• Title/Summary/Keyword: 2-dimethyl-3

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Uptake of the Fresh and Aged Residues of Carbofuran by Rice Plants from Soil (침투성(浸透性) 살충제(殺蟲劑) Carbofuran 토양(土壤) 잔류물(殘留物)의 벼에 의(依)한 흡수(吸收))

  • Lee, Jae-Koo;Kyung, Kee-Sung;Wheeler, W.B.
    • Korean Journal of Environmental Agriculture
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    • v.8 no.2
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    • pp.103-118
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    • 1989
  • In order to investigate the uptake of the systemic insecticide, carbofuran, 2,3-dihydro-2,2-dimethyl-7-benzofuranyl-N-methyl(arbamate) residues, fresh and aged, by rice plants, they were grown for 42 days in soils containing freshly treated (T-1), 3-month-aged (T-2), and 6-month-aged residues (T-3). The amounts of $^{14}CO_2$ evolved from $^{14}C-carbofuran$ during the 3-and 6-month aging in soil (temp. $22{\pm}1^{\circ}C$ ; moisture, 50% of the maximum water-holding capacity) were 8.9 and 26.7% of the original radioactivity applied, respectively. Mineralization of $^{14}C-carbofuran$ in soil to $^{14}CO_2$ during 42 days of rice growing was 4.4% (T-1), 11.0% (T-2), and 15.7 (T-3). The methanol extract of the 3-and 6-month-aged soils revealed that 3-keto carbofuran phenol (2,3-dihydro-2,2-dimethyl-3-oxo-7-benzofuranol) was the major metabolite, where as 3-hydroxy carbofuran (2,3-dihydro-2,2-dimethyl-3-hydroxy-7-benzofuranyl-N-methylcarbamate) turned out to be the major metabolite in the shoots by the enzymatic cleavage of the possible conjugate present in the methanol extract. Volatilization of $^{14}C-carbofuran$ in soil during 3-and 6-month-aging, and 42 days of rice growing was 0.026, 0.05, and 0.012-0.018% of the applied radioactivity, respectively. The $^{14}C-radioactivity$ which was absorbed from the soils by rice plants during 42 days of the growing period and persisted in rice plant tissues was 26.8, 21.4, and 10.3% in T-1, T-2, and T-3, respectively. The non-extractable bound residues were 8.3, 37.9, and 54.6% of the originally applied carbofuran in T-1. T-2, and T-3, respectively. The small translocation of $^{14}C-radioactivity$ in T-3 upwards suggests that major metabolite 3-keto carbofuran phenol is conjugated in roots and the low recovery in T-1 indicates the loss of carbofuran from the shoots.

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Effects of Achyranthoside C Dimethyl Ester on Heme Oxygenase-1 Expression and NO Production (Heme Oxygenase-1 발현과 NO 생성에 미치는 Achyranthoside C Dimethyl Ester의 효과)

  • Bang, Soo Young;Song, Ji Su;Moon, Hyung-In;Kim, YoungHee
    • Journal of Life Science
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    • v.25 no.9
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    • pp.976-983
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    • 2015
  • Achyranthoside C dimethyl ester (ACDE) is an oleanolic acid glycoside from Achyranthes japonica which has been used in traditional medicine for the treatment of edema and arthritis. In this study, we investigated the anti-inflammatory effects of ACDE in RAW264.7 macrophages. ACDE significantly induced heme oxygenase-1 (HO-1) gene expression in RAW264.7 cells, while ACDE improved LPS-induced toxicity of cells. And ACDE induced nuclear translocation of nuclear factor E2-related factor 2 (Nrf2), a transcription factor that regulates HO-1 expression. Further study demonstrated that ACDE-induced expression of HO-1 was inhibited by inhibitors of phosphatidylinositol 3-kinase (PI-3K) (LY294002), c-Jun kinase (JNK) (SP600125), extracellular signal regulated kinase (ERK) (PD98059) and p38 kinase (SB203580). Moreover, ACDE phosphorylated Akt, JNK, ERK, and p38 MAPK. In addition, ACDE inhibited LPS-induced NO secretion as well as inducible NO synthase (iNOS) expression in a dose-dependent manner. The inhibitory effects of ACDE on iNOS expression were abrogated by small interfering RNA (siRNA)-mediated knock-down of HO-1. Therefore, these results suggest that ACDE suppresses the production of pro-inflammatory mediator such as NO by inducing HO-1 expression via PI-3K/Akt/MAPK-Nrf2 signaling pathway. These findings could help us to understand the active principle included in the roots of A. japonica and the molecular mechanisms underlying anti-inflammatory action of ACDE.

