• Bulletin of the Korean Chemical Society
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• v.34 no.4
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• pp.1145-1152
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• 2013

The rate constant of alkaline fading of methyl green ($ME^{2+}$) was measured in the presence of non ionic (TX-100), cationic (DTAB) and anionic (SDS) surfactants. $ME^{2+}$ hydrolyses and fades in neutral water and in this work we search the effects of surfactants on its fading rate. The rate of reaction showed remarkable dependence on the electrical charge of the used surfactants. It was observed that the reaction rate constant decreased in the presence of DTAB and SDS and increased in the presence of TX-100. Binding constants of $ME^{2+}$ to TX-100, DTAB and SDS and the related thermodynamic parameters were obtained by classical (or stoichiometric) model. The results show that binding of $ME^{2+}$ to TX-100 and DTAB are two-region and that of SDS is three-region. Also, the binding constants of $ME^{2+}$ to surfactant molecules in DTAB/TX-100 and SDS/TX-100 mixed solutions and their stoichiometric ratios were obtained.

• YAKHAK HOEJI
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• v.32 no.5
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• pp.334-339
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• 1988

AraC-5'-methylthioacetate (araC-MTA, 1) and araC-5'-butylthioacetate (araC-BTA, 2) were prepared and their physical and chemical properties and in vivo antitumor activities were examined. Both compounds were found to have higher partiton coefficients (n-hexanol/water) than their parent araC and to be hydrolyzed to araC within an hour in mouse plasma and ascitic fluid solutions. In in vivo antitumor activity test they showed similar potency to araC, which were assumed due to too quick hydrolyses of them to parent in the body fluid.

• Journal of Life Science
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• v.12 no.1
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• pp.26-31
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• 2002

Choline esters that are used with substrate of BChE-catalyzed hydrolyses were synthesized by two methods. First, 2-chloroethyl thiohexanoate, 2-chloroethyl thioheptanoate, and 2-chloroethyl thiooctanoate were synthesized by the treatment of hexanoyl chloride with ethylene sulfide. Hexanoyl thiocholine and octanoyl thiocholine were synthesized by using 2-chloroethyl thiohexanoate and 2-chloroethyl thiooctanoate with trimethyl amine. Second, after reaction of ethylene sulfide and dimethyl amine, followed by acylation with acid anhydride and then heptanonyl thiocholine, decanoyl thiocholine were synthesized by treatment of methyl iodide.

• Bulletin of the Korean Chemical Society
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• v.11 no.1
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• pp.65-69
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• 1990

The nucleophilic substitution reactions of naphthalene-1,5-disulfonyl chloride and 4-fluorosulfonylbenzenesulfonyl chloride with p-substituted anilines and methyl substituted pyridines in methanol-acetonitrile mixtures and hydrolyses of those disulfonyl halides have been studied by means of conductometric and polarographic methods. A large difference in the selective parameter, ${\rho}_N$ between mono-sulfonyl chloride and disulfonyl halide can be taken as an evidence that the second $SO_2Cl$ grolup of naphthalene-1,5-disulfonyl chloride also takes part in the reaction in contrast to sulfonyl fluoride in 4-fluorosulfonylbenzenesulfonyl chloride, which only acts as a substituent in the nucleophilic substitution reaction.

• Korean Journal of Food Science and Technology
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• v.20 no.3
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• pp.338-343
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• 1988

Selected kinetic parameters and degree of hydrolysis(DH) were measured using commercial proteases(trypsin, alcalase and pronase) to study the affinity of these enzymes to 7S and 11S soy proteins. Electrophoretic patterns of the hydrolysates were also investigated. In general, the order of affinity between the proteins and the proteases was 11S(protein-rich fraction)and 7S PRF for unheated proteins, and 7S PRF and 11S PRF for preheated proteins. Substrate inhibition was present at a substrate concentration of 1.5% or higher when preheated protein was used as the substrate. The maximum DH values of alcalase were obtained from 7S PRF(60%) and 11S PRF(80%) at 1 hr hydrolysis, respectively. Trypsin hydrolyses did not affect 11S soy protein but the acidic subunits in contrast to alcalase and pronase hydrolyses which changed almost all subunits. Alcalase hydrolysis induced distinct changes on 2S soy protein.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.3
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• pp.422-429
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• 1997

For the complete and accurate amino acid determination of protein and food samples, 3 different hydrolysis procedures have been conducted in parallel for each sample, which include the alkaline hydrolysis for tryptophan determination, performic acid oxidation prior to the acid hydrolysis for the determination of cysteine and cystine, and the 6N HCl hydrolysis for the determination of the rest of amino acids. In the present study, amino acid concentrations obtained from the modified single hydrolysis procedure were compared with the values from the conventional hydrolysis procedures in casein and nine food and composite dish samples. In most of the samples tested, the modified single hydrolysis procedure gave significantly higher values of cysteins and cystein compared to the performic acid oxidation method, but resulted in a considerable destruction of tryptophan in food and composited dish samples. There was no consistent difference in the rest of amino acid concentrations between the two hydrolysis systems. Therefore, for complete amino acid determination of various foods and composite dishes, the single hydrolysis method may replace the 6N HCl hydrolysis and performic acid oxidation methods, and thereby reduces 3 hydrolyses to 2 steps with much higher recoveries of the sulfur containing amino acids.

