• The Korean Journal of Food And Nutrition
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• v.16 no.4
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• pp.296-302
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• 2003

First. the purification and analysis of alliin in garlic from different origins by alliin-HPLC determination method were studied. Allinase in garlic was inactivated by heating in boiling water followed by extraction of alliin in garlic with 80% methanol. To remove free amino acids and alliin homologs in garlic, garlic extract was separated by cation exchange column which was packed with amberlite CG-120 resin using 40L d-water as eluent. Alliin in garlic extract was crystallized in a mixture of acetone (50$^{\circ}C$)：H$_2$O：acetic acid=70:29:1 and then recrystallized in a mixture of acetone (50$^{\circ}C$)：H$_2$O：acetic acid=75:24:1. Obtained alliin was identified by melting point. TLC, microscope observation and mass spectrometry. High performance liquid chromatography (HPLC) following pre-column derivatization of cystein derivatives with o-phthaldialdehyde/2-mercaptoethanol has succeessfully been applied to the analysis of various garlics. Each alliic of standard solution and garlic extract was derivatized to isoindole derivative by o-phthaldialdehyde /2-mercaptoethanol and then analyzed by HPLC. Six point calibration was done by using alliin peak area. Lineality was observed at 0 ∼ 1.0mg/ml of alliin concentration. Weighted regression line function was Y=6254X - 256077. By this function, alliin contents in various garlics were 0.34 ∼ 0.73% fresh weight. Second study was designed to evaluate the effects of garlic extracts of various concentrations on the growth of various pathogenes (Eubacterium limonsum, Bacteroides fragilis, Salmonella typhimurium, Salmonella typhi, Shigella sonnei, Kiebsiella pneumoniae, Enterobacter cloacae, Pserdomonas aeruginosa, Escherichia coli). For antimicrobial effects against microorganism, totally minimal inhibition concentrations (MIC) of alliin were from 5,000 to 20,000ppm. MIC of ethanol extract were 1,250 to 10,000ppm.

• Food Science and Preservation
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• v.14 no.6
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• pp.702-708
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• 2007

The effects of pectinase treatment and other processing conditions on juice yield from Rubus coreanus, and physicochemical changes during alcohol fermentation, were investigated. The yield from R. coreanus increased by 8.60% with Pectinex 100L treatment (500 ppm, 30 min) compared to a control group. The soluble solid content in the group fermented at $24^{\circ}Brix$ by addition of sucrose (24B-group), and the group fermented at $8^{\circ}Brix$ by addition of 16% sucrose after 4 days of fermentation (8B-group) decreased to $8.2{\sim}8.3$ and $7.7{\sim}8.0%$ after 10 days of fermentation, respectively, and no significant differences were observed with Pectinex 100L treatment. Initial titratable acidity in the enzyme treatment was slightly higher ($1.18{\sim}1.22%$) than for the control group (1.02%). The initial $L^*$ and $b^*$ values of R. coreanus juice decreased with enzyme treatment, and the $a^*$ value increased, but the color difference (${\Delta}E$) between the control and enzyme treatment gradually decreased with fermentation time. The ethanol contents in the 24B-group and the 8B-group were $16.01{\sim}16.22%$ and $13.29{\sim}13.52%$, respectively, after 10 days of fermentation. The methanol contents in the enzyme treatment and the control were $0.359{\sim}0.404$ and $0.520{\sim}0.604$ mg/mL, respectively, and within standard regulations (1 mg/mL).

• The Korean Journal of Physiology
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• v.24 no.2
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• pp.363-375
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• 1990

