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John C. Chaput - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis of α-l-Threofuranosyl Nucleoside 3'-Monophosphates, 3'-Phosphoro(2-Methyl)imidazolides, and 3'-Triphosphates.
    The Journal of Organic Chemistry, 2017
    Co-Authors: Saikat Bala, Jen-yu Liao, Hui Mei, John C. Chaput
    Abstract:

    α-l-Threofuranosyl nucleic acid (TNA) is an artificial genetic polymer composed of vicinal 2′,3′-phosphodiester bonds linking adjacent threofuranosyl nucleosides. TNA is one of a small number of genetic polymers that are both highly resistant to nuclease digestion and capable of cross-pairing with DNA and RNA. Although an efficient method for synthesizing TNA nucleosides has been reported, very few advances have been made in the synthesis of phosphorylated TNA compounds. Here, we describe a highly efficient method for synthesizing α-l-threofuranosyl nucleoside 3′-monophosphates (tNMPs), 3′-phosphoro(2-methyl)imidazolides (2-MeImptNs), and 3′-triphosphates (tNTPs) bearing the four genetic bases of adenine (A), cytosine (C), thymine (T), and guanine (G). We suggest that this strategy, which provides access to grams of tNMPs, hundreds of milligrams of 2-MeImptNs, and tens of milligrams of tNTPs, will help advance the use of TNA monomers in Exobiology and biotechnology applications.

  • Synthesis of α‑l‑Threofuranosyl Nucleoside 3′-Monophosphates, 3′-Phosphoro(2-Methyl)imidazolides, and 3′-Triphosphates
    2017
    Co-Authors: Saikat Bala, Jen-yu Liao, Hui Mei, John C. Chaput
    Abstract:

    α-l-Threofuranosyl nucleic acid (TNA) is an artificial genetic polymer composed of vicinal 2′,3′-phosphodiester bonds linking adjacent threofuranosyl nucleosides. TNA is one of a small number of genetic polymers that are both highly resistant to nuclease digestion and capable of cross-pairing with DNA and RNA. Although an efficient method for synthesizing TNA nucleosides has been reported, very few advances have been made in the synthesis of phosphorylated TNA compounds. Here, we describe a highly efficient method for synthesizing α-l-threofuranosyl nucleoside 3′-monophosphates (tNMPs), 3′-phosphoro­(2-methyl)­imidazolides (2-MeImptNs), and 3′-triphosphates (tNTPs) bearing the four genetic bases of adenine (A), cytosine (C), thymine (T), and guanine (G). We suggest that this strategy, which provides access to grams of tNMPs, hundreds of milligrams of 2-MeImptNs, and tens of milligrams of tNTPs, will help advance the use of TNA monomers in Exobiology and biotechnology applications

Saikat Bala - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis of α-l-Threofuranosyl Nucleoside 3'-Monophosphates, 3'-Phosphoro(2-Methyl)imidazolides, and 3'-Triphosphates.
    The Journal of Organic Chemistry, 2017
    Co-Authors: Saikat Bala, Jen-yu Liao, Hui Mei, John C. Chaput
    Abstract:

    α-l-Threofuranosyl nucleic acid (TNA) is an artificial genetic polymer composed of vicinal 2′,3′-phosphodiester bonds linking adjacent threofuranosyl nucleosides. TNA is one of a small number of genetic polymers that are both highly resistant to nuclease digestion and capable of cross-pairing with DNA and RNA. Although an efficient method for synthesizing TNA nucleosides has been reported, very few advances have been made in the synthesis of phosphorylated TNA compounds. Here, we describe a highly efficient method for synthesizing α-l-threofuranosyl nucleoside 3′-monophosphates (tNMPs), 3′-phosphoro(2-methyl)imidazolides (2-MeImptNs), and 3′-triphosphates (tNTPs) bearing the four genetic bases of adenine (A), cytosine (C), thymine (T), and guanine (G). We suggest that this strategy, which provides access to grams of tNMPs, hundreds of milligrams of 2-MeImptNs, and tens of milligrams of tNTPs, will help advance the use of TNA monomers in Exobiology and biotechnology applications.

