• Bulletin of the Korean Chemical Society
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• v.16 no.4
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• pp.305-309
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• 1995

The enantiomeric separation of several amino acid derivatives by reversed-phase liquid chromatography using two (R)-and (S)-naphthylethylcarbamate-β-cyclodextrin(NEC-β-CD) bonded stationary phases was studied to illustrate the chiral recognition model of the enantiomeric separation. The retention and enantioselectivity of the chiral separations with (R)-and (S)-NEC-β-CD bonded phases were compared with similar separations with the native β-CD stationary phases. Especially, the enantioselectivity and elution orders between the derivatized amino acid enantiomers are carefully examined. These results can be illustrated by the chiral recognition models involving inclusion complexation, π-π interaction, and/or hydrophobic interaction. Inclusion complexation and hydrophobic interaction of the naphthyl group of the NEC moiety seem to be major chiral recognition components in the enantiomeric separation of 2,4-dinitrophenyl amino acids and dabsyl amino acids on (R)-and (S)-NEC-β-CD columns. For dansyl amino acids, only the inclusion complexation is the dominant factor. Three different chiral recognition models containing π-π interaction, inclusion complexation and hydrogen bonding were proposed for the separation of the 3,5-dinitrobenzoyl amino acid enantiomers, depending on the size and shape of amino acids.

• Korean Journal of Agricultural Science
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• v.9 no.1
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• pp.284-302
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• 1982

Development of protein resources as food has been a big issue especially in Southeast Asia region, and intake of protein is also insufficient in Korea. To cope with this shortage of protein resources and its improvement together with increased production of high nutritive animal protein, studies were carried out on feeding of Korean native goats. In the experiments were made absorption of carbohydrate and volatile fatty acid in miniature rumen, and absorption of amino acid in rumen as in vivo were conducted as part of studies on nutritional absorption in rumen. Those nutritional for improvement of feeding and management as described above are summarized as following. 1. According to the result of test on the nutritional absorption of native goat by means of miniature rumen method, absorption ratio of VFA measured at 0.5, 1 and 2 hours after injection of nutrition showed propionic acid 70-86%, acetic acid 74-87%, and lactic acid 76-89%. In the absorption of organic substances, ethyl alcohol of 0.5% showed 29-87% and lactic acid of 0.1M showed 12-27% of absorption ratio. 2. Result of absorption measurement in rumen from L-type free amino acid injection in the content of rumen vein showed lower rate at menthionine-free group compared to whole-egg amino acid injection in the content of rumen vein showed lower rate at methioine-free group compared to whole-egg amino acid group, and high absorption ratio was observed at methionine 3 times group and urea added group. Deficiency of methionine caused no change of the content in mucous membranes. 3. Absorption of amino acid in rumen muscular layer showed equal tendency as in the mucous membrane without exerting any influence of methionine deficiency. At the methionine3-times group, content of methionine and glutamine were increased by 14.7 and 4.4 times as compared to whole-egg amino acid group, an absorption ratio of glutamine, proline and valine were increased at urea added group. 4. In general, concentration of amino acid in rumen vein plasma was lower than in rumen mucous membrane and muscular layer. Absorption ratio of amino acid is decreased due to methionine deficiency, and tripling of methionine or urea adding caused increment of amino acid. Absorption pattern is thus varied depending on the composition of amino acid. 5. At the urea added group, content of ammonia-N, amino-N and urea were increased in rumen muscular layer. As the inside of goat's rumen was unable to clean thoroughly, investigation was made on remaining bacteria, however, variation of ammonia-N was affected by these bacterial content. 6. Variation in rumen structure by differential absorption of amino acid was observed by general microscope and fluorescent microscope. According to the result of observation in the methionine 3 times group, single cylinder epithelium of mucous membrane showed rather thin, and it was thick at urea added group though no significant differences existed among test groups in submucous membrane and muscular layer.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.42 no.3
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• pp.215-223
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• 2009

