• Title, Summary, Keyword: heterocyclic compounds

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Thermal Generation and Antimicrobial Activity of Unusual Heterocyclic Sulfur Compounds in Garlic

  • Chung, In-Shick;Chae, Kyung-Yun;Kyung, Kyu-Hang
    • Food Science and Biotechnology
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    • v.17 no.5
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    • pp.1032-1037
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    • 2008
  • Lowly volatile heterocyclic sulfur compounds generated in autoclaved garlic extract were isolated and identified, and their antimicrobial activity was determined. Two kinds of unusual volatile sulfur compounds were separated from heated garlic by preparative recycling high performance liquid chromatography (HPLC), and identified by gas chromatography (GC)-mass spectrometry (MS) and $^1H$-nuclear magnetic resonance (NMR). They had heterocyclic structures with 4 to 5 sulfur atoms in the molecules. 4-Methyl-1,2,3-trithiolane (MTTT) is highly volatile and was not able to be concentrated, and was identified by GCMS only. MTTT and 6-methyl-1,2,3,4,5-pentathiepane (MPTP) are lowly volatile and were obtained in pure states to be positively identified for the first time. All 3 heterocyclic sulfur compounds began to appear by the time when the early-formed diallyl sulfides started to disappear. The minimum inhibitory concentration range of MTTT and MPTP was determined to be between 1 and 6 ppm against all yeasts tested. MTTT and MPTP were lowly volatile and sparingly soluble in water.

Study of Oganophosphorus Compound (I). Synthesis of Heterocyclic Compounds Containing Phosphorus Atom

  • Dong-Young Oh;Byoung-Mog Kwon
    • Bulletin of the Korean Chemical Society
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    • v.1 no.2
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    • pp.54-57
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    • 1980
  • Trichloromethylphosphonyl dichloride was prepared by the aluminium chloride method. We synthesized several heterocyclic compounds containing phosphorus atom by the stepwise esterification of trichloromethylphosphonyl dichloride with ethylene glycol, 2-mercaptoethanol, ethylene diamine, and 2-aminoethanol and the resulting heterocyclic compounds are 2-trichloromethyl-1,3,2-dioxa-, 2-trichloromethyl-1,3,2-thioxa-, 2-trichloromethyl-1,3,2-diaza-, 2-trichloromethyl-1,3,2-diaza-, and 2-trichloromethyl-1,3,2-oxazaphospholane-2-oxide. The best results were obtained in the solution of triethylamine as hydrochloric acid trapping agent. The structure of five-membered heterocyclic phosphonates were characterized by their IR, NMR, and elementary analysis and the mass spectra of the compounds were analyzed.

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Simple Method of Preparation and Characterization of New Antifungal Active Biginelli Type Heterocyclic Compounds

  • Pothiraj, C.;Velan, A. Senthilkumara;Joseph, J.;Raman, N.
    • Mycobiology
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    • v.36 no.1
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    • pp.66-69
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    • 2008
  • A simple, efficient and cost effective method is described for the synthesis of Biginelli type heterocyclic compounds of dihydropyrimidinones analogous. They were prepared from a reaction mixture consisting of substituted benzaldehydes, thiourea and ethylacetoacetate using ammonium dihydrogenphosphate as catalyst. The procedure for the preparation of the compounds is environmentally benign and safe which is advantageous in terms of experimentation, catalyst reusability, yields of the products, shorter reaction times and preclusion of toxic solvents. The four new synthesised compounds were tested for their antifungal activity. They have good antifungal activity comparing to the standard (Fluconazole).

Ab Initio Study of Mechanism of Forming Spiro-Ge-Heterocyclic Ring Compound From C2Ge=Ge: and Formaldehyde

