• KSBB Journal
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• v.26 no.6
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• pp.483-490
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• 2011

Bioactive peptides (BAP) showed excellent cosmetic activity than bio-materials such as caffeic acid (CA), gallic acid (GA), and nicotinic acid (NA). Caffeoyl tripeptide-1 (CT-1) is a BAP that is stabilized with Gly-His-Lys (GHK) tripeptide and CA by using Fmoc solid phase peptide synthesis. Digalloyl tetrapeptide-19 (DT-19) is stabilized by combining Lys-Glu-Cys-Gly with GA and nicotinoyl tripeptide-1 (NT-1) is synthesized by GHK and NA. According to experiments, CT-1 has an excellent anti-oxidant function even with a very small amount of 10 ppm CT-1. DT-19's tyrosinase inhibition activity has the better effect of about 28.57% in 0.01% and 33.33% in 0.005% of concentration and about 7.89% in 0.001% concentration than vitamin-C. In addition, NT-1 is safer than the NA. Almost BAPs like pal-KTTKS, acetyl hexapeptide, and copper tripeptide-1 have the anti-wrinkle effect while DT-19 and NT-1 are applicable for potential BAPs focused on the whitening effect. The three kinds of BAPs like CT-1, DT-19, and NT-1 consisting of amino acids are safe to the skin, and have more excellent stability than bio-materials which are found to be unstable and cause skin irritation. Due to the high biological activity of BAP in the field of skin care, its utilization will increase constantly.

• Bulletin of the Korean Chemical Society
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• v.34 no.12
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• pp.3835-3839
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• 2013

A new synthesis route for Pt nanoparticles by direct electrochemical reduction of a solid-state Pt ion precursor ($K_2PtCl_6$) is demonstrated. Solid $K_2PtCl_6$-supported polyethyleneimine (PEI) coatings on the surface of glassy carbon electrode were prepared by simple mixing of solid $K_2PtCl_6$ into a 1.0% PEI solution. The potential cycling or a constant potential in a PBS (pH 7.4) medium were applied to reduce the solid $K_2PtCl_6$ precursor. The reduction of Pt(IV) began at around -0.2 V and the reduction potential was ca. -0.4 V. A steady state current was achieved after 10 potential cycling scans, indicating that continuous formation of Pt nanoparticles by electrochemical reduction occurred for up to 10 cycles. After applying the reduction potential of -0.6 V for 300 s, Pt nanoparticles with diameters ranging from $0.02-0.5{\mu}m$ were observed, with an even distribution over the entire glassy carbon electrode surface. Characteristics of the Pt nanoparticles, including their performance in electrochemical reduction of $H_2O_2$ are examined. A distinct reduction peak observed at about -0.20 V was due to the electrocatalytic reduction of $H_2O_2$ by Pt nanoparticles. From the calibration plot, the linear range for $H_2O_2$ detection was 0.1-2.0 mM and the detection limit for $H_2O_2$ was found to be 0.05 mM.

• Journal of Microbiology and Biotechnology
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• v.12 no.1
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• pp.46-52
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• 2002

As a functional additive for intestinal microflora, panose ($6^2-{\alpha}$-D-glucopyranosylmaltose) was synthesized during kimchi fermentation using the glucose transferring reaction of glucansucrase from Leuconostoc mesenteroides. For the glucose transferring reaction, sucrose and maltose were added ($2\%$ each, w/v) to dongchimi-kimchi as the glucosyl donor and acceptor molecule, respectively. After five days of incubation at $10^{\circ}C$, referring to the initial phase for the production of lactic acid in kimchi, over $60\%$ (w/v) of the total sugars were converted into panose and other branched oligosaccharides. Thereafter, the kimchi was stored at $4^{\circ}C$ and the amount of panose remained at a constant level for three weeks, thereby indicating the stability of panose to microbial degradation during the period of kimchi consumption. The use of maltose as the acceptor molecule in the kimchi also facilitated a lower viscosity in the kimchi-juice by preventing the synthesis of a dextran-like polymer which caused an unfavorable taste. Accordingly, the application of this new method of simultaneous biocatalytic synthesis of oligosaccharides during lactate fermentation should facilitate the extensive development of new function-added lactate foods.

• Bulletin of the Korean Chemical Society
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• v.35 no.7
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• pp.2004-2008
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• 2014

This paper reports the facile synthesis methods of zinc oxide (ZnO) nanoparticles, Z1-Z10, using diethylene glycol (DEG) and polyethylene glycol (PEG400). The particle size and morphology were correlated with the PEG concentration and reaction time. With 0.75 mL of PEG400 in 150 mL of DEG and a 20 h reaction time, the ZnO nanoparticles began to disperse from a collective spherical grain shape. The ZnO nanoparticles were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and a $N_2$ adsorption-desorption studies. The Brunauer-Emmett-Teller (BET) surface areas of Z4, Z5 and Z10 were 157.083, 141.559 and 233.249 $m^2/g$, respectively. The observed pore diameters of Z4, Z5 and Z10 were 63.4, 42.0 and 134.0 ${\AA}$, respectively. The pore volumes of Z4, Z5 and Z10 were 0.249, 0.148 and 0.781 $cm^3/g$, respectively. The photocatalytic activity of the synthesized ZnO nanoparticles was evaluated by methylene blue (MB) degradation, and the activity showed a good correlation with the $N_2$ adsorption-desorption data.

