• Applied Chemistry for Engineering
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• v.29 no.2
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• pp.225-228
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• 2018

Plasticizers added to thermoplastic polymers are known to shorten the life of products due to the elution to outside, and some of them are harmful to our environment and human body. Since the use of phthalate plasticizers suspected of being carcinogens has been gradually prohibited, there is a need for environmentally friendly plasticizers that can replace them. Most of the substances have a low compatibility with resin, high cost and lack of safety verification. Therefore, in this study, four kinds of norbornene dialkyl ester compounds possessing excellent physical properties, which are also reported as safe compounds from the toxicity evaluation, were added to PVC resin to evaluate the possibility of human exposure by leaching, and also the potential usage as plasticizer candidates alternative to commercial ones including DEHP, DINCH and DOTP. The test was carried out according to the American standard test method (ASTM). The results showed that di-2-ethylhexyl-5-norbornene-2,3-dicarboxylate (DEHN) in aqueous solvents and diisopentyl-5-norbornene-2,3-dicarboxylate (DIPN) compounds in oil solvents were superior or equivalent to DEHP. In addition, all four norbornene compounds showed lower values than 100 ppm, which is considered to have an influence on the environment, indicating that the polar norbornene structure affects the elution.

• Korean Journal of Crystallography
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• v.2 no.2
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• pp.13-21
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• 1991

X-ray methods have been used to determine the chain conformation and packing of the thermotropic liquid crystalline copolyester prepared from 50% tarephthaloyl chloride(TPA) and 50% (1-phenylethyl) hydroquinone(PEHQ). The x-ray patterns of annealed melt-spun fibers contain a series of annealed melt-Pointing to a well ordered crystalline structure, despite the random sense(2 or 3-) of the 1-phenylethyl substiuttion on the TPA-hydroquinone backbone. The crystalline fiber is monoclinic with space group P2l and the unit cell has dimensions 11=12.77 A, b=10.17 A (upique axis), c=12.58 h (fiber axis). and β=90.1° and contains TPA-PEHO units of to or chains. The random substitution of 1-phenylethyl groups was modelled by placing these groups at both the 2and 3 positions and giving each a weight of one-hal(. T he structure has been refined by linked a rom least square methods(LALS) against 16 observed and 21 unobserved reflections. and had a final R value of 0.20. Packing of the side chains is effected by staggering adjacent chains along the b axis by approximately c/2, so that the side chains are interleaved. The phenyl-COO and COO-phenyl torsion angles are -6.1 and 65.6, respectively, such that the main chain phenyls are mutually inclined at 59.5 (the ester groups are assumed to be planar). These torsion angles compare very well with those for the model compounds, notably phenylbenzoate, and can be used in future analyses of the structures of more complex random sequence copolyesters.

• Korean Journal of Food Science and Technology
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• v.32 no.6
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• pp.1358-1364
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• 2000

A mixed culture of bacteriocin-producing lactic acid bacteria and yeast was used to prepare unique fermented fruit and vegetable beverage which contains bacteriocin. Fruit and vegetable broth fermented by Lactococcus lactis 11454 showed inhibitory activity against foodborne pathogens such as Listeria monocytogens and Staphylococcus aureus, and Streptococcus mutans which is a major causative agent for dental caries. Bacteriocin was detected at the end of fermentation of fruit and vegetables and its antimicrobial activity was stable for 5 weeks during storage at $4^{\circ}C$. These results suggest that the presence of bacteriocin in beverages during fermentation and storage will provide a safeguard against foodborne pathogens and spoilage bacteria. To improve flavor of the fermented broth, post-fermentation of the fermented broth was carried out at $4^{\circ}C$ by using yeast isolated from raw material mixture. Total acidity of the post-fermented broth was slightly decreased, but significant increase in the concentration of succinic acid was observed in the post-fermented broth. It was also observed that bitter and disagreeable taste compounds such as phthalates were decreased, and mild acidic and fruity flavor esters and alcohols were increased by the post-fermentation of the fermented broth with yeast.

• Journal of Korean Society on Water Environment
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• v.21 no.5
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• pp.484-489
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• 2005

