The Experts below are selected from a list of 10257 Experts worldwide ranked by ideXlab platform
Thomas Carell - One of the best experts on this subject based on the ideXlab platform.
-
a one pot water compatible synthesis of pyrimidine Nucleobases under plausible prebiotic conditions
Chemical Communications, 2019Co-Authors: Hidenori Okamura, Sidney Becker, Niklas Tiede, Stefan Wiedemann, Jonas Feldmann, Thomas CarellAbstract:Herein, we report a new prebiotically plausible pathway towards a pyrimidine Nucleobase in continuous manner. The route involves simultaneous methylation and carbamoylation of cyanoacetylene-derived α,β-unsaturated thioamide with N-methyl-N-nitrosourea (MNU) in aqueous media. This provides S-methylpyrimidinone in one-pot, which can be converted into a variety of 4-substituted pyrimidine Nucleobases including cytosine and uracil.
-
The chemistries and consequences of DNA and RNA methylation and demethylation.
RNA Biology, 2017Co-Authors: Franziska R. Traube, Thomas CarellAbstract:Chemical modification of Nucleobases plays an important role for the control of gene expression on different levels. That includes the modulation of translation by modified tRNA-bases or silencing and reactivation of genes by methylation and demethylation of cytosine in promoter regions. Especially dynamic methylation of adenine and cytosine is essential for cells to adapt to their environment or for the development of complex organisms from a single cell. Errors in the cytosine methylation pattern are associated with most types of cancer and bacteria use methylated Nucleobases to resist antibiotics. This Point of View wants to shed light on the known and potential chemistry of DNA and RNA methylation and demethylation. Understanding the chemistry of these processes on a molecular level is the first step towards a deeper knowledge about their regulation and function and will help us to find ways how Nucleobase methylation can be manipulated to treat diseases.
Huantsung Chang - One of the best experts on this subject based on the ideXlab platform.
-
biomarkers of cigarette smoking and dna methylating agents raman sers and dft study of 3 methyladenine and 7 methyladenine
Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy, 2017Co-Authors: Scott G Harroun, Yaoting Zhang, Tzuheng Chen, Chingrong Ku, Huantsung ChangAbstract:3-Methyladenine and 7-methyladenine are biomarkers of DNA damage from exposure to methylating agents. For example, the concentration of 3-methyladenine increases significantly in the urine of cigarette smokers. Surface-enhanced Raman spectroscopy (SERS) has shown much potential for detection of biomolecules, including DNA. Much work has been dedicated to the canonical Nucleobases, with comparatively fewer investigations of modified DNA and modified DNA Nucleobases. Herein, Raman spectroscopy and SERS are used to examine the adsorption orientations of 3-methyladenine and 7-methyladenine on Ag nanoparticles. Density functional theory (DFT) calculations at the B3LYP level are used to support the conclusions via simulated spectra of the Nucleobases and of Ag+/Nucleobase complexes. The results herein show that 7-methyladenine adsorbs upright via its N3 and N9 atoms side, similarly to adenine. 3-Methyladenine adsorbs in a very tilted or flat orientation on the Ag nanoparticles. These findings will be useful for future SERS or other nanoparticle-based bioanalytical assays for detection of these methyladenines or other modified Nucleobases.
Sonia Perezyanez - One of the best experts on this subject based on the ideXlab platform.
-
porous materials based on metal Nucleobase systems sustained by coordination bonds and base pairing interactions
CrystEngComm, 2015Co-Authors: Garikoitz Beobide, Oscar Castillo, Antonio Luque, Sonia PerezyanezAbstract:The present work summarizes the different approaches that can be applied to achieve porous materials based on metal–Nucleobase systems. The rigidity and the multiple donor sites of the Nucleobases make them suitable linkers to provide coordination bond sustained metal–organic frameworks (MOFs). Furthermore, the ability of the Nucleobases to establish complementary hydrogen bonding interactions allows one to achieve similar metal–Nucleobase porous materials but sustained by hydrogen bond pairing interactions between the Nucleobases (supramolecular metal–organic frameworks, SMOFs).
-
metal carboxylato Nucleobase systems from supramolecular assemblies to 3d porous materials
Coordination Chemistry Reviews, 2013Co-Authors: Garikoitz Beobide, Oscar Castillo, Antonio Luque, Sonia Perezyanez, Javier Cepeda, Pascual Roman, Jintha ThomasgipsonAbstract:Abstract A complete overview of the preparation of metal–carboxylato–Nucleobase architectures that range from supramolecular assemblies to 3D porous materials is reported. The basic building units of these materials consist of metal–Nucleobase fragments which link together through coordination bonding or by means of supramolecular assembling among the Nucleobases anchored to metal centres. In the case of extended systems based on coordination bonds, the connectivity among the metal centres can be achieved through bridging Nucleobases and/or by auxiliary organic linkers such as carboxylate and dicarboxylate anions. The latter bridging mode confers to the Nucleobases a greater capacity to involve in molecular recognition processes with other biologically relevant species by means of the establishment of non-covalent interactions such as hydrogen bonding and/or π–π stacking among aromatic groups. On the other hand, the geometrical rigidity imposed by several metal–Nucleobase fragments and the base pairing interactions through complementary hydrogen bonding, lead to structural restraints that preclude an effective filling of the space, and as a consequence, it favours the growth of tailor-made open-frameworks based either on coordination bonds (MBioFs) or on non-covalent interactions (supraMBioFs).
Garikoitz Beobide - One of the best experts on this subject based on the ideXlab platform.
