• 제목/요약/키워드: gel fraction

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Preparation of Hydrophilic-Hydrophobic Composites by A Concentrated Emulsion Polymerization Method and Their Permselectivity to Mixture of Water-Ethanol (고농축에멀션중합방법을 이용한 분리막제조와 선택적 흡수성 연구)

  • Park, Jun-Seo
    • Applied Chemistry for Engineering
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    • v.8 no.1
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    • pp.29-38
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    • 1997
  • In the w/o concentrated emulsion, the volume fraction of the dispersed is greater than 0.74 and the hydrophilic liquid is dispersed in the hydrophobic liquid of the continuous phase. The emulsion has the same appearance and behaviour as a gel. The polarity of the hydrophilic liquids and hydrophobic liquids, the pH and the ionic strength of the hydrophilic liquid are found to be important factors in the stability at the polymerization temperature such as $50^{\circ}C$. The lower the polarity of the hydrophobic liquid and the higher the polarity of the hydrophilic liquid, the more stable the emulsion. Electron microscopy studies of the hydrophilic-hydrophobic polymer composites show that the particles of polyacrylamide, the dispersed phase, are separated by he network of the thin film of polystyrene, the continuous phase. This hydrophilic-hydrophobic polymer composites show higher permselectivity to water in the mixture of water-ethanol. The pervaporation experiment shows that the selectivity of the membrane ranges between 4-40 and increases with increasing enthanol concentration in the feed. The rate of permeation decreases with increasing ethanol concentration in the feed.

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Antioxidant Principles of Nelumbo nucifera Stamens

  • Jung, Hyun-Ah;Kim, Jung-Eun;Chung, Hae-Young;Choi, Jae-Sue
    • Archives of Pharmacal Research
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    • v.26 no.4
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    • pp.279-285
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    • 2003
  • In our ongoing study to identity antioxidants from natural sources, the antioxidant activity of Nelumbo nucifera stamens was evaluated for their potential to scavenge stable 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals, inhibit total reactive oxygen species (ROS) generation, in kidney homogenates using 2 ,7 -dichlorodihydrofluorescein diacetate (DCHF-DA), and scavenge authentic peroxynitrites ($ONOO^-$). A methanol (MeOH) extract of the stamens of N. nucifera showed strong antioxidant activity in the $ONOO^-$system, and marginal activity in the DPPH and total ROS systems, so were therefore fractionated with several organic solvents, such as dichloromethane ($CH_2 Cl_2$), ethyl acetate (EtOAc) and n-butanol (n-BuOH). The EtOAc soluble fraction, which exhibited strong antioxidant activity in all the model systems tested, was further purified by repeated silica gel and Sephadex LH-20 column chromatographies. Seven known flavonoids [kaempferol (1), kaempferol 3-Ο-$\beta$-D-glucuronopyranosyl methylester (2), kaempferol 3-Ο-$\beta$-D-glucopyranoside (3), kaempferol 3-Ο-$\beta$-D-galactopyranoside (4), myricetin 3 ,5 -dimethylether 3-Ο-$\beta$-D-glucopyranoside (5), kaempferol 3-Ο-$\alpha$-L-rhamnopyranosyl-(1$\rightarrow$6)-$\beta$-D-glucopyranoside (6) and kaempferol 3-Ο-$\beta$-D-glucuronopyranoside (7)], along with $\beta$-sitosterol glucopyranoside (8), were isolated. Compound 1 possessed good activities in all the model systems tested. Compounds 2 and 7 showed scavenging activities in the DPPH and $ONOO^-$ tests, while compounds 3 and 4 were only active in the $ONOO^-$ test. Conversely, compound 8 showed no activities in any of the model systems tested.

A Cytotoxic Activity of Panax Ginseng Extract Against Bome Cancer Cells In Vivo and In Vitro.