In order to determine the removal rate of non-biodegradable substances and the change of their structural properties, this study was carried out by an ozone-treatment experiment on leachate collected from the landfill area of D City in Chung chung nam-do and examined the change of the chemical properties of non-biodegradable substances. The main elements of non-biodegradable substances in landfill leachate were benzene, toluene, trichloroethane, trichloroethylene, xylene, etc. and the concentration of toluene was 15.7 mg/L on the average, benzene 7.2 mg/L, trichloroethane 1.1 mg/L, trichloroethylene 0.75 mg/L and xylene 0.5 mg/L. When leachate was treated with ozone for 10 min, 30 min and 60 min, UV absorbance was reduced with the increase of reaction time, and the reduction rate was 38.6% at 60 min. TOC was removed by 13.2% at 60 min. The low reduction rate of TOC may be because TOC reacts indirectly with OH radical produced from reaction with ozone while UV absorbance usually relies on direct reaction between organic matters and ozone molecules. Color was removed by up to 97%, which suggests that ozonation is highly effective in removing coloring elements in leachate. Sixteen kinds of non-biodegradable compounds were found in the leachate and most of them had the characteristic of aromatic hydrocarbon. Among them dibutyl phthalate was identical with a substance included in the list of US EPA, which is classified as a mutagen that may cause the mutation of genes and disorders in chromosomes. In addition, 2,5-Cyclohexadiene-1,4-dione, 1,2-Benzenedicarboxylic acid and butyl octyl ester were found to be similar to substances listed by USEPA. According to the result of analyzing structural changes before and after ozonation using GC-MS, cyclic compounds and aromatic compounds were observed in the original water and aliphatic compounds were newly observed after ozonation. In addition, through ozonation, humic substances of high molecular weight were oxidized and decomposed and produced low-molecular compounds such as aldehyde, ketone and carboxyl acid and highly biodegradable aliphatic carbon, which suggests the bio-degradability of non-biodegradable substances.

• Natural Product Sciences
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• v.20 no.3
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• pp.160-169
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• 2014

44 compounds and 9 minerals were isolated from and detected in the New Zealand deer velvet antler Cervus elaphus var. scoticus L$\ddot{o}$nnberg. The chemical structures of (1 - 26) were identified on the basis of the spectroscopic methods and comparisons with literature, respectively. The structures were identified as cholesterol (CS, 6), 7-keto-CS (7), $7{\beta}$-hydroxy-CS (8), and $7{\alpha}$-hydroxy-CS (9), and included 12 steroid $3{\beta}$-O-(palmitic/stearic/myristic acid esters; PM/SA/MS) [CS-$3{\beta}$-O-PM (1 - 1), CS-$3{\beta}$-O-SA (1 - 2), CS-$3{\beta}$-O-MR (1 - 3), 7-keto-CS-$3{\beta}$-O-PM (2 - 1), 7-keto-CS-$3{\beta}$-O-SA (2 - 2), 7-keto-CS-$3{\beta}$-O-MR (2 - 3), $7{\beta}$-hydroxy-CS-$3{\beta}$-O-SA (3 -1), $7{\beta}$-hydroxy-CS-$3{\beta}$-O-PM (3 - 2), $7{\beta}$-hydroxy-CS-$3{\beta}$-O-MR (3 - 3), $7{\alpha}$-hydroxy-CS-$3{\beta}$-O-SA (4 - 1), $7{\alpha}$-hydroxy-CS-$3{\beta}$-O-PM (4 - 2), and $7{\alpha}$-hydroxy-CS-$3{\beta}$-O-MR (4 - 3)], dinonyl phthalate (5), 8 nucleic acids analogues [uracil (10), deoxyguanosine (11), deoxyuridine (12), uridine (13), deoxyadenosine (14), adenosine (15), inosine (16), and guanosine (17)], and the 9 free amino acids [L-phenylalanine (18), L-isoleucine (19), L-leucine (20), L-tyrosine (21), L-valine (22), L-proline (23), L-threonine (24), L-alanine (25), and L-hydroxyproline (26)]. Also, there are 8 kinds of amino acids [asparagine, serine, glutamine, glycine, histidine, arginine, methionine, and lysine], 2 sialic acids [N-acetylneuraminic acid (27), ketodeoxynonulosonic acid (28)], and 9 minerals [Na > K > Ca > Mg > Fe > Zn > B > Al > Cu] were detected from the autoaminoacid analyzer and ICP spectrometer, HPAEC-PAD/HPLC-FLD, respectively. 9 kinds of oxycholesterol-$3{\beta}$-O-fatty acid ester (2 - 1, 2 - 2, 2 - 3, 3 - 1, 3 - 2, 3 - 3, 4 - 1, 4 - 2, and 4 - 3) and 3 nucleic acids (12, 14, and 15) were isolated from the velvet antler for the first time. 6 kinds of steroids (7, 8, 9, 2 - 1, 3 - 1, and 4 - 1) were examined for their anti-proliferative effects against L1210, P388D1, K562, MEG-01, KG-1, MOLT-4, A549, HepG2, MCF-7, SK-OV-3, and SW-620 cancer cell lines. They showed anti-proliferative effects with $IC_{50}$ values of 0.06, 2.16, 2.42, > 50.0, 1.66 and $8.31{\mu}M$ against L1210, while the values were 24.05, 9.44, 5.22, 0.25. 9.48 and $49.77{\mu}M$ against P388D1, respectively. The others were inactive.