• Title/Summary/Keyword: solvent system

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Solubilization of Biphenyl Dimethyl Dicarboxylate in Aqueous Solution (수용액중의 비페닐디메칠디카르복실레이트의 가용화)

  • Bae, Joon-Ho;Park, Eun-Seok;Chi, Sang-Cheol
    • Journal of Pharmaceutical Investigation
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    • v.27 no.3
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    • pp.199-205
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    • 1997
  • In order to formulate biphenyl dimethyl dicarboxylate(DDB) aqueous solutions, the effects of various solubilizing agents such as cosolvents(PG, PEG 400, glycerin, ethanol), surfactants,$(poloxamer\;407,\;Cremophor^{\circledR}\; RH40,\;Solutol^{\circledR},\;Tween\;80,\;sodium\;lauryl\;sulfate)$, complexation agent$(CELDEX^{\circledR}\;CH-20)$ and others(urea, niacinamide, propylene carbonate, HPMC) on the solubility of DDB in water were evaluated. The solubility of DDB in water was about $0.21\;{\mu}g/ml\;at\;20^{\circ}C$, while its solubility in PEG 400 was 5,000 times higher than that in water. 60% PEG 400 aqueous solution was selected as an optimum solvent system, and surfactants or other solubilizing agents were added to prevent DDB from recrystalization. The addition of surfactants in water increased the solubility of DDB from 15- to 34-fold, however, $CELDEX^{\circledR}\;CH-20$ and other agents studied showed negligible effects on the solubility of DDB in water. The 60% PEG 400 aqueous solution containing 5% $Cremophor^{\circledR}$ RH40 was appeared as the formula of choice. It showed acceptable physical stability after stored for 7 days at $4^{\circ}C$.

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Analysis of Dye Extracted from Phellodendron Bark Using Liquid Chromatography

  • Ahn, Cheun-Soon
    • Journal of the Korean Society of Clothing and Textiles
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    • v.35 no.12
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    • pp.1507-1517
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    • 2011
  • Berberine, palmatine, and Phellodendron bark dye was prepared in methanol for HPLC-DAD-MS analysis of liquid dye. Silk was dyed using berberine, palmatine, and Phellodendron bark dye prepared in water. The dye was extracted from the dyed silk using the HCl/methanol/water (2:1:1 v/v/v) solvent system with a slight modification. The liquid dyes and the dye extracted from the silk samples dyed with the three dye sources were examined using the HPLC-DAD-MS analysis to simultaneously detect berberine and palmatine from the plant dye and the dyeings. Colorimetric measurement was carried out using a spectrophotometer to examine the color and the intensities of berberine, palmatine, and Phellodendron bark dyed silk samples. From the liquid dyes, berberine eluted at 5.21 min with the molecular cation m/z=336 and the UV spectrum confirming that the product was berberine. Palmatine eluted at 5.12 min with the molecular cation m/z=352 and the UV spectrum confirming that the product was palmatine. From the silk dyed with berberine and palmatine dye, berberine and palmatine species eluted at 5.35 min and 5.24 min, respectively. From the silk dyed with Phellodendron bark, berberine and palmatine were detected simultaneously at 5.35 min and 5.26 min, respectively. All three dyes had yellow hue while palmatine dyed silk showed the highest hue and chroma. Palmatine dyed silk showed the highest K/S value that indicated the strongest color intensity and the highest dye uptake.

Synthesis and Phytotoxic Activities of (8S, 9S, 11R)-(-)-Monocerin and (9S, 11R)-(+)-Fusarentin 4, 5-dimethyl ether ((8S, 9S, 11R)-(-)-Monocerin and (9S, 11R)-(+)-Fusarentin 4, 5-dimethyl ether의 합성과 생리활성)

  • Ko, Byoung-Seob
    • Applied Biological Chemistry
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    • v.37 no.5
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    • pp.402-408
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    • 1994
  • For the examination of the role of monocerin(1) on the biological activity, (8S, 9S, 11R)-(-)-monocerin(20) and (9S, 11R)-(+)-fusarentin 4, 5-dimethyl ether(19) were synthesized by a condensation of the benzylic anion of ethyl 2, 3, 4-trimethoxy-6-methylbenzoate(16) with modifyed (R)-ethyl 3-hydroxyhexanoate (9). In a key step, bioreduction with active dried baker's yeast in organic solvent system was employed to get a chiral aldehyde 12. Their phytotoxic activities were tested on rice seedlings and lettuce seeds.