  • Synthesis of α‑l‑Threofuranosyl Nucleoside 3′-Monophosphates, 3′-Phosphoro(2-Methyl)imidazolides, and 3′-Triphosphates
    2017
    Co-Authors: Saikat Bala, Jen-yu Liao, Hui Mei, John C. Chaput
    Abstract:

    α-l-Threofuranosyl nucleic acid (TNA) is an artificial genetic polymer composed of vicinal 2′,3′-phosphodiester bonds linking adjacent threofuranosyl nucleosides. TNA is one of a small number of genetic polymers that are both highly resistant to nuclease digestion and capable of cross-pairing with DNA and RNA. Although an efficient method for synthesizing TNA nucleosides has been reported, very few advances have been made in the synthesis of phosphorylated TNA compounds. Here, we describe a highly efficient method for synthesizing α-l-threofuranosyl nucleoside 3′-monophosphates (tNMPs), 3′-phosphoro­(2-methyl)­imidazolides (2-MeImptNs), and 3′-triphosphates (tNTPs) bearing the four genetic bases of adenine (A), cytosine (C), thymine (T), and guanine (G). We suggest that this strategy, which provides access to grams of tNMPs, hundreds of milligrams of 2-MeImptNs, and tens of milligrams of tNTPs, will help advance the use of TNA monomers in Exobiology and biotechnology applications

Hui Mei - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis of α-l-Threofuranosyl Nucleoside 3'-Monophosphates, 3'-Phosphoro(2-Methyl)imidazolides, and 3'-Triphosphates.
    The Journal of Organic Chemistry, 2017
    Co-Authors: Saikat Bala, Jen-yu Liao, Hui Mei, John C. Chaput
    Abstract:

    α-l-Threofuranosyl nucleic acid (TNA) is an artificial genetic polymer composed of vicinal 2′,3′-phosphodiester bonds linking adjacent threofuranosyl nucleosides. TNA is one of a small number of genetic polymers that are both highly resistant to nuclease digestion and capable of cross-pairing with DNA and RNA. Although an efficient method for synthesizing TNA nucleosides has been reported, very few advances have been made in the synthesis of phosphorylated TNA compounds. Here, we describe a highly efficient method for synthesizing α-l-threofuranosyl nucleoside 3′-monophosphates (tNMPs), 3′-phosphoro(2-methyl)imidazolides (2-MeImptNs), and 3′-triphosphates (tNTPs) bearing the four genetic bases of adenine (A), cytosine (C), thymine (T), and guanine (G). We suggest that this strategy, which provides access to grams of tNMPs, hundreds of milligrams of 2-MeImptNs, and tens of milligrams of tNTPs, will help advance the use of TNA monomers in Exobiology and biotechnology applications.

  • Synthesis of α‑l‑Threofuranosyl Nucleoside 3′-Monophosphates, 3′-Phosphoro(2-Methyl)imidazolides, and 3′-Triphosphates
    2017
    Co-Authors: Saikat Bala, Jen-yu Liao, Hui Mei, John C. Chaput
    Abstract:

    α-l-Threofuranosyl nucleic acid (TNA) is an artificial genetic polymer composed of vicinal 2′,3′-phosphodiester bonds linking adjacent threofuranosyl nucleosides. TNA is one of a small number of genetic polymers that are both highly resistant to nuclease digestion and capable of cross-pairing with DNA and RNA. Although an efficient method for synthesizing TNA nucleosides has been reported, very few advances have been made in the synthesis of phosphorylated TNA compounds. Here, we describe a highly efficient method for synthesizing α-l-threofuranosyl nucleoside 3′-monophosphates (tNMPs), 3′-phosphoro­(2-methyl)­imidazolides (2-MeImptNs), and 3′-triphosphates (tNTPs) bearing the four genetic bases of adenine (A), cytosine (C), thymine (T), and guanine (G). We suggest that this strategy, which provides access to grams of tNMPs, hundreds of milligrams of 2-MeImptNs, and tens of milligrams of tNTPs, will help advance the use of TNA monomers in Exobiology and biotechnology applications

Jen-yu Liao - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis of α-l-Threofuranosyl Nucleoside 3'-Monophosphates, 3'-Phosphoro(2-Methyl)imidazolides, and 3'-Triphosphates.
    The Journal of Organic Chemistry, 2017
    Co-Authors: Saikat Bala, Jen-yu Liao, Hui Mei, John C. Chaput
    Abstract:

