• Korean Journal of Food Science and Technology
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• v.22 no.7
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• pp.732-737
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• 1990

In this study, the rutin contents in buckwheat and buckwheat foods were determined. Rutin in buckwheat and buckwheat foods was extracted with methanol and separated by High Performance Liquid Chromatography(HPLC) equipped with Lambda-Max Model 481 detector set at 355 nm using a ${\mu}$ Bondapak $C_{18}$ column and a 2.5% acetic acid:methanol:acetonitrile (35:5:10, v:v:v) solvent. There were differences in the rutin contents among the different species of buckwheat. The rutin contents in buckwheat groats were ranged from 8.84 mg to 24.77 mg/100g. The rutin contents in commercial buckwheat groats and flours were ranged from 15.04 mg to 20.92 mg/100g. The rutin contents in commercial dried buckwheat noodles, steamed buckwheat noodles, and buckwheat cookies were ranged from 1.76 mg to 10.84 mg/100g.

• Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.159-164
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• 2013

The mouse bioassay and high performance liquid chromatography (HPLC) post-column oxidation method are different methods of quantifying paralytic shellfish poisoning toxins. In this study, we compared their ability to accurately quantify the toxicity levels in two types of field sample (oysters and mussels) with different toxin profiles for routine regulatory monitoring. A total of 72 samples were analyzed by both methods, 44 of which gave negative results, with readings under the limit of detection of the mouse bioassay ($40{\mu}g/100g$ saxitoxin [STX] eq). In 14 oysters, the major toxin components were gonyautoxin (GTX) 1, -2, -3, -4, -5, decarbamoylgonyautoxin-2 (dcGTX2), and decarbamoylsaxitoxin (dcSTX), while 14 mussels tested positive for dcSTX, GTX2, -3, -4, -5, dcGTX2, neosaxitoxin (NEO), STX, and dcSTX. When the results obtained by both methods were compared in two matrices, a better correlation ($r^2=0.9478$) was obtained for mussels than for oysters ($r^2=0.8244$). Additional studies are therefore needed in oysters to investigate the differences in the results obtained by both methods. Importantly, some samples with toxin levels around the legal limit gave inconsistent results using HPLC-based techniques, which could have a strong economic impact due to enforced harvest area closure. It should therefore be determined if all paralytic shellfish poisoning toxins can be quantified accurately by HPLC, and if the uncertainties of the method lead to doubts regarding regulatory limits.

• Fisheries and Aquatic Sciences
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• v.16 no.3
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• pp.137-142
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• 2013

To understand critical aspects of paralytic shellfish poisoning (PSP) in a chief area of bivalve production in Korea, seasonal variation in PSP toxins in bivalves collected from Jinhae Bay, Korea in 2009 was surveyed by the pre-column high-performance liquid chromatography oxidation method. We also confirmed the profiles of major bivalves such as oysters Crassostrea gigas and mussels Mytilus galloprovincialis in Jinhae Bay. PSP toxins in the bivalves showed remarkable seasonal variation. PSP toxin levels were detected from April to May in 2009, and the highest total toxin levels at all stations were recorded in May. The major toxins in bivalves were gonyautoxin [GTX] 1&4 and C 1&2; in oysters GTX 2&3 were also detected as major components. GTX 1&4, which showed the highest PSP toxin levels at each station, accounted for the highest proportions of toxin components in mussels and oysters (64.5-71.3% and 41.4-42.4%, respectively). It was also confirmed that the highest toxicity (in ${\mu}g$ saxitoxin [STX] eq/g) was derived from GTX 1&4. The highest total toxicity (in ${\mu}g$ STX eq/g) was approximately 2-8-fold higher in mussels than in oysters collected from the same station. PSP toxin levels in bivalves differed significantly according to the sample collection station. However, the profiles of toxins in the bivalves did not show significant differences during the survey period according to sample collection station. This study shows that PSP toxin levels in some samples from Jinhae Bay were above the regulatory limit in Korea during a specific period in spring.

