• Korean Journal of Medicinal Crop Science
• /
• v.14 no.4
• /
• pp.212-216
• /
• 2006

Root of Scutellaria baicalensis G. was extracted with methanol and water to give the yield of 30.0% in order to find the antioxidant substance. The extract was fractionated with diethyl ether, n-butanol and water to test the inhibitive activity against xanthine oxidase. Three fractions inhibited the activities of xanthine oxidase by 48.2%, 10.2% and 2.8%, respectively, at the amount of $0.1\;{\mu}g$. A component that exhibited strong inhibition of xanthine oxidase was isolated from diethyl ether fraction (SE Fr.) by silica gel column chromatography and HPLC, and then identified by $^1H-NMR$, $^{13}C-NMR$ and MS spectrophotometry. EDA (Electron Donating ability) of the compound was 28.5% at the concentration $100\;{\mu}g/3\;ml$. That was identified to be 3,5,7-trihydroxy-2'-methoxyflavanone by spectrophotometric analysis using $^1H-NMR,\;^{13}C-NMR$ and Mass spectrophotometry.

• Microbiology and Biotechnology Letters
• /
• v.25 no.4
• /
• pp.391-395
• /
• 1997

It was proved that both ethanol extracts from Mori Folium from Kangwon do and silk worm had higher inhibition acitivity on $\alpha$-glucohydrolase than the water extracts. In adding above 8.5 (mg/L) of silkworm extracts, the inhibition rate on $\alpha$-1,4 glucosidase was saturated while the inhibition rate was continuously increased in adding the extracts from Moli Folium. It was also found that the diethyl ether fraction showed much better inhibition activity than water fraction from ethanol extracts, yielding ca. 85% of inhibition rate for the extract of Moli Folium, compared to 91% for a commercially available hypoglycemic drug, Chloropropamide. In separating the diethyl ether fractions by Consecutive Sephadex gel filtration and Thin layer chromatography, three and four active spots were obtained from Moli Folium and silkworm, respectively. It is interesting that the similar Rf spots from both species among several spots in TLC have the highest inhibition acitivity on a target enzyme, which can imply that the active substances from both species are same or similar molecular weight and structure. Glucose-lowering activities of both speciese were also examined in vivo, showing that the fraction from Moli Folium had better activity than that from silkworm, and its activity was similar to that of a commercial drug.

• Journal of the Korean Chemical Society
• /
• v.34 no.4
• /
• pp.352-359
• /
• 1990

An effecient gas chromatographic method is described to be used routinely for the rapid profiling and identification of biochemically important organic acids. It involves the solid-phase extraction of organic acids from aqueous samples using Chromosorb P as the solid sorbent and diethyl ether as the eluting solvent, with subsequent triethylamine treatment. The resulting triethylammonium salts of acids were directly converted to volatile tert-butyldimethylsiyl derivatives, which were simultaneously analyzed by two capillary columns of different polarity, DB-5 and DB-1701, under the identical temperature programming condition. The retention index (RI) and area ratio (AR) values of each peak measured on DB-5 and DB-1701 enabled rapid identification of acids by computer RI library search and AR comparison. The application of the present method to the organic acid profiling of various complex samples is demonstrated.

• Bulletin of the Korean Chemical Society
• /
• v.26 no.1
• /
• pp.139-145
• /
• 2005

Artificial neural networks (ANNs), for a first time, were successfully developed for the modeling and prediction of solvent effects on rate constant of [2+2] cycloaddition reaction of diethyl azodicarboxylate with ethyl vinyl ether in various solvents with diverse chemical structures using quantitative structure-activity relationship. The most positive charge of hydrogen atom (q$^+$), dipole moment ($\mu$), the Hildebrand solubility parameter (${\delta}_H^2$) and total charges in molecule (q$_t$) are inputs and output of ANN is log k$_2$ . For evaluation of the predictive power of the generated ANN, the optimized network with 68 various solvents as training set was used to predict log k$_2$ of the reaction in 16 solvents in the prediction set. The results obtained using ANN was compared with the experimental values as well as with those obtained using multi-parameter linear regression (MLR) model and showed superiority of the ANN model over the regression model. Mean square error (MSE) of 0.0806 for the prediction set by MLR model should be compared with the value of 0.0275 for ANN model. These improvements are due to the fact that the reaction rate constant shows non-linear correlations with the descriptors.

