• Korean Journal of Pharmacognosy
• /
• v.23 no.2
• /
• pp.77-80
• /
• 1992

The essential oils of Elscholtzia ciliata and the cultivated tissue have been studied. The composition and contents of essential oils were identified by gas chromatography and mass spectrometry. The main component of essential oils of E. ciliata was naginata ketone. The essential oils from the flowers, leaves and stems of E. ciliata showed similar patterns of gas chromatogram. In experimental studies on the tissue culture of callus, it has been found that NAA induced higher growth rate and higher content of essential oils than 2, 4-D. The essential oils from the cultivated callus showed different composition from that of mother plants.

• Korean Journal of Food Science and Technology
• /
• v.31 no.5
• /
• pp.1386-1391
• /
• 1999

The methanol extract of Gardenia jasminoides Ellis showed antimicrobial activity against bacteria and yeasts. The extract was successively purified with solvent fractionation, silica gel adsorption column chromatography, Sephadex LH-20 column chromatography, octadecylsilane column chromatography. The purified active substance was isolated by high performance liquid chromatography. The isolated compound was 3,4-dihydroxybenzoic acid which was determined by mass spectrometer, gas chromatograph-mass spectrometer, $^{1}H-nuclear$ magnetic resonance, $^{13}C-nuclear$ magnetic resonance and two-dimensional nuclear magnetic resonance. The content of 3,4-dihydroxybenzoic acid was $32.7\;{\mu}g/g$ in dried fruits of Gardenia jasminoides Ellis.

• Journal of Mushroom
• /
• v.20 no.4
• /
• pp.187-192
• /
• 2022

Wolfiporia cocos is an edible fungus commercially cultivated in Asia. To investigate metabolic changes of W. cocos mycelia under both light and dark culture conditions, gas chromatography mass spectrometry (GC-MS) and high-performance liquid chromatography (HPLC) analyses were performed. In terms of the total amount of sugars, alcohols, amino acids, organic acids, fatty acids, and purines, there no significant differences between the W. cocos mycelia cultivated under light (L) or dark (D) conditions (p < 0.05). However, there were some differences with respect to the production of particular sugars and proteins. The levels of trehalose (L: 17.2 ± 0.3% vs. D: 13.9 ± 1.6%), maltose (L: 0.9 ± 0.1% vs. D: 0.3 ± 0.1%), turanose (L: 0.7 ± 0.2% vs. D: 0.1 ± 0.1%), glutamine (L: 1.6 ± 0.3% vs. D: 0.7 ± 0.2%), and proline (L: 0.3 ± 0% vs. D: 0.1 ± 0%) were all significantly higher under light condition (p < 0.05). In contrast, the levels of galactose (L: 13.7 ± 1.2% vs. D: 17.6 ± 2.0%), aspartic acid (L: 0.6 ± 0.1 % vs. D: 0.9 ± 0.1%), cystathionine (L: 0.6 ± 0.1% vs. D: 0.8 ± 0 %), and malic acid (L: 0.7 ± 0.1% vs. D: 1.2 ± 0.1%) were higher under the dark condition. It is worth noting that the amount of pachymic acid, a pharmaceutically active compound of W. cocos, was 1.68 times greater under the light condition (p < 0.05).

• Journal of the Korean Society of Combustion
• /
• v.4 no.2
• /
• pp.23-33
• /
• 1999

A turbulent non-premixed ethylene flame, which was set up in a vertical wind tunnel, was examined to understand the effect of turbulent mixing on formations of soot and gaseous species in the flames. Temperature and velocity profiles were measured using uncoated thermocouples and LDV system. Gaseous samples were withdrawn by using a water cooled stainless iso-kinetic gas sampling probe. The samples for inorganic compounds and light hydrocarbons were collected with sampling bottles and were analyzed by a gas chromatography. The samples for aromatic hydrocarbons were collected on a sorbent tube and were analyzed on a GC/MS system. Some of main results were followed. CO and $CO_2$ were measured relatively in early part of flame and the concentration of CO was greater than that of $CO_2$ all over the early flame region due to the scavenging of the oxidizing species OH by soot particles. Aromatic hydrocarbons were measured at x/D=122 along the radial direction and main important species were benzene, xylene, toluene, styrene, indene, naphthalene. The peak points of these compounds occurred at r/D=0.8 apart from the center of flame, around in which the concentration of $C_2H_2$ decayed relatively rapidly from the maximum value.

