• Title/Summary/Keyword: water-alcohol precipitation

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Preparation of Poly(vinyl butyral) by Precipitation Method and Its Characterization (침전법에 의한 폴리비닐부티랄의 제조 및 특성분석)

  • 서광원;김덕준
    • Polymer(Korea)
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    • v.26 no.2
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    • pp.168-173
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    • 2002
  • Poly (vinyl butyral) (PVB) was synthesized by acetalization of poly (vinyl alcohol) (PVA) PVB was prepared in particulate forms in water, and chemical and physical properties of the products were characterized using various techniques. The prepared PVB had size distribution from 100 to 700 $\mu\textrm{m}$ with mean diameter of about 380 $\mu\textrm{m}$. The chemical structure of PVB was characterized using FT/IR and NMR, and the average degree of acetalization was determined to be 77% from the titration measurement. DSC data showed that the crystalline structure of PVA vanished as acetalization reaction proceeded to produce PVB, and the glass transition temperature emerged at about $70^{\circ}C$. TGA data showed that PVB was much more thermally stable than PVA, and showed no degradation up to $300^{\circ}C$. Solubility test showed that PVB was soluble in alcohols but Insoluble in water, being totally different from PVA.

Synthesis of Zinc Oxide Nanoparticle-(C60) Fullerene Nanowhisker Composite for Catalytic Degradation of Methyl Orange under Ultraviolet and Ultrasonic Irradiation

  • Ko, Jeong Won;Son, Yeon-A;Ko, Weon Bae
    • Elastomers and Composites
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    • v.55 no.4
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    • pp.321-328
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    • 2020
  • Zinc nitrate hexahydrate (Zn(NO3)2·6H2O) and sodium hydroxide (NaOH) were dissolved in distilled water and stirred for 30 min. The resulting solution was sonicated by an ultrasonic wave for 45 min. This solution was washed with distilled water and ethanol after centrifugation; next, it was placed in an electric furnace at 200℃ for 1 h under the flow of Ar gas to obtain zinc oxide nanoparticle. A zinc oxide nanoparticle-(C60) fullerene nanowhisker composite was synthesized using the zinc oxide nanoparticle solution, C60-saturated toluene, and isopropyl alcohol via the liquid-liquid interfacial precipitation method. The zinc oxide nanoparticle and zinc oxide nanoparticle-(C60) fullerene nanowhisker composite were characterized using X-ray diffraction, scanning electron microscopy, and Raman spectroscopy, and they were used for the catalytic degradation of methyl orange (MO) under ultraviolet (at 254 and 365 nm) and ultrasonic irradiation. In addition, the catalytic degradation of MO over the zinc oxide nanoparticle and zinc oxide nanoparticle-(C60) fullerene nanowhisker composite was evaluated using ultraviolet-visible spectroscopy.

Studies on the constituents of higher fungi of Korea

  • Kim, Byong-Kak;Choi, Eung-Chil;Chung, Kyeong-Soo;Kang, Chang-Yul;Kim, Sook-Hee;Kim, Jin-Sook;Kim, You-Jin;Lee, Kyong-Lim;Lee, Jong-Kil
    • Archives of Pharmacal Research
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    • v.5 no.1
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    • pp.21-23
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    • 1982
  • To develop new potent antitumor substancces with low toxicity from natural products, especially from higher fungi of Korea, the carpophores of some wild basidiomycetes were collected and the antitimor test for their polysaccharides was done. The dried carpophores were extracted with hot water, and from the extracts, crude polysaccharides were obtained by alcohol precipitation. The alcohol precipitated crude polysaccharides were partially purified by dialysis and then used as the samples for antitumor tests. Among tested, the polysaccharide of Laccaria laccata, Trametes sanguineus, Armlliariella mellea, Clitocybe in fundibuliformis, and Xeromphalina campanella respectively showed the inhibition ratio of 75%, 72%, 94% 55%, and 47% when administered i. p. once dailly for ten days at the dose level of 20mg/kg/day into the mice implanted with $10^{6}$ cells of sarcoma 180/mouse. However, those of Craterellus cornucopiodes, Daedaleopsis confrogosa, and Coriolus sp. showed almost no activities.