Syntheses and Reactivites with Olefins of Ruthenium(IV) Oxo/Ruthenium(II)-Aqua Complexes that Contain 2,6-Bis(N-pyrazolylpyridine)

  • Jo, Du-Hwan;Yeo, Hwan-Jin
    • Bulletin of the Korean Chemical Society
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    • v.14 no.6
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    • pp.682-686
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    • 1993
  • The syntheses and reactivities with olefins of $[Ru^{II}(L_3)(L_2)OH_2]^{2+}$ $[L_3$= 2,6-bis(N-pyrazolyl)pyridine(bpp), 2,6-bis(3,5-dimethyl-N-pyrazolyl)pyridine $(Me_4bpp);\;L_2$= 2,2'-bipyridine(bpy), 4,4'-dimethyl-2,2'-bipyridine $(Me_2bpy)$] are described. Their spectral and redox properties in aqueous solution were investigated. Evidence for each one electron redox process for the $Ru^{IV}-Ru^{III}$ and $Ru^{III}-Ru^{II}$ couples has been obtained. Oxidation of $[Ru^{II}(bpp)(bpy)OH_2]^{2+}$ with $Ce^{IV}$ gave $[Ru^{IV}(bpp)(bpy)O]^{2+}$. The $[Ru^{IV}$= 0 complex is paramagnetic $({\mu}_{eff}=2.82)$ and the complexes $[Ru(L_3)(L_2)OH_2]^{2+}$ are robust catalysts for the oxidation of styrene, cyclohexene, and cyclooctene with cooxidant such as NaOCl. Product distributions and selectivities are discussed by varying the number of the substituted-methyl group in the ring.

Cirsiumaldehyde from Gastrodia elata

  • YunChoi, Hye-Sook;Pyo, Mi-Kyung;Park, Kyung-Mi
    • Natural Product Sciences
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    • v.3 no.2
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    • pp.104-105
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    • 1997
  • In the course of continous work on tubers of Gastrodia elata, a new constituent was isolated from the ethyl acetate soluble fraction prepared from the methanol extract. The structure of the compound was identified as ${\alpha},{\alpha}'-[bis-2-(5-carboxaldehydo)furanyl]-dimethyl$ ether from the elemental analytical and spectroscopic data. This compound was once isolated from Cirsium chlorolepis and named as cirsiumaldehyde. This is the first furan type compound isolated from Gastrodia elata.

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Catalytic Dehydration of Methanol to Dimethyl Ether (DME) over Solid-Acid Catalysts

  • Jun, Ki-Won;Lee, Hye-Soon;Rho, Hyun-Seog;Park, Sang-Eon
    • Bulletin of the Korean Chemical Society
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    • v.23 no.6
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    • pp.803-807
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    • 2002
  • The conversion of dimethyl ether(DME) has been carried out over $\gamma-alumina$, silica-alumina, and modified $\gamma-aluminal$ catalysts. Especially, the water effect has been investigated on purpose to develop a suitable catalyst for one-step synthesis of DME from $CO_2$ hydrgenation, The $\gamma-Al_2O_3$ modified with 1 wt% silica is more active and less deactivated by water than unmodified one. $CO_2has$ no effect on catalytic dehydration of methanol to DME.

Photocatalytic Degradation Mechanism of Methyl Mercaptan using $TiO_2$ (TiO$_2$를 이용한 메틸메르캅탄의 광촉매 분해메커니즘)

  • Lee, Byung-Dae;Lee, Jin-Shik;Kim, Yeoung-Chan
    • Journal of the Korean Applied Science and Technology
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    • v.24 no.3
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    • pp.296-300
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    • 2007
  • This paper presents applicability of photocatalytic decomposition of methyl mercaptan using $TiO_2$. A quartz reactor was used in order to elucidate reaction pathway in photocatalytic decomposition of methyl mercaptan. Experimental results showed that more than 99.9% of methyl mercaptan was decomposed within 30 minutes. It was found that the photocatalytic decomposition of methyl mercaptan followed pseudo first order and its reaction coefficient was $0.05min^{-1}$ During 30 minutes in the photocatalytic reaction, the concentration of methyl mercaptan, dimethyl disulfide, $SO_2$, $H_2SO_4$, COS, $H_2S$ were determined. These results showed that 64% of methyl mercaptan were compensated for the increase in sulfur after 30 minutes through the mineralization. The proposed main photocatalytic decomposition pathway of methyl mercaptan was methyl $mercaptan{\rightarrow}dimethyl$ $disulfide{\rightarrow}SO_2{\rightarrow}H_2SO_4$.

Synthesis and Characterization of Two Different 1,3-Dithiole-2-thiones as the Precursors of TTF Donor Molecule (TTF 주게분자의 전구체로서 두 가지 다른 1,3-Dithiole-2-thione 화합물의 합성 및 특성화)

  • Kim, Young-Youn;Lee, Ha-Jin;Namgoong, Sung Keon;Hong, Jong-Ki;Noh, Dong-Youn
    • Journal of the Korean Chemical Society
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    • v.44 no.6
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    • pp.513-517
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    • 2000
  • As a precursor of tetrathiafulvalene (TTF) derivative, 5,6-dimethyl-1,3-dithiolo[4,5-b][1,4]dithiin-2-thione (compound 3) was synthesized by the unusual Lawesson's reaction. Depending upon the substituents such as dimethyl and diphenyl groups, two different products containing 1,4-dithiin and thiophene moieties, respectively, were obtained and characterized by $^{13}C$ NMR and high-resolution electron impact (HREI) mass spectroscopy. The formation of 3 was further characterized by X-ray structure analysis. Crystallographic data for 3: triclinic, space group P1, a=4.145(2)$\AA$, b=10.600(2)$\AA$, c=12.279(2)$\AA$, $\alpha$=71.440(10)$^{\circ}$, $\beta$=84.30(2)$^{\circ}$, $\gamma$=87.31(2)$^{\circ}$, Z=2 and R(wR$_2$)=0.0559(0.1416). The formation mechanism of two products was suggested and compared each other.