  • Hwang, Woo-Ik;Park, Gil-Hong;Paik, Jeong-Mi
    • Proceedings of the Ginseng society Conference
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    • 1987.06a
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    • pp.29-37
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    • 1987
  • This study was devised to observe the cytotoxlc activities of petroleum-ether extract of Panax ginseng root(crude Gx) and its partially purified fraction from silicon acid column chromatography(7:3 CX) against sarcoma-180(5-180) and Walker carcinosarcoma 256(Walker 256) in vivo, and murine leukemic lymphocytes(L1210) and human rectal cancer cell(HRT-18) and human colon cancer cells(HT-29 and HCT-48) in vitro . Each cell-line was cultured in medium containing serial concentrations of the crude Gx or 7:3 Gx in vitro. A highly lipid soluble compound in the extract of Panax ginseng root was cytocidal to murine leukemic cells and human colon and rectal cancer cells in vitro In the meantime, ginseng saponin derivatives did not cytotoxic effects at its corresponding concentration. The growth rates of the cancer cells in medium containing ginseng extracts were inhibited gradually to a significant degree roughly in proportion to the increase of the extract concentration. The cytotoxic activity of 7:3 Gx was about 3 times more potent than that of crude Gx, one unit of cytotoxic activity against L121f cells being equivalent to 2.54$\mu\textrm{g}$ and 0.88 $\mu\textrm{g}$ for the crude Gx and 7:3 Gx, respectively. The Rf value of the active compound on silica -gel thin layer chromatography with petroleum-ether/ethyl ether/acetic acid mixture (90:10:1, v/v/v) as a developing solvent was 0.23. The survival times of mice inoculated with S-180 cells were extended about 1.5 to 2 times by the 7:3 Gx treatment compared with their control group. The significantly decreased hemoglobin values of rats after inoculation with Walker 256 were recovered to normal range by oral administration of the crude Gx. The synthetic levels of protein, DNA and RNA in human colon and rectal cancer cells were significantly diminished by treatment with the crude Gx, which can explain a part of the origin of its anticancer activity.

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Isolation and Evaluation of Protective Effect against Fusarium Wilt of Sesame Plants of Antibiotic Substance from Bacillus polymyxa KB-8

  • Hyun, Jae-Wook;Kim, Young-Hoon;Lee, Yong-Se;Park, Won-Mok
    • The Plant Pathology Journal
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    • v.15 no.3
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    • pp.152-157
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    • 1999
  • An antibiotic compound was isolated from the culture of an antagonist against Fusarium oxysporum f. sp. sesami, Bacillus polymyxa strain KB-8, and tested for the control of Fusarium wilt of sesame in greenhouse conditions. Optimum conditions for culturing the antagonist to obtain the maximum antibiotic activity were determined using different culture media, initial medium acidity, and incubation periods for which yeast -malt extract agar with the initial acidity of pH 5 and over 13 days culture were best. Antibiotic substances extracted by methanol had 2 main fractions, KB-8A and KB-8B, in thin layer chromatography (OLC) with Rf values of 0.35 and 0.67 in a solvent system of chloroform : methanol = 7 : 3. The fraction KB-8A wa purified further by XAD-2, silica gel and Sephadex LH-20 column chromatography, and crystalization. Its minimum inhibitory concentrations (MICs) were $12.8\mu\textrm{g}$/ml for F. oxysporum and Alternaria mali, $6.4\mu\textrm{g}$/ml for Colletotrichum gloeosporioides and Rhizoctonia solani, and $3.2\mu\textrm{g}$/ml for Phytophthora capsici. Soil drenching of antibiotic KB-8A in the concentrations of $13.0\mu\textrm{g}$/ml and $26.0\mu\textrm{g}$/ml effectively inhibited the Fusarium wilt of sesame in a greenhouse test, which appeared to be comparable to the fungicide benlate of $6.5\mu\textrm{g}$ a. i./ml.

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Assessment of the Inhibitory Activity of Peptide Extracts from Hanwoo Musculus Longissimus on Angiotensin I-Converting Enzyme

  • Seol, Kuk-Hwan;Song, Ji-Hye;Prayad, Thirawong;Kim, Hyoun-Wook;Jang, Ae-Ra;Ham, Jun-Sang;Oh, Mi-Hwa;Kim, Dong-Hun;Lee, Moo-Ha
    • Food Science of Animal Resources
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    • v.31 no.5
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    • pp.663-667
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    • 2011
  • This study was performed to measure the angiotensin I-converting enzyme (ACE) inhibitory activity of peptide extracts derived from the enzymatic proteolysis of Hanwoo Musculus longissimus (M. longissimus) during cold storage. Thermolysin (80 ppm, w/w) and protease type XIII (100 ppm, w/w) were injected separately or in combination for the enzymatic proteolysis of sarcoplasmic and myofibrillar proteins prior to storage at $5^{\circ}C$ (T1) or at $-1^{\circ}C$ (T2) in a chilling room for 9 days. Beef injected with thermolysin (E2) and thermolysin+protease type XIII (E3) showed a significantly higher degree of hydrolysis at both storage temperatures (p<0.05). During the storage period, T1E2 at day 6 and T1E3 at day 9 showed the strongest ACE inhibitory activity with sarcoplasmic and myofibrillar protein proteolysates. Macromolecules greater than 10,000 Da were removed by ultra filtration, and the filtrates were separated into fractions using gel filtration. Five and three major fractions were collected from S-T1E2-6 and M-T1E3-9 extracts, respectively, and the $4^{th}$ fraction of the S-T1E2-6 extracts showed the highest ACE inhibitory rate of $61.96{\pm}7.41%$.

