• Title/Summary/Keyword: Alcohols and Phenols

Search Result 54, Processing Time 0.024 seconds

Antimicrobial Agents and Applications on Polymeric Materials (고분자재료에 대한 항균성 물질과 적용)

  • Lee, Jae-Woong
    • Textile Coloration and Finishing
    • /
    • v.20 no.3
    • /
    • pp.39-56
    • /
    • 2008
  • A wide variety of materials including aldehydes, cationic agents, alcohols, peroxygens, phenols and chlorinated phenols, metal ions are being employed as biocides. Among three levels for biocidal functions (sanitization, disinfection and sterilization), disinfection is an enough level for antimicrobial textiles. In terms of antimicrobial agents for textile applications, quaternary ammonium salts (QAS), chitosan, metal and metal salts, N-halamine based materials are developed with numerous research and the positive ions of those materials may result in disinfection of microorganisms. Photocatalysts, especially titanium dioxide (titania) produces the hydroxyl radical (${\cdot}\;OH$) which causes inactivation of microorganisms after UV radiation, have been used for antimicrobial applications.

Volatile flavor components of Ixeris dentata and Amaranthus mangostanus (씀바귀와 비름의 휘발성 풍미성분)

  • Kim, Mi-Kyung;Lee, Mie-Soon
    • Applied Biological Chemistry
    • /
    • v.31 no.4
    • /
    • pp.394-399
    • /
    • 1988
  • Volatile components of Ixeris dentata and Amaranthus mangostanus, Korean wild vegetables, were collected by Steam Distillation-Extraction(SDE) method. Essential oils were analyzed by gas chromatography(GC)and combined gas chromatography-mass spectrometry(GC-MS). Sixty one components, including 13 alcohols, 9 esters, 12 aldehydes, 6 ketones, 9 hydrocarbons, 6 acids, 3 phenols and 3 miscellaneous ones were confirmed in Ixeris dentata. Fifty six components, including 15 alcohols, 5 esters, 13 aldehydes, 8 ketones, 3 hydrocarbons, 9 acids and 5 miscellaneous ones were confirmed in Amaranthus mangostanus.

  • PDF

Stereoselective Total Synthesis of (-)-Cytoxazone

  • Kim, Ji-Duck;Hoon, Jung-Young
    • Proceedings of the PSK Conference
    • /
    • 2003.10b
    • /
    • pp.179.2-179.2
    • /
    • 2003
  • We have developed the novel one-pot synthetic method for regioselective and stereoselective N-protected amines through the reaction of various ethers with chlorosulfonyl isocyanate (CSI). Also, we found a novel technique to compare directly the stability of carbocations in the solution phase and established the stability order of the various carbocations. And we reported the cleavage of benzyl and p-methoxybenzyl protecting groups of alcohols and phenols in the presence of other functional groups using CSI. (omitted)

  • PDF

Reducing Characteristics of Potassium Tri-sec-butylborohydride

  • Yoon, Nung-Min;Hwang, Young-Soo;Yang, Ho-Seok
    • Bulletin of the Korean Chemical Society
    • /
    • v.10 no.4
    • /
    • pp.382-388
    • /
    • 1989
  • The approximate rates and stoichiometry of the reaction of excess potassium tri-sec-butylborohydride ($K_s-Bu_3BH$) with selected organic compounds containing representative functional groups were determined under the standard conditions (0$^{\circ}C$, THF) in order to define the characteristics of the reagent for selective reductions. Primary alcohols evolve hydrogen in 1 h, but secondary and tertiary alcohols and amines are inert to this reagent. On the other hand, phenols and thiols evolve hydrogen rapidly. Aldehydes and ketones are reduced rapidly and quantitatively to the corresponding alcohols. Reduction of norcamphor gives 99.3% endo- and 0.7% exo-isomer of norboneols. The reagent rapidly reduces cinnamaldehyde to the cinamyl alcohol stage and shows no further uptake of hydride. p-Benzoquinone takes up one hydride rapidly with 0.32 equiv hydrogen evolution and anthraquinone is cleanly reduced to the 9,10-dihydoxyanthracene stage. Carboxylic acids liberate hydrogen rapidly and quantitatively, however further reduction does not occur. Anhydrides utilize 2 equiv of hydride and acyl chlorides are reduced to the corresponding alcohols rapidly. Lactones are reduced to the diol stage rapidly, whereas esters are reduced moderately (3-6 h). Terminal epoxides are rapidly reduced to the more substituted alcohols, but internal epoxides are reduced slowly. Primary and tertiary amides are inert to this reagent and nitriles are reduced very slowly. 1-Nitropropane evolves hydrogen rapidly without reduction and nitrobenzene is reduced to the azoxybenzene stage, whereas azobenzene and azoxybenzene are inert. Cyclohexanone oxime evolves hydrogen without reduction. Phenyl isocyanate utilizes 1 equiv of hydride to proceed to formanilide stage. Pyridine and quinoline are reduced slowly, however pyridine N-oxide takes up 1.5 equiv of hydride in 1 hr. Disulfides are rapidly reduced to the thiol stage, whereas sulfide, sulfoxide, sulfonic acid and sulfone are practically inert to this reagent. Primary alkyl bromide and iodide are reduced rapidly, but primary alkyl chloride, cyclohexyl bromide and cyclohexyl tosylate are reduced slowly.

