• Current Research on Agriculture and Life Sciences
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• v.32 no.3
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• pp.145-148
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• 2014

To determine whether S-(-)-10,11-dihydroxyfarnesic acid methyl ester (DHFAME) produced by Beauveria bassiana CS1029 potentially causes acute skin irritation as a cosmetic ingredient, a skin toxicity test was conducted as recommended for compliance with Korea Food and Drug Administration regulations. New Zealand White rabbits were treated with 100 mg/dose of DHFAME according to standard guidelines. No significant skin lesions or inflammation was observed in the DHFAME-treated group. Furthermore, DHFAME did not appear to cause skin irritation, as assessed by clinical observation of the rabbits. Thus, when taken together, the present results suggest that DHFAME is a promising potential cosmetic ingredient that does not irritate the skin.

• Bulletin of the Korean Chemical Society
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• v.12 no.1
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• pp.71-74
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• 1991

Facile methods are reported for the synthesis of optically pure derivatives of (2S,3R)-3-amino-2-hydroxy-4-(4'-hydroxyphenyl)b utanoic acid. To avoid troublesome synthesis of O-benzyl-N-Boc-D-tyrosine, without the protection of phenolic OH group of tyrosine N-Boc-D-tyrosine methyl ester was reduced with DiBAL to the aldehyde. The aldehyde was converted via the cyanohydrin to (2S,3R)-3-amino-2-hydroxy-4-(4'-hydroxyphenyl)butanoic acid (AHpHBA). The mixture of diastereomers was converted to the corresponding Boc-AHpHBA methyl ester derivatives and separated by chromatography over silica gel. Optically active (2S,3R)-AHpHBA was used to synthesize aminopeptidase inhibitors.

• Journal of Applied Biological Chemistry
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• v.64 no.1
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• pp.13-17
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• 2021

Qantitative analysis of six compounds: (+)-catechin, benzoic acid, gallic acid methyl ester, paeonol, paeoniflorin, and albiflorin from Paeonia lactiflora extracts was performed using high-performance liquid chromatography and an ultraviolet (UV) detector, following different extraction methods. A reverse-phase column was used in a gradient elution system, and UV detection was performed at 280 nm. The results showed that the quantity of paeoniflorin was the highest in ethanol and water extracts (73.89 and 57.87 mg/g, respectively) among the six compounds. This study contributes a good analysis method for the contents of P. lactiflora and would be propitious for developing medicines and functional foods.

• Biomolecules & Therapeutics
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• v.31 no.5
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• pp.566-572
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• 2023

A chiral derivatization strategy with phenylglycine methyl ester (PGME) was employed to develop a straightforward method to determine the absolute configurations of N,N-dimethyl amino acids. The PGME derivatives were analyzed using liquid chromatography-mass spectrometry to identify the absolute configurations of various N,N-dimethyl amino acids based on their elution time and order. The established method was applied to assign the absolute configuration of the N,N-dimethyl phenylalanine in sanjoinine A (4), a cyclopeptide alkaloid isolated from Zizyphi Spinosi Semen widely used as herbal medicine for insomnia. Sanjoinine A displayed production of nitric oxide (NO) in LPS-activated RAW 264.7 cells.

• Textile Coloration and Finishing
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• v.2 no.4
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• pp.237-244
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• 1990

Syntheses and liquid-Crystallinites of thermotropic copoly (ester amide)s were investigated. The three components melt polycondensation of 4,4'-dicarboxy-$\alpha$, $\omega$-diphenoxyalkane as an A component, 4-4'diacetoxybiphenyl as a B, and p-N-acetoxy-aminobenzoic acid as a C gave the thrmotropic copoly(ester amide)s containing a flexible splacer in the polymer backbone. Diacetylated hydroquinone, methyl hydroquinone, chlorohydroquinone, and phenyl hydroquinone were used as anther B components. A polymer(6BPAB) having 10 mol% of C component and hexamethylene space. showed a typical nematic texture between $245^{\circ}C(T_m)\; and\; more\; than\; 360^{\circ]C(T_i)$. The melting points of the members of this series of polymers increased with decreasing methylene spacer. The polymer structure and mesomorphic nature were examined by solid and solution ^{13}C-NMR4 spectroscopy, cross polarizing microscopy with a hot stage, and X-ray diffactometry.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.244-245
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• 2005

Electrical insulation is one of the most important parts in a high voltage apparatus. Traditionally mineral oils and synthetic esters have been widely used as dielectric coolants for power transformers. Recently, researchers are interested in the environmental friendly vegetable oil from environmental viewpoint. This paper reports on the synthesis and characterization of soybean based ester oils. Two different types of soybean based transformer oils, named as methyl ester and isopropyl ester were synthesized. The synthesis of these esters was achieved by transesterification reactions of soybean oil and alcohol in the presence of catalyst. The GC and NMR spectroscopic analysis of the esters have been performed. The thermal stability of the esters was determined by thermal gravimetric analysis(TGA).