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Development of New Biocompatible Fiber form Composite of Chitin and Cellulose (카틴과 셀룰로우스의 복합체로부터 새로운 생체흡수성 봉합사의 개발)

  • 이충우;홍영근이화섭윤정원
    • KSBB Journal
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    • v.8 no.3
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    • pp.237-242
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    • 1993
  • Chitin-based fibers have low mechanical strength and hence cannot be used as surgery fiber due to fast degradation In tissues. A new fiber Chitulose was made by mixing chitin with cellulose, both of which have similar structure. A mixture of dimethylacetamide (DMAc) and 6% lithium chloride (LiCl) was found to be an effective solvent system for dissolvoing chitin and cellulose. The Chitulose fiber made by wet spinning of a mixture of chitin and cellulose resulted in the highest degree of strength and flexibility when the ratio of chitin to cellulose was 1.5; 0.2. The fiber maintained mechanical structure even after autoclaving, indicating thermal stability. A biodegradability test of the Chitulose fiber by imbeding in a rat showed that degradation was initiated in 14 days and completely done in 40 days.

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Development of New Biodegradable CHITULOSE film from Composite of Chitin and Cellulose (Chitin과 Cellulose 복합체로부터 새로운 생분해성 CHITULOSE film의 개발)

  • 류영석;이충우홍범식윤정원
    • KSBB Journal
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    • v.8 no.3
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    • pp.230-236
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    • 1993
  • A Chitulose film was made by dissolving chitin and cellulose in a dimethylacetamide/LiCl solvent system This film was completely degraded in 20 days in soil and penetrated by soil microorganisms in 16-26 hours. A permeability analysis of the film showed that water permeability was in the range of 0-187.5 $1/m^2$/day, depending upon the ratio of chitin to cellulose and decreased with increasing a cellulose content in the Chitulose film The permeabilities of organic compounds, $Na^+$ and oxygen change with the composition of the Chitulose file The film was tested with a burned 2~3degree rat for exploring its use as artificial skin. The rat was completely cured within 31 days without inflammation.

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Simultaneous HPLC Analysis of Three Flavonoids in the Extracts of Artocarpus heterophyllus Heartwoods

  • Septama, Abdi Wira;Panichayupakaranant, Pharkphoom
    • Natural Product Sciences
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    • v.22 no.2
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    • pp.77-81
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    • 2016
  • A reversed-phase high-performance liquid chromatographic method is described for the simultaneous determination of three antibacterial flavonoids, artocarpanone, artocarpin, and cycloartocarpin in ethyl acetate extracts from Artocarpus heterophyllus heartwoods. Separation was achieved using a TSK-gel ODS-80Tm column ($5{\mu}m$, $4.6{\times}150mm$) at $25^{\circ}C$ with a gradient elution system of methanol and water as follows: 0-8 min, 60:40; 8-27 min, 80:20; 27-35 min, 60:40, v/v, at a flow rate of 1 mL/min, and a quantitative UV detection at 285 nm. The method was validated by measuring the key parameters, including specificity, linearity, sensitivity, accuracy, repeatability and reproducibility. A high degree of specificity and sensitivity was achieved. The calibration curves for all three flavonoids showed good linearity with a coefficient of determinations ($R^2$) of ${\geq}0.9995$. The recoveries of the method were from 98-104%, with good reproducibility and repeatability (RSD values of less than 2%) were also achieved. Ethyl acetate was the best solvent for extraction of these three flavonoids using the heat reflux conditions for 1 h. This optimized sample preparation and HPLC method can be practically used for a routine standardization process of the extracts from the A. heterophyllus heartwoods.

Lipophilic Crown-4 Derivatives as Lithium Ionophores for Lithium Ion Selective Liquid Membrane Electrodes

  • Jae Sang Kim;Sung Ouk Jung;Shim Sung Lee;Si-Joong Kim
    • Bulletin of the Korean Chemical Society
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    • v.14 no.1
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    • pp.123-127
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    • 1993
  • New lipophilic Crown-4 compounds of 16-membered rings containing furan (neutral carrier,I), tetrahydrofuran (neutral carrier,II) and lithium complex of the latter (neutral carrier,III) have been synthesized and tested as the active sensors for lithium ion in poly(vinyl chloride) (PVC) membrane electrode, in the presence and absence of an anion excluder, tetrakis(4-chloro-phenyl)borate (KTClPB), 2-nitrophenyl phenyl ether (NPPE), tris(2-ethylhexyl)phosphate (TEHP), o-nitrophenyl octyl ether (NPOE), dioctyl adipate (DOA), bis(2-ethylhexyl)adipate (BEHA), di-n-octylphenyl phosphonate (DOPP) were used as plasticizing solvent mediators. The electrode response function had a nearly Nernstian slope of 54-61 mV per decade (25$^{\circ}$C) within the concentration range of $10^{-1}-10^{-4}$ M LiCl and the detection limits for all electrodes were ca. $5{\times}10^{-4}$ M. The response time of the electrode was faster at the higher lithium concentration and the response of the electrode was stable for longer than 6 months. The sensor membranes exhibit improved response times and increased lifetimes as compared to the system described earlier.