Reducing Characteristics of Potassium Triethylborohydride

  • Yoon, Nung-Min;Yang H.S.;Hwang, Y.S.
    • Bulletin of the Korean Chemical Society
    • /
    • v.8 no.4
    • /
    • pp.285-291
    • /
    • 1987
  • The approximate rates, stoichiometries and products of the reaction of potassium triethylborohydride $(KEt_3BH)$ with selected organic compounds containing representative functional groups under the standard condition $(0^{\circ}C,$ THF) were examined in order to explore the reducing characteristics of this reagent as a selective reducing agent. Primary alcohols, phenols and thiols evolve hydrogen rapidly whereas secondary and tertiary alcohols evolve very slowly. n-Hexylamine is inert to this reagent. Aldehydes and ketones are reduced rapidly and quantitatively to the corresponding alcohols. Reduction of noncamphor gives 3% exo- and 97% endo-norboneol. Anthraquinone is cleanly reduced to 9,10-dihydro-9,10-dihydroxyanthracene stage. Carboxylic acids liberate hydrogen rapidly and quantitatively but further reduction does not occur. Anhydrides utilize 2 equiv of hydride to give an equimolar mixture of acid and alcohol. Acid chlorides, esters and lactones are rapidly and quantitatively reduced to the corresponding alcohols. Epoxides are reduced at moderate rates with Markovnikov ring opening to give the more substituted alcohols. Primary amides liberate 1 equiv of hydrogen rapidly. Further reduction of caproamide is slow whereas benzamide is not reduced. Tertiary amides are reduced slowly. Benzonitrile utilizes 2 equiv of hydride in 3 h to go to the amine stage whereas capronitrile takes only 1 equiv. The reaction of nitro compounds undergo rapidly whereas azobenzene and azoxybenzene are reduced slowly. Cyclohexanone oxime rapidly evolves hydrogen without reduction. Phenyl isocyanate utilizes 1 equiv of hydride to proceed to formanilide stage. Pyridine N-oxide and pyridine is reduced rapidly. Disulfides are rapidly reduced to the thiol stage whereas sulfoxide, sulfonic acid are practically inert to this reagent. Sulfones and cyclohexyl tosylate are slowly reduced. Octyl bromide is reduced rapidly but octyl chloride and cyclohexyl bromide are reduced slowly.

Thermal Changes of Aroma Components in Soybean Pastes (Doenjang) (된장 가열조리 시 생성되는 향기성분 변화)

  • Lee, Seung-Joo;Ahn, Bo-Mi
    • Korean Journal of Food Science and Technology
    • /
    • v.40 no.3
    • /
    • pp.271-276
    • /
    • 2008
  • In this study, volatile compounds were isolated from traditional and commercial fermented soybean pastes according to different heating temperatures (room temperature, $50^{\circ}C$, $100^{\circ}C$) using headspace-solid phase microextraction (HS-SPME). The compounds were then analyzed by gas chromatography-mass spectrometry (GC-MS). A total of 51 volatile components, including 18 esters, 3 alcohols, 6 acids, 8 pyrazines, 5 volatile phenols, 6 aldehydes, and 5 miscellaneous compounds, were identified. Esters and acids such as ethyl hexadecanoate, acetic acid, and 2/3-methyl butanoic acid were the largest groups among the quantified volatiles. By applying principal component analyses to the GCMS data sets, differences were observed in the volatile components of the soybean pastes as to the different heating temperatures. A large variation was shown between the volatile components of the traditional and commercial soybean pastes by increasing the heating temperature. Commercial samples had significantly higher levels of longer chain ethyl esters, aldehydes, and thermal degradation products such as maltol and 2-acetyl pyrrole, while traditional samples showed higher concentrations of acids and pyrazines.

