• Journal of Applied Biological Chemistry
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• v.65 no.3
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• pp.183-187
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• 2022

The hot water extract from cinnamon (Cinnamomum cassia Presl) inhibited the activity of alcohol dehydrogenase (ADH) with IC₅₀ value of 45.6 ㎍/mL. The ADH inhibitory components in cinnamon extract were relatively stable to acid and heat, but were found to be volatile. The optimum temperature and time for extracting the ADH inhibitory components from cinnamon were 80 ℃ and 2 h, respectively. Among the essential oils of cinnamon, cinnamaldehyde was the main substance for ADH inhibition. Cinnamaldehyde is considered a competitive inhibitor of ethanol to ADH. Therefore, the cinnamon extract and cinnamaldehyde showed the potential to be used as natural materials for relieving symptoms of a hangover.

• The Korean Journal of Food And Nutrition
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• v.11 no.3
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• pp.354-358
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• 1998

The influence of hot water extracts and tannin obtained from persimmon leaves on xanthine oxidase were investigated. Above two samples had higher inhibitory effect against xanthine oxidase by hot water extracts and tannin obtained from persimmon leaves was 92.4% and 92.1% by addition of 2.0 mg/$m\ell$ of the hot water extracts and the tannin, respectively. The inhibitions by the hot water extracts and the tannin were of competitive mode with respect to xanthine as a substrate.

• Applied Biological Chemistry
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• v.48 no.1
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• pp.103-108
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• 2005

${\alpha}-Amylase$ inhibitor is used to control blood glucose level by inhibiting starch digestion in the small intestine and delaying the absorption of glucose. In this study, we investigated the effect of the ethanol extracts from more than 1400 species of plants against ${\alpha}-amylase$ with the aim of developing a new ${\alpha}-amylase$ inhibitor. In the results, Cornus walteri extracts showed the highest inhibition activity. The inhibitory effect of Cornus walteri extract on the carbohydrate hydrolysis enzymes has different sensitivities against ${\alpha}-amylase$ from salivary and pancreatin and against ${\alpha}-glucosidase$ from yeast and porcine small intestine. In the study of inhibition kinetics of ${\alpha}-amylase$ and ${\alpha}-glucosidase$, Cornus walteri extract showed competitive inhibition against salivary and pancreatin while showing the combination of uncompetitive and noncompetitive inhibition against ${\alpha}-glucosidase$. The Cornus walteri extract was stable at acidic and thermal conditions. As for the blood glucose and body weight levels of Cornus walteri extract, we confirmed anti-hyperglycemic and anti-obesity effects. Also, in the investigation of the mRNA lever, Cornus walteri extract upregulated the level of GLUT4 mRNA in the quadriceps muscle.

• Journal of Life Science
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• v.25 no.5
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• pp.487-495
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• 2015

We carried out pH stability, chemical inhibition, chemical modification, and pH-dependent kinetic parameter assessments to further characterize protocatechuate 3,4-dioxygenase from Pseudomonas pseudoalcaligenes KF707. Protocatechuate 3,4-dioxygenase was stable in the pH range of 4.5~10.5. L-ascorbate and glutathione were competitive inhibitors with $K_{is}$ values of 0.17 mM and 0.86 mM, respectively. DL-dithiothreitol was a noncompetitive inhibitor with a $K_{is}$ value of 1.57 mM and a $K_{ii}$ value of 8.08 mM. Potassium cyanide, p-hydroxybenzoate, and sodium azide showed a noncompetitive inhibition pattern with $K_{is}$ values of 55.7 mM, 0.22 mM, and 15.64 mM, and $K_{ii}$ values of 94.1 mM, 8.08 mM, and 662.64 mM, respectively. $FeCl_{2}$ was the best competitive inhibitor with a $K_{is}$ value of $29{\mu}M$. $FeCl_{3}$, $MnCl_{2}$, $CoCl_{2}$, and $AlCl_{3}$ were also competitive inhibitors with $K_{is}$ values of 1.21 mM, 0.85 mM, 3.98 mM, and 0.21 mM, respectively. Other metal ions showed noncompetitive inhibition patterns. The pH-dependent kinetic parameter data showed that there may be at least two catalytic groups with pK values of 6.2 and 9.4 and two binding groups with pK values of 5.5 and 9.0. Lysine, cysteine, tyrosine, carboxyl, and histidine were modified by their own specific chemical modifiers, indicating that they are involved in substrate binding and catalysis.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.3
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• pp.395-400
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• 2000