• Bulletin of the Korean Chemical Society
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• v.32 no.6
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• pp.1965-1969
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• 2011

1,2,4,5-tetraoxane, mono and dinitrate glycerol carbonate ester derivatives of stearic acid were synthesized along with the known 9(10)-keto methyl sterate, methoxy mono-nitrate and dinitrate of methyl stearate. Their cetane numbers (CNs) were investigated to evaluate their viability for use as CN improvers. The CN performances of tetraoxane and all of the nitrate derivatives were investigated at 500 and 1000 ppm concentrations and compared to that of a traditional CN improver 2-ethylhexyl nitrate (2-EHN). The experimental results suggest that all derivatives evaluated in this study showed better CN improvement than base diesel fuel. Specifically, the 1,2,4,5-tetraoxane derivative of stearic methyl ester was superior to all derivatives studied, also being superior to 2-EHN. We also discussed the correlations between the observed CN trends and thermo-analytical data resulted from thermo gravimetric analysis curves (TGA) and differential scanning calorimetry (DSC).

• Journal of Microbiology and Biotechnology
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• v.26 no.9
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• pp.1579-1585
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• 2016

Sugar esters are valuable compounds composed of various sugars and fatty acids that can be used as antibacterial agents and emulsifiers in toothpaste and canned foods. For example, fructose fatty acid esters suppress growth of Streptococcus mutans, a typical pathogenic bacterium causing dental caries. In this study, fructose laurate ester was chosen as a target material and was synthesized by a transesterification reaction using Candida antarctica lipase B. We performed a solvent screening experiment and found that a t-butanol/dimethyl sulfoxide mixture was the best solvent to dissolve fructose and methyl laurate. Fructose laurate was synthesized by transesterification of fructose (100 mM) with methyl laurate (30 mM) in t-butanol containing 20% dimethyl sulfoxide. The conversion yield was about 90%, which was calculated based on the quantity of methyl laurate using high-performance liquid chromatography. Fructose monolaurate (M_r 361) was detected in the reaction mixture by high-resolution mass spectrometry. The inhibitory effect of fructose laurate on growth of oral or food spoilage microorganisms, including S. mutans, Bacillus coagulans, and Geobacillus stearothermophilus, was evaluated.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.383.3-384
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• 2002

Rosmarinic acid (1) and methyl rosmarinic acid (2), isolated from the ethyl acetate soluble fraction of the methanolic extract of Salvia miltiorrhiza Bunge (Lamiaceae) were found to be the tyrosinase inhibitors and scavengers of 1, 1-diphenyl-2-picrylhydrzyl (DPPH) radical. Compounds 1 and 2 inhibited the oxidation of L-tyrosine catalyzed by mushroom tyrosinase with $IC_{50}$/ of 16.8 $\mu\textrm{M}$ and 21.5 $\mu\textrm{M}$. respectively. It compared well with kojic acid. a well-known tyrosinase inhibitor. with an $IC_{50}$ of 22.4 $\mu\textrm{M}$. The inhibitory kinetics, analyzed by a Lineweaver-Burk plot, found rosmarinic acid and its methyl ester to be competitive inhibitors with $K_{i}$ of $2.35{\times}10^{-5}M$ and $1.52{\times}10^{-5}M$ respectively. In addition, compounds 1 and 2 showed the scavenging activities on DPPH radical, with $IC_{50}$ of 4.27 $\mu\textrm{M}$ and 3.05 $\mu\textrm{M}$. respectively. These scavenging effects were more potent than that of L-ascorbic acid ($IC_{50}$ = 11.75$\mu\textrm{M}$).

• 보존과학연구
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• s.27
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• pp.203-214
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• 2006

The work focuses on the chemical analysis of organic residues in archaeological soils. Particularly, the detection of manuring in archaeological soils can provide important information concerning early human behavior, diet, parasites, ecological adeptation. In this study, archaeological soils excavated at bunto-ri, Haenam and kumjang-ri, Kyungju were used to assess the possibility as indicators of ancient human activity in archaeological areas. The sampled soils were analyzed soil color, pH for their physical and chemical properties and GC/MSD to detect and quantify specific compound. The results showed that the sampled soils were normal pH(6.8~7.2) and soil color of light brown to yellowish brown. Also, the result from the GC/MS analysis indicated that their compounds were hexadecanoic acid, octadecanoic acid, nonadecane, docosanoic acid, methyl ester, teracosanoic acidand methyl este from bunto-ri site and 1-heptadecene, cyclotetracosane, tetracosane, cyclotetracosane,1-docosene, n-nonadecane, tetracosanoic acid methyl ester, cyclooctacosane, 1-nonadecene, eicosane, cyclotriacontane from kumjang-ri site. These compounds are not only normal soil materials but also animal lipid compounds. And the more scientific analysis of the soils will solve a curiosity for artificially incoming.