• Title/Summary/Keyword: $NO_2$ inhibition

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Effects of Inhibition on Formation and Growth of Polymer in Butadiene Extraction Unit (Butadiene Extraction Unit 내의 Polymer 생성 억제 효과)

  • Im, Gyeong
    • The Journal of Natural Sciences
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    • v.5 no.2
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    • pp.63-73
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    • 1992
  • There are many methods of obtaining butadiene described in the literature. In the america it is produced largely from petroleum gases, i.e., by catalytic dehydrogenation of butene of butene-butane mixtures. Butadiene can be recovered from the $C_4$ residue of an olefin plant by distilling off a fraction containing most of the butadiene, catalytically hydrogenating the higher acetylenes to olefins and separating the product from other olefins and isobutane by extraction. Also it can be obtained by cracking naphtha and light oil. Among the individual dienes of commercial importance, 1, 3-butadiene is of first importance. It is used primarily for the production of polymers.In the present paper, it was investigated for a effect of the formation and the growth inhibition of popped corn polymer in butadiene extraction unit. As a result of study, inhibitors, $NaNO_2$ and TBC were good effective for inhibition of the formation and growth in popcorn polymer. The rational formula of popcorn polymer obtained was $(C_4H_6)_x$.

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Tyrosinase Inhibition and Mutagenicity of Phenolic Compounds from Mulberry Leaves - Research Note -

  • Kim, Young-Chan;Takaya, Yoshiaki;Chung, Shin-Kyo
    • Preventive Nutrition and Food Science
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    • v.12 no.2
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    • pp.119-121
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    • 2007
  • The tyrosinase inhibition activity and mutagenicity as assessed by the Ames test on phenolic antioxidants (5-Caffeoyl quinic acid, 3,4-Dihydroxy cinnamic acid, Quercetin 3-O-${\beta}$-D-glucopyranose, Kaempferol 3-O-${\beta}$- D-glucopyranose) and the ethyl acetate fraction isolated from mulberry leaves were examined. The ethyl acetate fraction and chlorogenic acid exhibited weaker tyrosinase inhibitory activities than kojic acid. In addition, the ethyl acetate fraction from mulberry leaves, containing phenolic antioxidants, showed no mutagenicity by the Ames test.

Stability of Separated ACE Inhibitory Peptides under Condition of Various pH, Temperature, Gastric Digestion (In Vitro)

  • Jang, Ae-Ra;Lee, Moo-Ha
    • Proceedings of the Korean Society for Food Science of Animal Resources Conference
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    • 2005.10a
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    • pp.329-333
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    • 2005
  • ACE inhibition activity of peptides was measured after 2 months of storage at $4^{\circ}C$ under condition of pH 6.0, 6.5, 7.0, 7.5, 8.0. and the ACE inhibitory activity were changed only slightly. After 2 months of chilled storage ($4^{\circ}C$), no dramatic change and significance was found. This indicates that acidic, neutral, weak alkali conditions did not affect ACE inhibitory activity of those peptides. Among peptide 1134, 1152, and 1155, peptides from thermolysin + protease A hydrolysates, inhibition activity of peptide 1134 and 1152 was decreased significantly at $60^{\circ}C$, however, they showed stable inhibition activity from $70^{\circ}C$ to $100^{\circ}C$ (P<0.001). Also, chromatogram of peptide 1134, 1152, and 1155 was shown that retention time of peptide of $60^{\circ}C$ was not correspond to the retention time of the rest of peptides. This indicated that temperature may change the inhibitory activity and profile of peptides.

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Effect of Sexual Pheromone on Phosphoryation of Membrane Protein in Heterobasidiomycetous Yeast Rhodosporidium toruloides (이담자효모 Rhodosporidium toruloides의 막단백질 인산화와 성 Pheromone, Rhodotorucine A의 작용)

  • 정영기
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.26 no.6
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    • pp.1246-1251
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    • 1997
  • When the membrane protein fraction of mating type a cells of heterobasidiomycetous yeast R. toruloides was phosphorylated in vitro, two phosphorylated proteins of 72Kd and 57Kd were detected on SDS-polyacryamide gel. The phosphorylation reaction was inhibited by rhodotorucine A(Rh. A) which is a sexual pheromone secreted by mating type A cells. The inhibition of phosphorylation by Rh. A was dependent on $Ca^{2+}$, and independent on $Mg^{2+}$ or calmodulin. When adding trigger peptidase(TPase) inhibitor, antipain, no inhibition of phosphory was observed. Also, by adding the trysin-digested product of Rh. A, the phosphorylation was inhibited as the action of Rh. A. From these results, it is expected that the inhibition of membrane protein phosphorylation should be caused by the digested product of Rh. A with TPase.

