• Journal of the Korean Chemical Society
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• v.37 no.12
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• pp.1035-1046
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• 1993

Some iron(III)porphyrin complexes were prepared, and identified by the spectroscopic methods. Elution behavior of iron(III)porphyrin complexes was investigated by reversed-phase HPLC. The optimum conditions for the separation of iron(III)porphyrin complexes were examined with respect to flow rate and mobile phase strength. These complexes were successfully separated on NOVA-PAK $C_{18}$ column using methanol / water(95/5) for $[T_pCF_3PP)Fe(R)]$ and methanol / water (98/2) for $[(P)Fe(C_6F_5)]$ as a mobile phase. It was found that these complexes were largely eluted in an acceptable range of capacity factor value ($0{\leq}logk'{\leq}1$). The dependence of the capacity factor (k') on the volume fraction of water in the binary mobile phase as well as the dependence of k' on the liquid-liquid extraction distribution ratio$(D_c)$ in methanol-water / n-pentadecane extraction system showed a good linearity. It means that the retention of iron(III)porphyrin complexes on NOVA-PAK $C_{18}$ column is largely due to the solvophobic effect. Also, there was a good linear dependence of the capacity factor(k') on the column temperature and enthalpy calculated by van't Hoff plot. From these results, it was confirmed that the retention mechanism of iron(III)porphyrin complexes in reversed-phase liquid chromatography was invariant under the condition of various temperature, and the solvophobic binding process exhibited isoequilibrium behavior.

• Korean Journal of Food Science and Technology
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• v.37 no.4
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• pp.678-684
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• 2005

Extraction conditions, spectrometric, and sensory properties of pigment extracts from green discolored garlic (GDG) were studied for development of green index to evaluate degree of green discoloration of garlic. GDG pigments were extracted using polar solvents, such as methanol, ethanol, and water. Methanol with 1% HCl resulted in highest extraction of green pigments. Extraction of pigments was affected by temperature, and extracted pigments were partially destroyed at high temperatures. Optimum conditions for extraction of green pigments were $20^{\circ}C$ for 30 min. Because green pigments are unstable at room temperature, and no method has been reported to evaluate degree of green discoloration of garlic, color chart was designed by mixing varying amounts of control and GDG. High correlation was observed between sensory scores and "a" value of color chart samples (y=-3.465x - 11.676) with $R^2$ of 0.993. Green index (GI) was developed based on linear regression equation between sensory scores and "a" values. Sensory panel recognized green discoloration of garlic at $GI{\geq}3.0$. GI developed in this study could be utilized to evaluate degree of green discoloration of garlic during cold storage and distribution of garlic.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.329-334
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• 2000

Two major oleananesaponins in Bupleuri radix, saikosaponin $\alpha$ and d, were extracted at various solvent compositions and leaching temperatures. Solvent composition was varied at 0 to 100%(v/v) of ethanol-water and methanol-water, whereas leaching temperature was adjusted to te range of 25~45$^{\circ}C$. The most effective extractant and leaching temperature were 70% ethanol and 45$^{\circ}C$, respectively. However, no major differences in saikosaponin content and cAMP phosphodiesterase inhibition were found at various leaching times. The cAMP phosphodiesterase inhibitions were alo the highest when 70% ethanol was used as the extractant.

• Korean Journal of Medicinal Crop Science
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• v.22 no.2
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• pp.147-153
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• 2014

The Ponciri fructus immaturus (Poncirus trifoliata Rafinesque) has been used in oriental medicine for uterine contraction, stomachache, abdominal distension and cardiovascular diseases. Two main compounds, poncirin and naringin were successfully analyzed by high performance liquid chromatography (HPLC) and carried out method validation according to ICH guideline. A successful resolution and retention times were obtained with a $C_{18}$ reversed phase column, at an $1m{\ell}min^{-1}$ flow rate, with a gradient elution of a mixture of methanol, water and acetonitrile. Poncirin and naringin showed good linearity ($R^2$ > 0.999) in relatively wide concentration ranged. The recovery of each compound was 95.81 ~ 101.48% with R.S.D. values less than 1.0%. The application of ultrasound-assisted extraction was shown to be more efficient in extracting poncirin and naringin from Ponciri fructus immaturus. The predicted optimal poncirin and naringin yield were poncirin 2.15%, naringin 1.65% under an extraction temperature of $40^{\circ}C$, an extraction time of 10 min in a solvent of 70% methanol.