• Journal of Ginseng Research
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• v.45 no.1
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• pp.58-65
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• 2021

Background: Panax ginseng, as one of the most widely used herbal medicines worldwide, has been studied comprehensively in terms of the chemical components and pharmacology. The proteins from ginseng are also of great importance for both nutrition value and the mechanism of secondary metabolites. However, the proteomic studies are less reported in the absence of the genome information. With the completion of ginseng genome sequencing, the proteome profiling has become available for the functional study of ginseng protein components. Methods: We optimized the protein extraction process systematically by using SDS-PAGE and one-dimensional liquid chromatography mass spectrometry. The extracted proteins were then analyzed by two-dimensional chromatography separation and cutting-edge mass spectrometry technique. Results: A total of 2,732 and 3,608 proteins were identified from ginseng root and cauline leaf, respectively, which was the largest data set reported so far. Only around 50% protein overlapped between the cauline leaf and root tissue parts because of the function assignment for plant growing. Further gene ontology and KEGG pathway revealed the distinguish difference between ginseng root and leaf, which accounts for the photosynthesis and metabolic process. With in-deep analysis of functional proteins related to ginsenoside synthesis, we interestingly found the cytochrome P450 and UDP-glycosyltransferase expression extensively in cauline leaf but not in the root, indicating that the post glucoside synthesis of ginsenosides might be carried out when growing and then transported to the root at withering. Conclusion: The systematically proteome analysis of Panax ginseng will provide us comprehensive understanding of ginsenoside synthesis and guidance for artificial cultivation.

• Journal of Electrical Engineering and Technology
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• v.2 no.2
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• pp.274-279
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• 2007

This study focuses on the enhancement of maskless photolithography as well as the peptide synthesis application with single crystalline silicon micromirrors. A single crystalline silicon micromirror array has been designed and fabricated in order to improve its application to the peptide synthesis. A micromirror rotates about ${\pm}\;9^{\circ}$ at the pull-in voltage, which can range from 90.7 V to 115.1 V. A $210\;{\mu}m-by-210\;{\mu}m$ micromirror device with $270\;{\mu}m$ mirror pitch meets the requirements of an adequately precise separation for peptide synthesis. Synthetic 16 by 16 peptide array corresponds to the same number of micromirrors. The large size of peptide pattern and the separation facilitate biochip experiments using fluorescence assay. The peptide pattern has been synthesized on the GPTS-PEG200 surface with BSA-blocking and thereupon the background was acetylated to reject non-specific bindings. Hence, an averaged slope at the pattern edge has been distinguishably improved in comparison to patterning results from an aluminum micromirror.

• Korean Journal of Pharmacognosy
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• v.45 no.3
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• pp.209-213
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• 2014

The anti-melanogenic substance was isolated from the root of Angelica gigas Nakai by silica gel column chromatography, preparative HPLC and TLC. As a result of the structure analysis by mass, $^1H$-NMR, and $^{13}C$-NMR spectrometry, the compound was identified as demethylsuberosin. Demethylsuberosin reduced melanin contents of B16F1 melanoma cells in a dose-dependent manner and decreased to about 74% at a concentration $5{\mu}g/ml$. Demethylsuberosin inhibited the expression in microphthalmia associated transcription factor (MITF), tyrosinase, tyrosinase related protein-1 (TRP-1), and tyrosinase related protein-2 (TRP-2) in melanocytes. These results suggest that the whitening activity of demethylsuberosin may be due to the inhibition of the melanin synthesis by down-regulation of MITF, tyrosinase, TRP-1 and TRP-2 expression. Thus, our results provide evidence that demethylsuberosin might be useful as a potential skin-whitening agent.

• Journal of Microbiology and Biotechnology
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• v.25 no.9
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• pp.1442-1448
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• 2015

The flavonoid apigenin and its O-methyl derivative, genkwanin, have various biological activities and can be sourced from some vegetables and fruits. Microorganisms are an alternative for the synthesis of flavonoids. Here, to synthesize genkwanin from tyrosine, we first synthesized apigenin from p-coumaric acid using four genes (4CL, CHS, CHI, and FNS) in Escherichia coli. After optimization of different combinations of constructs, the yield of apigenin was increased from 13 mg/l to 30 mg/l. By introducing two additional genes (TAL and POMT7) into an apigenin-producing E. coli strain, we were able to synthesize 7-O-methyl apigenin (genkwanin) from tyrosine. In addition, the tyrosine content in E. coli was modulated by overexpressing aroG and tyrA. The engineered E. coli strain synthesized approximately 41 mg/l genkwanin.

• Bulletin of the Korean Chemical Society
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• v.31 no.1
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• pp.87-91
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• 2010

For the discovery of new antivirals against Severe Acute Respiratory Syndrome-coronavirus (SARS-CoV), we prepared and evaluated several benzoquinoline compounds as its 3C-like protease (3CLpro) inhibitors. Based on the computer modeling study that each of the two rigid benzoquinolinone and N-phenoltetrazole moieties of the compound 1 is bound to the S1 and S2 sites, respectively, of the SARS protease by forming H-bonds and hydrophobic interactions, we designed and synthesized alkylated benzoquinolines at both the sites of the hydroxyl groups. We found that the compound 2a showed five times higher inhibiting activity against the 3CLpro compared to the compound 1.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.319-319
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• 2006

RAFT polymerization can produce under controlled conditions polymer chains incorporating well-defined chain ends. By designing a simple way of producing functional RAFT agents, a variety of ${\Box}-end$ groups was successfully introduced onto hydrophilic polymer chains. The ${\Box}-end$ group being a thiocarbonyl thio function was used as efficient chain transfer agent in dispersion or emulsion polymerization to produce original functional latex particles.