• Journal of Microbiology and Biotechnology
• /
• v.18 no.2
• /
• pp.314-321
• /
• 2008

Acaricidal effects of materials derived from Diospyros kaki roots against Dermatophagoides farinae and D. pteronyssinus were assessed using impregnated fabric disk bioassay and compared with that of the commercial benzyl benzoate. The observed responses varied according to dosage and mite species. The $LD_{50}$ values of the chloroform extract of Diospyros kaki roots were 1.66 and $0.96{\mu}g/cm^2$ against D. farinae and D. pteronyssinus. The chloroform extract of Diospyros kaki roots was approximately 15.2 more toxic than benzyl benzoate against D. farinae, and 7.6 times more toxic against D. pteronyssinus. Purification of the biologically active constituent from D. kaki roots was done by using silica gel chromatography and high-performance liquid chromatography. The structure of the acaricidal component was analyzed by GC-MS, $^1H-NMR,\;^{13}C-NMR,\;^1H-^{13}C$ COSY-NMR, and DEPT-NMR spectra, and identified as plumbagin. The acaricidal activity of plumbagin and its derivatives (naphthazarin, dichlon, 2,3-dibromo-1,4-naphthoquinone, and 2-bromo-1,4-naphthoquinone) was examined. On the basis of $LD_{50}$ values, the most toxic compound against D. farinae was naphthazarin $(0.011{\mu}g/cm^2)$ followed by plumbagin $(0.019{\mu}g/cm^2),$ 2-bromo-1,4-naphthoquinone $(0.079{\mu}g/cm^2)$, dichlon $(0.422{\mu}g/cm^2)$, and benzyl benzoate $(9.14{\mu}g/cm^2)$. Additionally, the skin color of the dust mites was changed from colorless-transparent to dark brown-black by the treatment of plumbagin. Similar results have been exhibited in its derivatives (naphthazarin, dichlon, and 2-bromo-1,4-naphthoquinone). In contrast, little or no discoloration was observed for benzyl benzoate. From this point of view, plumbagin and its derivatives can be very useful for the potential control agents, lead compounds, and indicator of house dust mites.

• International Journal of Automotive Technology
• /
• v.6 no.4
• /
• pp.323-332
• /
• 2005

A cylindrical constant volume combustion chamber was used to investigate the flow characteristics at the spark electrode gap and the combustion characteristics of a homogeneous charged methane-air mixture under various overall charge pressures, excess air ratios and ignition times. The flow characteristics, including the mean velocity and turbulence intensity, were analyzed with a hot wire anemometer. Combustion pressure development measured by piezoelectric pressure transducer, a flame propagation image acquired by ICCD camera and exhaust emissions measured by 2-valve gas chromatography were used to investigate effects of initial pressures, excess air ratios and ignition times on the combustion characteristics. It was found that the mean velocity and turbulence intensity had the maximum value around 200-300 ms and then decreased gradually to a near-zero value after 3000 ms and that the combustion duration was shorten and the flame speed and laminar burning velocity had the highest value under the condition of an excess air ratio of 1.1, an overall charge pressure of 0.15 MPa and an ignition time of 300 ms in the present study. The $CO_2$ concentration was proportional to the ignition time and overall charge pressure, the $CO_2$ concentration was proportional to the excess air ratio, and the UHC concentration was inversely proportional to the ignition time and overall charge pressure.