• Analytical Science and Technology
• /
• v.18 no.6
• /
• pp.453-459
• /
• 2005

Phenol compounds in water were simultaneously analyzed by extractive derivatization. Aqueous solution was controlled to pH 13 with sodium hydroxide, and then $500{\mu}L$ of benzoyl chloride was added to the solution. The solution was shaken for 15 minutes and extracted with diethyl ether and then analyzed using GC/MS-SIM. The calibration curves of phenolic compounds in the range of 0.05 to $5.0{\mu}g/mL$ showed a good linearity having the correlation coefficient of $r^2=0.9915$ and standard deviation of ${\leq}8.5%$, respectively. The recoveries by this method ware 58.4-114.0%.

• Applied Biological Chemistry
• /
• v.51 no.3
• /
• pp.228-232
• /
• 2008

In the present study, we investigated the glutathione S-transferase (GST) induction of medicinal plants using a cultured PC12 cells. The methanol extracts of Dendrobium nobile Lindley, Schizonepeta tenuifolia Briquet, Glycyrrhiza uralensis Fischer, Paenoia lactiflora Pall were tested. As the result, exposure of PC12 cells to G. uralensis resulted in the significant induction of GST. On the continuous experiment, G. uralensis was extracted with methanol, ethanol, and acetone. Among these extracts, methanol extracts showed the highest GST induction. The methanol extracts were further fractionated with hexane, diethyl ether, ethyl acetate, and water layer according to the degree of polarity. The diethyl ether layer showed the highest exhibited GST induction on PC12 cells. Based on these results suggest that the extracts of G. uralensis can be applicable for the development of a new antioxidant agent.

• Asian-Australasian Journal of Animal Sciences
• /
• v.13 no.2
• /
• pp.188-191
• /
• 2000

Appetite stimulant ether-soluble neutral extract of a high-grain compound feed was separated into four fractions with an open column of silica gel chromatograph using four carrier solutions containing n-pentane and diethyl ether as 100:0 (Fraction A), 90:10 (Fraction B), 75:25 (Fraction C) and 0:100 (Fraction D). The stimulative effects of the fractions were examined by comparing the intake of hay (with or without the fractions) in two-choice test bioassays with cattle. The Fractions A, B and C of the neutral extract stimulated (p<0.05) hay consumption in cattle, whereas Fraction D had no effect on selective feeding when compared with the control fraction. Furthermore, Fractions A, B and C had higher (p<0.05) feeding stimulative indices (FSI) than that of the Fraction D. The results suggest that chemical stimulants to increase palatability of hay are present in the neutral Fractions A, B and C of high-grain concentrate.

• Environmental Analysis Health and Toxicology
• /
• v.15 no.3
• /
• pp.107-113
• /
• 2000

Chlorophenoxy acids are one of the most useful classes of chlorinated herbicides. Specially 2, 4-D and 2, 4, 5-T were known to endocrine distruptors. In this study, these pesticides in water samples were extracted by liquid-liquid extration at acidic conditions and then derivatization of acidic group was carried out various esterifications using by CH$_3$I/Acetone -K$_2$CO$_3$, H$_2$SO$_4$/MeOH or TFAA/TFE. That result, Sensitivities of TFE derivatized 2, 4-D and 2, 4, 5-T are prior to the others. The recoveries of 2, 4-D and 2, 4, 5-T were 98% and 82% respectively using diethyl ether as an extracting solvent.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.5
• /
• pp.1449-1450
• /
• 2012

• Food Science and Biotechnology
• /
• v.16 no.6
• /
• pp.1055-1059
• /
• 2007

Two monoterpene glucosides, paeoniflorin and albiflorin, in peony (Paeonia lactiflora) were purified from 70% ethanol extract of Paeoniae Radix by diethyl ether washing and n-butanol partition, acetone dissolution, and gradient preparative HPLC. After the whole course of purification, yield of paeoniflorin, albiflorin, and the sum of them were 75.0, 38.8, and 68.7%, respectively, together with the corresponding purity of 96.2, 93.8, and 96.0%.