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Traceless Synthesis of Pyridine-Based Tricyclics

T1 - Synthesis of cis adducts of cyclopenta[cd]pyrene with deoxyguanosine and deoxyadenosine

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Report: Design and Synthesis of Novel Pyrene Discotics …

Here we report on the synthesis and characterization of two pyrene containing conjugates: 2- N -(4-(pyren-1-yl)butanoyl)ceramide 5′-phosphothymidine (Pbs–Cer–P–T) (XII) and 2- N -(10-(pyren-1-yl)decanoyl)ceramide 5′-phosphothymidine (Pds–Cer–P–T) (XIII).

Efficient Synthesis of Heteroaryl-Fused Benzopyranones from Biaryl O-Carbamates
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N2 - IT has been suggested that amino acids and other organic compounds found in carbonaceous meteorites formed by aqueous alteration in the meteorite parent bodies1. Observations of carbonaceous material in interstellar grains and interplanetary dust particles2-4 indicate that condensed organic compounds may have been present in meteorite parent bodies at the time of aqueous alteration. One group of compounds thought to be representative of this carbonaceous material is the polycyclic aromatic hydrocarbons (PAHs)5. Recently it was proposed that PAHs condense on SiC grains in the molecular envelopes of carbon-rich red-giant stars6, which would allow for their subsequent incorporation into meteorite parent bodies during accretion. This incorporation mechanism is supported by the identification of SiC grains in carbonaceous chondrites7. The possibility therefore exists that PAHs, and/or other condensed organic compounds, represent the starting material for aqueous alteration which leads to the formation of amino acids and other water-soluble organic compounds. Here we present calculations of the distribution of aqueous organic compounds in metastable equilibrium with representative PAHs as functions of the fugacities of O2, CO2 and NH3. The results reported here for pyrene and fluoranthene, two PAHs with different structures but the same stoichiometry, differ greatly but indicate that the formation of amino and carboxylic acids is energetically favourable at probable parent-body alteration conditions. The actual reaction mechanisms involved could be revealed by consideration of isotope data for PAHs, amino acids, other organic compounds and carbonates in carbonaceous chondrites8,9.

Synthesis of Large Pyrene-Fused Azaacenes - …

The 4 compounds elicited similar inhibitory effects on the synthesis of protein, RNA, and DNA.
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IT has been suggested that amino acids and other organic compounds found in carbonaceous meteorites formed by aqueous alteration in the meteorite parent bodies1. Observations of carbonaceous material in interstellar grains and interplanetary dust particles2-4 indicate that condensed organic compounds may have been present in meteorite parent bodies at the time of aqueous alteration. One group of compounds thought to be representative of this carbonaceous material is the polycyclic aromatic hydrocarbons (PAHs)5. Recently it was proposed that PAHs condense on SiC grains in the molecular envelopes of carbon-rich red-giant stars6, which would allow for their subsequent incorporation into meteorite parent bodies during accretion. This incorporation mechanism is supported by the identification of SiC grains in carbonaceous chondrites7. The possibility therefore exists that PAHs, and/or other condensed organic compounds, represent the starting material for aqueous alteration which leads to the formation of amino acids and other water-soluble organic compounds. Here we present calculations of the distribution of aqueous organic compounds in metastable equilibrium with representative PAHs as functions of the fugacities of O2, CO2 and NH3. The results reported here for pyrene and fluoranthene, two PAHs with different structures but the same stoichiometry, differ greatly but indicate that the formation of amino and carboxylic acids is energetically favourable at probable parent-body alteration conditions. The actual reaction mechanisms involved could be revealed by consideration of isotope data for PAHs, amino acids, other organic compounds and carbonates in carbonaceous chondrites8,9.

AB - Cyclopenta[cd]pyrene 3,4-epoxide, a potent bacterial mutagen, has been synthesized via the bromohydrin obtained from the addition of hypobromous acid to the ethylenic bridge of cyclopenta[cd]pyrene.

Synthesis of triphenylene and pyrene based aromatics …

T1 - Synthesis and structure determination of the adducts of dibenzo[a,f]pyrene diol epoxides and deoxyadenosine or deoxyguanosine
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N2 - Cyclopenta[cd]pyrene 3,4-epoxide, a potent bacterial mutagen, has been synthesized via the bromohydrin obtained from the addition of hypobromous acid to the ethylenic bridge of cyclopenta[cd]pyrene.

