• Polymer(Korea)
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• v.35 no.4
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• pp.289-295
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• 2011

Biomaterials for retinal tissue engineering must demonstrate several critical features for potential utility, including mechanical integrity, biocompatibility, and slow biodegradation. Silk film biomaterials were designed and characterized to meet these functional requirements. We prepared natural/synthetic hybrid silk/PLGA films using 0, 10, 20, 40, and 80 wt% of silk by a solvent evaporation method. MIT assay was used to confirm the number of cells attached on film at 1, 2, and 3 days, respectively. The morphology of cellular adhesion on films was also confirmed by scanning electron microscope (SEM). RT-PCR was conducted to confrrm mRNA expression of retinal pigment epithelitun (RPE) using RPE65 as a RPEs marker and the expression of cytokeratin were determined by immunofluorescence staining. We confirmed that the silk/PLGA film of 20~40 wt% silk was superior for the adhesion and proliferation of RPEs.

• Applied Chemistry for Engineering
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• v.9 no.5
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• pp.734-741
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• 1998

Electrode characteristics were studied in the interface between sample solutions and $K^+$ ion selective PVC membrane electrodes containing neutral carriers, dibenzo-18-crown-6(D18Cr6) and valinomycin(Val). The effect of doping of base electrolytes, the chemical structure and the content of carrier, variation of plasticizer, membrane thickness, and concentration variation of sample solution on the response characteristics of electrode such as the measured Nernstian slope, the detection limit, the linear response range, and potentiometric selectivity coefficients, were studied. In order to synthesize the membrane D18Cr6 and Val as neutral carriers were used, and complex between the carrier and $K^+$ ions were used as active materials. PVC membrane electrodes were made of plasticizers (DBP, DOS, and DBS), the base electrolyte[potassium tetraphenylborate(KTPB)], and solvent(THF). The chemical structure of carrier D18Cr6 was best for electrode and ideal electrode characteristics were appeared especially in case of doping of TPB. The optimum carrier content was about 3.23 wt % in case of D18Cr6 and Val. DBP was best as a plasticizer. As membrane thickness decreased the electrode characteristics was improved. But its characteristics were lowered below the optimum membrane thickness because of the elution of carrier, deterioration of membrane strength, etc. In the case of D18Cr6, the selectivity coefficients by the mixed solution method for the $K^+$ ion were in the order of $NH_4{^+}>Ca^{2+}>Mg^{2+}>Na^+$.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.31 no.4
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• pp.516-522
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• 1998

An Actinomycetes strain, MSA-1, containing antimicrobial component was isolated from the black sponge, Halichondzia okadai, and was identified to a genus level by morphological and chemotaxonornic methods. The gray colored spores were oval type with smooth surface and formed flexibilis spore chains. The cell wall of this strain was type I containing D-aminopimellic acid (D-DAP) and no specific sugar was detected. Phospholipid of the cell membrane was PII type including phophoethanolamine and the major fatty acids of total lipid were branched anteiso-15 : 0, iso-16 : 0, 16 : 0 and iso-17 ; 0. From these results and other characteristics described in the Bergey's Manual, this strain was identificated as a Streptomyces sp. Meanwhile, 10mg of pale yellow colored antimicreobial component was isolated by HPLC method from the cultured Streptomyces sp. (70g of cryophillized mycellis). By crystallographyc analysis, HIRESMS and NMR assignment, the antimicrobial component produced from the strain MSA-1 was elucidated as the staurosporine (indolo[2,3-a]carbazole alkaloid).