-
porous materials based on metal Nucleobase systems sustained by coordination bonds and base pairing interactions
CrystEngComm, 2015Co-Authors: Garikoitz Beobide, Oscar Castillo, Antonio Luque, Sonia PerezyanezAbstract:The present work summarizes the different approaches that can be applied to achieve porous materials based on metal–Nucleobase systems. The rigidity and the multiple donor sites of the Nucleobases make them suitable linkers to provide coordination bond sustained metal–organic frameworks (MOFs). Furthermore, the ability of the Nucleobases to establish complementary hydrogen bonding interactions allows one to achieve similar metal–Nucleobase porous materials but sustained by hydrogen bond pairing interactions between the Nucleobases (supramolecular metal–organic frameworks, SMOFs).
-
metal carboxylato Nucleobase systems from supramolecular assemblies to 3d porous materials
Coordination Chemistry Reviews, 2013Co-Authors: Garikoitz Beobide, Oscar Castillo, Antonio Luque, Sonia Perezyanez, Javier Cepeda, Pascual Roman, Jintha ThomasgipsonAbstract:Abstract A complete overview of the preparation of metal–carboxylato–Nucleobase architectures that range from supramolecular assemblies to 3D porous materials is reported. The basic building units of these materials consist of metal–Nucleobase fragments which link together through coordination bonding or by means of supramolecular assembling among the Nucleobases anchored to metal centres. In the case of extended systems based on coordination bonds, the connectivity among the metal centres can be achieved through bridging Nucleobases and/or by auxiliary organic linkers such as carboxylate and dicarboxylate anions. The latter bridging mode confers to the Nucleobases a greater capacity to involve in molecular recognition processes with other biologically relevant species by means of the establishment of non-covalent interactions such as hydrogen bonding and/or π–π stacking among aromatic groups. On the other hand, the geometrical rigidity imposed by several metal–Nucleobase fragments and the base pairing interactions through complementary hydrogen bonding, lead to structural restraints that preclude an effective filling of the space, and as a consequence, it favours the growth of tailor-made open-frameworks based either on coordination bonds (MBioFs) or on non-covalent interactions (supraMBioFs).
Ralph E. Pudritz - One of the best experts on this subject based on the ideXlab platform.
-
SEEDING THE PREGENETIC EARTH: METEORITIC ABUNDANCES OF NucleobaseS AND POTENTIAL REACTION PATHWAYS
The Astrophysical Journal, 2015Co-Authors: Ben K. D. Pearce, Ralph E. PudritzAbstract:Carbonaceous chondrites are a class of meteorite known for having high contents of water and organics. In this study, the abundances of the Nucleobases, i.e., the building blocks of RNA and DNA, found in carbonaceous chondrites are collated from a variety of published data and compared across various meteorite classes. An extensive review of abiotic chemical reactions producing Nucleobases is then performed. These reactions are then reduced to a list of 15 individual reaction pathways that could potentially occur within meteorite parent bodies. The Nucleobases guanine, adenine, and uracil are found in carbonaceous chondrites in amounts of 1–500 ppb. It is currently unknown which reaction is responsible for their synthesis within the meteorite parent bodies. One class of carbonaceous meteorite dominates the abundances of both amino acids and Nucleobases—the so-called CM2 (e.g., Murchison meteorite). CR2 meteorites (e.g., Graves Nunataks) also dominate the abundances of amino acids, but are the least abundant in Nucleobases. The abundances of total Nucleobases in these two classes are 330 ± 250 and 16 ± 13 ppb, respectively. Guanine most often has the greatest abundances in carbonaceous chondrites with respect to the other Nucleobases, but is 1–2 orders of magnitude less abundant in CM2 meteorites than glycine (the most abundant amino acid). Our survey of the reaction mechanisms for Nucleobase formation suggests that Fischer–Tropsch synthesis (i.e., CO, H2, and NH3 gases reacting in the presence of a catalyst such as alumina or silica) is the most likely candidate for conditions that characterize the early states of planetesimals.
-
seeding the pregenetic earth meteoritic abundances of Nucleobases and potential reaction pathways
arXiv: Earth and Planetary Astrophysics, 2015Co-Authors: Ben K. D. Pearce, Ralph E. PudritzAbstract:Carbonaceous chondrites are a class of meteorite known for having a high content of water and organics. In this study, abundances of the Nucleobases, i.e., the building blocks of RNA and DNA, found in carbonaceous chondrites are collated from a variety of published data and compared across various meteorite classes. An extensive review of abiotic chemical reactions producing Nucleobases is then performed. These reactions are then reduced to a list of 15 individual reaction pathways that could potentially occur within meteorite parent bodies. The Nucleobases guanine, adenine and uracil are found in carbonaceous chondrites in the amounts of 1$-$500 ppb. It is currently unknown which reaction is responsible for their synthesis within the meteorite parent bodies. One class of carbonaceous meteorites dominate the abundances of both amino acids and Nucleobases$-$the so-called CM2 (e.g. Murchison meteorite). CR2 meteorites (e.g. Graves Nunataks) also dominate the abundances of amino acids, but are the least abundant in Nucleobases. The abundances of total Nucleobases in these two classes are $330 \pm250$ ppb and $16 \pm13$ ppb respectively. Guanine most often has the greatest abundances in carbonaceous chondrites with respect to the other Nucleobases, but is 1$-$2 orders of magnitude less abundant in CM2 meteorites than glycine (the most abundant amino acid). Our survey of the reaction mechanisms for Nucleobase formation suggests that Fischer-Tropsch synthesis (i.e. CO, H$_2$ and NH$_3$ gases reacting in the presence of a catalyst such as alumina or silica) is the most likely for conditions that characterize early states of planetesimals.
