• The Korea Journal of Herbology
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• v.28 no.4
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• pp.63-69
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• 2013

Objectives : The purpose of present study was to investigate the vasorelaxant activities and mechanisms of action of the ethanol extract of P. yedoensis leaf (PYL) on isolated rat aortic rings. Methods : Dried P. yedoensis leaves were extracted 3 times with 100% ethanol for 3 h in a reflux apparatus. Isolated rat aortic rings were suspended in organ chambers containing 10 ml Krebs-Henseleit (K-H) solution. The rings were maintained at $37^{\circ}C$ and aerated with a mixture of 95% $O_2$ and 5% $CO_2$. Changes in their tension were recorded via isometric transducers connected to a data acquisition system. Results : PYL relaxed the contraction of aortic rings induced by phenylephrine (PE, 1 ${\mu}M$) or KCl (60 mM) in a concentration dependent manner. However, the vasorelaxant effects of PYL on endothelium-denuded aortic rings were lower than endothelium-intact aortic rings. And the vasorelaxant effects of PYL on endothelium-intact aortic rings were reduced by pre-treatment with $N{\omega}$-Nitro-L-arginine methyl ester (10 ${\mu}M$), methylene blue (10 ${\mu}M$), 1-H-[1,2,4]-oxadiazolo-[4,3-${\alpha}$]-quinoxalin-1-one (10 ${\mu}M$), tetraethylammonium (5 mM). In addition, PYL inhibited the contraction induced by extracellular $Ca^{2+}$ in endothelium-denuded aortic rings pre-contracted by PE or KCl in $Ca^{2+}$-free K-H solution. Conclusions : These results suggest that PYL exerts its vasorelaxant effects via the activation of Nitric Oxide (NO) formation by means of L-arginine and NO-cGMP pathways and via the blockage of receptor operated calcium channels, voltage dependent calcium channels and calcium-activated potassium channels.

• Korean Journal of Food Science and Technology
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• v.33 no.6
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• pp.737-744
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• 2001

This study was carried to investigate the changes in physical and chemical properties during preparation of Yukwa. Protein content of glutinous rice was decreased during soaking time and acid and pH values were increased while contents of lipid and ash were not changed. Particle size distribution showed thate average particle size of 7 days soaking treatment smaller than those of 3 days and starch damage of glutinous rice flour was increased during soaking time. The major flavor components after soaking were found ethyl ester acetic acid, ethanol, 2-butan -ol, 2-methyl 1-propanol, 1-butanol, 3-methyl 1-butanol and 1-pentanol, propanoic acid. Content of acetic acid and butanoic acid were rapidly increased during soaking time. Results for ratio of storage modulus(G') and loss modulus(G') in glutinous rice flour dough indicated $tan{\delta}$ was increased for a while and decreased as frequency increased. G' value was very similar with G' value after steaming which means rubber-like property while G' and G' value were changed after during storage time. Treatment at $-20^{\circ}C$ had the highest hardness for cutting degree of dough. There was no difference in color value between different water contents. Hardness of Bandegi (sheet) was decreased as water content increased and the highest popping value was obtained at 18% of water contents. Adding 3% soaked bean had higher redness value of Yukwa and lower value in yellowness.

• Journal of the Korean Chemical Society
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• v.37 no.5
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• pp.513-522
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• 1993

The purpose of this study is to optimize the selectivity of mobile phase solvents for separation of 25 phenols in reversed phase liquid chromatography and to accomplish the simultaneous preconcentration and separation of trace phenols from water samples. Phenols used in this study were classified into three groups, chloro-, methyl-, and nitrophenols. Quaternary solvent mobile phases were employed to improve the selectivity. Overlapping resolution maps(ORM) as a statistical simplex techniques was used to predict the optimum solvent system. Additional criterion such as pH and temperature were also investigated. In order to improve the resolution and decrease the analysis time, isoselective multisolvent gradient elution system was employed with ORM-Prism method. The simultaneous preconcentration and separation of trace phenols from water samples were performed by using XAD-2/Dowex 1-X8 tandem column. When the extraction efficiency was evaluated by sampling up to 1 L of distilled water, recovery of the phenols, except phenol, was above 90% and the limit of detection of the phenols was 5 ppb. The XAD-2/Dowex 1-X8 method was superior to C18 cartridge in terms of recovery and selectivity.

