• Title/Summary/Keyword: propene

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Effect of Exposing Eggs of Uzi Fly, Exorista bombycis (Louis) (Diptera : Tachinidae) to Volatiles of Allium sativum L. (Liliaceae)

  • Narayanaswamy, K.C.;Dandin, S.B.
    • Journal of Sericultural and Entomological Science
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    • v.40 no.1
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    • pp.23-26
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    • 1998

  • Exposure of freshly laid eggs of Exorista bombycis (Louis) to volatiles emanating from bulbs of Allium sativum L. for different durations resulted in signigicant reduction in their hatchability. Maggots hatched from the eggs exposured for 64 h and 72 h were failed to emerge from host larvae. The duration of development stages of E. bombycis was prolonged besides reduction in rate of pupation and adult emergence as the egg exposure period increased. The findings are interpreted as the chronic effects of volatiles of garlic affecting maggots following developmental defects sustainable during embryonic development. The known major chemical components of A. sativum such as allicin, thioacrolein, ajoune, 2-propene sulfenic acid, 2-propene thiol and propylene were presumed to be responsible for the adverse consequences reported in this paper.

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An Efficient Synthesis of Alkoxyallylthiopyridazine Derivatives from Maleic Anhydrides (Maleic Anhydrides로부터 Alkoxyallylthiopyridazines 유도체의 효과적 합성)

  • Lee, Jae-In;Yun, Young-Sook
    • Journal of the Korean Chemical Society
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    • v.48 no.6
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    • pp.609-615
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    • 2004

  • Alkoxyallylthiopyridazine derivatives which exhibit superior effect for the treatment of hepatic diseases were synthesized from maleic anhydrides. The reaction of maleic anhydrides with hydrazine monohydrate in aq HCl at reflux afforded dihydroxypyridazines, which were transformed to dichloropyridazines with phosphorus oxychloride. The substitution of the first chlorine atom in dichloropyridazines proceeded selectively with alcoholic sodium alkoxides in THF to afford alkoxychloropyridazines, which were converted to alkoxyallylthiopyridazines with lithium 2-propene-1-thiolate in high yields.

  • https://doi.org/10.5012/jkcs.2004.48.6.609 인용 PDF KSCI KPUBS HTML

Gas Phase Thernal cis-trans Isomerization Reaction of 1-Bromopropene

  • Huh, D- Sung;Um, Jae-Young;Yun, Sun-Jin;Choo, Kwang-Yul;Jung, Kyung-Hoon
    • Bulletin of the Korean Chemical Society
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    • v.11 no.5
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    • pp.391-395
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    • 1990

  • The kinetics of thermnal cis-trans isomerization reaction of 1-bromopropene(1-BP) was studied at temperatures from 620.8 to 753.15 K over the pressure range 0.17-50.3 Torr. Both the inhibition effect by cyclohexene or propene and the catalytic effect by HBr showed a radical process as the main mechanism of the isomerization. In the suppression of the radical process by the inhibitors, the molecular process also contributed to overall reaction rate. The reactions demonstrated the first order kinetics under both uninhibited and inhibited conditions and could be represented by the expressions (R = 1.987 cal/mol/K) $k_{un}/s^{-1} = (3.45{\pm}1.50){\times}10^{11}$exp$[(- 48100{\pm}2000)/RT]\;k_{ink}/s^{-1} = (2.98{\pm}1.40){\times}10^{12}$exp$[(- 55800{\pm}1800)/RT]$> where $k_{un}$ is the observed rate constant of cis-1-bromopropene(1-B$P_c$) to trans-1-bromopropene(1-B$P_t$) under uninhibited condition at initial pressure of 50 Torr and $k_{ink}$ is the rate constant under maximal inhibition by cyclohexene. The ratio of rate constants for bromine atom elimination from the allylic hydrogen of reactant(1-BP) and from the inhibitors, propene and cyclohexene, were measured from the observed rates of the uninhibited and inhibited reactions. The inhibition efficiencies of cyclohexene and propene were compared kinetically from the rate constants and shown to give good agreement with the previous results reported from other alkyl bromide pyrolyses.

  • https://doi.org/10.5012/bkcs.1990.11.5.391 인용 PDF

Storage Stability of the Concentrated Garlic Juices with Various Concentration Methods (농축방법에 따른 마늘 농축액의 저장 안정성)

  • Bae, Soo-Kyung;Kim, Mee-Ra
    • Korean Journal of Food Science and Technology
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    • v.30 no.3
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    • pp.615-623
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    • 1998

  • The garlic juices were extracted and concentrated by heating at $90^{\circ}C$, by using a rotary vacuum evaporator at $45^{\circ}C$, or by freezing at $-50^{\circ}C$ until the volume was reduced to 70% of the original volume. The concentrated juices were kept at $4^{\circ}C\;or\;25^{\circ}C$ for 60 days and the changes of bacteria and color were monitored every 10 days. Flavors of the raw garlic juices, concentrated garlic juices, and garlic powder by hot-air drying were analyzed monthly using GC and GC/MS. The CFUs/mL of mesophilic and psychrotrophic bacteria in the garlic juice concentrated at $90^{\circ}C$ were lower about 1 to 2 log cycles than those of other concentrated juices. Hunter L, a, and b values in the raw garlic raw juice and the juice concentrated at $-50^{\circ}C$ significantly increased at the beginning of storage, in particular, when they were stored at $25^{\circ}C$. The garlic juice concentrated at $45^{\circ}C$ showed relatively low L value but the juice concentrated at $90^{\circ}C$ showed high a value. The main peaks in chromatograms of volatile components identified by GC/MS were 3,3'-thiobis-1-propene, di-2-propenyl disulfide, 3-(methylthio)-1-propene in the raw garlic juice and the concentrated juices, and the juices concentrated at $45^{\circ}C\;or\;-50^{\circ}C$ showed relatively high preservation of garlic flavor.

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