This study was conducted to investigate the effect of diets supplemented with different levels (0, 2.5, 5.0, and 7.5%) of yuza (Citrus junas Sieb ex Tanaka) on nutritional composition of olive flounder. Four groups of fish (242.2$\pm$14.2 g) were fed to apparent satiation twice daily for 4 months. There were no significant differences in proximate composition among the treatment groups (P<0.05). Vitamin C content in flounder muscle was higher in the yuza-added groups than in the control group, and the content among the treatment groups increased as amount of yuza added to diets increased (P<0.05). Of the eight organic acids in flounder muscle, lactic acid was predominant, followed by oxalic acid, succinic-acid, tartaric acid, and acetic acid. Flounders fed 2.5% yuza diet had the highest lactic acid content of all treatments. Four sugars were found in all groups and glucose was the major sugar. Glucose and ribose were detected as the highest sugars in the 2.5% treatment, while maltose and galactose were the dominant sugars in the 5.0% treatment. The abundant fatty acids in fed flounders were 22:6n-3 (DHA), 16:0, and l8:1n-9, which were composed of over 60% of total fatty acids. The control and the 7.5% treatment group had higher 22:6n-3 (DHA) content than the other groups. Major amino acids in samples were glutamic acid, aspartic acid, lysine, leucine, valine, arginine, and alanine. The 2.5% yuza treatment had the highest content of total amino acids and essential amino acids. There were little differences in the free amino acid compositions among the treatments. However, taurine was the predominant amino acid and made up over 47% of total free amino acids. The 2.5% added yuza group contained higher amount of sweet amino acids such as alanine, serine, proline, glycine than the other groups. The addition of yuza to diet of olive flounder had no or little effect on the nutritional components of olive flounder except for vitamin C. However, the 2.5% yuza added group had the highest nutritional values of the treatment groups.

• Asian-Australasian Journal of Animal Sciences
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• v.11 no.2
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• pp.155-161
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• 1998

This study conducted to evaluate effects of popped soybean on levels of ruminal peptides and blood amino acids in Holstein calves fed sudan grass hay as a forage source and popped (PSB) soybean as a concentrate supplement. At 0, 2, 4 and 6 h after feeding, rumen fluid and blood samples were collected from the rumen and jugular vein, respectively, and amino acids, peptides and other nitrogen-containing compounds in the rumen were analyzed. Ruminal pH tended to be higher in the RSB than in the PSB treatments, and declined upto 4 h after feeding, since then increased in both treatments. The concentrations of ammonia-N in all treatments increased upto 2 h after feeding, and then decreased gradually with time after feeding. The concentrations of ammonia N in the rumen were not significantly different between the treatments, however, those in RSB treatment appeared to be higher. Also, protein concentrations in the rumen were not significantly different between the treatments. Peptide productions were the highest at 2 h after feeding in the group fed RSB which is rapidly degradable in rumen, whereas those in the group fed PSB which is slowly degradable in rumen were maximized at 4 h after feeding. The concentration of total free essential amino acids in plasma was higher in the RSB treatment than in the PSB, but disappearance rates of these amino acids out of plasma was higher in the PSB treatment than in the RSB treatment. Disappearance rates of free non-essential amino acids in plasma were not significantly different between the treatments. Consequently, this study implies that the production of peptide and utilization of blood amino acid may be controlled by the modification of protein degradability.

• Korean Journal of Veterinary Research
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• v.43 no.2
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• pp.219-230
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• 2003

Porcine epidemic diarrhea virus(PED), a member of Coronaviridea, is the etiological agent of enteropathogenic diarrhea in swine. The purpose of this study was to investigate genetic characteristic of PEDV isolated in Korea. Nucleocapsid(N) gene and membrane (M) gene of recent Korean PEDV strains isolated in 2001 were amplified, cloned, sequenced and analyzed. N gene of seven Korean PEDV field isolates bad 94.5% to 99.4% nucleotide and 92.4% to 99.4% amino acid sequence homology each other. Nucleotide and amino acid sequences of Korean field PEDVs were different from published foreign PEDVs, showing 95.1% to 98.0% nucleotide and 93.5% to 97.6% amino acid sequence homology. By phylogenetic tree analysis on based nucleotide sequences, PEDVs were clustered into four groups. By phylogenetic tree analysis based on amino acid sequences. PEDVs were clustered into five groups. M gene of our Korean PEDV field isolates had 99.6% to 100% nucleotide and 98.7% to 100% amino acid sequence homology each other. Nuclotide and amino acid sequences of Korean field PEDVs were different from published foreign PEDVs, showing 98.5% to 98.8% nucleotide and 97.3% to 97.8% amino acid sequence homology. By phylogenetic tree analysis based on nucleotide and amino acid sequences, PEDVs were clustered into two groups which were Korean PEDV isolate group and foreign PEDV isolate group.