    α-l-Threofuranosyl nucleic acid (TNA) is an artificial genetic polymer composed of vicinal 2′,3′-phosphodiester bonds linking adjacent threofuranosyl nucleosides. TNA is one of a small number of genetic polymers that are both highly resistant to nuclease digestion and capable of cross-pairing with DNA and RNA. Although an efficient method for synthesizing TNA nucleosides has been reported, very few advances have been made in the synthesis of phosphorylated TNA compounds. Here, we describe a highly efficient method for synthesizing α-l-threofuranosyl nucleoside 3′-monophosphates (tNMPs), 3′-phosphoro(2-methyl)imidazolides (2-MeImptNs), and 3′-triphosphates (tNTPs) bearing the four genetic bases of adenine (A), cytosine (C), thymine (T), and guanine (G). We suggest that this strategy, which provides access to grams of tNMPs, hundreds of milligrams of 2-MeImptNs, and tens of milligrams of tNTPs, will help advance the use of TNA monomers in Exobiology and biotechnology applications.

  • Synthesis of α‑l‑Threofuranosyl Nucleoside 3′-Monophosphates, 3′-Phosphoro(2-Methyl)imidazolides, and 3′-Triphosphates
    2017
    Co-Authors: Saikat Bala, Jen-yu Liao, Hui Mei, John C. Chaput
    Abstract:

    α-l-Threofuranosyl nucleic acid (TNA) is an artificial genetic polymer composed of vicinal 2′,3′-phosphodiester bonds linking adjacent threofuranosyl nucleosides. TNA is one of a small number of genetic polymers that are both highly resistant to nuclease digestion and capable of cross-pairing with DNA and RNA. Although an efficient method for synthesizing TNA nucleosides has been reported, very few advances have been made in the synthesis of phosphorylated TNA compounds. Here, we describe a highly efficient method for synthesizing α-l-threofuranosyl nucleoside 3′-monophosphates (tNMPs), 3′-phosphoro­(2-methyl)­imidazolides (2-MeImptNs), and 3′-triphosphates (tNTPs) bearing the four genetic bases of adenine (A), cytosine (C), thymine (T), and guanine (G). We suggest that this strategy, which provides access to grams of tNMPs, hundreds of milligrams of 2-MeImptNs, and tens of milligrams of tNTPs, will help advance the use of TNA monomers in Exobiology and biotechnology applications

M R Sims - One of the best experts on this subject based on the ideXlab platform.

  • beagle 2 the next Exobiology mission to mars
    General Meeting of the NASA Astrobiology Insititute, 2001
    Co-Authors: Everett K Gibson, C T Pillinger, I P Wright, A D Morse, Jenny Stewart, Geraint Morgan, Ian Praine, Dennis Leigh, M R Sims
    Abstract:

