• Journal of the Korean Chemical Society
• /
• v.25 no.2
• /
• pp.110-118
• /
• 1981

Kinetics and mechanism for the reaction of substituted phenacyl bromides with substituted pyridines have been determined at 25, 35 and $45^{\circ}C$ in methanol and dimethylformamide by the conductivity method. The rate constants for the reaction of various pyridines with phenacyl bromide shown that electron-donating substituents in the pyridine increase the rate, while electron-attracting one decrease in both solvents. The effect of substituents in substrate, the rate being increased by electron-attracting substituents. This is as expected for nucleophilic attack of amines on the carbon atom. Isokinetic and $Br{\psi}nsted$ linear relationship were shown in the reaction of phenacyl bromide with pyridines in both solvent in which isokinetic temperature were obtained 614, $202^{\circ}K$ and ${\beta}$ values were 0.29, 0.36 in methanol and dimethylformamide respectively. In the case of the reaction of substituted phenacyl bromide with pyridines, isokinetic temperature decreases with increasing electron-attracting ability of the substituents in the phenacyl bromide, while the ${\beta}$ values were reverse. From the above results, it can be inferred that N…C bond formation decreases progressively from p-chloro- to p-methoxyphenacyl bromide and the bond formation predominates in DMF than methanol. The ${\rho}$ values of Hammett equation of the reaction of phenacyl bromide with substituted pyridines are negative in both solvent, but its value was larger negative in DMF than methanol and the ${\rho}$ value of that of substitutted substrates with pyridine was 0.3, the low value is ascribed to direct $S_N2$ attack of the nitrogen atom in pyridine ring at the methylene carbon.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.39 no.3
• /
• pp.399-405
• /
• 2010

After Gomchui tea was prepared from leaves of Ligularia fischeri (Ledeb.) Turcz by blanching method, the antioxidant activity of major compounds in Gomchui tea was assessed. On-line HPLC-ABTS analysis revealed that caffeoylquinic acids (chlorogenic acids), such as 5-O-caffeoylquinic acid (5-CQA), 3,4-di-O-caffeoylquinic acid (3,4-DCQA), 3,5-di-O-caffeoylquinic acid (3,5-DCQA) and 4,5-di-O-caffeoylquinic acid (4,5-DCQA), were the major antioxidant compounds in Gomchui tea. The extraction efficiency of these compounds were examined in the various conditions such as extraction temperature, time and solvent. The results demonstrated that the extraction amount with water increased in proportion to extraction time (1~10 min) and temperature ($8{\sim}80^{\circ}C$). These active compounds were also extracted with water even at $8^{\circ}C$ (60% of $80^{\circ}C$), indicating that water is very good extraction solvent for extraction of these antioxidant constituents. However, the extraction efficiency of these compounds decreased when ethanol percentage in water increased. The extraction efficiency between Gomchui powder (no blanching) and tea was significantly different, and 60% of total antioxidant compounds in tea was removed from fresh leaves into water in blanching process, especially 3,5-DCQA (over 90%). Meanwhile, the sonication method didn't affect the extraction of these compounds in all solvents. These results suggest that Gomchui tea can be a good candidate for the tea beneficial to human health.

• Journal of the Korean Society of Food Science and Nutrition
• /
• v.15 no.2
• /
• pp.128-135
• /
• 1986

Wheat germ protein was extracted and isolated by a Modified Osborne fractionation method and some properties were investigated. The results are summarized as follows; 1. Approximate compositions of wheat germ were moisture 10.5%, crude protein 22.8%, crude fat 2.4%, crude ash 3.2%, crude fiber 1.5%, respectively. 2. Nitrogen solubilities on various solvents were the lowest as 45.58% by Osborne method and the highest as 79.49% after sequencial extraction of the $H_2O$, 0.5M-NaCl, 70%-ethanol, 0.1N-NaOH. 3. Isolated proteins yielded albumin, globulin, globulin, gliadin and glutelin in the proportion of 20.22: 17.49: 42.58: 19.71, respectively. 4. Spectrophometric chromatograms of isolated protein by Regel-filtration were two peaks in albumin (I ; 8.2%, II ; 91.8%), one peak in globulin (92.8%), respectively. 5. Disc-PAGE patterns were showed about 14 bands in 0.5M-Cl soluble protein, 3bands in crude albumin, 1band in main albumin, 2bands in crude globulin, one band in main globulin under pH 8.3 buffer system (Ornstein and Davis method).