• Food Science of Animal Resources
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• v.40 no.4
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• pp.497-511
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• 2020

This study aimed at comparing the storage stability, fatty acids profile, volatile flavor compounds and eating quality of Hanwoo beef longissimus thoracis (LT) muscles between two marbling morphological groups (fineness and coarseness). The 1⁺ grade Hanwoo LT muscles were measured for marbling fleck morphology at the 13^th thoracic vertebrae location by using computerized image analysis. Results reveal that both marbling groups had similar proximate composition (protein, fat, moisture and collagen), color and technological quality traits (p>0.05). However, the coarse marbling group presented greater C18:2n6 and polyunsaturated fatty acids contents compared to the fine marbling group (p<0.05). Furthermore, the fine marbling group presented lower volatile basic nitrogen (VBN) and 2-thiobarbituric acid reactive substance (TBARS) contents compared to the coarse marbling group after 14 d storage (p<0.05). Also, higher amounts of C18:2n6 oxidation-derived volatile compounds such as hexanal and 3-ethyl-2-methyl-1,3-hexadiene, were found in the coarse marbling group. In term of sensory aspects, the finely-marbled group received higher scores of flavor and taste compared to the coarse marbling group (p<0.05). Overall, the marbling flecks morphology partially showed its effects on the storage stability, fatty acids profile and eating quality of the 1⁺ grade Hanwoo beef LT muscle.

• The Journal of the Convergence on Culture Technology
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• v.9 no.6
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• pp.867-873
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• 2023

In this study, for the purpose of standardized quality control of a cold medicine, we simultaneous analyzed four main chemical components of a cold medicine: acetaminophen, caffeine, methyl paraben, and propyl paraben. The sample was subjected to quantitative analysis using high performance liquid chromatography (HPLC), after pretreatment of four components. The experiment was carried out by using Isocratic elution at wavelength of 270nm. Acetonitrile and water (H₂O) were used as a mobile phase at a flow rate of 1.0mL/min in a commercial C18 reversed-phase column. A volume of 10uL cold medicine were injected into the column with column oven temperature at 35℃. As a result of the experiment, the values of Resolution were 4.983, 1.596, 5.519, and 1.678 respectively-well over Rs >1.5, which indicates that the separation of four components were efficient. In addition, value of symmetry factor of the components was 1.056, 1.069, 1.032, and 1.133 respectively, to show its symmetrical stability. The calibration curve of all four components exhibits good linearity with R² >0.9995 to 0.9999. Furthermore, the limit of detection(LOD) were between 0.0118 to 1.5973 mg/mL, while the limit of quantification (LOQ) were between 0.0353 to 4.7919 ㎍/mL with the recovery rate of 79.6% ~ 120.5%. The results of this study showed an efficient quality evaluation of a simultaneous analysis method for cold medicine components.

• Journal of Food Hygiene and Safety
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• v.39 no.2
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• pp.72-82
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• 2024