    Beagle 2 is a 60 kg probe (with a 30 kg lander) developed in the United Kingdom for inclusion on the European Space Agency's 2003 Mars Express. Beagle 2 will deliver to the Martian surface a payload which consists of a high percentage of science instruments to landed spacecraft mass. Beagle 2 will be launched in June, 2003 with Mars Express on a Soyuz-Fregat rocket from the Baikonur Cosmodrome in Kazakhstan. Beagle 2 will land on Mars on December 26, 2003 in the Isidis Planitia basin (approximately 10 degrees N and 275 degrees W), a large sedimentary basin that overlies the boundary between ancient highlands and northern plains. Isidis Planitia, the third largest basin on Mars, which is possibly filled with sediment deposited at the bottom of long-standing lakes or seas, offers an ideal environment for preserving traces of life. Beagle 2 was developed to search for organic material and other volatiles on and below the surface of Mars in addition to the study of the inorganic chemistry and mineralogy. Beagle 2 will utilize a mechanical mole and grinder to obtain samples from below the surface, under rocks and inside rocks. A pair of stereo cameras will image the landing site along with a microscope for examination of surface and rock samples. Analyses will include both rock and soil samples at various wavelengths, X-ray spectrometer and Mossbauer spectrometer as well as a search for organics and other light element species (e.g. carbonates and water) and measurement of their isotopic compositions. Beagle 2 has as its focus the goal of establishing whether evidence for life existed in the past on Mars at the Isidis Planitia site or at least establishing if the conditions were ever suitable. Carbonates and organic components were first recognized as existing on Mars when they were found in the Martian meteorite Nakhla. Romanek et al showed the carbonates in ALH84001 were formed at low temperatures. McKay et al noted possible evidence of early life on Mars within the ALH84001 meteorite. Thomas-Keprta et al showed the magnetite biomarkers in ALH84001's carbonates are indistinguishable from those formed by magnetotactic bacteria found on Earth. Gibson et al showed there was significant evidence for liquid water and biogenic products present on Mars across a 3.9 billion year period. A mechanical arm (PAW) operates from the lander and is used for science operations along with sample acquisition. Instruments attached to the PAW include: stereo cameras, Mossbauer instrument, X-ray fluorescence instrument, microscope, environmental sensors, rock corer/grinder, a spoon, mirror, brushes, a mole attachment for acquisition of subsurface to depths of 1 to 2 meters and an illumination device. Each camera has 14 filters which have been optimized for mineralogy composition, dust and water vapor detection. The microscope's camera is designed for viewing the size and shape of dust particles, rock surfaces, microfossils, and characteristics of the samples prior to introduction into the gas analysis package (GAP). The camera has a resolution of 4 microns/pixel, features four color capability (red, green, blue and UV (ultraviolet) fluoresence), a depth of focus of 40 micrometers and translation stage of +3 millimeters. The heart of the Beagle 2's life detection package is the gas analysis package (GAP), which consists of a mass spectrometer with collectors at fixed masses for precise isotopic ratio measurements and voltage scanning for spectral analysis. Primary aim of the GAP is to search for the presence of bulk constituents, individual species, and isotopic fractionations for both extinct and extent life along with studying the low-temperature geochemistry of the hydrogen, carbon, nitrogen and oxygen components on Mars from both the surface and atmosphere. GAP is a magnetic sector mass spectrometer with the range of 1 to 140 amu which can be operated in both the static and dynamic modes. A triple Faraday collector array will be used for C, N and O ratios along with a double Faraday array for H/D. Pulse counting electron multiplier will be utilized for noble gases and selected organics. Anticipated detection limits are at the picomole level for operation in the static mode of operation and high precision isotopic measurements will be made in the dynamic mode. Sample processing and preparation system consists of reaction vessels along with references. Sample ovens capable of being heated are attached to the manifold for sample combustion. Surface, subsurface materials and interior rock specimens will be combusted in pure oxygen gas at various temperature intervals to release organic matter and volatiles. Combustion process will permit detection of all forms and all atoms of carbon present in the samples. A chemical processing system is capable of a variety of conversion reactions. Gases are manipulated either by cryogenic or chemical reactions and passed through the gas handling portion of the vacuum system. There are two modes of operation: quantitative analysis and precise isotopic measurements. Additional information is contained in the original extended abstract.

  • beagle 2 a proposed Exobiology lander for esa s 2003 mars express mission
    Advances in Space Research, 1999
    Co-Authors: M R Sims, C T Pillinger, I P Wright, J Dowson, S Whitehead, A Wells, J E Spragg, George W Fraser, L Richter, H Hamacher
    Abstract:

    Abstract The aim of the proposed Beagle 2 small lander for ESA's 2003 Mars Express mission is to search for organic material on and below the surface of Mars and to study the inorganic chemistry and mineralogy of the landing site. The lander will have a total mass of 60kg including entry, descent, and landing system. Experiments will be deployed on the surface using a robotic arm. It will use a mechanical mole and grinder to obtain samples from below the surface, under rocks, and inside rocks. Sample analysis by a mass spectrometer will include isotopic analysis. An optical microscope, an X- ray spectrometer and a Mossbauer spectrometer will conduct in-situ rock studies.

  • beagle 2 a proposed Exobiology lander for esa s 2003 mars express mission
    SPIE's International Symposium on Optical Science Engineering and Instrumentation, 1998
    Co-Authors: M R Sims, C T Pillinger, I P Wright, S Whitehead, A Wells, L Richter, Richard E Cole, K Wittmann, H Kochan, H Hamacher
    Abstract:

    The proposed Beagle 2 lander for ESA's 2003 Mars Express mission will be described. The aim of Beagle 2 will be to search for organic material on and below the surface of Mars in addition to a study of the inorganic chemistry and mineralogy of the landing site. The lander will utilize a small rover equipped with a mechanical and grinder to obtained samples from below the surface, under rocks, and inside rocks. Samples will be returned to the lander for analysis. Analysis performed by Beagle 2 will include examination of samples with an optical microscope and APX and Mossbauer Spectrometers as well as a search for organics and a measurement of their isotopic composition. The lander systems design as well as the experiment configuration will be described.