• 제목/요약/키워드: pKa value

검색결과 67건 처리시간 0.027초

고도처리공정과 나노여과공정에서의 미량유해물질 제거 평가 (Assessment of Micro Organic Pollutants Removal Using Advanced Water Treatment Process and Nanofiltration Process)

  • 강준석;최양훈;권순범;유영범
    • 대한환경공학회지
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    • 제36권8호
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    • pp.579-587
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    • 2014
  • 수계에서 검출되는 미량유해물질의 빈도와 종류가 다양해지고 있다. 따라서 정수처리시스템에서 고려되어야 할 부분으로 거론되고 있으며 제거공정과 처리효율에 대한 연구가 활발하게 진행되고 있다. 본 연구에서는 고도처리공정과 나노여과공정을 이용한 제거효율을 평가하였다. 나노여과공정의 경우 물질의 물리화학적 특성에 따라 제거율이 상이하게 나타났다. 물질의 분획분자량이 제거율이 가장 큰 영향을 미치는 것으로 확인되었다. 또한, 원수의 pH보다 높은 pKa 값을 갖거나 Log Kow 값이 2 이하인 물질의 제거효율이 감소되었다. 고도처리공정 중 산화공정에서는 대상물질의 분자량이 클수록 그리고 소수성을 띌수록 산화반응에 의한 제거효율이 감소되었다. 흡착공정에서는 산화되지 않은 대부분의 물질이 제거되었으며 $H_2O_2$에 의하여 산화가 더 잘 진행될수록 흡착반응이 향상되었다.

이부프로펜의 피페라진 유도체에 대한 약리활성연구 (Studies of Pharmacological Activity on the Piperazine Derivatives of Ibuprofen)

  • 조한진;나성범;남상철;박목순;지웅길
    • 약학회지
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    • 제34권2호
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    • pp.126-132
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    • 1990
  • To enhance the activity of ibuprofen, amides of ibuprofen, 1-piperazinyl-2-(4-isobutylphenyl)propionamide(Ibu-P.A.) and 1-(4-methylpiperazinyl)-2-(4-isobutylphenyl)propionamide (Ibu-M.P.), were synthesized and the pharmaceutical properties and the pharmacological activities of the amides were studied. The lipid:water partition coefficients and pKa values were examined in vitro, and the antiinflammatory effect, analgesic effects, acute toxicity, and intestinal absorption were studied for the amides and compared with ibuprofen in vivo. The results are summarized as belows; 1) The lipid:water partition coefficients of Ibu-M.P. were higher than those of ibuprofen. 2) The calculated pKa values of ibuprofen and Ibu-M.P. were 5.49 and 8.66, respectively. 3) The antiinflammatory effects of ibuprofen, Ibu-P.A., and Ibu-M.P. were same intensity, but the duration of the effects of Ibu-P.A. and Ibu-M.P. were longer than that of ibuprofen. 4) The analgesic effect of Ibu-M.P. was more potent than those of ibuprofen and Ibu-P.A. in the acetic acid-induced writhing test. 5) The $LD_{50}$ was 495 mg/kg for ibuprofen, 187 mg/kg for Ibu-M.P., and over 1250 mg/kg for Ibu-P.A.. 6) The absorption rate constants(k) and half-life($t_{1/2}$) were 0.74($hr^{-1}$) and 0.94(hr) for ibuprofen, and 0.72 ($hr^{-1}$) and 0.96 (hr) respectively for Ibu-M.P..

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치환 브롬화페나실과 이미다졸류의 반응에 대한 반응속도론적 연구 (Kinetics of Reactions of Phenacyl Bromides with Imidazoles)

  • 임동순;권종우;김창석;홍순영
    • 대한화학회지
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    • 제34권2호
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    • pp.184-188
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    • 1990
  • 치환 phenacyl bromide와 imidazole과의 반응 및 phenacyl bromide와 치환imidazole과의 반응속도를 전기전도도법으로 측정하였다. 반응속도는 phenacyl bromide의 전자 끄는기에 의하여 촉진되었으며 이 반응은 linear free energy relationship과 isokinetic relationship에 잘 맞았다. 반응속도와 imidazole의 pKa사이에는 Bronsted rule이 잘 적용되었으나 2-methylimidazole의 경우에는 위치장애현상으로 인해 여기서 벗어났다. Acetonitrile 용매하에서는 methanol 용매하에서보다 Kirkwood식에서 예상되는 것보다 훨씬 빠르게 반응속도가 관찰되었다.

