouts were grown under different light frequencies and conditions, including fluorescent white light, red LED or blue LED light and darkness. The sprout extracts were tested for their inhibitory effect on melanin synthesis. Two compounds from safflower sprout extract were isolated and tested for their activities. Safflower seeds were sown in growth chambers set to lights and harvested at 9 days after sowing. Methanolic extracts of safflower sprouts were subjected to melanin synthesis inhibitory effect on MTT [3-(4,5-Dimethylthiazol-2-yl)-2,5-Diphenyltetraxolium Bromide] and melanin bioassay methods with a dose dependent manner. Two compounds were identified by using open column chromatography and LC-MS (liquid chromatography-mass spectrometry) analysis. The MTT and melanin bioassays with the identified compounds were conducted. Darkness or fluorescent white light irradiation induced extracts with inhibitory effects on melanin synthesis (in a dose dependent manner). In contrast, blue light induced extracts to slightly increase melanin synthesis. It was found that 8-hydroxyarctigenin, a compound isolated from the safflower sprouts grown under fluorescent white light for 9 days after germination, induced inhibitory effect of melanin synthesis. The compound was contained more in the darkness or fluorescent white light treatment than others. Safflower sprouts grown under dark or fluorescent white light conditions were more effective on inhibiting melanin synthesis than conditions under red or blue light. An active compound, 8-hydroxyarctigenin, may be a useful whitening agent in cosmetic resources.
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- 2014
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15. New tocopherol analogue with radical-scavenging activity from the peels of Citrus unshiu Marcovich
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Dong-Geol Lee, Tae Gyu Nam, Dae-Ok Kim, Eun Kyung Kim, Dae Young Lee, Nam-In Baek, Hee-Cheol Kang, Kyeong-Hwa Seo, and Myoung-Chong Song
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chemistry.chemical_classification ,biology ,Oxygen radical absorbance capacity ,Chemistry ,Organic Chemistry ,Salt (chemistry) ,biology.organism_classification ,General Biochemistry, Genetics and Molecular Biology ,Citrus unshiu ,Biochemistry ,Bioorganic chemistry ,Organic chemistry ,Tocopherol ,Scavenging - Abstract
One new tocopherol analogue, methoxytocopherol (1), and two known analogues, α-tocopherol (2) and γ-tocopherol (3), were isolated from the peels of Citrus unshiu Marcovich. The chemical structures of compounds 1–3 were determined by interpretation of spectroscopic data. All isolated compounds were evaluated for radical-scavenging capacity using 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonic acid) diammonium salt, 1,1-diphenyl-2-picrylhydrazyl, and oxygen radical absorbance capacity assays.
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- 2013
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16. Lipid Peroxidation and Its Toxicological Implications
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Tae-gyu Nam
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chemistry.chemical_classification ,Antioxidant ,Isoprostane ,Health, Toxicology and Mutagenesis ,medicine.medical_treatment ,Linoleic acid ,Lipid peroxidation ,Toxicology ,Malondialdehyde ,Isoprostanes ,Article ,chemistry.chemical_compound ,chemistry ,Biochemistry ,medicine ,4-Hydroxy-2-nonenal ,Arachidonic acid ,Polyunsaturated fatty acid - Abstract
Lipid peroxidation is a free radical oxidation of polyunsaturated fatty acids such as linoleic acid or arachidonic acid. This process has been related with various pathologies and disease status mainly because of the oxidation products formed during the process. The oxidation products include reactive aldehydes such as malondialdehyde and 4-hydroxynonenal. These reactive aldehydes can form adducts with DNAs and proteins, leading to the alterations in their functions to cause various diseases. This review will provide a short summary on the implication of lipid peroxidation on cancer, atherosclerosis, and neurodegeneration as well as chemical and biochemical mechanisms by which these adducts affect the pathological conditions. In addition, select examples will be presented where antioxidants were used to counteract oxidative damage caused by lipid peroxidation. At the end, isoprostanes are discussed as a gold standard for the assessment of oxidative damages.
- Published
- 2011
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