Yu Lan Piao

Chungbuk National University, Tyundyu, North Chungcheong, South Korea

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Publications (7)10.48 Total impact

  • Dubok Choi, Yu Lan Piao, Ying Wu, Hoon Cho
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    ABSTRACT: Excessive scar formation is an aberrant form of wound healing and is an indication of an exaggerated function of fibroblasts and excess accumulation of extracellular matrix during wound healing. Much experimental data suggests that prostaglandin E2 (PGE2) plays a role in the prevention of excessive scarring. However, it has a very short half-live in blood, its oxidization to 15-ketoprostaglandins is catalyzed by 15-hydroxyprostaglandin dehydrogenase (15-PGDH). Previously, we reported that 15-PGDH inhibitors significantly increased PGE2 levels in A549 cells. In our continuing attempts to develop highly potent 15-PGDH inhibitors, we newly synthesized various thiazolidine-2,4-dione derivatives. Compound 27, 28, 29, and 30 demonstrated IC50 values of 0.048, 0.020, 0.038 and 0.048μM, respectively. They also increased levels of PGE2 in A549 cells. Especially, compound 28 significantly increased level of PGE2 at 260pg/mL, which was approximately fivefold higher than that of control. Scratch wounds were analyzed in confluent monolayers of HaCaT cells. Cells exposed to compound 28 showed significantly improved wound healing with respect to control.
    Bioorganic & medicinal chemistry 06/2013; · 2.82 Impact Factor
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    ABSTRACT: We investigated the effects of the antioxidant and the nitrite scavenging activities of the extracts from Pleurotus ferulae fruiting body grown on the solid state using corn cob and activated bleaching earth (CCABE media) and its mycelium grown in the liquid state. The total phenol and polysaccharide concentrations in hot water extract of fruiting body were approximately 3.6- and 4.3-fold higher than those of the mycelium. Using the hot water extract of fruiting body, the maximum DPPH radical scavenging activity at 9 mg/mL, hydroxyl radical scavenging activity at 12mg/mL, reducing power at 12 mg/mL, and chelating ability at 12 mg/mL were obtained, 80.5%, 72.4%, 0.99 OD (700 nm), and 77.0%, respectively. However, in the case of hydrogen peroxide scavenging activity, the ethanol extract was the highest, 78.7% at 12 mg/mL. The maximum nitrite scavenging activity was obtained, 89.7% at 6 mg/mL of hot water extract from fruiting body. Hot water extracts were more effective than ethanol extracts in scavenging activity on DPPH radicals and hydroxyl radical scavenging, reducing power, and chelating activity of ferrous, whereas ethanol extracts were more effective in hydrogen peroxide scavenging activity as evidenced by their lower EC50 values. These results indicate that the hot water extract of P. ferulae fruiting body using CCABE media has good potential to be used as a source of materials or additives for oxidation suppressant in food, cosmetics and drug compositions.
    Korean Journal of Chemical Engineering 01/2012; 29(10). · 1.06 Impact Factor
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    ABSTRACT: The homology model of the wild type alginate lyase (AlyVI) marine bacterium Vibrio sp. protein, was built using the crystal structure of the Family 7 alginate lyase from Sphingomonas sp. A1. To rationalize the observed structure-affinity relationships of aliginate lyase alyVI with its (GGG) substrate, molecular docking, MD imulations and binding free energy calculations followed by site-directed mutagenesis and alyVI activity assays were carried out. Per-residue decomposition of the (GGG) binding energy revealed that the most important contributions were from polar and charged residues, such as Asn138, Arg143, Asn217, and Lys308, while van der Waals interactions were responsible for binding with the catalytic His200 and Tyr312 residues. The mutants H200A, K308A, Y312A, Y312F, and W165A were found to be inactive or almost inactive. However, the catalytic efficiency (k(cat)/K(m)) of the double mutant L224V/D226G increased by two-fold compared to the wild type enzyme. This first structural model with its substrate binding mode and the agreement with experimental results provide a suitable base for the future rational design of new mutated alyVI structures with improved catalytic activity.
    Biochimica et Biophysica Acta 09/2011; 1814(12):1739-47. · 4.66 Impact Factor
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    ABSTRACT: For the development of functional food and cosmetics using the hot water extract of Undaria pinnatifida, the concentrations of vitamin, amino acid and element and activities of antioxidant and nitrite scavenging were investigated. The results are shown as follows: Vitamin C and E concentrations were 0.301 and 0.11 mg/100 g, respectively. Mineral concentrations were an order of Ca > Mg > K > Fe. The concentrations of total amino acids were an order of Glu > Ala > Val > Leu > Gly > Pro. Total phenol concentration and DPPH radical scavenging activity were increased with the increase of the concentration of extract. Especially, when the extract concentrationwas increased from 1.0 to 10.0 mg/mL, the total phenol concentration was increased from 0.043 to 0.125 OD 725 nm. DPPH radical scavenging activity at 50 mg/mL was 70.1%. The antioxidant activity of extract was stable in range of 80 to and pH 3-9. The nitrite scavenging activity was increased with the decreaseof pH and the increase of it's extract concentration. Especially, it was 83.4% at 50 mg/mL (pH 1.2). These results showed that the hot water extract of U. pinnatifida can be applied to functional food and cosmetics.
