• Parasites, Hosts and Diseases
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• v.50 no.2
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• pp.119-126
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• 2012

Carboxylic acids play an important role in both aerobic and anaerobic metabolic pathways of both the snail and the parasite. Monitoring the effects of infection by schistosome on Biomphalaria alexandrina carboxylic acids metabolic profiles represents a promising additional source of information about the state of metabolic system. We separated and quantified pyruvic, fumaric, malic, oxalic, and acetic acids using ion-suppression reversed-phase high performance liquid chromatography (HPLC) to detect correlations between these acids in both hemolymph and digestive gland gonad complex (DGG's) samples in a total of 300 B. alexandrina snails (150 infected and 150 controls) at different stages of infection. The results showed that the majority of metabolite pairs did not show significant correlations. However, some high correlations were found between the studied acids within the control group but not in other groups. More striking was the existence of reversed correlations between the same acids at different stages of infection. Some possible explanations of the underlying mechanisms were discussed. Ultimately, however, further data are required for resolving the responsible regulatory events. These findings highlight the potential of metabolomics as a novel approach for fundamental investigations of host-pathogen interactions as well as disease surveillance and control.

• Korean Journal of Veterinary Service
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• v.31 no.3
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• pp.385-395
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• 2008

This study was carried out to investigate the residue level of fluoroquinolones in hen's general eggs and specific eggs by microbiological assay method and high performance liquid chromatography (HPLC) method. HPLC separation was carried out by reversed phase chromatography on a Symmetry $C_{18}$ (250${\times}$4.6 mm, $5{\mu}m$ particle size) with a phase composed of distilled water (containing 0.4% triethylamine and phosphoric acid) : Methanol (780 : 220, v/v), pumped isocratically at a flow rate of 1.0ml/min. A fluorescence detector was utilized with an excitation wavelength of 278nm and an emission wavelength of 456nm. The calibration curves were linear $({\gamma}^2{\geq}0.999)$ over a concentration range of $0.025{\sim}0.4{\mu}g/ml$. Average recoveries of the five fluoroquinolones in whole eggs at fortified levels of $0.05{\sim}0.2{\mu}g/g$ were ranged mean $78.1{\sim}91.7%$ and low coefficient of variation was less than 10% for all analysed samples. The limits of detection and limits of quantification for whole eggs were $1.2{\sim}6.0ng/g$ and $2.3{\sim}9.1ng/g$, respectively. Only one hen's general eggfrom chicken farm in Incheon was detected with the residual fluoroquinolones (Microbiological assay method; 1 of 47 general eggs) ; the range of residual concentration enrofloxacin was 0.12ppm. Those in food stores were detected with the residual fluoroquinolones (Microbiological assay method; 4 of 88 general eggs) ; the ranges of residual concentration enrofloxacin were $0.15{\sim}2.2 ppm$, ciprofloxacin $0.01{\sim}0.06ppm$, and hen's specific eggs (40) in food stores were not detected. For the microbiological assay method of fluoroquinolones in hen's eggs, as the results of comparative analysis, the disc diffusion method with E coli may be a little highly detected for the residual fluoroquinolones.

• Journal of the Korean Society of Food Science and Nutrition
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• v.36 no.1
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• pp.117-123
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• 2007

HPLC quantifications of fresh and cooked (steamed/microwaved) spinach, one of the most frequently consumed vegetables in foodservice operations, were carried out to determine carotenoids compositions. An S-3 $\mu$m C30 stationary phase for reversed-phase columns with diode-array detection was used to separate and quantify geometric isomers of provitamin A carotenoids in the fresh and cooked spinach. The carotenoids in fresh spinach were identified and quantified: Lutein (63.0%), $\beta$-carotene isomers (all-trans 29.6%, 9-cis 3.2%, 13-cis 1.8%, $\alpha$-carotene 0.4%, zeaxanthin 2.1%) and cryptoxanthin. Cryptoxanthin, detected in a trace amount in HPLC, was not quantified in this study. Lutein was little affected by cooking methods and frozen conditions. 9-cis and 13-cis-$\beta$-carotene isomers were major types formed during cooking. Cooking (steam/microwave) did not alter carotenoid profiles of the samples, but the amounts of carotenoids quantified were greater than those in the fresh samples. Heat treatment such as steaming increased total carotenoids contents, especially trans-$\beta$-carotene (p<0.05). The carotenoid contents of the frozen spinach increased even after the microwaved treatment (p<0.05). These increases were likely to result from the increased extraction efficiency and inactivation of enzymes capable of carotenoids degrading during the heat treatments.

