• Bulletin of the Korean Chemical Society
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• v.22 no.8
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• pp.842-846
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• 2001

Solvolyses of N-methyl-N-phenylcarbamoyl chlorides in aqueous binary mixtures of acetone, ethanol, methanol and in water, D2O, and 50% D2O-CH3OD are investigated at 25.0 $^{\circ}C.$ The Grunwald-Winstein plots of first-ord er rate constants for N-methyl-N-phenylcarbamoyl chlorides with YCl (based on 2-adamantyl chloride) show a dispersion phenomenon. The ring parameter (I) has been shown to give considerable improvement when it is added as an hI term to the original Grunwald-Winstein and extended Grunwald-Winstein correlations for the solvolyses of N-methyl-N-phenylcarbamoyl chlorides. This study has shown that the magnitude of l, m and h values associated with a change of solvent composition is able to predict the dissociative SN2 transition state. The kinetic solvent isotope effects determined in deuterated water are consistent with the proposed mechanism of the general base catalyzed and/or a dissociative SN2 mechanism channel for N-methyl-N-phenylcarbamoyl chlorides solvolyses.

• Bulletin of the Korean Chemical Society
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• v.18 no.9
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• pp.1017-1021
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• 1997

Solvolyses of p-methoxyphenyl chloroformate in water, D2O, CH3OD, 50% D2O-CH3OD, and in aqueous binary mixtures of acetone, ethanol and methanol are investigated at 25.0 ℃. Product selectivities are reported at 25 ℃ for a wide range of ethanol-water and methanol-water solvent compositions. The Grunwald-Winstein plots of first-order rate constants for p-methoxyphenyl chloroformate with YCl (based on 1-adamantyl chloride) show marked dispersions into three separate curves for the three aqueous mixtures with a small m value and a rate maximum for aqueous alcohol solvents. Third-order rate constants, kww, kaw, kwa and kaa were calculated from the observed kww and kaa values together with kaw and kwa calculated from the intercept and slope of the plot of 1/S vs. [alcohol]/[water]. The calculated rate constants, kcalc and mol % of ester agree satisfactorily with those of the observed rate constants, kobs and mol % of ester, supporting the stoichiometric solvation effect analysis. The kinetic solvent isotope effects determined in water and methanol are consistent with the proposed mechanism of the general base catalyzed carbonyl addition-elimination.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.33 no.3
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• pp.104-109
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• 2023

Electrospinning was performed using an eco-friendly solvent composed of acetic acid, ethyl acetate and distilled water to investigate the effect of gelatin concentration on mechanical properties and cytotoxicity of absorbable poly(D,L-lactic acid) (PDLLA)/gelatin blend membrane. The tensile stress, strain at break, and WUC of the PDLLA/gelatin (97/3) scaffold at 26 wt% concentration were determined to be 3.9 ± 0.7 MPa, 37 ± 1.3 %, and 273 ± 33 %, respectively. FT-IR results revealed that PDLLA and gelatin were bound only by van der Waals interactions. The cell viability of PDLLA/gelatin membranes containing 0 %, 1 %, 2 %, 3 %, and 4 % gelatin were more than 100 %, which makes all membranes highly suitable as a barrier membrane for absorbable periodontal tissue regeneration due to their marketed physical properties and biocompatibility.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.37 no.4
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• pp.451-456
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• 2024

Organic photovoltaic (OPV) devices have attracted attention due to their high efficiency and simple manufacturing process. Applying an overlayer to OPV devices is one way to improve their performance because it can improve charge extraction and suppress vertical phase separation. In addition, dichloromethane (DCM) was used as an orthogonal solvent to minimize the effect on other layers. However, an coating problems due to the use of DCM were found, which affects surface morphology as rough or peeling. Additional research efforts are needed to solve these problems, and optimal results are expected to be obtained by utilizing various buffer layers or selective organic solvents.