• Culinary science and hospitality research
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• v.18 no.2
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• pp.149-161
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• 2012

The purpose of this study is to examine the quality characteristics of lamb stock by different salt contents in it. For this purpose, mechanical tests (color value, pH, sugar content, salinity, amino-acid content) and sensory evaluation (attribute difference test & acceptance) were conducted, showing the following results; Salinity and sugar increased significantly (p<0.01, p<0.001) with salt contents increased. The 0.1% salt addition group contained 32 kinds of free amino-acids, while 0.2% and 0.3% contained 34. 0.4% salt addition group turned out to contain 34 kinds of free amino-acid in it. The amount of the free amino-acid content was also the highest with 0.3% sample group, followed by 0.2%, 0.4%, and 0.1% sample group. In the test group, 9 kinds of essential amino-acid were discovered, and all samples contained histidine and arginine, which were essential in the growth of children. Among all samples, arginine appeared to be the highest in content. Each of the essential amino-acid content varied with statistical significance among the sample groups. In addition, 14 kinds of amino-acids other than the above mentioned were discovered, as well. The 0.3% salt addition group showed the highest 'after taste' value, and the differences among the sample groups were statistically significant(p<0.001). The acceptance test of the lamb stock showed that the flavor and mouth feel did not vary among the sample groups with statistical significance. The control group had the highest value for appearance, measuring scoring 4.32, and the sample group of 0.2% salt addition showed the lowest value of appearance, scoring 3.63. As for the preference on the taste, the highest value of 4.09 came from the 0.3% salt addition group. The differences between the sample groups were statistically significant. Finally, with regard to the overall quality, the 0.3% salt addition group had the highest value of 4.23 while the control group scored the lowest, 3.52. The differences among the samples were statistically significant. The overall result of the study indicated that the optimal rate of salt addition in making lamb stock was 0.3%.

• Asian-Australasian Journal of Animal Sciences
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• v.22 no.8
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• pp.1167-1173
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• 2009

This study was conducted to evaluate the effects of providing fermented soy protein to weaned pigs on nitrogen balance and apparent fecal and apparent ileal digestibility (AID) of AA. Four weaned ((Yorkshire${\times}$Landrace)${\times}$Duroc) barrows (BW = 6.58${\pm}$0.98 kg), surgically fitted with a simple T-cannula approximately 15 cm prior to the ileo-cecal junction, were fed four diets according to 4${\times}$4 Latin square design. Diets were a basal diet supplemented with one of the following: 3% SDPP (spray dried plasma protein), 5% RBP (soy protein fermented by Lactobacillus spp.), 5% PSP (soy protein fermented by Aspergillus oryzae and Bacillus subtilis), and 2.5% RPP (2.5% RBP+2.5% PSP). No differences were observed in DM and N intakes among treatments. However, the level of urine excretion was greater in the RPP group than in the PSP group. Additionally, fecal DM excretion, fecal N concentration and fecal N excretion were increased in the RBP, PSP and RPP groups when compared with the SDPP group (p<0.05). Furthermore, total excretion was increased in the RPP group when compared with the PSP group (p<0.05). In addition, N absorption and the N absorption ratio were higher in the SDPP group than in the RPP group (p<0.05). Moreover, the DM and N digestibilities were lower in the RBP, PSP and RPP groups than in the SDPP group (p<0.05), and the ash and energy digestibilities were higher in the SDPP and RBP groups than in the PSP and RPP groups (p<0.05). However, no significant differences were observed in the DM, N, Ash, Ca, P or ileal digestibilities among treatments, although the energy digestibility was higher in the SDPP group than the RBP group (p<0.05). In addition, the apparent ileal digestibilities of essential amino acids (Arg, His, Iso, Leu, Lys, Phe, Thr, and Val) were significantly higher in the SDPP group than in the other groups (p<0.05), and the levels of Ala, Cys, Glu and Try were greater in the SDPP treatment group than the RBP, PSP and RPP groups (p<0.05). Additionally, the levels of Asp, Gly and Ser were higher in the SDPP group than the PSP and RPP groups, and the level of Pro was higher in the SDPP group than the RPP group (p<0.05). Finally, total non-essential amino acid and total amino acid digestibility were higher in the SDPP group than in the other treatments (p<0.05). Taken together, the results of this study indicate that animal protein is more bioavailable than plant protein. However, the N absorption ratio and ileal digestibility were found to be similar in the SDPP and RBP groups.