• Applied Chemistry for Engineering
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• v.16 no.5
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• pp.609-613
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• 2005

Daidzein and genistein were extracted from Korean soybean by supercritical $CO_2$ and sub/supercritical water. The extracted sample was analyzed by reversed-phase high performance liquid chromatography (RP-HPLC). The retention time, retention factor, column efficiency, column selectivity and resolution of aglycons were compared with the change in the temperature and pressure of supercritical fluid and ethanol concentration. The characteristics of extraction of daidzein and genistein were more affected by ethanol concentration using supercritical $CO_2$. The most desirable extraction yield was obtained by supercritical $H_2O$ with $400^{\circ}C$ and 250 bar. Generally, the extraction yield of aglycons increased over 10 times using supercritical $CO_2$ than sub/supercritical $H_2O$.

• Korean Journal of Food Science and Technology
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• v.36 no.4
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• pp.537-541
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• 2004

Based on reaction time and substrate molar ratio, structured lipid (SL-corn) was produced at 1:2:2(corn oil/capric acid/CLA) and 4% immobilized lipase from Rhizomucor miehei (RM IM). Reaction was carried out for 24 hr at $55^{\circ}C$ in 1-L stirred-batch reactor. After reaction, 13.3 mol% capric acid and 8.9%, CLA were incorporated into corn oil. Iodine and saponification values of SL-corn were 68 and 202, respectively. Tocopherol content decreased after reaction (about 39%). SL-corn showed more yellowish color than corn oil (p<0.05). Reversed-phase HPLC indicated triacylglycerol species containing capric acid in SL-corn resulted in faster crystallization than that of corn oil.

• Journal of Crop Science and Biotechnology
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• v.11 no.1
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• pp.45-50
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• 2008

Lignans and neolignans are optically active plant secondary metabolites. Research on biosynthesis of lignans has already been advanced especially for the formation of (+) pinoresinol but information on the biosynthesis of 8-O-4'- neolignans is still limited. Moreover, the chemical structure(position of substituents on aromatic rings) and stereochemistry of 8-O-4' neolignans is not clear. Katayama and Kado discovered that incubation of cell-free extracts from E. ulmoides with coniferyl alcohol in the presence of hydrogen peroxide gave (+)-erythro- and (-)-threo- guaiacylglycerol 8-O-4'-(coniferyl alcohol) ether (GGCE)(diastereomeric ratio, 3:2) which is the first report on enzymatic formation of optically active -8-O-4' neolignans from an achiral monolignol. In this aspect, enzymatic formation of guaiacyl 8-O-4' neolignan is noteworthy to clarify its stereochemistry from incubation of coniferyl alcohol with enzyme prepared from Eucommia ulmoides. In this experiment, soluble and insoluble enzymes prepared from E. ulmoides were incubated with 30 mM coniferyl alcohol(CA) for 60 min. The enzyme catalyzed GGCE, dehydrodiconiferyl alcohol(DHCA), and pinoresinol identified by reversed phase HPLC. Consequently, diastereomeric compositions of GGCE were determined as erythro and threo isomer. Enantiomeric composition was determined by the chiral column HPLC. Both enzyme preparations enantioselectively formed (-)-erythro, (+)-erythro and (+)-threo, (-)-threo-GGCEs respectively.

• Journal of Pharmaceutical Investigation
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• v.27 no.4
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• pp.331-335
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• 1997

Xerostomia is caused by organic or functional changes affecting the salivary system at different levels. Patients suffering from xerostomia may also complain of an oral burning sensation, ulceration or soreness, difficulty in swallowing, and poor denture retention. And pilocarpine is administered orally to induce salivary secretion. In Seoul National University Hospital(SNUH) pharmacy, the pilocarpine chewing tablets are prepared and supplied to patients of xerostomia in request of the dental hospital in SNUH. And we tested the salivary flow induction and the dissolution patterns of these products in saliva by a double-blind, sequential cross-over trials to eight healthy human volunteers with placebo. The pilocarpine chewing tablet contained 5 mg of pilocarpine, and placebo consisted of same materials as test drug, but didn't contain pilocarpine. In vivo experiment, all subjects were instructed to chew as 60-80 times/min. Mixed saliva was collected in the ranges of intervals such as 0-2, 2-5, 5-10, 10-15, 15-20, 20-30, 30-45 and 45-60 min after pilocarpine chewing tablet or placebo administration. Saliva volume was measured in each collecting time interval, and saliva pilocarpine concentrations were determined by reversed phase HPLC. The 82.5 percent $(4.13{\pm}0.69\;mg)$ of pilocarpine was extracted from chewing tablets during mastication of 60-80 times per minute for 60 minutes. Among these dissolved amounts, 90 percent was extracted within 20 minutes. The salivary flow rates were more increased in a group who administered pilocarpine chewing tablet at the interval of 5-10, 10-15, 20-30 and 45-60 min rather than a placebo-group, but only extracted amount of pilocarpine at 45-60 min interval is significanly different between two groups (p<0.05). But total amounts of saliva secreted for 1 hour in two group-pilocarpine and placebo treated- were $46.36{\pm}9.72\;ml\;and\;39.09{\pm}7.81\;ml$, respectively, and were not significantly different between two groups.