This study aimed to develop a scientifically and systematically standardized xylooligosaccharide analytical method that can be applied to products with various formulations. The analysis method was conducted using HPLC with Cadenza C₁₈ column, involving pre-column derivatization with 1-phenyl-3-methyl-5-pyrazoline (PMP) and UV detection at 254 nm. The xylooligosaccharide content was analyzed by converting xylooligosaccharide into xylose through acid hydrolysis. The pre-treated methods were compared and evaluated by varying sonication time, acid hydrolysis time, and concentration. Optimal equipment conditions were achieved with a mobile phase consisting of 20 mM potassium phosphate buffer (pH 6)-acetonitrile (78:22, v/v) through isocratic elution at a flow rate of 0.5 mL/min (254 nm). Furthermore, we validated the advanced standardized analysis method to support the suitability of the proposed analytical procedure such as specificity, linearity, detection limits (LOD), quantitative limits (LOQ), accuracy, and precision. The standardized analysis method is now in use for monitoring relevant health-functional food products available in the market. Our results have demonstrated that the standardized analysis method is expected to enhance the reliability of quality control for healthy functional foods containing xylooligosaccharide.

• YAKHAK HOEJI
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• v.39 no.4
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• pp.360-366
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• 1995

1-$\beta$-Methyl carbapenem-2-substituted pyrroudine derivatives. CRB 529 and CRB 550, were synthesized as investigational carbapenem derivatives. It has been reported that the in vitro antibacterial activities of the compounds against G(+) and G(-) bacteria were almost the same or more effective than those of imipenem (IPM) and meropenem (MEPM), and also showed better in vivo efficacy than MEPM and inlipeneni/cilastatin (IPM/CS) against representative G(-) organisms, P. aeruginosa and MRSA organisms, S. aureus. The antibacterial activities, pharmacokinetics and protective efficacy of IPM/CS and CRB 529 and CRB 550 wereconducted after subcutaneous or intravenous administration to mice and rats. The pharmacokinetic parameters of CRB 529 and CRB 550 in mice were as follows: the observed maximal serum concentrations (C$_{max}$) following I.V. administration were 87.5 and 101 $\mu\textrm{g}$/ml for CRB 529 and CRB 550, respectively, and 63.6 $\mu\textrm{g}$/ml for IPM/CS. The half-lives (t$_{1/2}$) were 14.0 and 12.0 n-dn for CRB 529 and CRB 550, respectively, and 14.8 min for IPM/CS. In rats, $C_{max}$ after I.V. administration were 74.0 and 91.8 $\mu\textrm{g}$/ml for CRB 529 and CRB 550, respectively, and 41.2 $\mu\textrm{g}$/ml for IPM/CS. The tissue levels of CRB 529 and CRB 550 and IPM/CS after I.V. administration at a dose of 20 mg/kg decreased by the following order: lung, heart, kindney, liver and spleen for CRB 529, lddney, liver. lung, heart and spleen for CRB 550 and kidney, lung, liver, heart, spleen and brain for IPM/CS. In systemic infection, CRB 529 and CRB 550 showed excellent efficacies against P. aeruginosa and S. aureus (MRSA) at a dose of 5 mg/kg. The PD$_{50s}$ were 0.80, 0.36 mg/kg for CRB 529 and CRB 550, respectively, and 3.22 mg/kg for IPM/CS against P. aeruginosa. The corresponding values against S. aureus (MRSA) were 76.0, 55.3 mg/kg for CRB 529 and CRB 550, respectively, and 146 mg/kg for IPM/CS. In local infection, the antibacterial activities of CRB 529 and CRB 550 were more effective than those of IPM/CS against intrarenal infection with E. coli and P. aeruginosa and also showed as effective as IPM/CS against respiratory tract infection with E. coli and P. aeruginosa at a dose of 5 mg/kg.

• Journal of Ginseng Research
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• v.35 no.3
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• pp.325-330
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• 2011

