• Proceedings of the Korean Society of Applied Pharmacology
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• 2003.11a
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• pp.63-63
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• 2003

Opuntia ficus-indicavar. saboten Makino (Cactaceae) is a tropical or subtropical plant that has been widely used as folk medicine for the treatment of diabetes, asthma, burn, edema and gastritis. The purposes of the present study were to identify antioxidant constituents from fruits and stems of the plant cultivated in Cheju island, Korea, and examine their in vitro neuroprotective activities. Using a chromatographic fractionation method, ten chemical constituents were isolated from ethyl acetate extracts. By means of chemical and spectroscopic methods, those were identified as eight flavonoids such as kaempherol (a), quercetin (b), kaempferol 3-methyl ether (c), quercetin 3-methyl ether (d), narcissin (e), dihydrokaernpferol (f), dihydroquercetin (g) and erioclictyol (h), and two terpenoids such as 3-oxo-${\alpha}$-ionol-${\beta}$-d-glucopyranoside (i) and roseoside (j). Among the isolated compounds, comrounds c~e and h~j were those reported for the first titre from the plant. Compounds b, d and g showed DPPH free radical scavenging activities with IC$\sub$50/ values of 28, 19 and 31, ${\mu}$M respectively. Compounds d and g also inhibited iron-dependent lipid peroxidation with IC$\sub$50/ values of 2.4 and 3.5 ${\mu}$M. In a primary rat cortical neuronal cell culture system, compounds b, d and g inhibited xanthine/xanthine oxidase-induced (IC$\sub$50/ values of 18.2, 2.1 and 54.6 ${\mu}$M) and H$_2$O$_2$-induced (IC$\sub$50/ values of 13.6, 1.9 and 25.7 ${\mu}$M) cytotoxicities. In addition, compounds d and g inhibited NMDA-induced excitotoxicity by 21 and 33%, and only compound d inhibited growth factor withdrawal-induced apoptosis by 31% at a tested concentration of 3 ${\mu}$M. The results suggest that the antioxidant constituents with in vitroneuroprotective activities may serve as lead chemicals for the development of neuroprotective agent.

• Journal of Life Science
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• v.34 no.9
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• pp.656-665
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• 2024

Enzymes, as proteins that regulate various metabolic processes within the human body, play a crucial role in maintaining health. However, the overexpression of certain enzymes can disrupt metabolic balance, leading to various diseases. Enzyme inhibitors are vital in treating these diseases or conditions by inhibiting the action of these enzymes, making them indispensable in the development of effective therapies for a wide array of diseases. Quercetin, a natural product derived from plants, is a type of flavonoid that belongs to the polyphenol family. Quercetin, a natural flavonoid from the polyphenol family, has emerged as a potent enzyme inhibitor. This low-molecular-weight secondary metabolite is known for its inhibitory effects on enzymes such as α-glucosidase, acetylcholinesterase, bacterial neuraminidase, and xanthine oxidase due to its structural advantages. Quercetin is isolated from biomaterials and can be classified into glycosylated, methoxylated, and alkylated derivatives based on its structural variations. These natural quercetin derivatives possess unique substituents that enable specific binding patterns with catalytic residues in enzyme active sites. Therefore, quercetin derivatives can be expected to have better enzyme inhibitory activity than basic quercetin. Due to their specificity and enhanced activity, quercetin and its derivatives hold promise as candidates for developing potent enzyme inhibitors to treat diseases resulting from enzyme imbalances.

• Natural Product Sciences
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• v.11 no.3
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• pp.174-178
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• 2005

Oxidative stress is an important causative factor in several human chronic diseases, such as atherosclerosis, cardiovascular disorders, mutagenesis, cancer, several neurodegenerative disorders, and the aging process. Phenolics and tannins are reported to be good antioxidants. Anogeissus latifolia (Combretaceae) bark has been used in the Indian traditional systems of medicine for curing a variety of ailments, but scientific validation is not available till date. Hence the present study was undertaken to isolate antioxidant compounds by activity-guided isolation. Inhibtion of diphenyl picryl hydrazyl (DPPH) and Xanthine oxidase along with photochemiluminescence assay were used as bioassay for antioxidant activity. Activity guided isolation was carried out using silica column and the compounds were quantified using HPLC. Ethyl acetate and butanol fraction exhibited potent antioxidant activity. Bioassay-guided isolation led to isolation of ellagic acid (1) and dimethyl ellagic acid (2) as the main active compounds, which along with gallic acid were quantified by HPLC. Thus we conclude that these three major tannoid principles present in A. latifolia, are responsible for the antioxidant potential and possibly their therapeutic potential.