  • Lu, Xiuhui;Li, Yongqing;Ming, Jingjing
    • Bulletin of the Korean Chemical Society
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    • v.34 no.12
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    • pp.3690-3694
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    • 2013
  • The $H_2Ge=Ge:$ and its derivatives ($X_2Ge=Ge:$, X = H, Me, F, Cl, Br, Ph, Ar${\ldots}{\ldots}$) is a new species. Its cycloaddition reactions is a new area for the study of germylene chemistry. The mechanism of the cycloaddition reaction between singlet state Cl2Ge=Ge: and formaldehyde has been investigated with CCSD(T)//MP2/$6-31G^*$ method. From the potential energy profile, it could be predicted that the reaction has only one dominant reaction pathway. The reaction rule presented is that the two reactants first form a fourmembered Ge-heterocyclic ring germylene through the [2+2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge: atom in the four-membered Ge-heterocyclic ring germylene and the ${\pi}$ orbital of formaldehyde forming a ${\pi}{\rightarrow}p$ donor-acceptor bond, the four-membered Ge-heterocyclic ring germylene further combines with formaldehyde to form an intermediate. Because the Ge: atom in intermediate hybridizes to an $sp^3$ hybrid orbital after transition state, then, intermediate isomerizes to a spiro-Ge-heterocyclic ring compound via a transition state. The research result indicates the laws of cycloaddition reaction between $H_2Ge=Ge:$ and formaldehyde, and laid the theory foundation of the cycloaddition reaction between $H_2Ge=Ge:$ and its derivatives ($X_2Ge=Ge:$, X = H, Me, F, Cl, Br, Ph, Ar${\ldots}{\ldots}$) and asymmetric ${\pi}$-bonded compounds, which is significant for the synthesis of small-ring and spiro-Ge-heterocyclic compounds. The study extends research area and enriches the research content of germylene chemistry.

Gas Phase Proton Affinity, Basicity, and pKa Values for Nitrogen Containing Heterocyclic Aromatic Compounds

  • Hwang, Sun-Gu;Jang, Yun-Hee;Chung, Doo-Soo
    • Bulletin of the Korean Chemical Society
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    • v.26 no.4
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    • pp.585-588
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    • 2005
  • Bipyridine and its derivatives have been widely used as the ligands in transition metal complexes. The proton affinities of pyridine derivatives were calculated using an ab initio quantum mechanical method (B3LYP with various double zeta and triple zeta basis sets) in combination with the Poisson-Boltzmann continuum solvation model. Van der Waals radii of the atoms in the heterocyclic rings for the solvation energy calculation were set to values determined to reproduce the $pK_a$ values of guanine and oxoguanine derivatives and that of chlorine was optimized to reproduce the experimental values of relating compounds. The $pK_a$ values for the heterocyclic ring compounds were in agreement with the experimental values with a mean unsigned error of 0.45 $pK_a$ units.

Separation of Functionalized Heterocyclic Compounds by High Performance Liquid Chromatography (II) (고성능 액체 크로마토그래피에 의한 기능성 헤테로 고리 화합물의 분리(II))

  • Cho, Yun Jin;Lee, Young Cheol;Lee, Kwang-PiII;Park, Keung-Shik
    • Analytical Science and Technology
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    • v.11 no.4
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    • pp.292-296
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    • 1998
  • Normal phase or reversed phase liquid chromatographic separation of isoquinoline of heterocyclic compounds and structural isomers of external substituents, $COOCH_3$, CN and $CH_3$ has been carried out by using several different columns and various mobile phases. From this results, the order of elution of heterocyclic compounds appears to depend on the solvent effect with kinds of mobile phases. Retention mechanism of normal phase system for 2-methylindoline, 2-methylindole, benzoxazole and benzothiazole was also studied depending on adsorption strength between solute and stationary phase of column. However, retention factors of reversed phase system were found on hydrophobic interaction with solvophobic effect.

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Designs and Syntheses of Oxathiin Carboxanilide Analogues and their Antiviral Activities

  • Hahn, Hoh-Gyu;Rhee, Hee-Kyung;Lee, Chong-Kyo;Whang, Kyu-Ja
    • Archives of Pharmacal Research
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    • v.23 no.4
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    • pp.315-323
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    • 2000
  • Syntheses of new analogues of oxathiin carboxanilide (UC84) and their antiviral activities were described. The heterocyclic carboxylic acids including oxathiins (4), thiazines (9) and dithiins (13) in which the methyl was replaced either by lipophilic trifluoromethyl- or bulky phenylgroup were synthesized starting from $\beta$-keto esters (5). Reaction of 4, 9 and 13 with thionyl chloride followed by treatment of the substituted aniline 22 gave the corresponding carboxanilides (24a~24f). The carboxanilides were subjected to Laweson's reagent the corresponding thiocarboxanilides (24g~24k). The antiviral activities of the synthesized compounds against human immunodeficiency virus type 1 (HIV-1), poliovirus type 1 (PV-1 ), coxsackie B virus type 3 (CoxB-3), vesicular stomatitis virus (VSV) and herpes simplex virus type 1 (HSV-1) were presented. The antiviral activity against HIV-1 of dithiin carboxanilide (24e) was similar with that of UC84 (24a). The corresponding thiocarboxanilides (24g~24k) showed higher inhibitory activity against HIV-1 than the carboxanilides (24a, 24b, 24d, 24e). The compounds in which ether the lipophilic trifluorormethyl substituents (24d, 24f, 24i ,24k) or bulky phenyl substituent is present in the heterocyclic compounds showed lower inhibitory activity than that of the methyl substituents is present in the compounds against the HIV-1. But the trifluoromethylated dithiin (24f) showed higher inhibitory activity against PV-1 and CoxB-3 virus than commercial antiviral agents, ribavirin (RV).