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Inhibition of Herpes Simplex Viruses, Types 1 and 2, by Ginsenoside 20(S)-Rg3

  • Wright, Stephen M.;Altman, Elliot
    • Journal of Microbiology and Biotechnology
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    • v.30 no.1
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    • pp.101-108
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    • 2020
  • Infections by herpes simplex viruses have an immense impact on humans, ranging from self-limiting, benign illness to serious, life-threatening diseases. While nucleoside analog drugs are available, resistance has been increasing and currently no vaccine exists. Ginsenosides derived from Panax ginseng have been documented to inhibit several viruses and bolster immune defenses. This study evaluated 12 of the most relevant ginsenosides from P. ginseng for toxicities and inhibition of herpes simplex viruses types 1 and 2 in Vero cells. The effects of test compounds and virus infection were determined using a PrestoBlue cell viability assay. Time course studies were also conducted to better understand at what points the virus life cycle was affected. Non-toxic concentrations of the ginsenosides were determined and ranged from 12.5 μM to greater than 100 μM. Ginsenoside 20(S)-Rg3 demonstrated the greatest inhibitory effect and was active against both HSV-1 and HSV-2 with an IC50 of approximately 35 μM. The most dramatic inhibition-over 100% compared to controls-occurred when the virus was exposed to 20(S)-Rg3 for 4 h prior to being added to cells. 20(S)-Rg3 holds promise as a potential chemotherapeutic agent against herpes simplex viruses and, when used together with valacyclovir, may prevent increased resistance to drugs.

Protective Role of Light in Heat-Induced Inhibition of Photosynthesis in Isolated Chloroplasts

  • Jun, Sung-Soo;Kim, Chang-Hoon;Hong, Young-Nam
    • Journal of Photoscience
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    • v.5 no.4
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    • pp.157-162
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    • 1998
  • The effect of heat treatment in the light on the subsequent CO2 fixation was studied with isolated spinach chloroplasts to define the role of light during heat stress. The degree of inhibition in CO2 fixation after heat treatment at 35$^{\circ}C$ under full light intensity (600W/$m^2$) was same as that in the dark. However, heat treatment of isolated chloroplasts in the light manifested thylakoidal damage, which did not occur in the dark. Under weak light (10~30 W/$m^2$ ) where no thylakoidal damage occurred, the inhibition was substantially alleviated , showing protective effect of light . The inhibition caused by heat treatment in the dark or light is prevented by the addition of a few combined compounds to the medium prior to treatment. Fructose-1-6- bisphosphate(with aldolase)and ribose-5-phosphate, known to be effective combined with oxaloacetate in preventing inhibition after heat treatment in the dark were equally effective in the light even without oxaloacetate. Addition of sugar phosphate reduced the Mehler reaction, which may occur in fast rae under high light. However, the addition of bicarbnate and catalase that would remove Mehler reaction did not provide any protection, indicating that protective role of sugar phosphate is elsewhere. Furghermore, in whole plants rapid recovery from heat stress was observed in the light. The apparently lesser or equal inhibition in spite of additional thylakoidal damage under heat stres in the light and less requirement for the protection against heat treatment suggest that the inhibitory effect of heat stress is alleviated by light treatment.

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Monoamine Oxidase and Dopamine β-Hydroxylase Inhibitors from the Fruits of Gardenia jasminoides

  • Kim, Ji-Ho;Kim, Gun-Hee;Hwang, Keum-Hee
    • Biomolecules & Therapeutics
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    • v.20 no.2
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    • pp.214-219
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    • 2012
  • This research was designed to determine what components of Gardenia jasminoides play a major role in inhibiting the enzymes related antidepressant activity of this plant. In our previous research, the ethyl acetate fraction of G. jasminosides fruits inhibited the activities of both monoamine oxidase-A (MAO-A) and monoamine oxidase-B (MAO-B), and oral administration of the ethanolic extract slightly increased serotonin concentrations in the brain tissues of rats and decreased MAO-B activity. In addition, we found through in vitro screening test that the ethyl acetate fraction showed modest inhibitory activity on dopamine-${\beta}$ hydroxylase (DBH). The bioassay-guided fractionation led to the isolation of five bio-active compounds, protocatechuic acid (1), geniposide (2), 6'-O-trans-p-coumaroylgeniposide (3), 3,5-dihydroxy-1,7-bis(4-hydroxyphenyl) heptanes (4), and ursolic acid (5), from the ethyl acetate fraction of G. jasminoides fruits. The isolated compounds showed different inhibitory potentials against MAO-A, -B, and DBH. Protocatechuic acid showed potent inhibition against MAO-B ($IC_{50}$ $300{\mu}mol/L$) and DBH ($334{\mu}mol/L$), exhibiting weak MAO-A inhibition (2.41 mmol/L). Two iridoid glycosides, geniposide ($223{\mu}mol/L$) and 6'-O-trans-p-coumaroylgeniposide ($127{\mu}mol/L$), were selective MAO-B inhibitor. Especially, 6'-O-trans-p-coumaroylgeniposide exhibited more selective MAO-B inhibition than deprenyl, well-known MAO-B inhibitor for the treatment of early-stage Parkinson's disease. The inhibitory activity of 3,5-dihydroxy-1,7-bis (4-hydroxyphenyl) heptane was strong for MAO-B ($196{\mu}mol/L$), modest for MAO-A ($400{\mu}mol/L$), and weak for DBH ($941{\mu}mol/L$). Ursolic acid exhibited significant inhibition of DBH ($214{\mu}mol/L$), weak inhibition of MAO-B ($780{\mu}mol/L$), and no inhibition against MAO-A. Consequently, G. jasminoides fruits are considerable for development of biofunctional food materials for the combination treatment of depression and neurodegenerative disorders.