양파 조미액으로부터 ACE 저해활성 물질을 분리하기 위해 hexane, ethylether, ethylacetate, butanol과 물로 분획시, 4.8g의 당 함량과 31.9 mg의 phenol성 물질을 함유한 butanol 분획이 82.1%의 ACE 저해활성을 나타내었고, 70.3%의 ACE 저해활성을 보인 양퍄 조미액보다 높은 저해활성을 보였다. Butanol 분획을 Amberite XAD-2column으로 분리한 결과, ACE 저해활성을 보이는 미흡착 분획(F1)를 얻었다. 활성분획 F1을 Sephadex LH-20column으로 분획한 결과, 4개(F1-1,F1-2,F1-3,F1-4)의 분획을 얻었으며, 이중 F1-3 분획의 ACE 저해활성은 93%로 가장 높은 저해활성을 보였다. Sephadex LH-20 column chromatography에 의해 얻어진 활성분획F1-3을 Supercosil LC-18 column을 이용하여 분리한 결과, 6분대에서 ACE 저해활성을 가지는 단일 peak(F1-3a)를 얻었다. 각 정제 과정에서 얻은 분획들은 전형적인 flavonoid의 band I과 bandII의 피크를 보였다. 또한 ACE에 대한 저해기작은 flavonoid 물질이 보이는 전형적인 비경쟁적 저해양상을 보였다.

• Korean Journal of Microbiology
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• v.39 no.4
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• pp.230-234
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• 2003

An extracellular protease of Bacillus amyloliquefaciens S94 was purified to apparent homogeneity. The enzyme activity was strongly inhibited by general inhibitor for serine protease, PMSF, suggesting that the enzyme is a serine protease. The purified enzyme activity was inhibited by leucine peptidase inhibitor, bestatin, suggesting that the enzyme is a leucine endopeptidase. When the enzyme was chemically modified with PMSF, which specifically reacted with serine residue on the enzyme, the activity was eliminated. The endopeptidase activity was inhibited by the modifier which chemically modified carboxyl group of aspartate and glutamate. PLP, which would modify lysine residue, did not affect the endopepetidase activity to a greater extent. This demonstrates that serine and aspartate (or glutamate) residues of enzyme would participate in a important function of the endopeptidase activity.

• Journal of Korea Fair Competition Federation
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• no.104
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• pp.2-18
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• 2004

비가격제한행위를 포함한 불공정거래행위 전반에 걸쳐서 법집행의 효율성과 사업자의 자유로운 경제활동보장을 제고하기 위하여 시장점유율 등을 기준으로 한 심사면제제도의 도입을 검토할 필요가 있다. 즉, 수직적 거래제한, 그 중에서도 가격제한행위에 비하여 경쟁저해의 우려가 상대적으로 적을 수 있는 비가격제한행위에 대해서 관련사업자의 시장점유율이나 매출액을 기준으로 원칙적으로 심사대상에서 면제되는 범위를 설정하는 것이 필요하고도 바람직할 것이다.

• Korean Journal of Microbiology
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• v.50 no.4
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• pp.381-383
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• 2014

In the course of screening for ${\alpha}$-glucosidase inhibitor produced by microorganism, the active compound was isolated from the culture filtrate of Bacillus sp. SKU31-1 using a series of chromatography procedures. The structure of the active compound was elucidated as 5-amino-1-hydroxymethyl-1, 2, 3, 4-cyclohexanetetrol on the basis of spectroscopic evidence obtained and comparison with data from the literature. The active compound showed potent inhibitory activity against ${\alpha}$-glucosidase with an $IC_{50}$ value of $1.9{\mu}M$ for maltose and 4.9 mM for sucrose. A Lineweaver-Burk plot indicated that its inhibition of ${\alpha}$-glucosidase was competitive, with a $K_i$ value of 0.15 mM.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.2
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• pp.293-297
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• 2016

Hydroxy-3-methylglutaryl-CoA reductase (HMG-CoA reductase) is the rate-limiting enzyme in biosynthesis of cholesterol in animals. In this study, inhibitory effects of isoflavone glycosides on HMG-CoA reductase were investigated. At sample concentration of $100{\mu}M$, genistein-7-O-triglucoside (G2-genistin) inhibited HMG-CoA reductase activity by approximately 18%, whereas daidzein-7-O-triglucoside had no inhibitory effect. In the kinetic experiments with Syrian hamster HMG-CoA reductase, G2-genistin showed inhibitory efficacy with an invariable $V_{max}$ value, suggesting that G2-genistin works as a competitive inhibitor of HMG-CoA reductase and has potential for hypocholesterolemic action through direct regulation of HMG-CoA reductase.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.4
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• pp.719-725
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• 2000

This study focused on the purification and characterization of ACE inhibitor from Porphyra yezoensis. The dried Porphyra yezoensis was ground and hydrolyzed with 2.5 N HCl, followed by neutralization and centrifugation. Then, the subsequential purification of ACE inhibitor was carried out by Amberlite XAD 8, DEAE-Toyopearl 650C, Sephadex LH-20 column chromatography and reverse phase HPLC with C18 column. The purified ACE inhibitor was peptide which consisted of glycine (24.5%), arginine (56.8%) and proline (18.8%). Also, it showed the competitive inhibition pattern to ACE. The apparent molecular mass of purified peptide was 580 dalton, and an IC50 value of ACE inhibitor was 10.6 $\mu\textrm{g}$.