• Applied Biological Chemistry
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• v.47 no.1
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• pp.130-134
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• 2004

The arils of Euphoria longana L. was extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2O$. From the n-BuOH fraction, four compounds were isolated through the repeated silica gel, ODS and Sephadex LH-20 column chromatographies. From the result of physico-chemical data including NMR, MS and IR, the chemical structures of the compounds were determined as 1,1-dimethyl-2propenyl $1-O-{\beta}-D-glucopyranoside$, ethyl ,${\beta}-D-glucopyranoside$, 5-(hydroxymethyl)-2-furfur-aldehyde and uridine. Uridine exhibited inhibition effect of 79% on platelet aggregation at the concentration of$5\;{\mu}g/ml$.

• Applied Biological Chemistry
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• v.50 no.3
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• pp.224-227
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• 2007

Sajabalssuk (Artemisia princeps PAMPANINI) was extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_{2}O$, successively. From the EtOAc fraction, two phenylpropanoids were isolated through the repeated silica gel and ODS column chromatographies. From the results of physico-chemical data including NMR, MS and IR, the chemical structures of the phenylpropanoids were determined as eugenol (1) and (-)-sesamin (2). They were the first to be isolated from Sajabalssuk (Artemisia princeps PAMPANINI, Sajabalssuk). Also, eugenol inhibited LDL-oxidation with the inhibitory activity of 87.8 ${\pm}$ 1.0% at a concentration of 40 ${\mu}g/ml$.

• Applied Biological Chemistry
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• v.48 no.4
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• pp.418-420
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• 2005

In order to search for biologically active compounds from edible plant sources, the aerial parts of Sajabalssuk (Artemisia herba) were extracted with 80% aqueous MeOH, and the concentrated extract was partitioned with EtOAc, n-BuOH and $H_2O$, successively. From the EtOAc fraction, four compounds were isolated through the repeated silica gel and ODS column chromatographies. From the results of physico-chemical data including NMR, MS and IR, the chemical structures of the compounds were determined as eupatilin (1), jaceosidin (2), apigenin (3) and eupafolin (4). Among them, compounds 3 and 4 were isolated for the first time from Sajabalssuk (Artemisia herba).

• Applied Biological Chemistry
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• v.46 no.2
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• pp.117-122
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• 2003

Starches from 4 rice cultivars, including Whachungchalbyeo and Whachungbyeo, together with two correspondiug conversion mutants with giant embryonic phenotype, Whachungchal-giant embryonic rice and Whachung-giant embryonic rice, were isolated to compare its physico-chemical properties. The amylose content and the length of glucose chains in the fractionated amylose was reduced in response to conversion of the rice cultivars for developing giant embryonic phenotype. For the fine structure of amylopectin, conversion to giant embyonic rice cultivars accompanied with slight increase in the length of B chain plus decrease in the amount of A chain, and also a slight increase in average glucose chains length of amylopectin fractions could be observed. X-ray diffractogram revealed 4 cultivars to be the representative A types. We could also obtain the results that the hydrolysis rate by glucoamylase in the waxy rice cultivars decreased in response to conversion to the giant embryonic rice cultivars, while the rate increased in the non-waxy rice cultivas. Termination temperature for gelatinization was observed to decrease in response to conversion into the giant embryonic rice cultivars, however, the enthalpy for gelatinization was found to increase with the same conversion process.

• Applied Biological Chemistry
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• v.15 no.3
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• pp.229-240
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• 1972

Not only in order to determine reasonable application amounts of PCP in terms of soil texture, but also to get basic data for fish-toxicity-free treatment by estimating fish toxicity, some aspects of PCP adsorption were observed taking various paddy soils with different physico-chemical characteristics in the Choongbook Area as samples. The results obtained are summarized as follows: 1. There was a positive correlation between PCP adsorption and clay contents, total nitrogen, organic matter, cation exchange capacity, exchangeable bases, and phosphorus absorption coefficients, respectively; whereas there was a negative one between PCP adsorption and pH. Although they were not significant, it was remarkable that there was a relatively large amount of correlation between PCP adsorption and clay contents, $H^+,\;Mg^{++}$, and CEC, respectively. 2. PCP adsorption in terms of soil texture was in the order of Clay>Loam>Sandy loam. 3. Although PCP adsorption in the $H_2O_2-treated$ soils decreased remarkably, it was not proportional to the humus contents. 4. The order of PCP adsorption in the exchangeable base-treated soils was H^+-exchanged soil>$K^+-soil$>$Na^+-soil$>$Ca^{++}-soil$>Mg^{++}-soil. 5. Langmuir's and Freundlich's adsorption isotherms were applicable to the PCP adsorption, and thereby were able to be calculated maximum adsortion amounts of PCP, bond energy, and the depths of adsorption layers. 6. Maximum adsorbed amounts of PCP were 212.14 mg/100gr in Clayey loam, 97.28 to 121.59mg/100gr in Loam, and 32.92 to 91.74mg/100gr in Sandy loam, respectively. 7. The depths of mixed layers of limiting application for fish-toxicity-free treatment were 0.88cm of the Jinchun soil, the shallowest and 4.29 cm of the Naesan-ri Sandy loam, the deepest.