The Aroma Components of Duchung Tea and Persimmon Leaf Tea (두충차와 감잎차의 향기성분)

  • Choi, Sung-Hee
    • Korean Journal of Food Science and Technology
    • /
    • v.22 no.4
    • /
    • pp.405-410
    • /
    • 1990
  • The aroma components of duchung tea and persimmon leaf tea were collected simultaneous distillation and extraction method. Those were analyzed and identified by GC-MS using a fused sillica capillary column. Seventy seven components, including 17 alcohols, 3 hydrocarbons, 15 ketones, 16 aldehydes, 8 esters,8 acids, 8 heterocyclic compounds and 2 phenols were confirmed in duchung tea. Seventy one components, including 17 alcohols, 10 hydrocabrons, 11 ketones, 13 aldehydes, 8 esters, 6 acids, 5 heterocyclic compounds and 1 phenol were confirmed in persimmon leaf tea. The most abundant components of duchung tea were aldehydes(23.31%) including 2-pentenal and heterocyclic compounds(16.71%) including $epoxy-{\beta}-ionone$. The most abundant components of persimmon leaf tea were alcohols(25.57%) including linalool and aldehydes(19.45%) including hexanal and hydrocarbons(10.40%) including ${\alpha}-copaene$.

  • PDF

Composition of Methanol Extract from Hwangryeon (Coptidis rhizoma) and Antimicrobial Activity against Food Spoilage and Foodborne Disease Microorganisms

  • Lim, Mee-Kyoung;Kim, Mee-Ra
    • International Journal of Human Ecology
    • /
    • v.7 no.1
    • /
    • pp.145-153
    • /
    • 2006
  • Hwangryeon (Coptidis rhizoma) was extracted by methanol and its antimicrobial activities against food spoilage and foodborne disease microorganisms were investigated by the paper-disc method. The microorganisms used in this experiment included 5 species of bacteria (Escherichia coli, Pseudomonas aeruginosa, Salmonella typhimurium, Klebsiella pneumoniae, and Staphylococcus aureus) and 3 species of fungi (Fusarium solani, Aspergillus flavus, and Penicillium citreonigrum). The Hwangryeon extract showed antimicrobial effect against P. aeruginosa, S. aureus, S. typhimurium, and K. pneumonia. The minimum inhibitory concentration on S. aureus, S. typhimurium, and K. pneumoniae was 300 mg/mL, but on P. aeruginosa it was 200 mg/mL. In the methanol extracts from Hwangryeon, 190 compounds were separated by GC/MS. The extraction yields of phenols, furans, alcohols, acids and esters, ketones, and miscellaneous compounds were 28.10%, 2.67%, 1.79%, 12.89%, and 2.35%, respectively. The phenolic compounds, generally understood to be an antimicrobial active substance, was measured at 28.10%, a relatively remarkable amount.

Volatile Flavor Components of Traditional and Commercial Kochujang (재래식과 공장산 고추장의 향기성분)

  • Kim, Young-Soo;Oh, Hoon-Il
    • Korean Journal of Food Science and Technology
    • /
    • v.25 no.5
    • /
    • pp.494-501
    • /
    • 1993
  • The volatile flavor components of traditional and commercial kochujang were collected by simultaneous steam distillation-extraction (SDE) method. Essential oils were analyzed by gas chromatography (GC) and combined gas chromatography-mass spectrometry (GC/MS). Tested kochujang included Sunchang kochujang prepared with glutinous rice, Boeun kochujang prepared with barley, Sachun kochujang prepared with wheat and commercial kochujang. One hundred and twelve volatile flavor components which included 30 esters, 15 alcohols, 14 aldehydes, 13 acids, 9 ketones, 7 alkenes, 6 phenols, 3 alkanes, 3 pyrazines, 2 benzenes and 2 furans were identified. The major volatile compounds in traditional and commercial kochujang were 2-methyl propanal and ethanol, which represented $21{\sim}36%\;and\;2{\sim}44%$ of total GC peak area, respectively.

  • PDF

Headspace-Solid Phase Microextraction (HS-SPME) Analysis of Korean Fermented Soybean Pastes

  • Lee, Seung-Joo
    • Food Science and Biotechnology
    • /
    • v.18 no.3
    • /
    • pp.700-705
    • /
    • 2009
  • In this study, the volatile compounds in 9 commercial fermented soybean pastes were extracted and analyzed by headspace-solid phase microextraction (HS-SPME) and gas chromatography-mass spectrometry (GC-MS), respectively. A total of 63 volatile components, including 21 esters, 7 alcohols, 7 acids, 8 pyrazines, 5 volatile phenols, 3 ketones, 6 aldehydes, and 6 miscellaneous compounds, were identified. Esters, acids, and pyrazines were the largest groups among the quantified volatiles. About 50% of the total quantified volatile material was contributed by 5 compounds in 9 soybean paste samples; ethyl hexadecanoate, acetic acid, butanoic acid, 2/3-methyl butanoic acid, and tetramethyl-pyrazine. Three samples (CJW, SIN, and HAE) made by Aspergillus oryzae inoculation showed similar volatile patterns as shown in principal component analyses to GC-MS data sets, which showed higher levels in ethyl esters and 2-methoxy-4-vinylphenol. Traditional fermented soybean pastes showed overall higher levels in pyrazines and acids contents.