• Analytical Science and Technology
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• v.20 no.5
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• pp.442-447
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• 2007

The properties of garlic (Allium sativum L.) are attributed to organosulfur compounds. In this paper, an analytical technique with a rapid and simple sample preparation procedures for determination of diallyl disulfide (DADS) in garlic was reported. The DADS was simply extracted with various solvents (methanol, benzene or tetrahydrofuran) from garlic and prepared for HPLC analysis. From the results, the methanol was select as an optimal extraction solvent. The mobile phase was composed from methanol and water, and the gradient elution mode was applied. 0.61 mg of DADS per g garlic powder can be extracted with methanol. This work offers some advantages over the currently accepted techniques and would be useful for chemical and biological studies of garlic and its products.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.3
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• pp.494-499
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• 2004

This study was investigated the antimicrobial activity of clove extracts according to extraction solvents. The extracts were tested for their antimicrobial activity against several food spoilage microorganisms including Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Salmonella typhimurium and Pseudomonas aeruginosa. The methanol extract showed stronger antimicrobial activities than water extract. However, petroleum ether extract did not show antimicrobial activity. The water extract of clove showed growth inhibition effect against Escherichia coli, Salmonella typhimurium and Staphylococcus aureus, whereas no effect against Bacillus subtilis. The methanol extract of clove extracts showed more sensitive antimicrobial activity in Gram (+) bacteria than in Gram (-) bacteria. The antimicrobial activities were increased with increasing concentration of the clove extract.

• Korean Journal of Food Science and Technology
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• v.28 no.1
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• pp.109-116
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• 1996

The relationship between antioxidant activities and physicochemical properties of several fractions obtained from freeze-dried (FD) coffee were investigated. The nine kinds of fraction were consecutively extracted from FD coffee with solvents in increasing order of polarity, and the higher polarity of the solvent the higher extraction yield of the fraction. The antioxidant activities of the fractions were determined by Rancimat and oven test on edible oils. The antioxidant activities of the fractions increased in the order of acetone>ethanol>methanol>50% methanol/water>water fraction, and the antioxidant activities of them were higher on lard than on soybean oil. The antioxidant activity of each fraction was strongly related to the contents of total phenol, total nitrogen content and acidity, whereas color intensity, reducing power, carboxylic acid content showed little contribution to the activity. All fractions had three peaks maxima at 208, 275 and 324 nm on UV-visible spectra, but the only one at 324 nm was linealy proportional to the antioxidant activities of the fractions.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.55 no.3
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• pp.310-318
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• 2022

Cnidium japonicum a biennial plant belonging to the family Umbelliferae, is a halophyte that grows in high-salinity areas of coastal sand dunes and sandy shores. This study was conducted to investigate the constituents, antioxidant activities, and physiological activities of C. japonicum. Mineral analyses revealed that potassium, sodium, calcium, and magnesium were the most prevalent minerals in C. japonicum. We used 80% ethanol, 80% methanol, and distilled water as solvents to prepare extracts from C. japonicum tissues, and the obtained extraction yields ranged between approximately 26% and 32%. Among the three extracts, the ethanol and methanol extracts had higher total polyphenol and flavonoid levels than the water extracts did. The antioxidant activities of methanol extracts were the highest among the various solvent extracts of C. japonicum as was the elastase/collagenase inhibitory activity. In contrast, the ethanol extract exhibited the highest tyrosinase inhibitory activity. Furthermore, the methanol extract possessed over 80% BACE1 (β-secretase) inhibitory activity at a final concentration of 20 ㎍/mL. Therefore, these results indicate that methanol and ethanol extracts of C. japonicum may be useful as antioxidant and functional substances in food and pharmaceutical material.

• Analytical Science and Technology
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• v.30 no.1
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• pp.20-25
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• 2017

An analytical method for determining potential endocrine disruptors (bisphenol A, 2-chlorophenol, 2,4-dichlorophenol, 2,4,6-trichlorophenol, pentachlorophenol, p-t-butylphenol, p-pentylphenol, p-hexylphenol, p-t-octylphenol, p-heptylphenol, nonylphenol) by solid-phase extraction (SPE) and High Perfomance Liquid Chromatography(HPLC) equipped with fluorescence and variable wavelength detector has been developed. The SPE process for sample concentration was performed on a commercially available Oasis HLB cartridge packed with polymeric sorbents. The effect of elution solvent and elution volume on the recoveries of the analytes were investigated with HPLC. Average recovery of >85% was achieved with 60mg sorbents using 5mL of methanol as elution solvent. Phenolic compounds in canned drinks, beverages and water samples were surveyed by this proposed method.

• Bulletin of the Korean Chemical Society
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• v.32 no.3
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• pp.829-835
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• 2011

A dispersive liquid-liquid microextraction based on solidification of floating organic droplet (DLLME-SFO) has been developed as a new approach for the extraction of trace copper in water and beverage samples followed by the determination with flame atomic absorption spectrometry. In the DLLME-SFO, 8-hydroxy quinoline, 1-dodecanol, and methanol were used as chelating agent, extraction solvent and dispersive solvent, respectively. The experimental parameters related to the DLLME-SFO such as the type and volume of the extraction and dispersive solvent, extraction time, sample volume, the concentration of chelating agent and salt addition were investigated and optimized. Under the optimum conditions, the enrichment factor for copper was 122. The method was linear in the range from 0.5 to $300\;ng\;mL^{-1}$ of copper in the samples with a correlation coefficient (r) of 0.9996 and a limit of detection of $0.1\;ng\;mL^{-1}$. The method was applied to the determination of copper in water and beverage samples. The recoveries for the spiked water and beverage samples at the copper concentration levels of 5.0 and $10.0\;ng\;mL^{-1}$ were in the range between 92.0% and 108.0%. The relative standard deviations (RSD) varied from 3.0% to 5.6%.