• Title/Summary/Keyword: alkaline hydrolysis

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A New Method of Colorimetric Determination of Piperine Using p-Nitrophenyl Diazonium Fluoborate in Pepper (Piper Nigrum L.) (p-Nitropheneyl Diazonium Fluoborate를 이용한 후추 Piperine의 새로운 비색정량법)

  • Rhee, Seong-Kap
    • Korean Journal of Food Science and Technology
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    • v.6 no.2
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    • pp.56-60
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    • 1974
  • A survey of the available methods for the determination of piperine was made, and a new method, developed based upon alkaline hydrolysis at about $140^{\circ}C$ followed by colorimetric determination of the liberated piperidine. Piperidine on treatment with p-nitrophenyl diazonium fluoborate reagent gives a red colored complex which has an adsorption maximum at 530nm. The method measures the total pungency in pepper and applicaple to piperine of black pepper and oleoresin of black pepper. The advantage of the present method is that the pungent compounds can be determined in micro samples.

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Molecular Cloning and Expression of Candida antarctica lipase B in Corynebacterium genus

  • Gonzalez, Tamara;M'Barek, Hasna Nait;Gomaa, Ahmed E.;Hajjaj, Hassan;Zhen, Chen;Dehua, Liu
    • Microbiology and Biotechnology Letters
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    • v.47 no.4
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    • pp.546-554
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    • 2019
  • This study, for the first time, reports the functional expression of lipase B derived from the yeast Candida antarctica (CALB) in Corynebacterium strain using the Escherichia coli plasmid PK18. The CALB gene fragment encoding a 317-amino-acid protein was successfully obtained from the total RNA of C. antarctica. CALB was readily produced in the Corynebacterium strain without the use of induction methods described in previous studies. This demonstrated the extracellular production of CALB in the Corynebacterium strain. CALB produced in the Corynebacterium MB001 strain transformed with pEC-CALB recombinant plasmid exhibited maximum extracellular enzymatic activity and high substrate affinity. The optimal pH and temperature for the hydrolysis of 4-nitrophenyl laurate by CALB were 9.0 and 40℃, respectively. The enzyme was stable at pH 10.7 in the glycine-KOH buffer and functioned as an alkaline lipase. The CALB activity was inhibited in the presence of high concentration of Mg2+, which indicated that CALB is not a metalloenzyme. These properties are key for the industrial application of the enzyme.

Dehydropolycondensation of Aminophenols under the Catalytic Action of Metallic Chelate Compounds (II) Effects of the Ligands, Structures of the Mixed Complexes, and Side Reactions (金屬킬레이트 化合物의 觸媒作用에 依한 Aminophenol 類의 酸化的 重縮合反應 (Ⅱ) Ligands 種의 效果, 混合錯物의 構造및 副反應)

  • Choi, Kyu-Suck
    • Journal of the Korean Chemical Society
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    • v.12 no.3
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    • pp.121-127
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    • 1968
  • In the oligomerization of p-aminophenol under the catalytic action of the metallic complexes, the effects of the ligands are studied. When the initial velocity of $O_2$ uptake at pH 8 using Fe(Ⅲ) as the central metal and N-hydroxylethylethylenediaminetriacetic acid (HEDTA), ethylenediaminetetraacetic acid (EDTA), diethylenetriaminepentaacetic acid (DTPA), 1,2-cyclohexanediaminetetraacetic acid(CyDTA) as the ligands respectively are compared, the velocities are as the following order: HEDTA > EDTA > DTPA > CyDTA. Further when the effect of the ligands, nitrilotriacetic acid (NTA), HEDTA, EDTA, and DTPA, on the yields of oligomers are compared, the result shows as the following order: NTA > HEDTA > EDTA > DTPA. These are nearly reverse order of the stability constants of the complexes. In order to determine the composition of the mixed complexes at the initial step, the method of continuous variation is used, and it is found that the composition ratio of Fe-EDTA complex to monomer in the mixed complexes is one at pH 5-8 range. It is also found that at pH 9 or in the more alkaline range, side reactions occur to form water soluble dimer of quinone type and the catalytic action of the metallic complex markedly decreases on account of the hydrolysis of the central metal by the $OH^-$ ion.

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Characteristics of Acid Fermentation and Alkali Pretreatment of Organic Wastes (유기성 폐기물의 산발효 특성 및 알카리 전처리에 관한 연구)

  • 박종안;허준무
    • Journal of environmental and Sanitary engineering
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    • v.16 no.1
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    • pp.108-116
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    • 2001
  • It is difficult to task to achieve high biological nutrient removal from municipal wastewater because of low organic content. Volatile fatty acids(VFAs) produced from acid fermentation of food wastes can be utilized as external carbon sources for the biological nutrient process. Significant reduction and stabilization of the food wastes can also be obtained from the acid fermentation. The objective of this study is to evaluate characteristics of acid fermentation of the food wastes. Results obtained from the batch experiment of various organic wastes showed that the food wastes had high potential to be used as an external carbon source because of the largest production of the VFAs with low nitrogen and phosphorus content. The fish waste was found to be the next possible organic waste, while the others such as radish cabbage and molasses waste showed high VFAs consumption potential as a results of high nitrogen and phosphorus content. alkaline hydrolysis of the food waste was carried out using NaOH prior to the acid fermentation. As the alkali addition increased, solubilization of the organics as well as TSS reduction increased. However, fraction of soluble COD to total COD became stable after a sharp increase. Alkali addition greater than 0.5g NaOH per g TS resulted in significant increase in pH.