• The Korean Journal of Mycology
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• v.19 no.4
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• pp.253-257
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• 1991

Cellular carbohydrates were hydrolysed and analyzed in the strains of Leucosporidium scottii and its related species of basidiomycetous yeasts by HPLC methods without any derivatization. Xylose was detected from the hydrolyses of the cellular carbohydrates of L. lari-marini, but not from those of three strains of L. antarcticum, L. fellii, and Rhodosporidium fluviales. not also from those of six strains of L. scottii contrary to other data reported. L. antarcticum and L. lari-marini were considered to be placed on the different genus of Cystofilobasidium or Mrakia, as based on the numerical analyses.

• Journal of Microbiology and Biotechnology
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• v.14 no.2
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• pp.344-349
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• 2004

A gene encoding inulin-degrading enzyme of Bacillus sp. snu-7 with ORF of 1536 nucleotides was cloned. And it was overexpressed as His-tagged protein in E. coli BL21(DE3) pLysS using pRSET B vector containing mature enzyme sequence. Maximum enzyme production was achieved by IPTG (0.1 mM) induction at $OD_{600}$ 1.2 and $30^{\circ}C$ followed by 6 h incubation. The expressed protein purified through immobilized metal affinity chromatography showed molecular mass of 60 kDa on SDS-PAGE. Results of thin-layer chromatography using inulin as a substrate showed the enzyme to be an exotype inulinase capable of producing only monomeric fructose as a product. $K_m$ and $k_{cat}$, for the hydrolyses of inulin and sucrose were $2.28\pm0.08$ mM and 358.05$\pm$20.38 $min^{-l}$, and 22.02$\pm$0.41 mM and 4619.11$\pm$215.12 $$min^{-1}, respectively. Optimal activity of the exoinulinase occurred at pH 7.0 and $50^{\circ}C$.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.81-81
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• 2018

The present study was investigated on in vitro anti-obesity effect of 4-hydroxybenzyl alcohol from Cudrania tricuspidata. We isolated various compounds from Cudrania tricuspidata. Among these compounds, anti-obesity effects of 4-hydroxybenzyl alcohol was examined by lipase activity assay, cyclic adenosine monophosphate (cAMP)-specific phosphodiesterase type IV (PDE4) activity assay, and citrate synthase activity assay. 4-hydroxybenzyl alcohol and Cudrania tricuspidata extracts inhibited the enzymatic activities of lipase, PDE4, and citrate synthase. Lipase is known to mediate the hydrolysis of triacylglycerol in adipose tissue and cholesterol esters in other tissue or cells. Also, PDE4 hydrolyses cAMP, a crucial secondary messenger for in metabolic pathways including glucose and lipid metabolism, lipolysis, and thermogenic function. 4-hydroxybenzyl alcohol and Cudrania tricuspidata extracts induced the inhibitory effect against each enzymatic activity on several specific substrates as observed by detection at 405 or 412 nm. These findings might be attributable to the inhibition of adipogenesis, and partial prevention of obesity. In conclusion, these results show that 4-hydroxybenzyl alcohol and Cudrania tricuspidata may be a critical candidate as a natural anti-obesity source.

• Archives of Pharmacal Research
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• v.25 no.1
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• pp.80-85
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• 2002

The incubation of porcine renal proximal tubules (PTs) resulted in the release of the Glycosylphosphatidylinositol (GPI)-anchored renal dipeptidase (RDPase, EC 3. 4. 13. 19) from the membrane after a lag period of approximately 6 hours. This spontaneous release of RDPase from the membrane was inhibited by antibiotics. When the incubation supernatant was added back to fresh PTs, both the antibiotic inhibition of RDPase release and the lag period disappeared. The released RDPase reacted with an anti-cross reacting determinant antibody indicating the presence of the Ins (1, 2-cyc)P. These results suggest that bacteria in the PTs, when incubated, grow find Secrete a phosphatidylinmsitol-specific phospholipase C (PIPLC). This enzyme then hydrolyses the GPI-anchored RDPase and is transferable. RDPase was purified following its release from the membrane by this simple and inexpensive method which may also be applied to other GPI-anchored proteins.