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무독부자(無毒附子)의 제조에 관한 연구 (Studies on the Preparation of Processed Aconiti Tubers)

  • 박신영;정보섭;이형규;이현선;류종현
    • 생약학회지
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    • 제20권1호
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    • pp.25-31
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    • 1989
  • In order to establish the standard method for the preparation of processed Aconiti Tuber, Aconiti Tubers were processed under various conditions and the amount and the composition of alkaloids were determined by HPLC. The ratio of sum of benzoylhypaconine and benzoylmesaconine over the sum of acinitine, mesaconitine, benzoylmesaconine and benzoylhypaconine was used as a detoxification index ((BM+BH)${\times}$100/MA+AC+BM+BH). The adequate value of index was obtained from Japanese 'ka-gong bu-ja' which has been used in Japan. The processing procedure was largely devided into two categories. First is heat treating at $120^{\circ}$ and 1. 2 lbs for 60 min. Second is treatment with various kinds of alkaline solutions followed by heat treatment at $120^{\circ}$ and 1. 2 lbs for 60 min. Among the source of processed Aconiti Tubers, dried bu-ja and yom bu-ja, dried bu-ja was more adequate than yom bu-ja because yom bu-ja has the lower value of index than dried bu-ja and lost active components through the desalting periods. Dried bu-ja whish was treated with alkaline solutions followed by heat treatment has the detoxification index, 50% and dried bu-ja which was treated only with hear has 71. 8%. Compared to the value of index of Japanese 'ka-gong bu-ja', 72%, the dried bu-ja treated with heat at $120^{\circ}$ and 1, 2 lbs for 60min was the most adequate. The $LD_{50}$ value of the processed bu-ja was higher than 15 g crude drugs/kg, p.o. in mice.

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Breeding of New Productive Bivoltine Hybrid, CSR12 $\times$ CSR6 of Silkworm Bombyx mori L.

  • Datta, R.K.;Basavaraja, H.K.;Reddy, N.Mal;Kumar, S.Nirmal;Kumar, N.Suresh;Babu, M.Ramesh;Ahsan, M.M.;Jayaswal, K.P.
    • International Journal of Industrial Entomology and Biomaterials
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    • 제3권2호
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    • pp.127-133
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    • 2001
  • With an objective of evolving quantitatively and qualitatively superior bivoltine breeds/hybrids of silkworm Bombyx mori L. for tropical conditions, breeding work was initiated in Central Sericultural Research and Training Institute, Mysore during 1992 by utilizing two Japanese hybrids namely BNl8$\times$BCS25 and Shunrei$\times$Shogetsu along with Indian evolved breed, KA. The breed CSR12 which is characterized with sex-limited larval marking and white oval cocoons was evolved from the Japanese hybrid BNl8 ${\times}$ BCS25 by crossing with KA, while the breed CSR6 which is characterized with normal marking (marked larvae) and white dumbbell cocoons was extracted from the Japanese commercial hybrid Shunrei${\times}$Shogetsu through continuous inbreeding coupled with selection. After fixation, these breeds along with other newly evolved breeds were subjected to hybrid study under optimum environmental conditions in the laboratory for expression of full potential of the genotypes. These hybrids were evaluated by Multiple Trait Evaluation Index (Mano et al., 1993). The hybrid CSR12${\times}$CSR6 was selected based multiple trait evaluation index value. The hybrid CSR12$\times$CSR6 recorded survival of 96.0%, shell weight of 50.0 cg, shell ratio of 24.3%, raw silk percentage of 19.6, filament length of 1,216 m, boil off loss of 22.4% and renditta of 5.1. On the other hand, the control hybrid (KA ${\times}$ NB4D2) has recorded survival of 90.6%, shell weight of 42.1 cg, shell ratio of 20.4%, raw silk percentage of 15.9, filament length of 999 m, boil off loss of 24.8% and renditta of 6.3. The hybrid CSR12$\times$CSR6 was authorized during 1997 by Central Silk Board, Government of India for commercial exploitation during favourable months based on national level race authorization test.