• Preventive Nutrition and Food Science
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• v.3 no.4
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• pp.351-355
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• 1998

The purpose of this study was to investigate the effect of protein and dietary fiber levels on the activities of ehanol metabilizing enzymes of the brain in acute and chronic ethanol-treated rats. Male Sprague-Dwley rats were fed on diets containing two levels of protein(7%, 20%)) with two levels of fiber(5%, 105) for 5 weeks. Rats were orally administered 40% (v/v) ethanol(5g/body weight) 90 min before decapitation in the acute ethanol-treated groups and 25% (v/v) ethanol (5g/kg body weight) once a day for 5 weeks in the chronic ethnol-treated groups. Cytosilic alcohol dehydrogenase (ADH) activities were higher than those of mitochondrial ADH. The ADH activities were increased by 20% protein and %% fiber levels in the diet in two fractions , but were decreased by chronic ethanol treatment. Mitochondrial aldehyde dehydrogenase (ALDH) activities did not change by ethanol treatment but were increased by the 20% protein level. However, cytosilic ALDH activities were decreased by chronic ethanol treatment at the 5% fiber level and did not change with protein levels. Both ALDH activities were higher in the 10% fiber groups than the 5% fiber groups. Cytochrome P-450 contents were significantly increased in the chronic ethanol-treated groups but xanthine oxidase (XO) activities did not change. P-450 contents and XO activities were significantly decreased in both the low protein and fiber groups.

• The Korean Journal of Malacology
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• v.11 no.1
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• pp.51-61
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• 1995

A horizontal starch gal electrophoresis for enzyme proteins extracted from 3 species of Korean planorbid snails; Gyraulus convexiusculus, Hippeutis cantori and Segmentina hemisphaerula was carried out in order to elucidate their genetic relationships.The results from 12 enzymes employed in three different kinds of buffer systems are summarized as follows:1) Two loci from each enzyme of aldehyde oxidase, esterase, glucose phosphate isomerase. isocitrate dehydrogenase, leucine aminopeptidase, malate dehyogenase, peptidase and xanthine oxidase were detected, and only one locus was observed from each of the following four enzymes: 6-phosphogluconate dehydrogenase, glyceraldehyde-phosphate dehydrogenase, glutamate oxaloacetate transaminase and glycerol-3-phosphate dehydrogenase.2) Most of loci in 3 species of planorbid snails employed showed homozygous and monomorphic banding patterns and some of them were specifis as genetic markers among different species. However, a few of loci (EST-1. EST-2 and GPI-2)showed polymorphic banding patterns. 3)Hippeutis cantori and Segmentina hemisphaerula were more closely clustered in a dendrogram with the genetic iddentity value of 0.431, and these two species were lineated with Gyraulus convexiusculus as another cluster at the value of 0.294.In summarizing the above results, three species of Korean planorbid snails employed in this study mostly showed monomorphic enzyme protein banding patterns and genetic differences specific among 3 species.

• Food Industry
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• s.172
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• pp.38-56
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• 2003

The volatile compounds of traditional Kyungsando squid sikhe were identified by GC-MS. the amount of-zingibirene among identified volatile compounds was 19.73 mg/kg. The major volatile compounds of sikhe was (Z)-Di-2-propenyl disulfide,-curcumene, methyl

• Food Science and Biotechnology
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• v.17 no.3
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• pp.608-612
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• 2008

In Korea and China, cherry elaeagnus (Elaeagnus multiflora Thunb.) has been used traditionally to treat cough, diarrhea, itching, and foul sores. Therefore, in this study, the ethanol and water extracts of cherry elaeagnus leaves were examined for their antioxidant activities. The ethanol extract of the cherry elaeagnus leaves contained more phenolics than the water extract. All the cherry elaeagnus leaf extracts had higher 1,1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging ability than ascorbic acid at concentrations of $250-1,000\;{\mu}g/mL$. The ethanol extract also showed higher superoxide dismutase (SOD)-like activity compared to the water extract. Furthermore, the SOD-like activity of the ethanol extract amounted to 89% of that of ascorbic acid at a concentration of $500\;{\mu}g/mL$. The nitrite scavenging ability and xanthine oxidase inhibitory (XOI) activity of the ethanol extract were higher than those of the water extract. In particular, the ethanol extract had higher XOI activity than ascorbic acid at a concentration of $1,000\;{\mu}g/mL$.