• Bulletin of the Korean Chemical Society
• /
• v.31 no.4
• /
• pp.976-980
• /
• 2010

A series of arylacetylene resins with siloxane units were synthesized by the condensation reactions of m-diethynylbenzene magnesium reagents with various $\alpha,\omega$-bis(chloro)dimethylsiloxanes. These resins are liquids and are miscible with common organic solvents at room temperature. The structures of the resins were characterized by FT-IR, $^1H$ NMR, $^{13}C$ NMR, $^{29}Si$ NMR, and gel permeation chromatography (GPC). The thermal behaviors of the resins were examined with differential scanning calorimetry (DSC). These resins have good processability. They can be thermally cross-linked through the ethynyl groups to produce cured resins. The thermal and thermooxidative stabilities of the cured resins were studied by thermogravimetric analysis (TGA). The cured resins possess high thermal and thermooxidative stability. Their decomposition occurs at above $500^{\circ}C$ in both $N_2$ and air. With increasing the length of siloxane units in the resins, the thermal stability of the cured resins decreases in $N_2$. When the cured resins were sintered above $1450^{\circ}C$ under argon, hard and glassy SiOC ceramics were obtained. These SiOC ceramics have the decomposition temperatures at 5% weight loss above $800^{\circ}C$ in air.

• Journal of Mushroom
• /
• v.11 no.3
• /
• pp.164-170
• /
• 2013

This study was carried out to compare the medicinal effects of various fruiting body of Ganoderma species and Cordyceps militaris, Phelinus linteus extracts. ${\beta}$-glucan and polyphenol are useful ingredient in mushrooms and they were known to have antioxidant activity. We analyzed ${\beta}$-glucan and polyphenol contents of fruiting body of Ganoderma spp., Cordyceps militaris, and Phellinus linteus. Most Ganoderma spp. exhibited ${\beta}$-glucan contents of 15 to 20%. Cordyceps militalis showed the highest ${\beta}$-glucan level of 25%. Interestingly, eight strains of Ganoderma spp. was analyzed to have higher contents of ${\beta}$-glucan than Phelinus linteus. Polyphenol contents was measured after extraction with different solvents. (D.W., 70% EtOH, 80% MeOH) The level of polyphenol in ASI 7020 strain was at maximum in the water extraction and ASI 7086 showed the highest level in the 70% EtOH extraction. The amounts of polyphenol in strain ASI 7113 was at maximum in the 80% MeOH extraction.

• Clean Technology
• /
• v.18 no.4
• /
• pp.366-372
• /
• 2012

Three acrylic copolymers containing tris(8-hydroxyquinoline) aluminum (AlQ3) pendant group (25 wt%), acrylateco-HEMA-$AlQ_3$ (25 wt%), were successfully synthesized by free radical polymerization from acrylates [methyl methacrylate (MMA), acrylonitrile (AN) or 2-hydroxyethyl methacrylate (HEMA)] with HEMA functionalized with AlQ3 pendant groups (HEMA-p-$AlQ_3$). The glass transition temperatures ($T_g$) of MMA-co-HEMA-p-$AlQ_3$ (copolymer 1), AN-co-HEMA-p-$AlQ_3$ (copolymer 2) and HEMA-co-HEMA-p-$AlQ_3$ (copolymer 3) were found to be 158, 150 and $126^{\circ}C$, respectively. They have good thermal stability: a very desirable feature for the stability of OLEDs. Their solubility, thermal properties, UV-visible absorption and photoluminescence behaviors were investigated. They were found to be soluble in various organic solvents such as tetrahydrofuran (THF), dimethylformamide (DMF), toluene and chloroform. It was also found that the UV-visible absorption and photoluminescence behaviors of these copolymers were similar to those of pristine $AlQ_3$. Green organic light-emitting diodes (OLEDs) have also been fabricated using these copolymers as light emission/electron transport components obtained easily by spin coating, and their current density voltage (J-V) curves were compared. The OLED device of the copolymer 3 had the lowest turn-on voltage of about 2 V compared to other copolymer types devices.

• KSBB Journal
• /
• v.21 no.2
• /
• pp.151-156
• /
• 2006

Vitamin-C is one of the typical bioactive substances widely used in the cosmetic and pharmaceutical applications. It is well known that the bioavailability of vitamin-C decreases with time because it is spontaneously oxidized in the presence of oxygen. In this study, vitamin-C inclusion complexes were prepared by formulating vitamin-C with 2-hydroxypropyl-${\beta}$-cyclodextrin (HP-${\beta}$-CD) to protect vitamin-C from being oxidized. Vitamin-C inclusion complexes were prepared by a solvent evaporation method using a rotary evaporator and various solvents of different dielectric constant such as ethanol, methanol and distilled deionized water to investigate the effect of solvent polarity on the stability of vitamin-C. To estimate the stability of inclusion complexes, samples were stored in a 50 mM phosphate buffer solution of pH 7.0 for 24 hours at $25{\pm}0.1^{\circ}C$ and the degradation rate of vitamin-C was calculated using a high performance liquid chromatography. The stability of vitamin-C was observed to improve with the increase of solvent polarity.