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Characterization and distribution of phenolics in carrot cell walls

  • Kang, Yoon-Han
    • Proceedings of the Korean Society of Postharvest Science and Technology of Agricultural Products Conference
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    • 2003.10a
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    • pp.134.1-134
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    • 2003
  • The purpose of this study was to investigate the release of p-hydroxybenzoic acid and other compounds from cell wall materials(CWM) and their cellulose fraction from carrot with chemical and enzymatic hydrolysis. To investigate this effect on cell wall chemistry of carrot, alcohol insoluble residue(AIR) of CWM were prepared and were extracted sequentially with water, imidazole, CDTA(-1, -2), Na$_2$CO$_3$(-1, -2), KOH(0.5, 1.0 and 4M), to leave a residue. These were analysed for their carbohydrate and phenolic acids composition. Arabinose and galactose were the main noncellulosic sugars. Phenolics esterified to cell walls in carrot were found to consist primarily of p-hydroxybenzoic acid with minor contribution from vanillin, ferulic acid and p-hydroxybenzaldehyde. p-Hydroxybenzoic acid was quite strongly bound to the cell wall. The contents of p-hydroxybenzoic acid in 0.5M KOH, Na$_2$CO$_3$-2, IM KOH, and ${\alpha}$-cellulose were 2,097, 1,360, 1,140, and 717 $\mu\textrm{g}$/g AIR from CWM, respectively. Alkali labile unknown aromatic compound(C$\sub$7/H$\sub$10/O$_2$) was found in ${\alpha}$ -cellulose hydrolyzate digested with driselase and cellulase. This compound was also found in hydrolyzate of 2 M trifluoroacetic acid at 120$^{\circ}C$ for 2 hours. Driselase treatment solubilized only 46.6 $\mu\textrm{g}$/g of the p-hydroxybenzoic acid from carrot AIR. These results indicate that p-hydroxybenzoic acid was associated with neutral polysaccharides, long chain galactose and branched arabinan from graded alcohol precipitation.

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Quantitative comparison of acidic polysaccharides in the endosperm of two major varieties of rice

  • Hyun, Gyu Hwan;Lim, Dong Kyu;Kwon, Sung Won
    • Analytical Science and Technology
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    • v.30 no.4
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    • pp.205-212
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    • 2017
  • Rice endosperm, the portion that remains after milling, is the part of the rice seed that is primarily consumed as a source of nutrients. There have been many studies on polysaccharides, such as hemicellulose, cellulose, and pectins, derived from the cell walls of various plant groups. It has been reported that the acidic polysaccharide fractions, which contain water-soluble pectins that have been shown to have pharmacological effects in vivo and in vitro, have common chemical structures that include galacturonic acid polymers, rhamnose, arabinose, and galactose. However, few studies have been conducted on the acidic polysaccharides contained in the endosperm of rice. In this study, we quantitatively compared the differences in the acidic polysaccharide contents from samples from two of the main varieties of rice consumed as staple foods, japonica and indica, using a colorimetric method. Rice samples were collected from 39 different regions in Korea, China, Thailand and Vietnam. Acidic polysaccharide fractions were obtained by precipitation of the alcohol-insoluble residue (AIR) and enzyme treatment of each sample. The total amount of carbohydrates and uronic acid in each acidic polysaccharide fraction were measured using the phenol-sulfuric acid method and the carbazole-sulfuric acid method, respectively. The differences in the total polysaccharide contents in the acidic polysaccharide fractions were not statistically significant (p = 0.07), but the uronic acid contents were significantly different between the two groups (p = 0.04).