• The Korean Journal of Pesticide Science
• /
• v.12 no.1
• /
• pp.43-49
• /
• 2008

This study is conducted to determine the potential of zerovalent iron (ZVI), pyrolusite and birnessite to remediate water contaminated with chlorothalonil. The degradation rate of chlorothalonil by treatment of ZVI, pyrolusite and birnessite was much higher in low condition of pH. Mixing an aqueous solution of chlorothalonil with 1.0% (w/v) ZVI, pyrolusite and birnessite resulted in 4.7, 13.46 and 21.38 hours degradation half-life of chlorothalonil, respectively. Dechlorination number of chlorothalonil by treaonent of ZVI, pyrolusite and birnessite exhibited 2.85, 1.12 and 1.09, respectively. Degradation products of chlorothalonil by teartment of pyrolusite and birnessite were confirmed as trichloro-1,3-dicyanobenzene and dichloro-1,3-dicyanobenzene which were dechlorinated one and two chlorine atoms from parent chlorothalonil by GC-mass. Degradation products of chlorothalonil by ZVI were identified not only as those by pyrolusite and birnessite but as further reduced chloro-1,3-dicyanobenzene and chlorocyanobenzene.

• Journal of Korean Society of Forest Science
• /
• v.103 no.2
• /
• pp.211-217
• /
• 2014

A metabolomic study using GC/MS analysis was conducted to identify key metabolic components regulating the growth of open-pollinated Pinus koraiensis families, which were grown for 29 years at three different locations. Among 110 individual metabolites identified, the contents of 62 metabolites were higher in the superior than in the inferior families (p<0.05), together with 22 metabolites, such as phosphoric acid, alanine, glycine, malic acid, and sucrose, being accumulated 1.5-fold higher in the superior families. In addition, 15 metabolites including alanine, malic acid, sucrose, d-turanose, and succinic acid showed positive correlation with the growth (p<0.01). Furthermore, the metabolites, of which contents were correlated with the growth but not significantly changed at different locations, were acetic acid, succinic acid, butanoic acid, glutamic acid, and inositol. Therefore we suggest that several metabolites selected in this study may be used as metabolic markers for quantitative growth trait in P. koraiensis.

• Journal of Microbiology and Biotechnology
• /
• v.23 no.6
• /
• pp.843-849
• /
• 2013

A dye-decolorizing bacterium was isolated from a soil sample and identified as Bacillus thuringiensis using 16S rRNA sequencing. The bacterium was able to decolorize three different textile dyes, namely, Reactive blue 13, Reactive red 58, and Reactive yellow 42, and a real dyehouse effluent up to 80-95% within 6 h. Some non-textile industrially important dyes were also decolorized to different extents. Fourier transform infrared spectroscopy and gas chromatography-mass spectrometer analysis of the ethyl acetate extract of Congo red dye and its metabolites showed that the bacterium could degrade it by the asymmetric cleavage of the azo bonds to yield sodium (4-amino-3-diazenylnaphthalene-1-sulfonate) and phenylbenzene. Sodium (4-amino-3-diazenylnaphthalene-1-sulfonate) was further oxidized by the ortho-cleavage pathway to yield 2-(1-amino-2-diazenyl-2-formylvinyl) benzoic acid. There was induction of the activities of laccase and azoreductase during the decolorization of Congo red, which suggests their probable role in the biodegradation. B. thuringiensis was found to be versatile and could be used for industrial effluent biodegradation.

• Korean Journal of Pharmacognosy
• /
• v.34 no.3 s.134
• /
• pp.246-249
• /
• 2003

The major polysaccharide, named EAP, was purified from the aerial parts of Eclipta alba by Sepharose CL-2B ion exchange chromatography and recycling HPLC. The molecular weight of EAP was estimated to be 20911.9 D by MALDI-TOF MS. In addition, the sugar composition was determined to be arabinose (23.6%), mannose (24.8%), galactose (12.3%), and glucose (41.3%), respectively, by GC analysis. The EAP decreased the blood sugar level, which was induced by alloxan in rats, dose dependently.