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Modification of Wool Treated with Alkali and Alkali/CTAB (I) -Changes of chemical properties- (알칼리와 CTAB 처리에 의한 양모섬유의 개질(I) -화학적 성질의 변화-)

  • 김영리;유효선
    • Journal of the Korean Society of Clothing and Textiles
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    • v.20 no.5
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    • pp.728-737
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    • 1996
  • The purpose of this study is to investigate the change of the chemical properties of wool treated with six kinds of alkali (NaOH, Naac03, NH40H, NH2CH3CH30H, TMAH and BTMAH) with or without CTAB. Content of bound fatty acid liberated from wool surface, elemental composition and allw6rden time were measured to compare the surface modification of untreated and alkali treated wool. Also, the chemical degradation of the fiber was investigated by measuring cystine contents and urea-hydrogensulfite solubility. The result were as follows: 1. By the alkali treatment of wool, the covalently bound fatty acid of the epicuticle was removed and the allworden time was shortened, and in the case of wool treated with TMAH, BTMAH, the allw6rden sacs were formed unevenly and rarely. Also, cystine contents and urea-hydrogensulfite solubility were decreased by alkali treatment on wool. 2. The modification of epicuticle and the chemical degradation of wool were occurred due to alkaline hydrolysis in the order of TMAH, BTMAH > NaOH, Na3c03> NH2CH3CHaOH, NH40H. 3. As a treating time increased, the modification of epicuticle and chemical degradation of wool were accelerated. By the addition of CTAB to the alkali solution, the modification of epicuticle was increase, and the cystine contents and urea-hydrogensulfite solubility were reduced than that of wool teated with alkli without CTAB due to reduction of negative charge on the wool surface by the adhesion of CTAB.

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Effective Interfacial Area in an Agitated Liquid-Liquid Contactor by a Chemical Method (화학방법에 의한 액-액 계면 면적)

  • Park, Sang-Wook;Moon, Jin-Bok;Shin, Jeung-Ho;Park, Dae-Won;Kim, Jong-Hyeon
    • Applied Chemistry for Engineering
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    • v.4 no.1
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    • pp.103-112
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    • 1993
  • The rates of overall mass transfer of n-butyl acetate in the alkaline hydrolysis of n-butyl acetate were measured by using a mechanically agitated vessel in order to get the relationship between the mass transfer rates and experimental variables. The interfacial area between liquid-liquid heterogeneous phases could be obtained by comparing the theoretical values of reaction enhancement factor from an approximated solution of a diffusion equation based on the film theory with the experimental data.

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Mechanical and Surface Properties for Akaline Hydrolyzed Polyester Fabrics (알칼리 감량가공 된 폴리에스테르 직물의 역학적 특성과 표면특성에 관한 연구)

  • Kim, Kyung-Ae
    • Journal of the Korean Home Economics Association
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    • v.36 no.8
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    • pp.51-61
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    • 1998
  • This paper discussed the assessment of hand of polyester fabrics changed by alkaline hydrolysis. This study analyzed the relations between the change of mechanical property and the hand value according to the weight loss of polyester fabrics. The results are as follows; Objective hand by KES-FB system, revealed that for tensile properties, as the weight loss increased, WT, RT increased and LT decreased. For bending properties, as the weight loss increased, B and 2HB showed smaller values. For shear properties, as the weight loss increased, G, 2HG and 2HG5 decreased. For surface properties, as the weight loss increased, MIU increased, but MMD and SMD did not show any trend. For compression properties, LC, WC and RC did not show significant differences according to the degree of weight loss. In case of hand value, Koshi(stiffness), Hari(anti-drape stiffness), Kisimi(scrooping feeling) and Shinayakasa(flexibility with soft feeling) showed a meaningful results depending on the degree of weight loss. However, Shari(crispness) and Fukurami(fullness and softness) did not show meaningful result. Koshi, Hari and Shinayakasa are high correlation with tensile property, bendibg property shear properties, thickness and weight. Kisimi is high correlation with tensile property, bending property, thickness and weight. Shari, Fukurami and THV did not show any meaningful difference whth any mechanical properties.