Cytoprotective effect of polysaccharide isolated from different mushrooms against 7-ketocholesterol induced damage in mouse liver cell line (BNL CL. 2)

  • Kim, Joo-Shin;Chung, Hau Yin;Na, Keun
    • Nutrition Research and Practice
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    • v.1 no.3
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    • pp.180-183
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    • 2007
  • Cytoprotective ability of polysaccharides isolated from different edible mushrooms was investigated on the 7-ketocholesterol-induced damaged cell line. Polysaccharide extracts from six different edible mushrooms-Flammulina velutipes, Peurotus ostreatus, Lentinus edodes, Agrocybe aegerita, Agaricus blazei, and Cordyceps militaris- were prepared by hot water extraction and alcohol precipitation. Cytoprotective ability was evaluated by measuring the viable cells of the normal embryonic liver cell line (BNL CL. 2) in the presence of 7-ketocholesterol. At $80\;{\mu}g/mL$ of 7-ketocholesterol, cytotoxicity was very high with a loss of 98% of viable cells after 20 h of incubation. With the addition of $200\;{\mu}g/mL$ of each polysaccharide isolate to the cell line containing $80\;{\mu}g/mL$ of 7-ketocholesterol, polysaccharide isolates from both Flammulina velutipes and Peurotus ostreatus could significantly inhibit the 7-ketochoelsterol-induced cytotoxicity in the cells. But other polysaccharide isolates were not effective in inhibiting cell damage caused by the oxLDL-induced cytotoxicity.

Preparation of C60 Nanowhiskers/WO3 Nanocomposites and Photocatalytic Degradation of Organic Dyes

  • Kim, Keun Hyung;Ko, Jeong Won;Ko, Weon Bae
    • Elastomers and Composites
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    • v.50 no.2
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    • pp.126-131
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    • 2015
  • $C_{60}$ nanowhiskers were synthesized from $C_{60}$ by liquid-liquid interfacial precipitation (LLIP) using $C_{60}$-saturated toluene and isopropyl alcohol. The $WO_3$ nanoparticles were synthesized by adding $3.8{\times}10^{-4}$ mole amount of ammonium metatungstate hydrate ($H_{26}N_6O_{40}W_{12}{\cdot}H_2O$) to 500 ml of distilled water, and the resulting solution was heated on a hot plate for 4 h. The $C_{60}$ nanowhiskers/$WO_3$ nanocomposites were prepared with $C_{60}$ nanowhiskers and $WO_3$ nanoparticles in an electric furnace at $700^{\circ}C$ in an argon gas atmosphere for 2 h. The $C_{60}$ nanowhiskers/$WO_3$ nanocomposites were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. UV-vis spectroscopy was used to evaluate the performance of the $C_{60}$ nanowhiskers/$WO_3$ nanocomposites as a photocatalyst in the degradation of organic dyes, such as methylene blue (MB) and brilliant green (BG) under ultraviolet light (254 nm).

Analysis of the Chemical Constituents of Agaricus brasiliensis

  • Cho, Soo-Muk;Jang, Kab-Yeul;Park, Hong-Ju;Park, Jeong-Sik
    • Mycobiology
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    • v.36 no.1
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    • pp.50-54
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    • 2008
  • This study examined the chemical composition of A. blasiliensis and the chemical structural properties of an immuno-stimulating polysaccharide. The amino acids, free sugars, and organic acids by HPLC and fatty acids by GC were analyzed. The immuno-stimulating substance from A. blasiliensis was extracted with hot water and purified by ethanol precipitation. It underwent ion exchange chromatography on DEAE-cellulose and gel filtration on Toyopearl HW 65F. Through GP-HPLC, the substance was found to be homogeneous. Its chemical structure was determined by $^{13}C-NMR$. Fatty acids, organic acids, and sugar alcohol composition consisted exclusively of linoleic acid, fumaric acid and mannitol, respectively. The amino acids were mainly glutamic acid, glycine, and arginine. By $^{13}C-NMR$ analysis, the immuno-stimulating substance was identified as ${\beta}-(1{\rightarrow}3)\;(1{\rightarrow}6)$-glucan, composed of a backbone with $(1{\rightarrow}3)$-linked D-glucopyranosyl residues branching a $(1{\rightarrow}6)$-linked D-glucopyranosyl residue. The ${\beta}$-glucan from A. blasiliensis showed pronounced immuno-stimulating activity on the antibody-production ability of B-lymphocytes by the hemolytic suspension assay. In these results, A. blasiliensis was estimated to have potent pharmacological properties and potential nutritional values.