N2 - Polycyclic aromatic hydrocarbons are widespread in nature with a toxicity range from non-toxic to extremely toxic. A series of pyrenyl derivatives has been synthesized following a four-step strategy where the pyrene nucleus is attached with a basic heterocyclic moiety through a carbon linker. Virtual screening of the physicochemical properties and druggability has been carried out. The cytotoxicity of the compounds (1-8) have been evaluated in vitro against a small panel of human cancer cell lines which includes two liver cancer (HepG2 and Hepa 1-6), two colon cancer (HT-29 and Caco-2) and one each for cervical (HeLa) and breast (MCF-7) cancer cell lines. The IC50 data indicate that compound 6 and 8 are the most effective cytotoxic agents in the present set of pyrenyl derivatives, suggesting that having a 4-carbon linker is more effective than a 5-carbon linker and the presence of amide carbonyl groups in the linker severely reduces the efficacy of the compound. The compounds showed selectivity toward cancer cells at lower doses (

(1983) A Fourier-transform infrared spectrometic study of the pyrosynthesis of nickel tetracarbonyl and iron trentacarbonyl by combustion of tobacco.
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  • A Convenient New Synthesis of Benzo[ a ]pyrene | …

    The ability of nickel compounds to inhibit DNA synthesis and excision repair should also be noted (Table 27).

  • Synthesis and intermembrane transfer of pyrene …

    Synthesis, fluorescence properties and the promising cytotoxicity of pyrene–derived aminophosphonates

  • A Convenient New Synthesis of Benzo[ a ]pyrene

    Computational modelling of de novo synthesis of Dibenzofuran: oxidative pathways of Pyrene ..

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(Fmoc)protecting group on amines in peptide synthesis.[2]

Recently, organic semiconductors have been studied extensively as materials for electro luminescence and field-effect transistors. The organic semiconductors which are the component of organic transistors have advantages such as lightness, flexibility, application for a large area. However, they have disadvantage such as a low electric conductivity, a low stability in the atmosphere and a low reproducibility. On the other hand pyrenes have characteristics such as large -conjugated systems and stability in air. Thus, in this study novel fused aromatic ring compounds consisting of the pyrene unit have been synthesized and characterized by their UV-vis spectra, CV and the displacement current measurement (DCM) technique. The expansion of the conjugated system in those compounds was indicated by the UV-vis spectra. And the stability in the atmosphere was much increased.

Synthesis of thiophene-substituted pyrene ..

AB - Expecting a preorganization effect, tripodal anion host molecules were designed and synthesized. It was demonstrated that two kinds of new thiourea derivatives having a six-fold substituted benzene ring as a preorganized spacer were effective for recognition of the tetrahedral dihydrogen phosphate anion. A tripodal fluororeceptor 1 having a pyrene moiety adjacent to the thiourea binding site showed long-wavelength emission upon addition of guest anions in acetonitrile. On the other hand, a tripodal thiourea receptor 2 connected to anthracene groups via methylene units showed a decrease in fluorescence intensity upon addition of anions. In both cases, the degree of the change in emission intensity was in the order of H2PO4- > CH3COO- > Cl- ≫ ClO4-, which is clearly different from that of reference compounds having only one binding site. Association constants (Ka) of these tripodal fluororeceptors also confirmed the dihydrogen phosphate selectivity over the more basic acetate anion in this homogeneous solution system. The characteristics of the fluororeceptors using the preorganization effect were shown to be promising for the development of chemical ion sensors with a specific anion selectivity.

Synthesis and properties of novel aromatic compounds …

N2 - Expecting a preorganization effect, tripodal anion host molecules were designed and synthesized. It was demonstrated that two kinds of new thiourea derivatives having a six-fold substituted benzene ring as a preorganized spacer were effective for recognition of the tetrahedral dihydrogen phosphate anion. A tripodal fluororeceptor 1 having a pyrene moiety adjacent to the thiourea binding site showed long-wavelength emission upon addition of guest anions in acetonitrile. On the other hand, a tripodal thiourea receptor 2 connected to anthracene groups via methylene units showed a decrease in fluorescence intensity upon addition of anions. In both cases, the degree of the change in emission intensity was in the order of H2PO4- > CH3COO- > Cl- ≫ ClO4-, which is clearly different from that of reference compounds having only one binding site. Association constants (Ka) of these tripodal fluororeceptors also confirmed the dihydrogen phosphate selectivity over the more basic acetate anion in this homogeneous solution system. The characteristics of the fluororeceptors using the preorganization effect were shown to be promising for the development of chemical ion sensors with a specific anion selectivity.

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