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이온 강도(强度)가 다른 용액내(溶液內)에서 이탄표면(泥炭表面)의 하전특성(荷電特性) (Distribution of the Surface Charges of the Peats in Different Ionic Strengths)

  • 장상문;최정
    • Applied Biological Chemistry
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    • 제30권1호
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    • pp.1-8
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    • 1987
  • 전해질(電解質) 용액내(溶液內)에서 이탄표면(泥炭表面)의 하전량변화(荷電量變化)와 이탄유기물(泥炭有機物)의 화학적(化學的) 성질(性質)에 관하여 조사(調査)하였다. 두이탄(泥炭)의 유기물(有機物) 함량(含量)은 영양산(産) 이탄(泥炭)이 43.3%, 평택산(産) 이탄(泥炭)이 53.7%이였으며 점토(粘土) 광물(鑛物)은 대부분(大部分)의 석영(石英)과 미량(微量)의 illite 장석류(長石類), kaolinite, hydated-halloysite가 각각(各各) 혼재(混在)되어 있었다. 시료중(試料中)의 총산기(總酸基)의 량(量)은 평택산(産) 이탄(泥炭)이 1,257me/g로서, 영양산(産) 이탄(泥炭)보다 약간 많았으며, 유기물(有機物)의 pKa값은 영양산(産) 이탄(泥炭)이 13.1, 평택산(産) 이탄(泥炭)이 12.65이었다. 산(酸), 알칼리 적정곡선(滴定曲線)은 영양산(産) 이탄(泥炭)은 pH 3.9와 4.4에서, 평택산(産) 이탄(泥炭)은 pH 3.8과 4.0에서 교차 되었다. 음양(陰陽) ion 흡착량(吸着量)의 경우 영양산(産) 이탄(泥炭)에서는 $pH\;4.55{\sim}5.20(NaCl),\;pH\;3.95{\sim}5.70(CaCl_2)$에서, 평택산(産) 이탄(泥炭)의 경우에는 $pH\;4.15{\sim}5.40(NaCl),\;pH\;3.80{\sim}4.15(CaCl_2)$에서 각각(各各) 총하전량(總荷電量)이 양(陽)에서 음(陰)으로 바뀌었다. 그래서 본이탄(本泥炭)의 ZPC(Zero point of charge)는 pH 4.0 부근에서 형성(形成)되는 것으로 나타났다.

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테프(Eragrostis tef) 분말을 첨가하여 제조한 글루텐프리 면의 품질 특성과 검의 상관관계 (Effects of Gum on Quality Characteristics of Gluten-free Noodles prepared with Eragrostis tef Flour)

  • 정기영;송가영;오현빈;신소연;김영순
    • 한국식품영양학회지
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    • 제30권5호
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    • pp.1025-1034
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    • 2017
  • As the consumption of wheat has increased recently, the number of people who have digestive problems resulting from gluten in wheat has also increased. Teff has an attractive nutritional profile, as it not only gluten-free but also high in dietary fiber, protein, iron, and calcium. Seven samples were prepared for this study. The quality characteristics of gluten-free noodles were evaluated based on pH, salinity, water absorption, turbidity, color, texture properties, tensile strength, and SEM. The pH value was the highest in TF100 with a pH of 6.66 and the lowest in the control with a pH of 6.42. Salinity showed no significant difference among all samples, and it ranged from 0.02~0.04% (p<0.05). Water absorption was the highest in TFX with a value of 66.11%, and the lowest in the control with a value of 44.81%. Turbidity showed no significant difference among all samples, and it ranged from 0.14~0.21 O.D. (p<0.05). While the lightness and yellowness values decreased with an increase in teff flour content, the redness value tended to decrease. The color difference value was the highest in the sample group without gluten. Based on the texture profile analysis, the hardness was highest in the control with a value of 46.74 N and lowest in TF100 with a value of 18.34 N. The springiness showed no significant difference among all samples. The cohesiveness was highest in the control with a value of 0.92 N. The chewiness decreased with an increase in teff flour content. Although the control with gluten had the highest tensile strength at $3.42kg/cm^2$, TFX had considerable tensile strength at $2.30kg/cm^2$. This study demonstrated the processability of gluten-free noodles using teff flour.

아스파라거스 분말을 첨가한 설기떡의 품질 특성 및 항산화 활성 (Quality Characteristics and Antioxidant Activities of Sulgidduck with Asparagus (Asparagus officinalis L.) Powder)