Purification and Enzymatic Properties of Alkaline Lipase from the Pseudomonas sp.S4-14 (Pseudomonas sp. S4-14가 생산하는 Alkaline Lipase의 정제 및 효소학적 성질)

  • Park, Sang-Ho;Choi, Soo-Chul;Rhee, Joon-Shick;Sung, Nack-Kie
    • Microbiology and Biotechnology Letters
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    • v.22 no.3
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    • pp.271-276
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    • 1994
  • The strain S4-14 which produced alkaline lipase and had resistance against linear alkylbenzene sulfonate was isolated from soil or water samples. The isolated strain S4-14 was identified a species belong to Pseudomonas. Alkalin lipase secreted by Pseudomonas sp. S4-14 was purified by ammonium sulfate precipitation procedure follwed by DEAE-Cellulose, DEAE-Sepharose and gel filtration chromatohraphies with 995.15 U/mg protein and 16.1% yield. The molecular weight of the enzyme was estimated to be 65,000 dalton by SDS-PAGE. The optimum pH and temperature of the purified enzyme was 10.5 and 45$\circ $C, respectively. The emzyme was stable at 45$\circ $C for 1 hr and in a pH range from 8.0 to 12.0 for 24 hr at 4$\circ $C. The activity of lipase was enhanced by Ca$^{2+}$ while inhibited strongly by Pb$^{2+}$, Zn$^{2+}$ or Fe$^{3+}$. The activity of lipase was inactivated about 50~60% in the presence of 50 mg/l linear alkylbenzene sulfonate, $\alpha $-olefin sulfonate, alcohol ethoxylate or perborate.

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Dietary Effect of Hemicellulose from Shiitake Mushroom(Lentinus edodes) on Blood Glucose and Cholesterol Content in Rats (표고버섯 헤미셀룰로즈의 식이가 쥐의 혈당과 콜레스테롤 함량에 미치는 영향)

  • 김순동;김미향;이명예
    • Journal of the East Asian Society of Dietary Life
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    • v.14 no.3
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    • pp.243-250
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    • 2004
  • The effect of hemicellulose extracted from Shiitake mushroom(Lentinus edodes) on the level of blood sugar and cholesterol in the diabetes-induced rat by streptozotocin(STZ) was investigated. The yield of hemicellulose by extraction process of 5% salt extraction, preparation of alcohol insoluble substance, IN KOH extraction, acid precipitation(pH 3.0), and dialysis was 9.24%. The experimental plots divided to 1% cellulose group(control), 0.5% hemicellulose group(H-l) and 1% hemicellulose group(H-2). The groups were fed for 6 weeks, then continuously fed for 1 week after induction of diabetes by STZ. Feed intakes, weight gain and feed efficiency of the each groups were not significantly different, while water intakes and liver weight of H-2 group were lower than those of control and H-l group. Weight of liver in the H-2 group was significantly lower than those of control and H-l groups. The amounts of feces were 0.32 g/day in the control group, 0.43∼0.44 g/day in the H-l and H-2 groups, while the amounts of urine were 15.28 mL/day in the control group, 10.83∼11.20 mL/day in the H-l and H-2 groups. The content of blood glucose before diabetes induction(fed for 3∼5 weeks) was 111.2-132.6 mg/dL in the control group, not significantly different from others; After diabetes induction, however, the contents were 212.8 mg/dL in the control group, 140.0-144.0 mg/dL in the H-l and H-2 groups, which showed significant difference. Urine glucose contents of H-2 group before and after diabetes induction were lower than those of control and H-l groups. There was no significant difference in the content of neutral lipid between each groups. Total cholesterol contents were 101.6 mg/dL in the control group, 56.∼64.0 mg/dL in the hemicellulose groups. HDL-cholesterol content and atherogenic index of hemicellulose groups were lower than those of control group, respectively. In conclusion, the hemicellulose extracted from Shiitake mushroom represented improving and preventing effects for diabetes.

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