• Journal of the Korean Society of Food Science and Nutrition
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• v.44 no.11
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• pp.1682-1686
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• 2015

This study was conducted to establish an HPLC analysis method for determination of marker compounds as part of materials standardization for development of health functional food materials from pear pomace. The quantitative determination method of caffeic acid and chlorogenic acid as marker compounds of pear pomace extract (PPE) was optimized by HPLC analysis using a C18 column ($5{\times}250mm$, $5{\mu}m$) with a 0.2% elution gradient of acetic acid and methanol as the mobile phase at a flow rate of 0.8 mL/min and detection wavelength of 330 nm. The HPLC/UV method was applied successfully to the quantification of marker compounds in PPE after validation of the method with linearity, accuracy, and precision. The method showed high linearity of the calibration curve with a coefficient of correlation ($R^2$) of 0.9999, and limit of detection and limit of quantification were $1.14{\mu}g/mL$ (caffeic acid) and $1.61{\mu}g/mL$ (chlorogenic acid) as well as $4.9{\mu}g/mL$ (caffeic acid) and $4.9{\mu}g/mL$ (chlorogenic acid), respectively. Relative standard deviation values from intra- and inter-day precision were less than 3.1% (caffeic acid) and 4.0% (chlorogenic acid), respectively. Recovery rates of caffeic acid and chlorogenic acid at 12.5, 25, and $50{\mu}g/mL$ were 93.66~106.32% and 97.33~105.68%, respectively. An optimized method for extraction of caffeic acid and chlorogenic acid in PPE was established through diverse extraction conditions, and the validation indicated that the method is very useful for evaluation of marker compounds in PPE to develop a health functional food material.

• The Korean Journal of Mycology
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• v.31 no.3
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• pp.148-154
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• 2003

Extracts from 52 samples of mushrooms were prepared by using water, ethanol and methanol, and then yields and angiotensin I-converting enzyme(ACE) inhibitory activity were investigated. Sample mushrooms contained crude proteins of $7.1{\sim}56.5%$, curde lipids of $0.2{\sim}4.4%$ and carbohydrates of $30.3{\sim}86.6%$. Among 52 samples, the water extract from fruiting body of Pholiota spp. ASI 24027 showed the highest extraction yield of 68%. Water extract of Pholiota spp. ASI 24012 fruiting body had potential ACE inhibitory activity of 66%. The optimal extraction condition of the ACE inhibitor from the fruiting bodyies of Pholiota spp. ASI 24012 was In water at $30^{\circ}C$ for 1 hr and ACE inhibitory activity was 67.6% on the condition with 0.2 mg of $IC_{50}$.

• YAKHAK HOEJI
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• v.57 no.2
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• pp.87-94
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• 2013

An analytical methodology based on solid-space extraction (SPE) with with Bond Elut Certify cartridge (Varian, 130 mg) has been developed for the qualification and quantitation of strychnine in blood. After the elution layer was evaporated, the residue was reconstituted with methanol for GC/MS. Internal standard was used 10 mg/l dextromethorphan. Strychnine is a potent central nervous stimulant and convulsant, and an alkaloid found in seeds of Strychnos nux-vomica. It was used therapeutically to improve circulation and muscle tone in oral or intramuscular doses of 0.05~8 mg. The fatal dose of strychnine for humans is 50~100 mg. A man was found dead lying curled up the corner of the large room in a roof house after the fire fighter opened a locked door inside to put out the fire. The postmortem blood and gastric contents were analyzed for toxicological testing. Strychnine and brucine were detected using GC/MS first in gastric contents extracts. The contents of strychnine was 0.083 mg/l in heart blood, 0.088 mg/l in peripheral blood and 4.0 mg/kg in gastric contents, respectively. Method validation was carried out in terms of linearity, accuracy, precision (intraday, interday) in blood. The assay is linear over 0.05~10 mg/l ($r^2$=0.999). Limit of detection (LOD) and limit of quantitation (LOQ) in blood were determined 0.02 mg/l (S/N=3) and 0.07 mg/l (S/N=10), respectively. Accuracy (bias%) of strychnine with 0.1, 1 and 10 mg/l was 12.0% (n=6), 9.3% (n=6) and 6.9% (n=6), respectively. Intraday precision (CV%) of strychnine with, 0.1, 1 and 10 mg/l were 6.4%, 10.4%, 1.2% (n=6), respectively. Interday precision (CV%) of strychnine with 0.1, 1 and 10 mg/l over three days were 24.0%, 18.5%, 13.8% (n=18), respectively. Relative recovery with 0.1, 1 and 10 mg/l (in blood) were 114.9%, 99.3% and 87.4% (n=6), respectively. The described method can be applied in forensic toxicology to determine strychnine in blood samples.