    KSBB Journal. 01/2011; 26(2).
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    ABSTRACT: A marine bacterium was isolated from seawater near the Korean south coast for efficient saccharification from alginate. Based on 16S rDNA sequence, the isolated strain was identified as Pseudoalteromonas agarovorans. Various environmental factors affecting saccharification of alginate using P. agarovorans CHO-12 have been investigated in flask cultures. The optimum concentration of sugar was obtained at 30 rpm and 29 degrees C. Among various NaCl concentrations, when NaCl concentration was increased from 10 to 30 g/l, the cell concentration sharply increased, while there is no increase at above 40 g/l. The maximum sugar concentration was obtained at 13.8 when 30 g/l of NaCl was used. Yeast extract and corn steep liquor were the best nitrogen source for efficient saccharification. Especially, the sugar concentration of 14.9 g/l was obtained after 3 days of culture using a mixture of 1.0 g/l of yeast extract and 1.5 g/l of corn steep liquor. Scale up was carried out at 50 l of reactor for 3 days using P. agarovorans CHO-12 and Stenotrophomonas maltophilia sp. When S. maltophilia was used, cell concentration was about twofold higher than that of P. agarovorans CHO-12. On the other hand, when P. agarovorans CHO-12 was used, the maximum saccharification rate was obtained, 7.5 g/l/day after 2 days of culture, which was about tenfold higher than that of S. maltophilia.
    Applied biochemistry and biotechnology 02/2009; 159(2):438-52. · 1.94 Impact Factor
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    ABSTRACT: For effective saccharification from raw seaweed using the enzyme method, various environmental factors affecting the apparent viscosity were investigated. When 0.75% of ascorbic acid was used, the apparent viscosity decreased from 500 to 125cP after 1h of sterilization, and did not decrease after 2h of sterilization. In the case of the raw seaweed without the addition of ascorbic acid, it did not decrease significantly. However, when HCl was used, it decreased from 480 to 389cP after 1h of sterilization, after which it did not decrease. The apparent viscosity of raw seaweed was strongly affected by the ascorbic acid concentration. For instance, when 1.0% ascorbic acid was used, the apparent viscosity was 92cP. On the other hand, no further decrease in apparent viscosity occurred upon increasing the concentration above 1.5%. A scale up of the saccharification of raw seaweed using the new enzyme method was carried out. When the new enzyme method was used for the saccharification, 8.8g/l of sugar was obtained after 6h of reaction, which was about four times higher than that obtained without the addition of the ascorbic acid and liquozyme. In particular, the sugar production rate was 1.6g/l/h, which was about 33 times higher than that of the saccharification using Stenotrophomonas maltophilia. A fed-batch experiment for the saccharification was also carried out, where the sugar concentration reached 27.2g/l after 16h of reaction.
    Journal of Industrial and Engineering Chemistry - J IND ENG CHEM. 01/2009; 15(1):12-15.
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    ABSTRACT: Various environmental factors affecting saccharification from alginate using Stenotrophomonas maltophilia were investigated in flask cultures. The cell concentrations increased from 0.6 to 0.92 optical density (OD) at 660nm when the agitation rate increased from 15 to 90rpm. On the other hand, the maximum concentration of sugar was obtained at 3.8g/l after 4 days of culture at 15rpm. After 3 days of preculture at 33°C, the sugar concentration peaked at 5.0g/l after 5 days of culture. When 10g/l of NaCl was used, the maximum concentration of sugar, 5.3g/l, was obtained after 5 days of culture. Yeast extract and peptone were the best nitrogen source for effective saccharification. Especially, the sugar concentration was 6.1g/l after 5 days of culture using a mixture of 1.0g/l of yeast extract and 1.0g/l of peptone.Under optimum conditions of culture and media, scale-up for effective saccharification from alginate was carried out in 5l flasks. The cell concentration after 2 days of culture was 0.61 OD at 660nm and showed no further increase after 3 days of culture. The sugar concentrations from alginate were increased with increasing culture time to 7.9g/l after 9 days of culture.
    Journal of Industrial and Engineering Chemistry - J IND ENG CHEM. 01/2008; 14(2):182-186.

Publication Stats

13 Citations
10.48 Total Impact Points


  • 2013
    • Chungbuk National University
      • College of Pharmacy
      Tyundyu, North Chungcheong, South Korea
  • 2008–2012
    • Chosun University
      • • Department of Polymer Science and Engineering
      • • Research Center for Resistant Cells
      • • Department of Chemical and Biochemical Engineering
      Gwangju, Gwangju, South Korea