Disappearance of the ${\alpha}$-Effect : Reaction of p-Nitrophenyl Acetate with Various Aryloxides and Benzohydroxamates in the Presence of Cetyltrimethylammonium Bromide

  • Dong Sook Kwon;Seung Eun Lee;Jin Kyung Jung;Jong Yoon Park;Ik Hwan Um
    • Bulletin of the Korean Chemical Society
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    • v.13 no.5
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    • pp.486-491
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    • 1992
  • The rate constants for the reactions of p-nitrophenyl acetate with 6 different aryloxides and 2 benzohydroxamates have been measured spectrophotometrically in water containing various concentrations of cetyltrimethylammonium bromide (CTAB). The reactivity of the nucleophiles has been demonstrated to be significantly enhanced as the concentration of the surfactant increases up to a certain point. When the basicities of the aryloxides are comparable, the rate enhancement is more prominent for the aryloxide having larger binding constant to the micellar aggregate. Benzohydroxamates exhibitis significantly large ${\alpha}$-effect in the absence of the surfactant, although, the ${\alpha}$-effect nucleophiles are considered to be more solvated in water than the corresponding normal nucleophile. Thus, the solvation effect does not appear to be solely responsible for the ${\alpha}$-effect. Interestingly, the large ${\alpha}$-effect disappears in the presence of the surfactant. Therefore, one might attribute the disappearance of the ${\alpha}$-effect to solvent effect. However, a structural change of the reactive ${\alpha}$ -effect nucleophile into unreactive ones would also be considered to be responsible for the absence of the ${\alpha}$-effect in the present system.

Study on Experience of Industrial Accidents and Awareness Level for Beauty Product Safety of Beauty Industry Employee (미용업 종사자의 사고재해 경험 및 사용제품의 안전 인식도에 관한 연구)

  • Choi, Seo-Yeon;Hur, Kuk-Kang;Park, Dong-Hyun
    • Journal of the Korea Safety Management & Science
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    • v.14 no.4
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    • pp.59-70
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    • 2012
  • This study compared data regarding industrial accidents and awareness level for beauty product safety for four main parts of beauty industry such as hair-care, nail-care, skin-care, and make-up. Major risk factors in beauty industry are dust, musculoskeletal disorders, and organic solvent of beauty product in order of percentage. The specific types of industrial accidents in beauty industry are mainly associated with musculoskeletal system such as cuts, sprain, and varicose vein. They are mainly compensated by personal budget. The awareness levels of chemical and heavy metal containment for beauty product by beauty industry employee were 77.2% and 59.1% respectively. Most employee confirmed only important items of labelling requirement of beauty product. Also, most employee did not understand MSDS(Materila Safety Data) for chemicals used in beauty industry. Only 38.1% of beauty industry employee has had safety education while most employee (73.6%) realized that they needed safety education. Also, safety education supervised by KOSHA(Korea Occupational Safety and Health Agency) was the most preferred. This study would be good basis for safe and healthy working environment of beauty industry employee.

Efficient Preparation of Radioiodine Labelled 3,5,3'-Triiodothyronine and Thyroxine for Medical Use

  • Kim, Jaerok;Kim, Tae-Ho
    • Nuclear Engineering and Technology
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    • v.7 no.2
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    • pp.127-133
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    • 1975
  • For isotopic exchange labelling of 3,5,3'-triiodothyronine (T$_3$) and thyroxine (T$_4$) with radioiodide in the presence of molecular iodine, T$_3$:I$_2$ or T$_4$:I$_2$ molar ratios, pH, and reaction time are. considered to be important factors. A modified labelling and separation method is proposed in present paper, by which T$_3$-$^{125}$ I and T$_4$-$^{125}$ I can be obtained with the mean labelling yields of 45%, and 50%, respectively. The whole reaction products can be separated by adoption of thin-layer chromatography technique using silica gel plate and the solvent system composd of chloroform, methanol and ammonia.

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