• Polymer(Korea)
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• v.26 no.6
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• pp.737-744
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• 2002

Thermodynamic miscibility of the binary blends composed of semi-crystalline poly (butylene 2,6-naphthalate) (PBN) and amorphous poly (4-vinylphenol) (PVPh) was investigated using differential scanning calorimetry (DSC) and Fourier transform infrared (FTIR) spectroscopy. DSC scan results showed that there was a single glass transition temperature (T$\_$g/) for each blend. Crystalline melting temperature (T$\_$m/) depression of the PBN in the blends was also observed with the increase of PVPh content. Both results of the single T$\_$g/ and the depression of T$\_$m/ for the PBN/PVPh blends indicate that the blends are thermodynamically miscible at the molecular level. FTIR spectroscopic analysis confirmed that strong intermolecular hydrogen bonding interactions between the ester carbonyl groups of the PBN and the hydroxyl groups of the PVPh are occurred.

• Journal of the Korean Chemical Society
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• v.20 no.5
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• pp.333-339
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• 1976

The rates of solvolysis for 2-thenoyl chloride have been measured in aqueous acetone and aqueous ethanol at various temperatures ranging from 20 to $40^{circ}C$. The activation parameters and the Grundwald-Winstein's slope are determined by the analysis of solvolysis rates. The results indicated that the reaction rates of solvolysis are considerably slower than those of the reaction for benzoyl chloride due to the electron donating effect of thiophene nucleus. The results also showed that the reaction proceeds with the $S_N1$ mechanism in water-rich solvents whereas the $S_N2$ character increases with the decrease of water content, and overall reaction is subject to entropy control.

• Journal of the Korean Chemical Society
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• v.20 no.5
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• pp.424-430
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• 1976

Isocyanate-terminated SBR-prepolymers were prepared from SBR-diol and excess toluene diisocyanate. These prepolymers were then used as initiators for the sodium-catalyzed polymerization of ${\varepsilon}$-caprolactam. The resulting block copolymers, presumably the structure of nylon 6-SBR-nylon 6, were confirmed from their IR spectra. The viscosities of these polymers were measured in phenol/tetrachloroethane and the molecular weights were estimated. The polymerization reaction was not affected by the change in concentration of catalyst, but significantly faster at $185^{\circ}C$ than at $150^{\circ}C$. And the initiator concentration of 0.5 mole % gave good results.

• Journal of Acupuncture Research
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• v.19 no.2
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• pp.51-64
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• 2002

We have compared(using the same series of experimental tissue samples) the levels of proteolytic enzyme activities and free radical-induced protein damage in synovial fluid from RA and CPH cases. Many protease types showed significantly increased (typically by a factor of approximately 2-3-fold) activity in RA, compared to normal rats. However, CPH significantly reduced the cytoplasmic enzyme activities of arginyl aminopeptidase, leucyl aminopeptidase, pyroglutamyl aminopeptidase, tripeptidyl aminopeptidase, and proline endopeptidase to almost about 1/10 each. For the Iysosomal proteases, synovial fluid samples from RA rats, CPH significantly reduced the enzyme activities of cathepsin B, dipeptidyl aminopeptidase I and dipeptidyl aminopeptidase II. In extracellular matrix degrading(collagenase, tissue elastase) and leukocyte as sociated proteases (leukocyte elastase, cathepsin G), CPH decreased these enzyme activities of collagenase, tissue elastase and leukocyte associated elastase in RA. In cytoplasmic and lysosomal protease activities in plasma from RA. CPH and normal plasma samples were not significantly different, suggesting that altered activity of plasma proteases (particularly those enzymes putatively involved in the immune response) is not a contributory factor in the pathogenesis of RA. In addition, the level of free radical induced damage to synovial fluid proteins was approximately twice that in RA, compared with CPH. CPH significantly decreased the level of ROS induced oxidative damage to synovial fluid proteins (quantified as protein carbonyl derivative). Therefore we conclude that both proteolytic enzymes and free radicals are likely to be of equal potential importance as damaging agents in the pathogenesis of inflammatory joint disease, and that the design of novel therapeutic strategies for patients with the latter disorder should include both protease inhibitory and free radical scavenging elements. In addition, the protease inhibitory element should be designed to inhibit the action of a broad range of protease mechanistic types (i.e. cysteine-, metallo- and serine- proteinases and peptidases). However, increased protein damage induced by ROS could not be rationalised in terms of compromised antioxidant total capacity, since the latter was not significantly altered in RA synovial fluid or plasma compared with CPH.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.19 no.2
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• pp.127-135
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• 1986

Each molecular weight (Mw) fraction of melanoidins prepared from a D-glucose and glycine system, i. e., Mw below 1,000, Mw between 1,000 to 5,000 and Mw above 5,000 and nondialyzable and ozone-treated melanoidins were reacted with heat-induced mutagens such as Trp-P-1, Trp-P-2, Glu-P-1, Glu-P-2 and IQ at $37^{\circ}C$ for 30 min. The inhibitory effects of the melanoidins on the mutagens increased with increasing molecular weight. The reducing ability ana antioxidative activity of melanoidins also increased in proportion to the increase in molecular weight, whereas the mutagenic inhibitory effect decreased on reduction of the melanoidins with sodium borohydride. It was also observed that a part of Trp-P-1 was adsorbed to melanoidin molecules. On modification of amino groups of these mutagens with carbonyl compounds derived through the Maillard reaction such as diacetyl and glyceraldehyde, their mutagenic activities were remarkably suppressed. Accordingly, it is speculated that the mutagenic inhibitory action of melanoidins is due to their reducing ability and antioxidative activity, and electrostatic binding and carbonyl groups of the melanoidin molecules.