Gallium(III) Nitrate Inhibits Pathogenic Vibrio splendidus Vs by Interfering with the Iron Uptake Pathway

  • Song, Tongxiang;Zhao, Xuelin;Shao, Yina;Guo, Ming;Li, Chenghua;Zhang, Weiwei
    • Journal of Microbiology and Biotechnology
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    • v.29 no.6
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    • pp.973-983
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    • 2019
  • It is well known that iron is critical for bacterial growth and pathogenic virulence. Due to chemical similarity, $Ga^{3+}$ competes with $Fe^{3+}$ for binding to compounds that usually bind $Fe^{3+}$, thereby interfering with various essential biological reactions. In our present study, gallium(III) nitrate [$Ga(NO_3)_3$] could repress the growth of V. splendidus Vs without complete inhibition. In the presence of $Ga(NO_3)_3$, the secretion of homogentisic acid-melanin (HGA-melanin) in V. splendidus Vs cells could be increased by 4.8-fold, compared to that in the absence of $Ga(NO_3)_3$. HGA-melanin possessed the ability to reduce $Fe^{3+}$ to $Fe^{2+}$. In addition, HGA-melanin increased the mRNA levels of feoA and feoB, genes coding Fe2+ transport system proteins to 1.86- and 6.1-fold, respectively, and promoted bacterial growth to 139.2%. Similarly, the mRNA expression of feoA and feoB was upregulated 4.11-fold and 2.71-fold in the presence of $640{\mu}M$ $Ga(NO_3)_3$, respectively. In conclusion, our study suggested that although $Ga(NO_3)_3$ could interfere with the growth of V. splendidus Vs, it could also stimulate both the production of $Fe^{3+}$-reducing HGA-melanin and the expression of feoA and feoB, which facilitate $Fe^{2+}$ transport in V. splendidus Vs.

Suppressive Effects of Furonaphthoquinone NFD-37 on the Production of Lipopolysaccharide-Inducible Inflammatory Mediators in Macrophages RAW 264.7

  • Kim Min-Hee;Shin Hyun-Mo;Lee Yong Rok;Chung Eun Yong;Chang Yoon Sook;Min Kyung Rak;Kim Youngsoo
    • Archives of Pharmacal Research
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    • v.28 no.10
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    • pp.1170-1176
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    • 2005
  • 2-Methyl-2-(2-methylpropenyl)-2,3-dihydronaphthoquinone[2,3-b]furan-4,9-dione (N FD-37) is a synthetic furonaphthoquinone compound. In this study, we determined that NFD-37 could inhibit the lipopolysaccharide (LPS)-induced production of inflammatory mediators in macrophages RAW 264.7. This compound inhibited LPS-induced nitric oxide (NO) or prostaglandin (PG) $E_{2}$ production in dose-dependent manners, with $IC_{50}$ values of 7.2 ${\mu}M$ and 5.3 ${\mu}m$, respectively. As the positive controls, pyrrolidine dithiocarbamate (30 ${\mu}M$) exhibited a $57{\%}$ inhibition of NO production, and NS-398 ($1{\mu}M$) manifested a $48{\%}$ inhibition of $PGE_2$ production. The inhibitory effects of NFD-37 on NO and $PGE_2$ production were determined to occur in conjunction with the suppression of inducible NO synthase or cyclooxygenase-2 expression. NFD-37 also inhibited the production of LPS-inducible tumor necrosis factor-${\alpha}$, interleukin (IL)-$1{\beta}$ and IL-6, at $IC_{50}$ values of 4.8-8.9 ${\mu}M$. We also determined the anti-inflammatory efficacy of NFD-37 using carrageenin-induced paw edema in experimental mice.