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Tissue Factor Inhibitory Sesquiterpene Glycoside from Eriobotrya japonica

  • Lee, Ming-Hong;Son, Yeon-Kyoung;Han, Yong-Nam
    • Archives of Pharmacal Research
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    • v.27 no.6
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    • pp.619-623
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    • 2004
  • Tissue factor (TF, tissue thromboplastin) is a membrane bound glycoprotein, which acceler-ates the blood clotting, activating both the intrinsic and the extrinsic pathways to serve as a cofactor for activated factor VII (Vila). The TF-factor Vila complex (TF/VIIa) proteolytically activates factors IX and X, which leads to the generation of thrombin and fibrin clots. In order to isolate TF inhibitors, by means of a bioassay-directed chromatographic separation technique, from the leaves of Eriobotrya japonica Lindley (Rosaceae), a known sesquiterpene glycoside (2) and ferulic acid (3) were isolated as inhibitors that were evaluated using a single-clotting assay method for determining TF activity. Another sesquiterpene glycoside (1) was also isolated but was inactive in the assay system. Compound 3 was yielded by alkaline hydrolysis of compound 2. The structures of compounds 1, 2, and 3 were identified by means of spectral analysis as $3-O-{\alph}-L-rhamnopyranosyl-(1{\rightarrow}4)-a-L-rhamnopyranosyl-(1{\rightarrow}2)-[{\alph}-L-rhamnopyrano-syl-(1{\rightarrow}6)]-{\beta}-D-glucopyranosyl nerolidol$ (1), $3-O-{\alph}-L-rhamnopyranosyl-(1{\rightarrow}4)-{\alph}-L-rhamnopyr-anosyl-(1{\rightarrow}2)-[{\alph}-L-(4-trans-feruloyl)-rhamnopyranosyl-(1{\rightarrow}6)]-{\beta}-D-glucopyranosyl$ nerolidol (2) and ferulic acid (3), respectively. Compounds 2 and 3 inhibited 50% of the TF activity at con-centrations of 2 and $369{\;}\mu\textrm{m}/TF$ units, respectively.

Preparation of Electromagnetic Wave Shielding Fabrics by Electroless Silver Plating using PdCl2 and Dextrose (포도당 환원제와 PdCl2 촉매를 사용한 무전해 은도금 PET 직물의 제조)

  • Kim, Su-Mi;Song, Wha-Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.2
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    • pp.319-327
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    • 2008
  • The purpose of this study is to propose the development of high quality electromagnetic wave shielding fabrics. Silver nitrate is used for polyester fabric as an electromagnetic wave shielding material. The effects of activators and electroless silver plating condition on the evenness and adhesion of silver to fabrics, are observed through the SEM micrographs. Surface morphology and wash-ability are measured using SEM. The results are as follows: The optimum weight loss by alkaline hydrolysis of polyester fabrics is about 20%. The optimum concentration of $SnCl_2$ and $PdCl_2$in catalyst reaction using $PdCl_2$ as an activator is 2.5g/L and 0.5g/L, respectively. The optimum concentration of dextrose to improve adhesion between the silver plating and fabrics is 45g/L. The optimum concentration of silver nitrate in the catalyst reaction, using $PdCl_2$ as an activator is 56g/L, respectively. The optimum plating temperature and time are $15^{\circ}C$ and 30minutes, respectively.

Application of a Membrane Bioreactor in Denitrification of Explosives Hydrolysates (Membrane Bioreactor를 이용한 폭발성 물질의 가수분해 부산물의 탈질과정에의 적용)

  • Zoh, Kyung-Duk
    • Journal of Korean Society on Water Environment
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    • v.18 no.2
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    • pp.113-122
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    • 2002
  • A bench-scale anoxic membrane bioreactor (MBR) system, consisting of a bioreactor coupled to a ceramic crossflow ultrafiltration module, was evaluated to treat a synthetic wastewater containing alkaline hydrolysis byproducts (hydrolysates) of RDX, The wastewater was formulated the same as RDX hydrolysates, and consisted of acetate, formate, formaldehyde as carbon sources and nitrite, nitrate as electron accepters. The MBR system removed 80 to 90% of these carbon sources, and approximately 90% of the stoichiometric amount of nitrate, 60% of nitrite. The reactor was also operated over a range of transmembrane pressures, temperatures, suspended solids concentration, and organic loading rate in order to maximize treatment efficiency and permeate flux. Increasing transmembrane pressure and temperature did not improve membrane flux significantly. Increasing biomass concentration in the bioreactor decreased the permeate flux significantly. The maximum volumetric organic loading rate was $0.72kg\;COD/m^3/day$, and the maximum F/M ratio was 0.50 kg N/kg MLSS/day and 1.82 kg COD/kg MLSS/day. Membrane permeate was clear and essentially free of bacteria, as indicated by heterotrophic plate count. Permeate flux ranged between 0.15 and $2.0m^3/m^2/day$ and was maintained by routine backwashing every 3 to 4 day. Backwashing with 2% NaOCl solution every fourth or fifth backwashing cycle was able to restore membrane flux to its original value.