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Synthesis of Selenoflavonoid and Selenoisoflavonoid.

  • Kim, Dong-Myung;Jeong, Jin-Hyun
    • Proceedings of the PSK Conference
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    • pp.351.1-351
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    • 2002
  • Heterocyclic compounds with oxygen atoms are known to have potent biological effect. The flavonoids. isoflavonoids. and coumarins which form the bulk of these compounds are very polar and have limited use as drugs which have to pass through membranes. The non-polar property is increased by exchange oxygen to selenium as a part of heterocyclic compound. Our group is focused on synthesizing selenoheterocyclic compound with the above property. (omitted)

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Analysis of Heterocyclic Amines in Mainstream Cigarette Smoke using by LC-MS/MS (LC-MS/MS를 이용한 담배 연기 중 Heterocyclic Amines의 분석)

  • Kim, Ick-Joong;Jang, Gi-Chul;Ji, Sang-Un;Min, Hye-Jeong;Kim, Hyo-Keun;Hwang, Geon-Jung
    • Journal of the Korean Society of Tobacco Science
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    • v.30 no.1
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    • pp.33-38
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    • 2008
  • This study was carried out to determine the analytical methods for heterocyclic amines(HAs) of the tobacco smoke by LC/MS/MS. HAs have been found in pyrolysate of protein and cooked food including protein, were known the Sugimura compound. HAs content of the smoke were known to exist very low ppb level. Especially, some of HAs are mutagenic and carcinogenic compounds. In according to IARC, the toxicity of N-heterocyclic amines classified IARC class 2A or 2B group. Precursors of these compounds are glutamic acid, protein and free amino acids including tryptophan, therefore, the precursors have been proved in cooked food continuously. This study was investigate multiple analysis methods for HAs and HAs contents of some commercial products. In this study, we used the linear type smoking machine for HAs analysis. At the ISO conditions, mainstream smoke was collected on cambridge filter pad, and then cambridge filter pad was extracted by 0.1% acetic acid. The extracted solution were passed cation exchange SPE cartridge to remove matrix, samples were analyzed using LC/MS/MS on MRM mode. From the result that optimized this methods, the correlation coefficient(R) of the individual compounds were good linearity over 0.999, recovery rate over 96% and the limit of detection were good values between 0.06 to 0.37 ng/mL, In addition, HAs content of some commercial products were in range of 0.02 to 43.8 ng/cig.

The Reaction of 6,7-Dichloro-5,8-quinoxalinedione with Aromatic and Aliphatic Dinucleophiles and Molecular Modeling Study of Their Intercalation Complexes

  • 유희원;서명은;신계중;박상우
    • Bulletin of the Korean Chemical Society
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    • v.18 no.5
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    • pp.484-488
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    • 1997
  • The angular and planar heterocyclic compounds containing nitrogen, sulfur and oxygen were synthesized by reaction of 6,7-dichloro-5,8-quinoxalinedione with aromatic and aliphatic dinucleophiles. Nucleophilic reactivity was somewhat different between 2,3-dichloro-1,4-naphthoquinone and 6,7-dichloro-5,8-quinolinedione with dinucleophiles. The distribution of electron in heterocycle appeared to contribute to this difference. The intercalation comple of planar heterocyclic compound between GC/GC base pairs showed the optimum intercalation but the intercalation of angular heterocyclic compound was not good. Thus, the planar compound was expected to have antitumor activity.

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