• Korean Chemical Engineering Research
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• v.48 no.4
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• pp.413-416
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• 2010

In this research, root extracts of Nelumbo nucifera was tested to see the possibility for functional cosmetic agent. 70-100% ethanol was used as solvent and nuciferin was confirmed as active component. To test cosmetic effect of root extracts of Nelumbo nucifera, safety effect(MTT assay), anti-wrinkle effect(elastase inhibition assay) and antioxidation effect(DPPH free radical scavenging assay) were measured. When 100% ethanol was used as extracting solvent, cell viability was over 80% at $100{\mu}g/ml$, which indicated that root extract of Nelumbo nucifera was suitable for cosmetic agent. Root extract of Nelumbo nucifera showed 40~50% elastase inhibition at $100{\mu}g/ml$ so that it had good anti-wrinkle characteristics. 50% antioxidation capacity($FSC_{50}$) was $5.0{\sim}38{\mu}g/ml$ and root extract of Nelumbo nucifera showed excellent antioxidation effect. From the research, root extracts of Nelumbo nucifera showed strong possibility for anti-wrinkle functional cosmetic agent.

• Preventive Nutrition and Food Science
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• v.4 no.2
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• pp.107-112
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• 1999

Effect of solvent extracts and juice supernatants from kimchis on the growth of various human cancer cells was studied, comparing with the actions on the normal cells. Inhibitory effect of kimchi extracts on[3H] thymidine incorporation n cancer cells was also investigated. The methanol extract, hexane extract and methanol soluble fraction (MSF) of 3-week fermented kimchi did not have growth inhibitory effect on Ac2F rat normal liver cells at the concentrations of 0.5~2%. However, marked decrease in the growth of AGS human gastric cancer cells was shown by the treatment of those extacts. The juice from the kimchi samples also suppressed the growth of K-562 human leukemia cells and MG-63 human osteosarcoma cells. Especially, the juice of 3-week fermented kimchi exhibited the strong growth inhibitory effect in MG-63 human osteosarcoma cells. At the photomicrographs, growth inhibition and morphological change of the cells treated with kimchi juice were observed. And the solvent extracts of 3-week fermented kimchi suppressed the growth of cancer morethan the extracts or juices from fresh and 6-week fermented kimchi. When AGS human gastric cancer cels were treated with the extracts of 3-week fermented kimchi, [3H] thymidine incorporation in the cells also decreased. These results showed that kimchi extracts and juices had growth inhibitory effects on human osteosarcoma, leukemia and gastric cancer cells, but had no toxicity to the normal cells. We suggest that kimchi might have anticancer effect in part due to inhibition of the growth and DNA synthesis of cancer cells.

• Horticultural Science & Technology
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• v.28 no.5
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• pp.857-863
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• 2010

This study was conducted to evaluate the antioxidant activity, Angiotensin I Converting Enzyme (ACE) inhibitory activity, ${\alpha}$-glucosidase inhibitory activity, nitrate synthesis inhibitory activity, and antiproliferation inhibitory effect on ethanol extract and its solvent fractions of $Coreopsis$ $tinctoria$ Nutt. Ethyl acetate fraction was the strongest at 1,1-diphenyl-2-picryl hydrazyl (DPPH) ($IC_{50}=0.100mg{\cdot}mL^{-1}$) and 2,2'-Azino-bis-(3-ethylbenozothiazoline-6-sulfonic acid) (ABTS) (15.785 mg AA $eq{\cdot}10mg^{-1}$) radical scavenging activity, ACE (40.96% at $1mg{\cdot}mL^{-1}$), and ${\alpha}$-glucosidase ($IC_{50}=0.125mg{\cdot}mL^{-1}$) inhibitory effect among the solvent fractions. Nitrate synthesis inhibitory activity of ethanol extract, chloroform fraction, and ethyl acetate fraction effectively inhibited NO formation in a dose-dependent manner without the cytotoxic effect. Ethanol extract and its solvent fractions inhibited growth of HCT-116 colon cancer cells in a dose-dependent manner. n-Hexane fraction showed the highest antiproliferation inhibitory effect of $0.041mg{\cdot}mL^{-1}$ among fractions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.10 no.4
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• pp.189-197
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• 1977