• Bulletin of the Korean Chemical Society
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• v.32 no.5
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• pp.1569-1574
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• 2011

The presence of replication-competent adenovirus (RCA) subpopulations in adenoviral vector products raises a variety of safety issues for development of therapies based on gene therapy. To analyze the differing effects of adenoviral vector and RCA in vivo, we examined alterations in amino acids (AAs) using rat plasma following injection of ${\beta}$-galactosidase expressing recombinant adenovirus (designated rAdLacZ) or RCA. Plasma AAs were examined by gas chromatography-mass spectrometry. A total of 16 AAs were positively measured. In the rAdLacZ group compared to the control group, the level of aspartic acid was significantly increased (Student's t-test), while the level of glutamic acid was significantly reduced. Additionally, in the RCA group compared to the control group, the level of four AAs, valine, leucine, and isoleucine as branched-chain amino acids, and proline were significantly increased, whereas the levels of three AAs, glycine, threonine, and glutamic acid were significantly reduced. Altered plasma free AA metabolic patterns in rAdLacZ and RCA groups, compared with the control group, may explain the disturbance of AA metabolism related to viral infection.

• Journal of Veterinary Clinics
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• v.25 no.3
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• pp.139-145
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• 2008

To investigate the genotypic diversity of the porcine reproductive and respiratory syndrome viruses (PRRSV) in Korea, we examined 92 clinical samples from three provinces by RT-PCR and a nested PCR, and the complete open-reading frame 7 (ORF 7) sequences of 15 samples selected from 72 PCR-positive specimens were analyzed. When we compared nucleotide (amino acid) sequences of 80 isolates from Korea and overseas countries, the sequences of 7 samples belonged to North American (NA)-genotype, and those of 8 samples, to European (EU)-genotype. The nucleotide (amino acid) identities between two genotypes were 63.7% (59.8%) to 65.1% (63.1%). When compared with NA prototype VR-2332, the 7 strains of NA-genotype shared 89.8% (93.6%) to 91.2% (96.0%) identity of nucleotide (amino acid) sequence. The 8 strains of EU-type shared 93.6% (92.3%) to 94.3% (93.8%) identity of nucleotide (amino acid) sequence as compared to EU prototype Lelystad. In phylogenetic tree analysis by neighbor-joining method, all of the 8 EU-type strains were clustered into group 4 distinct from ED-prototype Lelystad (group 1). In NA-genotype, 24 domestic isolates reported previously and the 7 strains of NA-type determined in this study were clustered into group 1, while US prototype VR 2332 was classified into different group (group 2). These results suggest that emergence of EU-genotype and the dual-infection of NA- and EU-genotypes may be prevalent in the pig farms in Korea. The high degree of genetic diversity of field PRRSVs should be taken into consideration for control and preventive measures.

• Applied Chemistry for Engineering
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• v.5 no.3
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• pp.517-523
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• 1994

The effects of cure kinetics and mechanism of DGEBA(diglycidyl ether of bisphenol A)/MDA(4,4'-methylene dianiline) with SN(succinonitrile) and HQ(hydroquinone) as an additive and accelerator were investigated. Cure kinetics was evaluated by Kissinger equation and fractional-life method through DSC analysis. The activation energy has hydroxyl group as an accelerator, the activation energy and the starting cure-temperature were lower than those of DGEBA/MDA/SN system. Cure mechanism of those systems was investigated through FT-IR according to the various SN contents. The ratio was SN : HQ = 4 : 1. It has been known that the cure reactions of an epoxy-diamine system are composed of primary amine-epoxy reaction, secondary amino-epoxy reaction and epoxy-hydroxyl group reaction. But in DGEBA/MDA/SN system, primary amino-CN group reaction and CN group-hydroxyl group reaction were added to the above mentioned reactions. These reactions attributed to the long main chain and the low crossliking density. And in DGEBA/MDA/SN/HQ system, hydroxyl group of HQ formed a transition state with epoxide group and amime group and also opened the ring of the epoxide group rapidly, then amino-epoxy reaction took place easily.