• Korean Journal of Food Science and Technology
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• v.50 no.1
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• pp.111-116
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• 2018

Roasting process of grains modifies their physicochemical characteristics that affect flavor, color, taste, and textures, as well as composition of bioactive compounds. We roasted oats at different temperatures (150, 200, and $250^{\circ}C$) and for different time periods (15 and 30 min). The polyphenol and flavonoid contents in different solvent extracts (methanol, fermented ethanol, and water) were also investigated. The total polyphenol and flavonoid contents were highest in the methanolic extract (135 mg gallic acid equivalent/g and 29 mg catechin equivalent/g, respectively, at $250^{\circ}C/30min$ roasting) and increased with roasting time and temperature. In addition, the avenanthramides were most abundant as accessed ($266{\mu}g/g$) in the methanolic extract upon roasting at $200^{\circ}C$ for 15 min. The radical scavenging activities, using 2,2-diphenyl-1-picrylhydrazyl and 2,2'-azino-bis-3-ethylbenzothiazoline-6-sulphonic acid scavenging, increased with roasting temperature and time. The roasting process may modify the physicochemical structure of oats, thereby, improving polyphenol extraction and antioxidant activity. The results of this study could be used for the manufacture of foods using roasted oats.

• Journal of the Korean Chemical Society
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• v.63 no.5
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• pp.342-345
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• 2019

The standards for the contents of glyphosate and glufosinate in foods are specific and well categorized. However, the standard of content in animal feeds is relatively inadequate and the classification is insufficient. There is also constant debate about the risk of glyphosate and glufosinate to human health, but the risk to animals has not been well studied. In this study, we established an analytical method in feeds that is estimated to be the path for animals to ingest glyphosate. The solvent extraction was carried out using 25% methanol. After centrifugation, samples were purified using solid phase extraction (SPE) and quantitatively analysed using LC-MS/MS after concentrated. Assessment of validation was conducted through detection limits, accuracy, and precision tests. The detection limits for the established method were 1.8 of ${\mu}g/kg$ of glufosinate and $2.4{\mu}g/kg$ of glyphosate. Accuracy was ranged from 94.4% to 103.4% and precision was range from 1.5% to 7.2%. Glufosinate was detected in one sample ($ND{\sim}8.8{\mu}g/kg$) and glyphosate was detected in all but one sample ($ND{\sim}337.0{\mu}g/kg$) by applying the analytical method to animal feeds (n=13).

• Journal of Life Science
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• v.29 no.1
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• pp.69-75
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• 2019

Rosemary (Rosmarinus officinalis L.) is widely used as a food material. Although various physiological activities of rosemary have been reported, there have been no studies on the physiological activity of solvent extracts with different polarities. Rosemary extracts were obtained by extraction of dried powder using 0%, 25%, 50%, 70%, and 95% ethanol (EtOH) in distilled water, methanol, ethyl acetate, and hexane. As these ratios of EtOH are generally chosen by default and scarcely optimized, we investigated the impact of the composition of EtOH in distilled water on extract-related characteristics, such as DPPH free radical scavenging and ${\alpha}$-glucosidase inhibition, on the differentiation of 3T3-L1 adipocytes and inhibition of tyrosinase. Adipogenesis inhibition was highest at 70% EtOH. DPPH scavenging activity and inhibition of tyrosinase activity were reduced with 50% EtOH in water. However, inhibition of ${\alpha}$-glucosidase activity was higher in 50% EtOH in water. The best solvents in terms of DPPH scavenging activity, inhibition of tyrosinase and ${\alpha}$-glucosidase, and differentiation of adipocytes obtained with different concentrations of EtOH, although a lower similar activities were found with 50% ethanol. Considering the extraction solvents, a ratio of EtOH in water gives different content and constituents of compounds. These differences will give activities inhibition of adipogenesis, tyrosinase, ${\alpha}$-glucosidase activity, and DPPH scavenging activity.

• International Journal of Industrial Entomology and Biomaterials
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• v.5 no.2
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• pp.195-199
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• 2002

In order to find potential anticancer agents, we extracted pheophytin in the silkworm feces from various larval stages by water, chloroform and methanol extraction. The cytotoxicity of the pheophytin extracts of various silkworm feces was measured in the CT-26 cells originated from murine metastatic colon cancer, by dye uptake assay. The cytotoxicity of those pheophytins in 2nd, 3rd and 4th instars was better than remaining larval stages. The in vitro anticoagulant and fibyinolytic activities of ethanol extract from varietal mulberry leaves, mulberry branches and silkworm feces and pheophytin extracts from silkworm feces obtained at various larval stages were evaluated in order to find effective therapeutic drugs for the treatment of myocardial and cerebral thrombosis. The fibrinolytic activity was tested using the activated partial thromboplastin time (APTT) and thrombin time (TT) was measured for blood clotting activity. With regards to the fibrinolytic system, ethanol extracts of silkworm feces were better than varietal mulberry leaves and mulberry branches. The pheophytin extracts from 7th days of 5th instar contained the highest percentage of pheophytin and good fibrinolytic activity.