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.1
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• pp.117-123
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• 2007

HPLC quantifications of fresh and cooked (steamed/microwaved) spinach, one of the most frequently consumed vegetables in foodservice operations, were carried out to determine carotenoids compositions. An S-3 $\mu$m C30 stationary phase for reversed-phase columns with diode-array detection was used to separate and quantify geometric isomers of provitamin A carotenoids in the fresh and cooked spinach. The carotenoids in fresh spinach were identified and quantified: Lutein (63.0%), $\beta$-carotene isomers (all-trans 29.6%, 9-cis 3.2%, 13-cis 1.8%, $\alpha$-carotene 0.4%, zeaxanthin 2.1%) and cryptoxanthin. Cryptoxanthin, detected in a trace amount in HPLC, was not quantified in this study. Lutein was little affected by cooking methods and frozen conditions. 9-cis and 13-cis-$\beta$-carotene isomers were major types formed during cooking. Cooking (steam/microwave) did not alter carotenoid profiles of the samples, but the amounts of carotenoids quantified were greater than those in the fresh samples. Heat treatment such as steaming increased total carotenoids contents, especially trans-$\beta$-carotene (p<0.05). The carotenoid contents of the frozen spinach increased even after the microwaved treatment (p<0.05). These increases were likely to result from the increased extraction efficiency and inactivation of enzymes capable of carotenoids degrading during the heat treatments.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.343-349
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• 2021

The rhizomes of Cnidium officinalis were extracted in aqueous MeOH, and the concentrate was fractionated via systematic solvent fractionation to EtOAc, n-BuOH, and aqueous fractions. The repeated column chromatography of EtOAc and n-BuOH fractions using silica gel, octadecyl silica gel, and Sephadex LH-20 as stationary phase to afford five lipids. They were identified to be methyl linoleate (1), linoleic aicd (2) 6-linoleoyl-𝛼-D-glucopyranosyl 𝛽-D-fructofuranoside (3), 1-linolenoyl-3-(𝛼-D-galactopyranosyl (1→6)-𝛽-D-galactopyranosyl) glycerol (4), and 1-linoleoyl-3-(𝛼-D-galactopyranosyl (1→6)-𝛽-D-galactopyranosyl) glycerol (5) on the basis of spectroscopic data such as IR, MS, and Nuclear magnetic resonance (NMR). Compounds 1 and 3-5 were isolated for the first time from this plant in this study. The NMR data of fatty acids 1 and 2 reported in literatures are different each other. Authors identified the NMR data without ambiguity. Compound 3, a conjugate of sucrose and fatty acid, and compounds 4 and 5, digalactosyl monoglyceride, are very rarely occurred in natural source. Through the immune enhancement and anticancer activity of the reported lipid compounds, the potential as various pharmacologically active materials of Cnidium officinalis rhizome can be expected.

• Applied Chemistry for Engineering
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• v.32 no.5
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• pp.509-515
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• 2021

In this study, poly lactic-co-glycolic acid (PLGA) nanoparticles (PNP) were prepared through double (w/o/w) emlusion and emulsifying solvent-evaporation technique using PLGA, which has biocompatibility and biodegradability. To maximize stability and bioavailability of the particles, chitosan-coated PLGA nanoparticles (CPNP) were prepared by charge interaction between PNP and chitosan. We demonstrated that CPNP can be utilized as a drug carrier of oral administration. The chemical structure of CPNP was analyzed by ¹H-NMR and FT-IR, and all characteristic peaks appeared, confirming that it was successfully prepared. In addition, particle size and zeta potential of CPNP were analyzed using dynamic light scattering (DLS) while morphological images were obtained using transmission electron microscope (TEM). Thermal decomposition behavior of CPNP was observed through thermogravimetric analysis (TGA). In addition, the cytotoxicity of CPNP was confirmed by MTT assay at HEK293 and L929 cell lines, and it was proved that there is no toxicity confirmed by the cell viability of above 70% at all concentrations. These results suggest that the CPNP developed in this study may be used as an oral drug delivery carrier.

