• Journal of the Korean Chemical Society
• /
• v.68 no.1
• /
• pp.9-11
• /
• 2024

• Applied Biological Chemistry
• /
• v.35 no.4
• /
• pp.248-253
• /
• 1992

Volatile flavor components of soybean pastes, manufactured with traditional Meju and improved Meju, were extrated by simultaneous steam distillation-extraction apparatus and concentrated at atmosphere press. The concentrates were investigated GC-sniff evaluation by preparative gas chromatograph, and then analyzed and identified by GC/MS and Kovats retention index. Thirty nine components, including 11 alcohols, 4 aldehydes, 2 pyrazines, 4 acids, 3 fuans, 3 phenols, 3 esters, 3 hydrocarbons, 1 ketone, 5 miscellous ones were confirmed in soybean paste manufactured with traditional Meju. Twenty one components, including 4 alcohols, 2 aldehydes, 2 pyrazines, 2 acids, 1 fuan, 2 esters, 1 hydrocarbon, 2 ketones, 4 miscellous ones were confirmed in soybean paste manufactured with improved Meju. Ten components such as 3-methyl-1-butanol, 4-methyl-3-heptanol, trimethyl-pyrazine, 1-octen-3-ol, 2-furancarboxaldehyde, tetramethyl-pyrazine, benzaldehyde, 3-methyl-butanoic acid, naphthalene, 2-ethyl-3-methyl-oxetane were identified together in soybean pastes manufactured with traditional Meju and improved Meju.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.11 no.3
• /
• pp.212-218
• /
• 2001

This study was performed to estimate environmental and biological monitoring of workers exposed to methyl bromide through quarantine fumigation. Airborne methyl bromide and it's metabolites were analyzed by gas chromatography and ion chromatography, respectively. The results are as followings; airborne concentration of methyl bromide(TWA) was $2.08{\pm}1.56ppm$(N=8). Dispersion and setting/degas groups were $0.67{\pm}0.12ppm$(N=2) and $2.54{\pm}1.53ppm$(N=6), respectively. Bromide ion concentration in serum was $23.40{\pm}14.91mg/{\ell}$(N=10) in the exposed workers and $4.74{\pm}0.82mg/{\ell}$(N=21) in the non-exposed workers. Bromide ion concentration in urine was $35.56{\pm}26.89mg/{\ell}$(N=11) in exposed group and $6.62{\pm}2.31mg/{\ell}$(N=21) in non-exposed group. Good correlation was observed between concentration of serum and urine ($r^2$=0.890 p<0.01). No significant correlations of other determinants were observed. Calculated from a regressive curve, the biological half lifes of serum and urine were 10.7 and 5.9 days. In these results, biological monitoring of bromide ion of serum and urine provided useful information for evaluating exposure of workers to methyl bromide, so that an availability of bromide ion of biological samples was showed as biological monitoring indices for methyl bromide.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2011.08a
• /
• pp.214-214
• /
• 2011

The adsorption and reactions of methanol and methyl iodide on ZnO(0001) and ZnO(11-20) single crystal surfaces have been investigated using the temperature programmed desorption (TPD) technique. The interaction of methanol and methyl iodide with ZnO is stronger on the polar ZnO(0001) surface than the non-polar ZnO(11-20) surface. On ZnO(0001), methanol is decomposed to produce formaldehyde and hydrogen. Two desorption features of formaldehyde and hydrogen are observed at around 500 and 580 K. The interaction of methanol and pre-adsorbed hydrogen has been also investigated. The reaction mechanism of methanol on ZnO will be proposed.

• Macromolecular Research
• /
• v.11 no.6
• /
• pp.514-517
• /
• 2003

In the solution polymerizations of methyl methacrylate with (${\alpha}$-diimine)nickel(II)/methylaluminoxane (MAO), we observed effects of the position of two methyl substituents in the ligand on both the activities of the catalysts and the polymer microstructure. ${\alpha}$-Diimine nickel(II) catalysts gave syndiotactic-rich poly(methyl methacrylate) with high molecular weight and narrow molecular weight distribution.