• The Korea Journal of Herbology
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• v.31 no.3
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• pp.29-35
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• 2016

Objectives : Ijung-tang (IJT) is a traditional herbal formula and has been used to treat digestive diseases such as abdominal pain, vomiting, and diarrhea. IJT consists of four herbal medicines, Ginseng radix, Atractylodis rhizoma alba, Zingiberis rhizoma, and Glycyrrhizae radix et rhizoma, containing various bioactive compounds. Quality assesment of IJT preparations was performed by analytical method for determining marker compounds.Methods : Determination of seven marker compounds in IJT preparations was quantitatively conducted by high-performance liquid chromatography equipped with a diode-array detector. The marker compounds were separated on a reversed-phase C18 column and the analytical method was successfully validated. Chemometric analysis was performed to compare IJT water extracts and commercial IJT granules.Results : Limit of detection and limit of quantification values were in the ranges of 0.093-2.649 μg/mL and 0.283-8.027 μg/mL, respectively. Precisions were 0.30-3.87% within a day and 0.23-2.35% over three consecutive days. Recoveries of the marker compounds ranged from 87.35-107.05%, with relative standard deviation (RSD) values < 6.15%. Repeatabilities were < 1.20% and < 1.71% of RSD value for retention time and absolute peak area, respectively. The results from quantitative analysis showed that the quantities of seven marker compounds of IJT samples varied, as were found in principal component analysis and hierarchical clustering analysis.Conclusions : The analytical method developed in the present study was precise and reliable to simultaneously determine marker compounds of IJT. Therefore, it can be used for the quality assessment of IJT preparations.

• Korean Chemical Engineering Research
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• v.56 no.3
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• pp.376-380
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• 2018

The astaxanthin recovery efficiencies were compared in acetonitrile, acetone, methanol, dichloromethane : methanol (1:3, v/v) and ethylacetate : ethanol (1:1, v/v) as a extraction solvent after the grinding of the H. pluvialis cells. The astaxanthin extraction yield in acetone was 1.13~1.29 times higher than other extraction solvents. It was also found that 96.7% of astaxanthin accumulated in H. pluvialis could be recovered by a single extraction. Since astaxanthin exists mainly as astaxanthin esters in H. pluvialis, a gradient reversed-phase HPLC analysis was carried out for the separation of astaxanthin esters from the extracts of H. pluvialis. Among the astaxanthin inside the H. pluvialis cell, free astaxanthin was 45.9% and astaxanthin esters were the rest.

• Korean journal of food and cookery science
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• v.11 no.3
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• pp.303-308
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• 1995

When we prepared the cooked namul, bugak and kimchi by the leaves of Cedrela sinensis, the changes of quercitrin which was isolated from the leaves of this plant in each preparations were analysed by HPLC. Separation by reversed phase chromatography on u-Bondapak C/Sub 18/ column was achieved by isocratic elution with THF-dioxane-MeOH-HOAc-5％ H/Sub 3/PO/Sub 4/-H/Sub 2/O (145: 125:50:20:2:658). When Kimchi was stored at 5$^{\circ}C$ for 20 days, the content of quercitrin in the methanol extract of Kimchi was 7.21％ and Kimchi at 20$^{\circ}C$ was reduced by 5.78％ (w/w). Contents of quercitrin in the leaves of Cedrela sinensis kimchi obsered to be gradually decreased during storage at 5$^{\circ}C$ and 20$^{\circ}C$. Contents of quercitrin of stored kimchi at 5$^{\circ}C$ was higher than that stored at 20$^{\circ}C$. The contents of quercitrin in Namul and Bugak were 13.06 and 5.03％ (w/w), respectively, which were lower than control.