• Preventive Nutrition and Food Science
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• v.21 no.1
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• pp.68-72
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• 2016

To examine the possibility of using thiacremonone isolated from high-temperature-high-pressure treated garlic, this study investigated the physiological activities properties. The $IC_{50}$ values of hydroxyl, superoxide, hydrogen peroxide, and nitric oxide radical scavenging activities of thiacremonone were 92.50, 65.05, 12.60, and $81.53{\mu}g/mL$, respectively. On the other hand, the activities of vitamin C were 104.93, 99.43, 42.42, and $122.64{\mu}g/mL$, and the activities of butylated hydroxyanisole were 37.22, 68.45, 22.47, and $40.54{\mu}g/mL$, respectively. The $IC_{50}$ value of ACE inhibition activities of thiacremonone and captoprill were 0.265 and $0.036{\mu}g/mL$, respectively. The $IC_{50}$ value of xanthine oxidase inhibition activities of thiacremonone and allopurinol were 39.430 and $9.346{\mu}g/mL$, respectively. The $IC_{50}$ value of tyrosinase inhibition activities of thiacremonone and kojic acid were 101.931 and $65.648{\mu}g/mL$, respectively.

• BMB Reports
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• v.45 no.3
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• pp.200-205
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• 2012

Enzymatic oxidation of commercially available pyrogallol was efficiently transformed to an oxidative product, purpurogallin. Purpurogallin plays an important role in inhibiting glutathione S-transferase, xanthine oxidase, catechol O-methyltransferase activities and is effective in the cell protection of several cell types. However, the anti-inflammatory functions of purpurogallin are not well studied. Here, we determined the effects of purpurogallin on lipopolysaccharide (LPS)-mediated proinflammatory responses. The results showed that purpurogallin inhibited LPS-mediated barrier hyper-permeability, monocyte adhesion and migration and such inhibitory effects were significantly correlated with the inhibitory functions of purpurogallin on LPS-mediated cell adhesion molecules (vascular cell adhesion molecules, intracellular cell adhesion molecule, E-selectin). Furthermore, LPS-mediated nuclear factor-${\kappa}B$ (NF-${\kappa}B$) and tumor necrosis factor-${\alpha}$ (TNF-${\alpha}$) releases from HUVECs were inhibited by purpurogallin. Given these results, purpurogallin showed its anti-inflammatory activities and could be a candidate as a therapeutic agent for various systemic inflammatory diseases.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.10
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• pp.1378-1382
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• 2004

Zinc (Zn) is a micromineral and functions as a cofactor of many enzymes and its deficiency induces retardation of growth and dysfunction of the immune system in animals. This study was conducted to determine lipogenic activity of Zn in bovine intramuscular adipocytes. Preadipocytes were isolated from intramuscular fat depots of 26 month old Korean (Hanwoo) steers and cultured in media containing Zn. At confluence, the cells were treated with insulin, dexamethasone, and 1-methyl-3-isobutyl-xanthine to induce differentiation (accumulation of lipid droplets in cells). The sources of Zn were zinc chloride (${ZnCl}_2$) and zinc sulfate (${ZnSO}_4$), and the final concentrations of both Zn sources were 0, 5, 25, 50 and 100 ${\mu}$M. Glycerol-3-phosphate dehydrogenase (GPDH) activity, an index of adipocyte differentiation, was increased as the concentration of Zn in media increased showing the highest activity (25.74 ng/min/mg protein) at 25 ${\mu}$M of ${ZnSO}_4$. Supplementation of Zn during differentiation of bovine intramuscular adipocytes tended to decrease the production of nitric oxide (NO). Peroxisome proliferator-activated receptor gamma 2(PPAR$\gamma$2) gene expression was increased 10 days after differentiation induction. The current results indicate that Zn has a strong lipogenic activity in cultured bovine intramuscular adipocytes with remarkable suppression of NO production.