The present investigation was performed to purify bombesin-like immunoreactivity (BBS-LI) from the skin of frogs, B. orientalis inhabiting Korea. For extraction of BBS-LI, the fresh skin of 360 g from frogs was immersed in 1,800 ml of 100% methanol and then kept at $4^{\circ}C$ for 5 days. BBS-LI was partially purified by liquid chromatography using an alkaline alumina column followed by a Sephadex G-10 column. BBS-LI was further purified by using sequential HPLC of reversed phase C18 preparation, gel permeation, SP-ion exchange and reversed phase C18 analysis. BBS-LI in fractions of each step was monitored by radioimmunoassay for which bombesin antiserum with a titer of 1 : 188,800 was raised in a guinea pig. Eventually, two different BBS-LI were successfully purified and each BBS-LI showed the following character. 1) BBS-LI was well separated into two peaks in SP-ion exchange HPLC. One (BBS-LI-K1) bound to the column while the other (BBS-LI-K2) did not. 2) BBS-LI-K1, 73.8% of total BBS-LI, was not differentiated from synthetic bombesin in reversed phase C18 analytical and gel permeation HPLC. 3) BBS-LI-K2, 26.2% of total BBS-LI, eluted later than synthetic bombesin in reversed phase C18 analytical HPLC, but it eluted with a retention time identical to that of synthetic bombesin in gel permeation HPLC. 4) The two forms of BBS-LI and synthetic bombesin identically stimulated gastrin release and pancreatic exocrine secretion including volume, protein output and amylase output in anesthetized rats. It is concluded from the above results that the skin of B. orientalis contains two different forms of BBS-LI which are very identical to bombesin immunologically and biologically. In comparison with synthetic bombesin containing 14 amino acid residues, the major form shows quite similar pattern in all HPLC used in the present study, but the minor form exhibits quite different pattern in SP-ion exchange and reversed phase C18 analytical HPLG.

• Applied Chemistry for Engineering
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• v.25 no.1
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• pp.116-120
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• 2014

Light cycle oil (LCO), one of the by-products of the catalytic cracking gasoline manufacturing process, contains a lot of valuable aromatics. In particular, 2,6-dimethylnaphthalene (2,6-DMN) contained in LCO has been becoming important as the basic material of polyethylene naphthalate plastic and liquid crystal polymer, etc. If it were possible to separate and purify the valuable aromatic hydrocarbons (such as 2,6-DMN) from LCO, which have only been used as fuel mixed with heavy oil, it would be very meaningful in terms of the efficient use of resources. We investigated the high-purity purification of 2,6-DMN by the combined method of melt crystallization (MC) and solute crystallization (SC). The enriched DMN isomer mixtures (concentration of 2,6-DMN : 10.43%) recovered from LCO by distillation-extraction combination and the crystal recovered by MC used as raw materials of MC and SC, respectively. The solvent of SC used was a mixture of methanol and acetone (60 : 40 wt%). The crystal of 2,6-DMN with a high-purity of 99.5% was recovered by MC-SC combination. We confirmed that the MC-SC combination was one of the very useful combinations for the high-purity purification of 2,6-DMN contained in the enriched DMN isomer mixtures.

• Korean Journal of Food Science and Technology
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• v.34 no.3
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• pp.505-509
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• 2002

In the course of screening program for VHR DS-PTPase (dual-specificity protein tyrosine phosphatase) from natural sources, Gastrodia elata was selected. One compound showing potent inhibitory activity was isolated by the solvent extraction and column chromatography including silica gel, ODS RP-18, Sephades LH-20, and HPLC. This compound was identified as baicalein by several NMR techniques such as $^1H-NMR$, $^{13}C-NMR$, and DEPT. Baicalein showed selective inhibitory activity against VHR DS-PTPase with $IC_{50}=2.4\;{\mu}M$, and showed cytotoxicity against several human cancer cell lines with an $GI_{50}$ of $5.26{\sim}12.93\;{\mu}g/mL$ range, including, melanoma (LOX-IMVI), lung cancer (NCI H23 and A549), colon cancer (HCT 116 and SW 620), prostate cancer (PC-3), and leukemia (MOLT 4F).

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.5
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• pp.769-777
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• 2004

A Helicobacter pylori urease inhibitor from Rubus coreanus Miquel has been isolated and partially characterized for aiming to Prevent H. pylori growth and decrease harmful accumulation of ammonia in human gastric mucosa. We screened urease inhibitory activities in 519 extracts library prepared by solvent extraction from 173 kinds of edible plants, medicinal herbs, herbs and seaweeds using a colorimetric urease assay system. As results of primary and secondary screening, 70% acetone extract of Rubus coreanus Miquel was selected as potent candidate, showing about 24% inhibitory activity. The acetone extract was sequentially partitioned into RCE/RCWI and RCB/RCW2 layers with ethyl acetate and butanol. The major active component in RCW2, water layer from butanol fractionation was revealed to be peptidic or proteinous substance by inhibitory activity determination after pronase digestion and periodate oxidation. RCW2-IIIc a was isolated by sequential column chromatography on DEAE-Toyopearl 650C, Butrl-Toyopearl 650M and Sephadex LH-20. The isolated urease inhibitor RCW2-IIIc $\alpha$, was highly pure proteinous substance with molecular weight of 13kDa by high-performance gel permeation liquid chromatography. RCW2-IIIc$\alpha$ has about 5 times higher inhibitory activity than 70％ acetone extract, showing high stability against heat treatment and peptic digestion.