• Journal of the Korean Applied Science and Technology
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• v.35 no.4
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• pp.1088-1095
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• 2018

In this study, reduced graphene oxide/polyaniline composite was fabricated tomaximize their advantages with electrochemical performances and use as a electrodematerial for supercapcaitor. Polyaniline as an electrode material was synthesized bychemical polymerization of aniline monomer and reduced graphene oxide wasintroduced to prepare composite with polyaniline without any pre-treatment. Thereduced graphene oxide, polyaniline and their composite electrodes were fabricatedon gold coated PET(polyethylene terephthalate) substrate through spray coatingmethod which can also apply to industrial scale. we have also prepared reducedgraphene oxide and polyaniline single material electrode to compare theirelectrochemical properties with reduced graphene oxide/polyaniline composite electrode. We have analyzed and compared electrochemical properties of eachelectrodes by using cyclic voltammetry(CV), galvanostaticcharge-discharge(GCD) and electrochemical impedancespectroscopy(EIS) at same condition. As a result, reduced graphene oxide /polyaniline composite electrode showed higher capacitance value more thanpolyaniline and reduced graphene oxide electrode, respectively. Internal resistanceof reduce graphene oxide/polyaniline composite electrode was 24% and 58% lessthan polaniline and reduced graphene oxide electrode respectively. These resultsconsidered that reduced graphene oxide/polyaniline composite electrode has potential ability and enable to apply flexible energy storage and wearable devices.

• Journal of Life Science
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• v.29 no.10
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• pp.1111-1119
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• 2019

Prunus mume, known as maesil in Korea, has been widely cultivated in East Asia and used as medication and food. However, because most of the previous studies concerning P. mume had been investigated its under extract state, detailed studies are still required for its extensive utilization. In this study, we evaluated the antioxidant and ${\alpha}-glucosidase$ inhibitory activities of solvent fractions of P. mume ethanol extracts. The ethyl acetate fraction showed higher DPPH radical scavenging activity, ABTS radical scavenging activity, reducing power, and hydrogen peroxide scavenging activity than other fractions. The DPPH radical scavenging activities of ethyl acetate fraction was 67.79%; ABTS radical scavenging activity was 60.03%; reducing power ($OD_{670}$) was 1.26; and hydrogen peroxide scavenging activity was 93.18% at $500{\mu}g/ml$. Also, the ethyl acetate and methanol fraction showed effective levels of ${\alpha}-glucosidase$ inhibition activity (69.25% and 72.29% at $500{\mu}g/ml$). Total polyphenol contents and total flavonoid contents of the ethyl acetate fraction were 88.28 mg/g (gallic acid equivalent) and 70.38 mg/g (quercetin equivalent), respectively. These results suggest that the physiological activities of the ethyl acetate fraction are associated with its polyphenol and flavonoid contents. Therefore, this study can be used as basic data for developing natural antioxidants and potential functional material using P. mume.

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.25-32
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• 2021

Phytochemicals include plant-derived natural products that promote and improve the human metabolism and physiological activity, and there is a lot of research to find the value of the molecules is in progress. Likewise, we obtained 288 fractions of Capsicum annuum L. extract in less than 20 h using HPLC/SPE/HPLC coupling experiment through Sepbox system, an effective separation system to search for active substances in natural resources and ensure efficacy and reliability. Therefore, this experiment allowed rapid identification of biologically active molecules from the extract compared to traditional separation processes. Of the above fractions, eight fractions showed the α-glucosidase inhibitory (AGI) activity and subsequent LC-MS analysis revealed one of the active molecules as luteolin 7-O-glucoside. In addition, we proved the increase in AGI activity according to deglycosylation of flavonoid glycoside. Therefore, this study suggests that the Sepbox system can quickly separate and identify active components from plant extract, and is an effective technique for finding new active substances.

• Applied Chemistry for Engineering
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• v.34 no.1
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• pp.80-85
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• 2023

New yellow quinoline-dione dye derivatives were designed and synthesized for use in image sensor color filters. The synthesized compounds have a basic chemical structure composed of quinoline and dione groups. New materials were evaluated on the basis of their optical and thermal properties under conditions mimicking those of a commercial device fabrication process. A comparison of their related performances revealed that, between the two prepared compounds, 2-(3-hydroxyquinolin-2(1H)-ylidene)-1H-indene-1,3(2H)-dione (HQIDO) exhibited the superior performance as an image sensor color filter material, including a solubility greater than 0.5 wt% in propylene glycol monomethyl ether acetate solvent and a high decomposition temperature of 298 ℃, respectively. The results suggest that HQIDO can be used as a yellow dye additive in an image sensor colorant.