In present study, the effects of various factors including the solvent concentration, extraction time and temperature, the ratio of sample vs extraction solvent, (w/v) and pH upon the extractability of the NaCl and alcohol soluble proteins of marine algae were investigated. Eight species of fresh algae, the major ones in consumption as food, namely Porphyra suborbiculata, Undarie pinnatifida, Hizikia fusiforme, Sargassum, fulvellum, Enteromorpha linza, Sargassum kjellmanianum, Codium coarctatum, and Ulva pertusa were used for the extraction of NaCl soluble protein and dried materials of four species, Perphyra suborbiculata, Undaria pinnatifida, Enteromorpha linza and Sargassum fulvellum were used for the extraction of alcohol soluble protein. The frozen and mascerated samples were prepared by the same method described in previous paper (Ryu, 1977). And the dried materials were moistened with alcohol solution before freezing. The effect of solvent concentration on the extractability of NaCl soluble protein differed from species. The extractability of Undaria Pinnatifide, Hizikia fusiforme, Perphyra suborbiculata, Enteromorpha linza, and Ulva pertusa reached maxima at 0.25M NaCl solution while the 1.0M for Sargassum fulvellum, Saygassum kjellmanianum and Codium coarctatum. In case of alcohol soluble proteins, it was shown at $20\%$ ethanol solution for Porphyra suborbiculata, Undaria pinnatifida, Enteromorpha linza, and Sargassum fulvellum. Variation of the ratio of sample vs solvent gave slight effect upon the extractability, but the ratio of 1:30(w/v) seemed most efficient for the extraction of NaCl soluble proteins and 100 ml solvent added to 1 g dried sample was effective in case of alcohol soluble proteins. Extraction time has a minimal effect upon the extraction of alcohol soluble protein, and approximately 21 to $43\%$ of algal protein was extracted within 1 hour. But in case of NaCl soluble protein extraction, the effect of time revealed differently from species to species resulting in that the extraction for 1 hour gave a maximum extractability in Ulva pertusa and Enteromorpha linza, 2 hours in Porphyra suborbiculata, Codium coarctatum and 3 hours in Undaria pinnatifica, Hizikia susiforme, Sargassum fulvellum and Sargassum kjellmanianum. When the NaCl soluble protein of Undaria pinnatifida and Enteromopha linza was extracted at various temperature, the most effective extraction temperature was $40^{\circ}C$ while the temperature was $50^{\circ}C$ for Undaria pinnatifida and $60^{\circ}C$ for Hixikia fusiforme, Sargassum fulvellum, Sargassum kjellmanianum and Codium coarctatum. Bus in case of alcohol soluble extraction, the optimum temperature was $30^{\circ}C$ for Enteromorpha linza and $40^{\circ}C$ for Undaria pinnatifida, Sargassum fulvellum and Porphyra suborbiculata. In the effect of pH on extractability, the maximum extractability of NaCl soluble proteins was obtained at pH 7to 8 and pH 8 to 9 for alcohol soluble protein.

• Ocean and Polar Research
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• v.34 no.4
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• pp.385-394
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• 2012

In this study, crude extracts of the marine eelgrass Zostera japonica and their solvent-partitioned fractions were evaluated for their inhibitory effect against AGS, HT-1080 and MCF-7 human cancer cells using MTT assay. Each of the crude extracts (acetone/methylene, chloride, and methanol) of Z. japonica showed a significant inhibitory effect on the growth of human cancer cells. The combined crude extracts were partitioned between $CH_2Cl_2$ and water. The organic layer was further partitioned between 85% aq. MeOH and n-hexane, and the aqueous layer was then fractionated into n-BuOH and $H_2O$, successively. Growth inhibition effects of solvent-partitioned fractions from Z. japonica on human cancer cells increased in a dose-dependent manner. Among these tested samples, the 85% aq. MeOH fraction revealed good inhibitory effects on the growth of AGS and HT-1080 human cancer cells, while the n-hexane fraction exhibited good inhibitory effects on the growth of AGS and MCF-7 human cancer cells. In addition, 85% aq. MeOH and n-hexane fractions enhanced mRNA expression of p53 gene. These results suggest that there is further scope for the isolation of active compounds from Z. japonica, which should show much stronger anticancer activity.

• Journal of Applied Biological Chemistry
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• v.60 no.3
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• pp.219-226
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• 2017

In this study, the activity of Takli-san for anti-oxidation, anti-wrinkle and whitening effect was verified and its applicability as a cosmetic material was confirmed. 1-1-diphenyl-2-picryl-hydrazyl radical scavenge, 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) radical scavenge, elastase and tyrosinase inhibitory activity were investigated by solvent fraction, and ethyl acetate fraction of water extract from Takli-san (TW-EA) showed the highest inhibitory activity. Western blot was performed to confirm anti-wrinkle and whitening effect in the cells, and it was investigeted that the TW-EA inhibition effect was superior to that of the positive contol used for the comparison test. Through the results of the experiments, the applicability as a cosmetic material of Takli-san was verified.