• KSBB Journal
• /
• v.19 no.2
• /
• pp.143-147
• /
• 2004

Biodegradation of dimethyl sulfide (DMS) was studied in a batch culture using Gordonia sihwaniensis PKL-1 isolated from a compost biofilter after 100 days of operation for the removal of volatile organic compounds. Optimal pH and temperature for the removal of DMS were 7 and $25^{\circ}C$, respectively. The Michaelis-Menten kinetic constants for DMS removal, $\upsilon_{max}$ and $K_s$, were 0.0016 mg/(mg-protein)ㆍhr, and 8.05 mg/L, respectively.

• Korean Journal of Microbiology
• /
• v.40 no.2
• /
• pp.127-132
• /
• 2004

We isolated 50 strains from sludge of wastewater treatment aeration tank using selective medium for Thio-bacillus sp. by membrane filtration method. They were identified as Thiobacillus neapolitanus (7), T. tepidarius (4), T. dientrificans (5), T. versutus (23), T. intermedius (2) and T. perometabolis (9). We selected Thiobacillus versutus strain KT51, which had the highest removal efficiency (100％) of hydrogen sulfide and the highest removal efficiency (85％) of dimethyl sulfide for 30 min in screen test. Also Thiobacillus versutus strain KT81 had the highest removal efficiency (26％) of dimethyl disulfide for 30 min in screen test. In applification of lab-scale reactor (closed-biological treatment) using Thiobacillus versutus strain KT51, results were 99.8％ (＜0.02 ppm) removal efficiency of hydrogen sulfide for 15 min.

• Proceedings of the Korean Society of Dyers and Finishers Conference
• /
• 2008.10a
• /
• pp.7-8
• /
• 2008

• Journal of the Korean Chemical Society
• /
• v.38 no.5
• /
• pp.377-381
• /
• 1994

New bis-crown ethers containing siloxane chain were synthesized. 1,3-Bis(trimethylsiloxy)-1,3-dimethyl-1,3-dipentaoxacyclohexadecamethyl disiloxane (1) was synthesized by reaction of 3-methylene-16-crown-5 (8) with 1,3-bis(trimethylsiloxy)-1,3-dimethyl disiloxane (10) in the presence of Pt catalyst. 1,1,3,3,5,5-Hexamethyl-1,5-dipentaoxacyclohexadecamethyl trisiloxane (2) was synthesized by the reaction of crown ether (8) with 1,1,3,3,5,5-hexamethyl trisiloxane (11) in the presence of Pt catalyst. 3-Methylene-13-crown-4 (7), 3-methylene-16-crown-5 (8), and 3-methylene-19-crown-6 (9) were synthesized by the reaction of triethylene glycol (3), tetraethylene glycol (4), and pentaethylene glycol (5) respectively with 3-chloro-2-chloro-methyl-1-propene (6) in the presence of NaH.

• Natural Product Sciences
• /
• v.16 no.1
• /
• pp.32-38
• /
• 2010

From the polar fractions of a 70% EtOH extract of the flower buds of Lonicera japonica (Caprifoliaceae), ten constituents were isolated and identified as iridoid glycosides 7-dehydrologanin (7-ketologanin, 2), secologanin dimethyl acetal (3), (E)-aldosecologanin (centauroside, 5), dimethyl secologanoside (6), secoxyloganin (7) and epivogeloside (8). Other identified constituents were 1-O-$\beta$-D-glucopyranosyl-(2S,3S,4R,8E/Z)-2-[(2R)-2-hydroxy(docosanoyl, tricosanoyl, tetracosanoyl, pentacosanoyl)amino]-8-octadecene-1,3,4-triol (1), uracil (4), D-mannitol (9), and sucrose (10). Among them, 1, 2, 4, and 10 were isolated for the first time from this plant.