• Preventive Nutrition and Food Science
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• v.21 no.3
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• pp.208-220
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• 2016

The aim of this study was to investigate the protective effects of juice powders from sweet orange [Citrus sinensis (L.) Osbeck], unshiu mikan (Citrus unshiu Marcow), and mini tomato (Solanum lycopersicum L.), and their major flavonoids, hesperidin, narirutin, and rutin in tert-butyl hydroperoxide (t-BHP)-induced oxidative stress in HepG2 cells. The increased reactive oxygen species and decreased glutathione levels observed in t-BHP-treated HepG2 cells were ameliorated by pretreatment with juice powders, indicating that the hepatoprotective effects of juice powders and their major flavonoids are mediated by induction of cellular defense against oxidative stress. Moreover, pretreatment with juice powders up-regulated phase-II genes such as heme oxygenase-1 (HO-1), thereby preventing cellular damage and the resultant increase in HO-1 expression. The high-performance liquid chromatography profiles of the juice powders confirmed that hesperidin, narirutin, and rutin were the key flavonoids present. Our results suggest that these fruit juice powders and their major flavonoids provide a significant cytoprotective effect against oxidative stress, which is most likely due to the flavonoid-related bioactive compounds present, leading to the normal redox status of cells. Therefore, these fruit juice powders could be advantageous as bioactive sources for the prevention of oxidative injury in hepatoma cells.

• Polymer(Korea)
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• v.26 no.4
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• pp.422-430
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• 2002

The kinetics of polycondensation of bishydroxyethyl naphthalate has been studied in the range of 241 -$260^{\circ}C$ using antimony trioxide catalyst. The reaction was performed in a batch reactor and the concentration of reaction mixture was measured with HPLC. The activation energy values of forward and reverse reaction determined from molecular species model were found to be 19.7 and 31.4 kcal/mole, respectively, and the equilibrium constants were in the range of 1.4-2.0, which were larger than that of polycondensation of PET and varied to some degree with temperature. It was confirmed by applying the Flory's distribution function that the reaction rate of the hyroxyethyl group does not depend on the molecular size. By applying functional group model, we observed that there was few difference between the activation energy of the forward reaction and that of reverse reaction, therefore the equilibrium constant has almost constant value of 1.4. The rate constants obtained from functional group model was about 3-4 times larger than that from molecular species model, which showed that both model explains the reaction system well. Although the molecular species model should predict the concentration of as many as ten molecules, it fits for the experimental results well.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.36 no.4
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• pp.295-301
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• 2010

To develop wrinkle care cosmetic ingredients, various species of plant extracts were investigated. Accordingly, Ligustrum japonicum was selected as a candidate for developing cosmetic ingredient. By high performance liquid chromatography, 31.06 % of oleanolic acid and 8.92 % of ursolic acid which are well-known for anti-wrinkle effect were analyzed. The possibility of Ligustrum japonicum fruits extract (LJE) as a cosmetic ingredient was investigated using several biomarkers related to anti-aging, including anti-wrinkle, moisturizing and anti-inflammation. Procollagen type I and hyaluronan synthase-3 gene expression were increased by LJE in a concentration-dependent manner, whereas elastase activity and matrix metalloproteinase (MMP)-1, MMP-2 and cyclooxygenase-2 gene expression were inhibited. As the results LJE is applicable for a potential cosmetic ingredient focused on anti-aging effect.

• Archives of Pharmacal Research
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• v.18 no.5
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• pp.340-345
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• 1995

A nebumetone tablet in development $(Navuton^R)$ was tested for its bioequivalence to the erference tablet $(Uniton^R)$. Seventeen healthy Korean male subjects participated in this study. Each subject received a 1-g dose of nabumetone (2tables each) in an unbalanced, randomized, two-way crossover investigation. Serum concentrations of 6-methoxy-2-na-phthylacetic acid (6-MNA), a major metabolite of nebumetone, were measured over 120 hr interval by a high-performance liquid chromatography. The maximum serum concentration $(C_{max})$ and time to reach the maximum concentration$(T_{max})$ were read directly, but area under the serum concentration time curve from time 0 to 120 hr (AUC) and mean residence time serum curves showed multiple peaks of 6-MNA in most subjects, and the $C_{max}$ and $T_{max}$ were read from the highest serum peaks. calculated bioavailability parameters for test and reference tablets were 148.6 : 1377.9 $\mug \cdot hr/ml$ for AUC; 25.2:23.1 $\mu/ml$ for $C_{max}$; 11.8:16.4 hr for $T_{max}$, and 42.6 : 43.8 hr for MRT, respectively. The paired t-test revealed no significant differences in all the parameters between the two tablets. Analysis ofl variance (ANOVA) revealed no significant differences between groups and formulations in all the parameters ($C_{max}$ and $T_{max}$, AUC and MRT) indicating the crossover design of the experiment was properly performed. But significant differences (p<0.05) between subject/groups and periods were found for all the parameters indicating substantial intersubject and interperiodic variations for these parameters.