• Applied Biological Chemistry
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• v.36 no.4
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• pp.290-295
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• 1993

In order to utilize effectively fish skin from fish processing, characteristics of the yellowfin sole and dover sole skins were investigated. In the yellowfin sole, the crude protein content and yield of fish skin used for the preparation of gelatin were 22.3% and 11.3%, respectively and in the dover sole, 17.2% and 8.9%, respectively. In the yellowfin sole skin, the soluble and insoluble collagen occupied 66.1% and 33.9%, respectively and in the dover sole skin, 78.8% and 21.1%, respectively. No difference in the amino acid composition between soluble and insoluble collagen was detected. The sum of proline and hydroxyproline content in the collagen extracted from fish skin was lower than that of those from pork skin or bone. The molecular weight of the two major subunits from the soluble collagen in the yellowfin sole skin were found to be 143 KDa and 202 KDa. Those in the dover sole skin were 142 KDa and 207 KDa. The physico-chemical properties such as the melting point and gelling point of yellowfin sole skin gelatin were superior to those of dover sole skin gelatin.

• Applied Biological Chemistry
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• v.27 no.3
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• pp.169-173
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• 1984

In order to determine the optimum harvesting time based on grain filling and physico-chemical qualities for malting, three cultivars were harvested at every five days from 30th day after heading date at two experimental sites in the southern part of Korea. Starch accumulation and kernel weight increment were remarkable until 45th day after heading, but negligible after that. Content of ash, crude protein and polyphenolics and ${\alpha}-amylase$ activity decreased with maturation of grains and reached to the lowest value at 45th day after heading date. Germinative energy and capacity were good enough for malting from 40th day after heading date. The optimum harvesting time were estimated at 45th day after heading date in the increment of starch accumulation and kernel weight. At this time matured and immatured kernels were in the ratio 93 : 7. However, it is estimated that early harvesting time was at 40th day after heading date.

• Applied Chemistry for Engineering
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• v.7 no.1
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• pp.186-193
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• 1996

Several chitosan beads were prepared by W/O emulsion and capillary extrusion methods. The surface structures were observed through SEM pictures, the surface areas were determined by BET method, the available amine contents were measured by picric acid titration method, and the results were correlated each other. The beads from W/O emulsion method were smaller in size but had higher hardness, surface area, and available amine contents than the ones from capillary extrusion method. Moreover, the surface area, available amine contents, apparent density and the hardness showed large differences according to the drying processes. As compared between the solvent dehydration and the freeze drying technique in W/O emulsion method, the former showed higher surface area, higher available amine contents and hardness than the latter. SEM pictures revealed that in case of solvent dehydration method, very small pores existed, whereas in case of freeze drying method, cell-like pores existed on the surface. The results of picric acid titration showed that the beads dried by solvent dehydration method were 10 times higher in amine contents than those from freeze drying method, and the amount of amine contents were increased as the surface area was increased. After fluorescamine was reacted with chitosan beads, the fluorescence labeled beads were observed through fluorescence microscope. The results showed that most of primary amine existed on the surface of beads and pores.

• Korean Journal of Ecology and Environment
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• v.46 no.4
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• pp.541-550
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• 2013

The objective of this study was to understand the distribution characteristics of largemouth bass as an exotic species in relation to water chemistry. The survey was conducted in 10 reservoirs in Korea that showed different properties in size, location and eutrophic state. Total number of fish species observed in the artificial reservoirs was 52 (13 family) and the relative abundance of the bass was 13% of the total, which is the third dominant species in the whole sample. The relative abundance of bass was the highest in the Pyungtak reservoir (60%), whereas the Daechung reservoir showed the lowest abundance (only 3%). Although no significance difference statistically were founded in the relationship between bass abundance and water quality parameters. The reservoir trophic state showed some relationships. As result, the higher abundance was observed in hypertrophic reservoirs that located in the esturine regions compared to other large and medium reservoirs classified as meso- or eutrphic state. In conclusion, bass distribution in the reservoir ecosystem can not be directly explained by water chemistry only but other environmental factors should be considered.

• Applied Chemistry for Engineering
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• v.31 no.4
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• pp.443-451
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• 2020

In this study, the physico-chemical properties and pyrolysis kinetics of livestock mature solid fuel were investigated to know its feasibility as a fuel. Ultimate and proximate analysis results showed that livestock mature solid fuel has high contents of volatile matter (64.94%), carbon (44.35%), and hydrogen (5.54%). The low heating value of livestock mature solid fuel (3880 kcal/kg) was also higher than the standard requirement of solid fuel (3000 kcal/kg). Thermogravimetic analysis results indicated that livestock mature solid fuel has three decomposition temperature regions. The first temperature zone (130~330 ℃) was consisted with the vaporization of extracts and the decomposition of hemicellulose and cellulose. The second (330~480 ℃) and third (550~800 ℃) temperature regions were derived from the decomposition of lignin and additional decomposition of carbonaceous materials, respectively. The activation energy derived from model free kinetic analysis results including Friedman, Flynn-Wall-Ozawa (FWO), and Kissinger-Akahira-Sunose (KAS) methods for the pyrolysis of livestock mature solid fuel was in the range of 173.98 to 525.79 kJ/mol with a conversion rate of 0.1 to 0.9. In particular, the activation energy increased largely at the higher conversion than 0.6. The kinetic analysis using a curve-fitting method suggested that livestock mature solid fuel was decomposed via a multi-step reaction which can be divided into five decomposition steps.