• Applied Chemistry for Engineering
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• v.21 no.2
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• pp.238-241
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• 2010

The purification of indole from 54.3wt% indole fraction (temperature range of distillate: $250{\sim}255^{\circ}C$) recovered by extraction-distillation combination of coal tar fraction (temperature range of distillate: $240{\sim}265^{\circ}C$) was examined by solute crystallization. The feed consists of eight components such as quinoline, iso-quinoline, indole, quinaldine, 1-methylnaphthalene, 2-methylnaphthalene, biphenyl and phenyl ether. Hexane and an aqueous solution of methanol (50 : 50 vol%) were used as the crystallization solvent and the coolant, respectively. A batch stirred tank of glass material was used as a crystallization apparatus. By increasing the operation temperature and the volume ratio of solvent to feed at initial, the purity of indole increas ed, but yields of indole showed a decreasing tendency. Solute crystallization method using hexane as a solvent was excellent because the purity of 99.3 wt% indole was recovered at the yield of 50% without washing operation.

• Bulletin of the Korean Chemical Society
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• v.31 no.5
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• pp.1143-1148
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• 2010

We investigated the separation of nitrogen heterocyclic compound (NHC) contained in a model coal tar fraction comprising four kinds of NHC [indole (In), quinoline (Q), iso-quinoline (iQ), quinaldine (Qu)], three kinds of bicyclic aromatic compound (BAC) [1-methylnaphthalene (1MN), 2-methylnaphthalene (2MN), dimethylnaphthalene (DMN) mixture with ten structural isomers (DMNs; regarded as one component)], biphenyl (Bp) and phenyl ether (Pe) by liquid membrane permeation (LMP). A batch-stirred tank was used as the permeation unit. An aqueous solution of saponin and n-hexane were used as the liquid membrane and the outer oil phase, respectively. Yield and selectivity of individual NHC was much larger than that of BAC, Bp and Pe. Increasing the initial mass fraction of the saponin to the membrane solution ($C_{sap,0}$) and the initial volume fraction of O/W emulsion to total liquid in a stirred tank (${\phi}_{OW,0}$) resulted in deteriorating the yield of individual NHC, but increasing the stirring speed (N) resulted in improving the yield of each NHC. With increasing $C_{sap,0}$, the selectivity of each NHC based on DMNs increased. Increasing ${\phi}_{OW,0}$ and N resulted in decreasing the selectivity of individual NHC based on DMNs. At an experimental condition fixed, the sequence of the yield and selectivity in reference to DMNs for each NHC was Q > Qu = iQ > In. Furthermore, we compared LPM method with methanol extraction method in view of the separation efficiency (yield, selectivity) of NHC.

• YAKHAK HOEJI
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• v.57 no.5
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• pp.330-336
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• 2013

"The Act on Medication Treatment of Sexual Impulse of Sex Offenders" known as chemical castration has been effective since July 2011 in Korea. According to the law, monitoring of male sex hormone in urine is enforced to request National Forensic Service more than once a month after injection of medicine designed to reduce sex impulse. We established a rapid and sensitive method for the monitoring of testosterone (T) and epitestosterone (E) in human urine by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Three mL of urine was pretreated by solid-phase extraction for purification and performed enzymatic hydrolysis. The pretreated samples were extracted twice with 2 ml of ethyl acetate and n-hexane (2 : 3). The separation was applied on Thermo Hypersil GOLD C18 column ($1.9{\mu}m$, $100{\times}2.1mm$). A gradient elution of methanol and water of 0.1% formic acid were used as mobile phase and the retention time was less than 10 min. LC-MS/MS system coupled with an electrospray ionization source was performed in multiple reaction monitoring mode. The transitions of the analytes executed as following: m/z $289{\rightarrow}97$, 109 for T and E, m/z $292{\rightarrow}109$ for $T-d_3$ and $E-d_3$ as internal standards. The validation results of the method were satisfactory. The limits of detection were 0.05 ng/ml and the limits of quantification were 0.1 ng/ml. This method was successfully applied to real human urine sample. The developed method will be useful for monitoring T/E ratio in urine of sex offenders.