  • 장양양;김종희;송가영;오현빈;김영순
    • 동아시아식생활학회지
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    • 제26권1호
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    • pp.63-72
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    • 2016
  • Asparagus (Asparagus officinalis L.) is a vegetable that has been reported to have a variety of pharmacological effects such as antioxidant and antitumor effects. In order to examine the quality characteristics and antioxidant characteristics of asparagus, asparagus Sulgidduck was prepared with different ratios of freeze-dried asparagus powder (0%, 0.5%, 1%, 2%, 3%, and 4%, w/w). As asparagus powder content in Sulgidducks increased, moisture contents of Sulgidducks decreased significantly. The pH of Sulgidducks decreased with higher amounts of added asparagus powder. Furthermore, the pH of Sulgidduck containing 4% asparagus powder showed the lowest value of 5.98. As asparagus powder content of Sulgidducks increased, L-value (lightness) decreased while a-value (redness) and b-value (yellowness) increased. In texture analysis, hardness and chewiness of Sulgidducks with freeze-dried asparagus powder increased with higher asparagus powder. The cohesiveness of Sulgidducks containing 4% asparagus powder showed the lowest value of 65.72%. Both total polyphenol content and DPPH (1,1-diphenyl-2-picryl hydrazyl) radical scavenging activity increased significantly with higher levels of asparagus powder content in Sulgidducks. In the sensory evaluation using a 7-point test, Sulgidduck containing 2% asparagus powder showed the highest sensory preference scores. Therefore, the results of this study suggest addition of 2% asparagus powder is the most appropriate ratio for making Sulgidduck with optimal quality characteristics.

Mutational Analysis of Two Conserved Active Site Tyrosine Residues in Matrilysin

  • Jaeho Cha
    • Journal of Life Science
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    • 제9권2호
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    • pp.44-48
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    • 1999
  • The ionization of tyrosine residue is known to be involved in the stabilization of transition-state in catalysis of astacin based upon the astacin-transition state analog structure. Two tyrosine residues, Tyr-216 and Tyr-219, are conserved in all MMPs related with astacin family, We replaced Tyr-216 and Tyr-219 into phenylalanine, respectively and the zinc binding properties, kinetic parameters, and pH dependence of each mutant are determined in order to examine the role of tyrosine residue in matrilysin catalysis. Both mutants contain two zinc atoms per mol of enzyme, indicating that either tyrosime does not affect the zinc binding property of the enzyme. Y216F and Y219F mutants are highly active and the kcat/Km values are only decreased 1.1-1.5-fold compared to the wild-type enzyme. The decrease in the activity of the mutants is essentially due to the increase in Km value. The pH dependencies of the kcat/Km values for both mutants are similar to the corresponding dependencies obtained with the wild type enzyme. The pKa values at the alkaline side of both mutants are not changed. These kinetic and pH dependence results indicate that the ionization of active site tyrosine residue of matrilysin is not reflected in the kinetics of peptide hydrolysin as catalyzed by astacin.

Teff (Eragrostis tef) 분말을 첨가한 Gluten-free 쿠키의 품질 특성 및 항산화 활성 비교 (Quality Characteristics and Antioxidant Activities of Cookies containing Teff (Eragrostis tef) Flour)

  • 정기영;송가영;오현빈;장양양;신소연;김영순
    • 한국식품영양학회지
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    • 제30권3호
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    • pp.501-509
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    • 2017
  • This study investigated the quality characteristics and antioxidant activities of gluten-free cookies containing teff flour. By substituting 0% (control), 25% (TF25), 50% (TF50), 75% (TF75), and 100% (TF100) of wheat flour with teff flour, five samples were produced. Baking loss rate was the highest in TF25 at 13.76% and the lowest in TF75 at 4.03%. Spread factor was significantly higher in cookies made with teff flour (83.00~85.00) than in the control (81.33) (p<0.05). There was no significant difference in density among the samples at 1.17~1.25 g/mL (p<0.05); however, pH significantly decreased at 6.42~6.04 (p<0.05). While the L-value and b-value significantly decreased with the amount of teff flour, the a-value significantly increased (p<0.05). The ${\Delta}E$ value was the highest in the control at 31.31 and the lowest in TF100 at 58.69. Hardness was the highest in the control at 42.04 N than in cookies containing teff flour. The content of polyphenols was the highest in TF100 at $3.37{\mu}g\;GAE/mg$ and the lowest in the control at $1.32{\mu}g\;GAE/mg$. The content of flavonoids was the highest in TF100 at $3.66{\mu}g\;QE/mg$ and the lowest in controls at $0.45{\mu}g\;QE/mg$. The value of DPPH $IC_{50}$ was the highest in the control at $3,723.00{\mu}g/mL$ and the lowest in TF 100 at $405.27{\mu}g/mL$. The value of ABTS $IC_{50}$ was the highest in the control at $1,822.32{\mu}g/mL$ and the lowest in TF100 at $529.30{\mu}g/mL$. In sensory evaluation, while control, TF75, and TF100 had a higher score in appearance at 5.52~5.60, all samples had no significant differences in flavor, sweetness, savory taste, chewiness, and overall acceptability (p<0.05). These results showed that the gluten-free cookies containing teff flour can improve the quality characteristics and antioxidant activities of a cookie. We concluded that gluten-free cookies containing 100% teff flour are desirable.