Red ginseng saponin fraction-A (RGSF-A) contains a high percentage of panaxadiol saponins that were isolated from Korean red ginseng by ultrafiltration. The aim of this study was to elucidate the effects of RGSF-A on the porcine distal left anterior descending (LAD) coronary artery. The relaxant responses to RGSF-A were examined during contractions induced by 100 nM U46619 (9,11-dideoxy-9a,11a-methanoepoxy-prostaglandin F2a), a stable analogue of thromboxane A2. RGSF-A dose-dependently induced biphasic (fast- and slow-) relaxation in the distal LAD coronary artery in the presence of an intact endothelium. The fast-relaxation was quickly achieved in a minute, and then the slow-relaxation was slowly developed and sustained for more than thirty minutes after the administration of RGSF-A. The slow-relaxation had a tendency to be bigger than the fast-relaxation. Fast relaxation induced by RGSF-A was almost blocked by $N_{\omega}$-Nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase synthase inhibitor and 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ), a guanylate cyclase inhibitor. However slow relaxation induced by RGSF-A was only partially inhibited by L-NAME and ODQ. In the endothelium-removed ring, RGSF-A evoked only slowrelaxation to a certain extent. These data suggest that RGSF-A induced both endothelium dependent fast- and slow-relaxation and endothelium independent slow-relaxation in the porcine distal LAD coronary artery. The endothelium dependent fast-relaxation is mediated by the nitric oxide (NO)-cGMP pathway, and the endothelium dependent slow-relaxation is at least partially mediated by the NO-cGMP pathway. However, the endothelium-independent slow-relaxation remains to be elucidated.

• Korean Journal of Food Science and Technology
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• v.26 no.2
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• pp.147-151
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• 1994

Hydrogen donating activities(HDA) of solvent extracts of Hololeion maximowiczii roots which were treated with freeze drying, hot air drying and hot air drying after steam blanching were investigated by the method of ${\alpha},{\alpha}'$-diphenyl-${\beta}$-picrylhydrazyl(DPPH). Hydrogen donating activity of hot air drying after steam blanching group showed the highest activity among three drying methods. Among the extracts of freeze dried root extracted with various solvents, color intensity at 420 nm of aqueous extract was highest, but hydrogen donating activity was shown in order of 50%, ethyl alcohol, methyl alcohol, water extracts. By heating the powder of freeze dried root at $100^{\circ}C$, color intensity of its water extract was decreased until 20 min, thereafter it was increased slowly but hydrogen donating activity was rapidly increased until 30 min. Hydrogen donating activity at the concentration of 6.05 mg/ml of 50% alcohol extract was similar to that of ${\alpha}-tocopherol$ at the concentration of $2{\times}10^{-4}M$. Comparison of hydrogen donating activity of the inner and outer solution after dialysis of water extract showed that the outer solution had a stronger hydrogen donating activity than those of the inner one.

• Korean Journal of Weed Science
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• v.5 no.2
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• pp.175-186
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• 1985

Research situation and recent research activities of the RDA of Korea were reviewed and summarized for rice nurserybed. Sixty five percent of total 784 weed research items were carried out as rice research while only 6 percent was belonged to nurserybed within rice research. The floristic composition based on the degree of dominance significantly affected by herbicide properties, type of nurserybed and seeding itself. Herbicidal phytotoxicity of currently used several herbicides was greatly dependent upon the covering, absorption, germination, and irrigation regimes. The new safening agent "CGA 123 407" (4,6-dichloro-2-phenyl-pyrimidine) permited the safe application of pretilachlor (2-chloro-2',6-diethyl-N-(2-propoxyethyl) acetanilide) as a pre-emergence herbicide without reducing herbicidal efficacy. Several new herbicides, pyrazolate (4-(2,4-dichlorobenzoyl)-1,3-dimethylpyrazol-5-yl-p-toluenesulphonate), SL-49 (1,3-dimethyl-4-(2,4-dichlorobenzoyl)-5-phenacyloxy-pyrazole) MY-93 (S(1-methyl-1-phenethyl)-piperidine-1-carbathioate) and DPX-84 ((methyl 2- ((4,6-dimethoxypyrimidin-2-yl) amino-carbonyl) aminosulfonylmethyl)) benzolate)) performed satisfactorily in terms of safety and herbicidal efficacy for both surface covered and surface pressed nurserybed after herbicide application and thus expected very significant contributions not only for all kind of nurserybeds but also for direct seeding.