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Atomic Layer Deposition of Al2O3 Thin Films Using Dimethyl Aluminum sec-Butoxide and H2O Molecules

  • Jang, Byeonghyeon;Kim, Soo-Hyun
    • Korean Journal of Materials Research
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    • v.26 no.8
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    • pp.430-437
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    • 2016
  • Aluminum oxide ($Al_2O_3$) thin films were grown by atomic layer deposition (ALD) using a new Al metalorganic precursor, dimethyl aluminum sec-butoxide ($C_{12}H_{30}Al_2O_2$), and water vapor ($H_2O$) as the reactant at deposition temperatures ranging from 150 to $300^{\circ}C$. The ALD process showed typical self-limited film growth with precursor and reactant pulsing time at $250^{\circ}C$; the growth rate was 0.095 nm/cycle, with no incubation cycle. This is relatively lower and more controllable than the growth rate in the typical $ALD-Al_2O_3$ process, which uses trimethyl aluminum (TMA) and shows a growth rate of 0.11 nm/cycle. The as-deposited $ALD-Al_2O_3$ film was amorphous; X-ray diffraction and transmission electron microscopy confirmed that its amorphous state was maintained even after annealing at $1000^{\circ}C$. The refractive index of the $ALD-Al_2O_3$ films ranged from 1.45 to 1.67; these values were dependent on the deposition temperature. X-ray photoelectron spectroscopy showed that the $ALD-Al_2O_3$ films deposited at $250^{\circ}C$ were stoichiometric, with no carbon impurity. The step coverage of the $ALD-Al_2O_3$ film was perfect, at approximately 100%, at the dual trench structure, with an aspect ratio of approximately 6.3 (top opening size of 40 nm). With capacitance-voltage measurements of the $Al/ALD-Al_2O_3/p-Si$ structure, the dielectric constant of the $ALD-Al_2O_3$ films deposited at $250^{\circ}C$ was determined to be ~8.1, with a leakage current density on the order of $10^{-8}A/cm^2$ at 1 V.

The Estimation of Harmful Air Pollutant Emission from Landfill Site - A Subject of Sulfide Compounds - (쓰레기매립장에서의 유해대기오염물질 배출특성에 관한 연구 - 황화합물을 대상으로-)

  • 노기환;전의찬
    • Journal of environmental and Sanitary engineering
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    • v.16 no.1
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    • pp.47-52
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    • 2001
  • In this study, we focused on typically problematic sulfide compounds Gas samples were captured at Unjung-ding landfill site in Metropolitan Kwangju with flux chamber and floating chamber, and analyzed for the amount of hydrogen sulfide($H_2S$), dimethyl sulfide $((CH_3)_2S)$ and dimethyl disulfide$((CH_3)_2S_2)$. From the gas pipe, landfill surface and leachate treatment plant, estimated total amount of $H_2S$ emission are 12.6ton/yr, 0.01ton/yr and 1.04ton/yr; estimated total amount of $((CH_3)_2S)$ 30.7ton/yr, 0.08ton/yr and 1.72ton/yr; and estimated total amount of ($((CH_3)_2S_2)$ 2.2tom/yr, 0.02ton/yr and 1.03ton/yr, respectively. Further in-depth study on co-relation between age, packing characteristics, temperature and humidity of landfill site and gas emission characteristics is needed.

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Mechanistic Studies on the Anormalous Photocycloaddition Reaction of 5-Styryl-1,3-dimethyluracil and 2,3-Dimethyl-2-butene: Formation of the “Apparent Forbidden” [$_\pi4_s + _\pi2_s$] Cycloadduct

  • Eun Ju Shin;Ho Kwon Kang;Sang Chul Shim
    • Bulletin of the Korean Chemical Society
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    • v.12 no.4
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    • pp.434-437
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    • 1991
  • Irradiation of 5-styryl-1,3-dimethyluracil (5-SDU) with 2,3-dimethyl-2-butene (DMB) gives a [4+2] cycloadduct which is converted into a [2+2] cycloadduct on the prolonged irradiation. Triplet sensitization, quenching, and external heavy atom effect on the [4+2] photocycloaddition reaction demonstrate the singlet pathway and salt effect excludes a radical ion pair precursor possibility. Polar solvents increase the reaction efficiency implying a polar exciplex involvement in the [4+2] photocycloaddition reaction. Inverse temperature dependence both on the reaction and DMB fluorescence quenching of 5-SDU indicates the presence of a singlet exciplex intermediate.