• KSBB Journal
• /
• v.23 no.6
• /
• pp.557-560
• /
• 2008

The micelle process was developed for pre-purifying paclitaxel from plant cell cultures of Taxus chinensis, giving a high purity and yield. The approach in this work was to transfer paclitaxel in the crude extract to an aqueous surfactant solution as a micelle, allowing organic solvents to be used for removal of lipids and non-polar impurities. In this work, the effects of various surfactants such as CPC, CTMAC, LTMAC, SDS, AOT, Tween, PEG, and Triton were examined on the yield, purity, and phase separation time in micelle process. Among these surfactants, CTMAC (5%, w/v) gave the best result in terms of paclitaxel yield (${\sim}99%$), purity (${\sim}21%$), and phase separation time (30 min). The use of micelles in the pre-purification process allows for rapid and efficient separation of paclitaxel from interfering compounds and dramatically increases the yield and purity of crude paclitaxel for subsequent purification steps.

• Journal of Environmental Health Sciences
• /
• v.3 no.1
• /
• pp.27-44
• /
• 1976

This study was carried out to evaluate the harmful factors in working environments and to investigate the labor productivity after improvement of environments, surveying 93 industrial establishments of 10 industries located in Youngdeungpo industrial area in Seoul. The results obtained were as follows: 1) The highest noise level of 125dB(A) was indicated at the rolling process of transport equipment manufacturing industry. 2) The best illumination level was shown in precise machinery industry and the worst was indicated in rubber products, metallic products and transport equipment manufacturing industries. 3) Thermal conditions were above threshold limit value (TLV) at more than two processes of all industries except printing industry. 4) The highest dust concentration was determined in textile and wearing manufacturing industry. 5) Organic solvents were detected at 52 processes in 93 industrial establishments and 33 processes of them showed higher than TLV. The results about harmful chemicals were as follows: a) sulfur dioxide ($SO_2$)was determined higher than TLV on welding process of metallic product manufacturing industry and heat treatment process of transport equipment manufacturing industry. b) Carbon monoxide (CO) concentration was 700ppm at heat treatment process of transport equipment manufacturing industry, indicating 14 times of TLV. c) vinylchloride concentration in the air of PVC raw material mixing process and PVC preparation process of chemical product manufacturing industry was determined higher than TLV. d) Hydrochloride (HCl) concentration in the air of wire expanding process of transport equipment manufacturing industry was determined higher than TLV. 7) Higher values of lead concentration than TLV were determined at lead welding metallic product manufacturing industry and type planting process of process of printing industry, $1.8mg/m^3$ and $0.3mg/m^3$ respectively. 9) 22, 968 of 52, 855 workers (i.e. 43.5%) in 93 industries were exposed to various harmful agents. 10) It was found that the improvement of illumination in electric apparatus manufacturing industry (from 20~40 lux to 420 lux) resulted in an increase in productivity of 6.5% per capita and a decrease in faulty products of 19%. 11) Improvement of environments using local exhaust ventilation system resulted in a decrease of harmful substances lower than TLV and an increase in productivity of 11.4%. 12) Improvement of shovelling tools based on ergonomics resulted in a reduction in energy expenditure of 25.3% and an increase in productivity of 32.2% per capita.

• Journal of Korean Society of Forest Science
• /
• v.99 no.4
• /
• pp.546-552
• /
• 2010

The aim of the study was to assess the cosmeceutical activity of Pyrus ussuriensis leaves and it is possible that can be used as a cosmetic ingredient for application of cosmetic industries. P. ussurensis leaf was extracted with various solvents including water, 70% ethanol and 60% acetone. In the result of DPPH (1,1-diphenyl-2-picryl-hydrazyl) scavenging radical activity, water, ethanol and acetone extract of P. ussuriensis leaf were higher than 70%, 80% and 85% at 50 ppm concentration, respectively. Xanthine oxidase inhibition activity and superoxide dismutase (SOD)-like activity by P. ussuriensis extract were higher than 30%. In addition, SODlike activity of all extracts showed tendency of the significant increase with the increase of concentration. In the anti-inflammatory test, P. ussuriensis leaf extract inhibited generation of nitric oxide (NO) stimulated by LPS in the macrophage cell line (raw 264.7) after 12 to 24 hours. As above results, P. ussuriensis has a great potential as a cosmeceutical raw material as well as anti-oxidant and anti-inflammatory ability.