• Journal of Integrative Natural Science
• /
• v.6 no.4
• /
• pp.197-204
• /
• 2013

The crystal structure of the potential active 4,6-dimethyl-9-phenyl-8,12-dioxa-4,6-diazatetracyclo [8.8.0.02,7.013,18] octadeca-2(7),13,15,17-tetraene-3,5,11-trione 2-ethoxyphenyl (2E)-but-2-enoate ($C_{22}H_{18}N_2O_5$) has been determined from single crystal X-ray diffraction data. In the title compound crystallizes in the monoclinic space group $P_12_1/c_1$ with unit cell dimension a=15.2039(8), b=12.3888(6) and c= 9.8162(5) [alpha & $gamma=90^{\circ}$ beta=98.113(2)]. In the structure fused pyrone and pyran rings each adopt a sofa/envelop conformation. The crystal structure is stabilized by intramolecular C-H... O hydrogen bond interaction.

• Journal of the Korean Chemical Society
• /
• v.45 no.4
• /
• pp.318-324
• /
• 2001

The reaction of 6-chloro-2-hydrazinoquinoxaline(4) or 6-chloro-2-hydrazinoquinoxaline 4-oxide(7) with alkyl (ethoxymethylene)cyanoacetates gave pyrazolylquinoxalines(5, 8). The reaction of compounds 8 with dimethyl acetylenedicarboxylate resulted in the 1,3-dipolar cycloaddition reaction and then ring transformation to afford pyrazolylpyrrolo[1,2-a]quinoxalines(9).

• Korean Journal of Crystallography
• /
• v.9 no.1
• /
• pp.1-5
• /
• 1998

The complex[Cu(L)I2, 2H2O(1) (L:3,14-Dimethyl-2,6,13,17-tetraazatricyclo [14,4,01.18, 07.12]docosane) has been prepared and structurally characterized. The complex (1) crystallizes in the triclinic system, space group P1, a=8.400(1)Å, b=8.986(3) Å, c=9.156(1) Å, α=82.42(1)˚, β=73.61(1)˚ λ=81.04(2)˚, Z=1, R for 1926 observed reflections of [F0>40(F0)], measured at 288K, was 0.042. The tetracoordination around Cu atom of complex(1) is square plane and the average bond distance of Cu-N is 2.029 (11) Å. Both six-membered chelate rings adopts a chair conformation and the five-membered ring are gauche with the sec-NH centers having the RRSS configuration.

• Journal of Integrative Natural Science
• /
• v.8 no.1
• /
• pp.19-29
• /
• 2015

In view of the growing medicinal importance of chromene and its derivatives, the single crystal X-ray diffraction study was carried out for the potential active 4,6-dimethyl-9-phenyl-8,12-dioxa-4,6-diazatetracyclo [8.8.0.02,7.013,18]octadeca-2(7),13,15,17-tetraene-3,5,11-trione-2-ethoxyphenyl (2E)-but-2-enoate ($C_{18}H_{20}N_2O_5$). In the title compound are two molecules exist in the asymmetric unit. It crystallizes in the monoclinic space group $P2_1/c$ with unit cell dimension a=14.608(3) ${\AA}$, b=12.845(3) and c= 17.781(4) [alpha & gamma=$90^{\circ}$ beta=$91.233(5)^{\circ}$]. Both pyran and pyran ring of the chromene moiety adopts sofa conformation in the molecule A & B. The crystal structure is stabilized by intramolecular C-H...O hydrogen bond interaction.

• Journal of Environmental Science International
• /
• v.11 no.8
• /
• pp.783-791
• /
• 2002

A laboratory-scale dual-column biofilter system was used to study the biofiltration of dimethyl disulfide(DMDS). The biofiltration of DMDS was found to depend on the pollutant loadings rather than the inlet concentrations. It was estimated that the pollutant was only inhibitory to the operation of the biofilters at DMDS concentrations greater than 5500 ppmv A residence time of 30 seconds(120 m$^3$/m$^2$/h volumetric loading) was determined as appropriate for efficient operation(>90%). The maximum elimination capacity for both compost mixtures under the current experimental conditions was found to range from 7.5 to 10 g-DMDS/m$^3$/h. A lower DMDS maximum elimination capacity was exhibited under acidified conditions.