• 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.

• Analytical Science and Technology
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• v.19 no.1
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• pp.107-114
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• 2006

Early diagnosis and medical intervention are critical for the treatment of patients with metabolic disorders. A rapid analytical method was developed for simultaneous quantification of organic acids and amino acids in urine without labor-intensive pre-extraction procedure showing high sensitivity and specificity. A new method consisted of simple two-step trimethylsilyl (TMS)-trifluoroacetyl (TFA) derivatization using GC/MS-selective ion monitoring (SIM). Filter paper urine specimens were dried under nitrogen after being fortified with internal standard (tropate) in a mixture of distilled water and methanol. Methyl orange was added to the residue as indicator reagent. Silyl derivative of carboxylic functional group was followed by trifluoroacetyl derivative for amino functional group. N-methyl-N-(trimethylsilyl-trifluoroacetamide) and N-methyl-bistrifluoroacetamide were consecutively added and heated for 15-20 min at $65^{\circ}C-70^{\circ}C$, for TMS-TFA derivative, respectively. This reactant was analyzed by GC/MS-SIM. Linear dynamic range showed 0.001-50 mg with the detection limit of (S/N=3) 10-200 ng, and the quantification limit of 80-900 ng in urine. Correlation coefficient of regression line was 0.994-0.998. When the method was applied to the patients 'urine, it clearly differentiated the normal from the patient with metabolic disorder. The study showed that the developed method could be the method of choices in rapid and sensitive screening for organic aciduria and amino acidopathy.

• Analytical Science and Technology
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• v.21 no.6
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• pp.535-542
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• 2008

A liquid chromatography-electrospray ionization tandem mass spectrometry (LC-ESI/MS/MS) method was developed for the determination and confirmation of clenbuterol in bovine muscle and milk. Clenbuterol and clenbuterol-D9 using as an internal standard in samples were extracted with ethyl acetate after hydrolysis and evaporated to dryness. The extracts were dissolved in 20% methanol and cleaned using HLB solid-phase extraction cartridge. The analytes were detected by LC-ESI/MS/MS on a $C_{18}$ column. Mass spectral acquisition was done in selected reaction monitoring (SRM) in positive ion mode to provide a high degree of sensitivity. Using MS/MS with SRM mode, the transitions (precursor to product) monitored were m/z 277${\rightarrow}$203 for clenbuterol, and m/z 286${\rightarrow}$204 for internal standard. The limits of quantitation (LOQ) and mean recoveries of clenbuterol in bovine muscle were $0.2{\mu}g/kg$ and 84.3~91.1%, respectively. The LOQ and mean recoveries in milk were $0.05{\mu}g/kg$ and 87.7~98.3%, respectively.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.11
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• pp.1610-1616
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• 2016

This study aimed to establish an optimal extraction process and high performance liquid chromatography-ultraviolet (HPLC-UV) analytical method for determination of 3,5-dicaffeoylquinic acid (3,5-DCQA) as a part of materials standardization for the development of a xanthine oxidase inhibitor as a health functional food. The quantitative determination method of 3,5-DCQA as a marker compound was optimized by HPLC analysis using a Luna RP-18 column, and the correlation coefficient for the calibration curve showed good linearity of more than 0.9999 using a gradient eluent of water (1% acetic acid) and methanol as the mobile phase at a flow rate of 1.0 mL/min and a detection wavelength of 320 nm. The HPLC-UV method was applied successfully to quantification of the marker compound (3,5-DCQA) in Aster glehni extracts after validation of the method with linearity, accuracy, and precision. Ethanolic extracts of A. glehni (AGEs) were evaluated by reflux extraction at 70 and $80^{\circ}C$ with 30, 50, 70, and 80% ethanol for 3, 4, 5, and 6 h, respectively. Among AGEs, 70% AGE at $70^{\circ}C$ showed the highest content of 3,5-DCQA of $52.59{\pm}3.45mg/100g$ A. glehni. Furthermore, AGEs were analyzed for their inhibitory activities on uric acid production by the xanthine/xanthine oxidase system. The 70% AGE at $70^{\circ}C$ showed the most potent inhibitory activity with $IC_{50}$ values of $77.01{\pm}3.13{\sim}89.96{\pm}3.08{\mu}g/mL$. The results suggest that standardization of 3,5-DCQA in AGEs using HPLC-UV analysis would be an acceptable method for the development of health functional foods.