Effect of Follicular Fluid Proteins and Gonadotropins on Progesterone Secretion by Buffalo Granulosa Cells In vitro

  • Vinze, Mukesh;Sharma, M.K.;Singh, Dheer
    • Asian-Australasian Journal of Animal Sciences
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    • v.17 no.11
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    • pp.1496-1500
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    • 2004
  • In the mammalian ovary the follicular fluid contains proteins and peptides which play an important role in growth, development and maturation of oocytes. The gonadotropins and some other factors work synergistically and regulate ovarian functions. In the present study the effect of follicular fluid proteins (FFP) and gonadotropins on progesterone secretion by granulosa cells (GC) from buffalo ovary, was investigated during culture. The follicular fluid was collected from small (<5 mm), and medium (5-8 mm) follicles obtained from buffalo ovaries. The follicular fluid from medium follicles was fractionated with ammonium sulphate at 80% saturation. The precipitated protein fraction was further resolved in to minor (peaks I, III) and major (peak II) proteins using gel filtration (Sephadex G-200). The FFP from small follicles and major FFP (peak II) at a dose of 200 $\mu$g/well, significantly stimulated progesterone secretion by pooled GC (3${\times}10^{5}$ cells/2 ml medium/well). The minor FFP did not show any stimulatory effect. There was a significant increase in progesterone secretion by pooled GC in presence of FFP and LH (10 ng/well), however, FSH (20 ng/well) with FFP exhibited an inhibitory effect. The major FFP and gonadotropins were also studied for their effect on progesterone production by GC isolated from medium and large size follicles. The GC from medium follicles were more responsive to FSH and FFP whereas GC from large follicles exhibited enhanced progesterone secretion with LH and FFP. These results indicated that FFP have their own stimulatory effect and also act synergistically with gonadotropins. The significantly different response shown by GC, for steroid hormone secretion, is based on their stage of growth and differentiation. The purification and characterization of such steroidogenic proteins may help in elucidating their role in growth and differentiation of granulosa cells.

Characterization of an Endoxylanase Produced by an Isolated Strain of Bacillus sp.

  • Lee, Jay-J.;Hahm, Kyoung-Soo;Lee, Ki-Young;Lee, Sung-Taik
    • Journal of Microbiology and Biotechnology
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    • v.7 no.2
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    • pp.114-120
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    • 1997
  • Microorganisms producing xylanase were screened for the enzymatic production of xylo-oligo saccharides from xylan. One of the bacteria isolated from compost produced an endoxylanase extracellularly. The bacterium was identified as Bacillus sp. according to its taxonomic characteristics examined. Xylanase production reached upto 5 U/ml after 22 h of culture in LB medium at $30^{\circ}C$. The xylanase was purified by ammonium sulfate precipitation and gel filtration. The molecular weight of the xylanase was estimated to be 20,400 by SDS-PAGE. Optimal temperature and pH for the xylanase activity was $60^{\circ}C$ and 6.5, respectively. The enzyme was stable at temperatures upto $40^{\circ}C$ and pH values from 4 to 10. The xylanase was completely inhibited by the addition of 2 mM mercury ion. Apparent $K_m$ and $V_max$ values for oat spelt xylan were 9.2 mg/ml and 1954 U/mg protein, respectively. For birchwood xylan, the values were 6.3 mg/ml and 1009 U/mg protein. The predominant products of the xylan hydrolysis were xylobiose, xylotriose and xylotetraose, indicating that the enzyme is an endoxylanase. Upto $85{\%}$ of the initially added enzyme (2 U/ml) was bound to 50 mg/ml of the insoluble fraction of oat spelt xylan after incubation at $30^{\circ}C$ for 30 min.