• Archives of Pharmacal Research
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• v.23 no.2
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• pp.182-186
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• 2000

Chondroitin sulfates proteoglycans were isolated from human placenta. For the identification of enzymatic digestion products of isolated proteoglycan, strong anion exchange-high performance liquid chromatography (SAX-HPLC) was performed. By the action of chondroitin ABC and chondroitin B lyase, three unsaturated disaccharides 2-acetamide-2-deoxy-3-O-($\beta$-D-gluco-4-enepyranosyluronic acid)-D-galactose ($\delta$Di-OS), 2-acetamide-2-deoxy-3-O-($\beta$-D-gluco-4-enepyranosyluronic acid)-6-O-su lfo-D-galactose ($\delta$Di-6S) and 2-acetamide-2-deoxy-3-O-($\beta$-D-gl uco-4-enepyranosyluronic acid)-4-O-sulfo-D-galactose ($\delta$Di-4S) were produced from the human placenta proteoglycan. The anticoagulant activity of chondroitin sulfate proteoglycan was evaluated by activated partial thromboplastin time (aPTT) assay and thrombin time (TT) assay. The clotting times of aPTT and TT were increased from 72 to 144 sec and 19 to 27 sec, respectively. The Immune-modulating activity of chondroitin sulfate proteoglycan was examined by cell proliferation assay and these results suggest that it may play a role in suppression of the function of immune-related cells.

• YAKHAK HOEJI
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• v.54 no.3
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• pp.157-163
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• 2010

A high-performance liquid chromatography (HPLC) with DAD detector and electrospray ionization mass spectrometry (ESI-MS) was established for the simultaneous determination of coniferin (1), loganic acid (2), demethylsecologanol (3), sweroside (4) and loganin (5) from caulis Lonicera joponica. The optimal chromatographic conditions were obtained on an ODS column ($5{\mu}m$, $4.6{\times}150mm$) with the column temperature $35^{\circ}C$. The mobile phase was composed of (A) water with 0.1% formic acid and (B) methanol with 0.1% formic acid using a gradient elution, the flow rate was 0.3 ml/min. Detection wavelength was set at 254 nm. All calibration curves showed good linear regression ($r^2$>0.998) within test ranges. The developed method provided satisfactory precision and accuracy with overall intra-day and interday variations of 0.16~3.28% and 0.14~1.99%, respectively, and the overall recoveries of 99.39~105.89% for the five compounds analyzed. The verified method was successfully applied to quantitative determination of the two types (phenolic compounds and iridoids) of bioactive compounds in 24 commercial caulis L. japonica samples from different markets in Korea and China. The analytical results demonstrated that the contents of the five analytes vary significantly with sources.

• Journal of Ginseng Research
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• v.40 no.4
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• pp.382-394
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• 2016

Background: Ginsenosides are the characteristic and principal components which manifest a variety of the biological and pharmacological activities of the roots and rhizomes of Panax ginseng (GRR). This study was carried out to qualitatively and quantitatively determine the ginsenosides in the cultivated and forest GRR. Methods: A rapid and sensitive ultra-high-performance liquid chromatography coupled with diode-array detector and quadrupole/time of flight tandem mass spectrometry (UPLC-DAD-QTOF-MS/MS) was applied to the qualitative analysis of ginsenosides and a 4000 QTRAP triple quadrupole tandem mass spectrometer (HPLC-ESI-MS) was applied to quantitative analysis of 19 ginsenosides. Results: In the qualitative analysis, all ingredients were separated in 10 min. A total of 131 ginsenosides were detected in cultivated and forest GRR. The method for the quantitative determination was validated for linearity, precision, and limits of detection and quantification. 19 representative ginsenosides were quantitated. The total content of all 19 ginsenosides in the forest GRR were much higher than those in the cultivated GRR, and were increased with the growing ages. Conclusion: This newly developed analysis method could be applied to the quality assessment of GRR as well as the distinction between cultivated and forest GRR.