• The Korean Journal of Food And Nutrition
• /
• v.12 no.5
• /
• pp.513-517
• /
• 1999

Theessential oils of anise darkopal lettuce and sweet basils cultivated in Korea were extracted by simulatneous steam distillation and extraction method and were analyzed by GC/MSD. Total 41 com-ponents were identified in essential oils including 11 alcohols, 6 carbonyls 19 hydrocarbons and 5 esters components. The major components were 1,8-cineole linalool $\alpha$-bergamotene $\beta$-elemene methyl chavicol, $\beta$-cubebene methyl cinnamate and eugenol. Darkopal lettuce and sweet basils were rich in linalool(30.1-36.5%) methyl chavicol(8.1-25.5%) and relatively poor in methyl cinnamate(0-2.71%) Anise basil was rich in linalool(28.5%) and methyl cinnamate(23.1%) However methyl chavicol which was known as one of the main components of bisil was not detected.

• Biomolecules & Therapeutics
• /
• v.15 no.1
• /
• pp.46-51
• /
• 2007

Bioassay-directed chromatographic fractionation of an ethyl acetate extract from leaves of sweet potato (Ipomoea batatas L.) afforded six quinic acid derivatives: 3,5-epi-dicaffeoylquinic acid (1), 3,5-dicaffeoylquinic acid (2), methyl 3,5-O-dicaffeoylquinate (3), methyl 3,4-dicaffeoylquinate (4), methyl 4,5-dicaffeoylquinic acid (5),4,5-dicaffeoylquinate (6), and two phenolic compounds: caffeic acid (7) and caffeic acid methyl ester (8) together with three flavonoids: quercetin 3-O-${\beta}$-D-glucopyranoside (9), quercetin 3-O-${\beta}$-D-glucopyranoside, isoquercitrin (10) and kaempferol 3-O-${\beta}$-D-glucopyranoside (11). The structures of these compounds were elucidated by the aid of spectroscopic methods. These compounds were assessed for antioxidant activities using three different cell-free bioassay systems. All isolates except 11 showed potent DPPH and superoxide anion radicals scavenging, and lipid peroxidation inhibitory activities. 3,5-epi-DCQA (1) and methyl quinates (3-5) along with flavonoide 9 were isolated for the first time from this plant.

• Korean Journal of Food Science and Technology
• /
• v.29 no.6
• /
• pp.1144-1150
• /
• 1997

Volatile flavor components of soybean koji kochujang made from a glutinuous rice by improved method were analyzed by using a purge and trap method during fermentation, and identified with GC-MSD. Fifty-six volatile flavor components including 16 alcohols, 15 esters, 7 acids, 4 aldehydes, 5 alkanes, 3 ketones, 1 benzene, 1 alkene, 2 phenol and 2 others were found in improved kochujang. The number of volatile flavor components detected immediately after making kochujang were 32 and increased to 46 components after 30 day of fermentation. The most number 55 of volatile flavor components were found after 90 day of fermentation. Thirty-one kinds of volatile flavor components were commonly found through the fermentation period 9 alcohols such as 2-methyl-1-propanol, ethanol, 3-methyl-1-butanol, 8 esters such as methyl acetate, ethyl acetate, 2-methylpropyl acetate, 3 aldehydes such as butanal, acetaldehyde, furfural and 11 othesrs. Although the various types of peak areas (%) of volatile flavor components were shown in kochujang during the fermentation days, ethanol. ethyl acetate, ethyl butanoate, 2-methylpropyl acetate, 2-methyl-1-propanol and 3-methyl-1-butanol were mainly detected during fermentation. Those might be the major volatile flavor components in kochujang made by improved method. Peak area of ethanol was the highest one among the volatile flavor components at immediately after mashing and 90 day while ethyl acetate showed the highest Peak area after $30{\sim}60$ day of fermentation and 3-methyl-1-butanol showed the highest peak area after $120{\sim}150$ day of fermentation.

• Journal of the Korean Applied Science and Technology
• /
• v.15 no.2
• /
• pp.93-99
• /
• 1998

2-phenyl-N-methyl-1,3-thiazolium perchlorate(PTP)derivatives were synthesized via addition and substitution reactions. PTP was hydrolyzed under aqueous hydrochloride. The structures of the compounds were conformed by N.M.R.,I.R., and elemental analysis.

• Archives of Pharmacal Research
• /
• v.11 no.1
• /
• pp.52-55
• /
• 1988

From the ether soluble alkaloidal fraction of Panax ginseng, 4-methyl-5-thiazoleethanol, norharman and barman were isolated. 4-Methyl-5-thiazoleethanol was isolated for the first time from natural resources.