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Isolation of Antioxidative Compound from Scutellaria baicalensis G. (황금으로부터 항산화 활성 성분의 분리)

  • Kim, Seok-Chang;Ahn, Kun-Seok;Park, Chae-Kyu;Jeon, Byeong-Seon;Lee, Jong-Tae;Park, Won-Jong
    • Korean Journal of Medicinal Crop Science
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    • v.14 no.4
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    • pp.212-216
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    • 2006
  • Root of Scutellaria baicalensis G. was extracted with methanol and water to give the yield of 30.0% in order to find the antioxidant substance. The extract was fractionated with diethyl ether, n-butanol and water to test the inhibitive activity against xanthine oxidase. Three fractions inhibited the activities of xanthine oxidase by 48.2%, 10.2% and 2.8%, respectively, at the amount of $0.1\;{\mu}g$. A component that exhibited strong inhibition of xanthine oxidase was isolated from diethyl ether fraction (SE Fr.) by silica gel column chromatography and HPLC, and then identified by $^1H-NMR$, $^{13}C-NMR$ and MS spectrophotometry. EDA (Electron Donating ability) of the compound was 28.5% at the concentration $100\;{\mu}g/3\;ml$. That was identified to be 3,5,7-trihydroxy-2'-methoxyflavanone by spectrophotometric analysis using $^1H-NMR,\;^{13}C-NMR$ and Mass spectrophotometry.

Studies on Constituents of the Higher Fungi of Korea(LIV) -Studies on Toxic Component of Auricularia polytricha- (한국산(韓國産) 고등균류(高等菌類)의 성분연구(成分硏究)(제54보)(第54報) -털목이의 독성(毒性) 성분(成分)에 관한 연구(硏究)-)

  • Kim, Ha-Won;Choi, Eung-Chil;Kim, Byong-Kak
    • The Korean Journal of Mycology
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    • v.14 no.4
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    • pp.265-271
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    • 1986
  • To screen biologically active components of the higher fungi of Korea, the dried carpophores of Auricularia polytricha were extracted with water. The extract was examined for acute toxicity in ICR mice. A low molecular weight toxin of this fungus was purified by a acetone precipitation followed by cellulose, silica gel and Sephadex LH-20 column chromatography. Major symptoms of this toxin were decreasing of normal motility, eye extrusion, hair erection, shivering, trembling of head, paralysis, rapid running or moving before death and depression of respiration. The median lethal doses of the total extract were 1. 28 g/kg and 4. 31 g/kg by i.p. and p.o. administrations, respectively. The amounts of one mouse lethal unit of the total extract and final fraction that killed a 20 g mouse within 30 minutes were 28.5 and 12.0 mg/mouse, respectively.

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Biochemical Changes Induced due to Staphylococcal Infection in Spongy Alphonso Mango(Mangifera indica L.) Fruits

  • Janave, Machhindra Tukaram
    • Journal of Crop Science and Biotechnology
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    • v.10 no.3
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    • pp.167-174
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    • 2007
  • Spongy Alphonso mangoes were found to be infected with Staphylococcus bacteria. A Gram positive Staphylococcus strain was isolated from spongy pulp and identified from CABI Bioscience, UK, by partial 16S rDNA sequence analysis and by morphological and biochemical characterization through IMTECH, Chandigarh, India. Although identification by both of these methods indicated the organism belonged to same genus, different species names were given. Changes in total phenolics, reducing, and non-reducing sugars, respiration rate, total carotenoids, peroxidase(POX), and catalase activities were monitored during ripening of these fruits. The climacteric rise in spongy fruits was marked by an increase in respiration rate and a decrease in sugar content. Total phenolics content increased in spongy fruits as compared to ripe non-spongy fruits. Development of corky white tissue in spongy fruits was associated with about a 2.5-fold reduction in total carotenoids and a concomitant increase in lipoxygenase-mediated, $\beta$-carotene co-oxidation. A marked decrease in soluble protein content and about a 1.5-fold increase in POX activity was observed. Maximum POX activity was confined to 50-70%$(NH_4)_2SO_4$ fraction. The intense dark bands visible after POX specific substrate staining of the Native gel indicated a high expression of isoenzymes of POX in spongy fruits. Similarly, changes in levels of catalase activity were also observed in spongy fruits. The results suggest that infection of Alphonso mangoes with Staphylococcus bacteria affects the normal ripening processes of the fruit interfering with the carbohydrate and carotenoid metabolism. Also, the studies indicate the expression of POX and catalase enzymes as a plant defense response to microbial invasion.

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