• Journal of Life Science
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• v.19 no.10
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• pp.1389-1395
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• 2009

Generally, it takes a long time to purify wood vinegar, and it contains toxic compounds such as tar, methanol, phenol and benzopyrene. To reduce the toxicity of wood vinegar itself, we have developed a new purification method of wood vinegar using an oxidation-cohesion reaction and distillation with an active carbon. We have investigated the physico-chemical change (pH, specific gravity, refractive index and dissolved tar), the change of amount of toxic compounds (carbonyl group, phenol, benzopyrene and residual solvents) and organic acids (formic acid (FA), acetic acid (AA), propionic acid (PA)) of the purified wood vinegar under the long term and accelerated storage conditions. Also, we have evaluated the effect of the purified wood vinegar on hair growth using an alopecia model of C57BL/6 mice. As a result, we could find out that the purified wood vinegar was stable and remained without decay under the storage conditions and benzopyrene, a carcinogenic agent, was not detected in the purified wood vinegar. After topical treatment of the purified wood vinegar solution or minoxidil (MXD) for 2 weeks to dorsal skin, the hair regrowth of the mice accelerated faster than that of the control, with no clinical signs. In conclusion, we could suggest a guideline for quality control of process to reduce the toxic compounds in wood vinegar and it might be a useful hair growth promoter in the treatment of baldness or alopecia.

• Korean Journal of Food Science and Technology
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• v.33 no.1
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• pp.1-6
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• 2001

Emulsion products with water soluble protein were exposed under light at $5^{\circ}C$ for 8 days. Peroxide value (POV) was increased significantly at the bigining of storage and 2-thiobarbituric acid (TBA) value also increased until 4 days of storage with increase of the production of carbonyl compounds, suggesting that the condition was reacted different from that of the lipid autoxidation. The reaction was similar to the flavor reversion that usually produced from the bigining of soybean oil oxidation. The reason might be the meat pigment, myoglobin, oxidation and it would be due to the singlet oxygen rather than superoxide anion. When the light was excluded general pattern was similar but the production of oxidation products were smaller than that when the sample was exposed under light. The effect of the singlet oxygen was also smaller which meant that the singlet oxygen produced during emulsion process may affect on the flavor reversion at the bigining of storage. The POV of the emulsion without water soluble protein increase gradually by storage and the results indicated that the degradation rate of the peroxides were lower than the sample with water soluble protein. Especially after 4 days of storage, production of carbonyl compounds were decreased. During storage it would be possible to produce the singlet oxygen and the sensitizer from the plants that can be produced during decoloration of soybean oil may be responsible for it. When the light was excluded the production of oxidation products were reduced at the begining of storage and the effect of quencher also was not detected. Therefore the results indicated that the light can accelerate the lipid oxidation.

• Journal of the Korean Chemical Society
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• v.26 no.1
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• pp.7-17
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• 1982

In order to predict substituent and Lewis acid effects on the regiospecificity of the Diels-Alder reaction, and to investigate the competition for the complexation of Lewis acid between diene and dienophile, frontier orbital theory has been applied to thermal and catalyzed Diels-Alder reaction by means of CNDO/2 MO method. It has been found that: (1) Lewis acid coordinated preferentially with diene rather than dienophile when carbonyl oxygen of acetoxy substituted diene had larger negative atomic charges than that of dienophile. (2) Most of the reaction were neutral electron demand type, and hence 4-C, 2-C and quantitative secondary orbital interacion methods were generally in good accord with experiments. (3) Sulfur activated the adjacent terminal carbon atom greatly to increase diene LUMO-dienophile HOMO interaction through vacant-d-orbital participation, and played an important role in controlling regioselectivity of neutral electron demand reaction type.

• Journal of the Korean Chemical Society
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• v.23 no.5
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• pp.314-319
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• 1979

The electronic spectrum of marine dinoflagellate antenna pigment, peridinin, has been described in terms of PPP SCF MO CI computations and fluorescence polarization of the peridinin component in photosynthetic pigment complex of Amphidinium carterae. The main absorption band at 470 nm, $^1B{\leftarrow}A$, is polarized nearly along the long molecular axis. There appear to be two ${\pi}{\rightarrow}{\pi}^*$ transitions (C and $D{\leftarrow}A$) in the socalled "cis" peak region, and they are polarized roughly parallel to the main $B{\leftarrow}A$ absorption. In addition, we have found that the carbonyl group undergoes very 1ittle reorganization of the electronic structure in going from the ground to the $^1B$ excited states of peridinin, while the allenic group shows a strong charge transfer tendency in producing an electron-deficient allente allene group in the excited state.

• Journal of the Korean Chemical Society
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• v.29 no.4
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• pp.441-447
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• 1985

Several benzanilides were prepared by acylation of anilines with substituted benzoyl chlorides. While 2-chlorobenzanilides were photocyclized, 2-methylbenzanilide and 2'-methylbenzanilide were cleaved to give photo-Fries type products. 2-Nitrobenzanilide and 2'-nitrobenzanilide were inert in the above conditions due to lowering energy of the excited state by the nitro group. N, N-dibenzoylaniline and N, N-di-(2-chlorobenzoyl) aniline gave photo-Fries type reaction products effectively. In the benzanilide photo-Fries type reaction the excited singlet state was believed to be involved, since no oxygen effect was observed on the reaction rate. Quantum yield for 2-methylbenzanilide is higher in nonpolar and less viscous solvents than in polar and viscous solvents. The solvent cage radical pair is suggested in the photo-Fries type reaction of benzanilides.