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Nucleic bases

The quantum yield of the nucleic acids depends largely on the temperature. [Pg.123]

The fluorescence polarization is high even at ambient temperature [Pg.123]

Puric bases fluoresce at least three times more than pyrimidic bases The guanidine is the most fluorescent basis. [Pg.123]

DNA and RNA display in the native state a veiy weak fluorescence, to the difference of the transfer RNA of yeast (t-RNA) that contains a highly fluorescent basis called Y. baas. [Pg.123]

At 77 K, fluorescence of DNA and RNA increases. This fluorescence is owed to the formation of dimers of adenine and thymine, while the fluorescence of the guanine and the cytosine is inhibited. [Pg.123]


The fundamental problem of oligodeoxyribonucleotide synthesis is the efficient formation of the intemucleotidic phosphodiester bond specifically between C-3 and C-5 positions of two adjacent nucleosides. Any functional group (NH of nucleic base the other OH of deoxy-... [Pg.215]

Copper(I) tends towards a tetrahedral coordination geometry in complexes. With 2,2 -bipyr-idine as a chelate ligand a distorted tetrahedral coordination with almost orthogonal ligands results. 2,2 -Bipyridine oligomers with flexible 6,6 -links therefore form double helices with two 2,2 -bipyridine units per copper(I) ion (J. M. Lehn, 1987,1988). J. M. Lehn (1990 U. Koert, 1990) has also prepared such helicates with nucleosides, e.g., thymidine, covalently attached to suitable spacers to obtain water-soluble double helix complexes, so-called inverted DNA , with internal positive charges and external nucleic bases. Cooperative effects lead preferentially to two identical strands in these helicates when copper(I) ions are added to a mixture of two different homooligomers. [Pg.345]

Genesis of nucleic bases, nucleotides, and nucleosides the problem of RNA origin and its role in life origin 99T3141. [Pg.263]

In sum, RNAi clearly has the potential to change the nucleic-based therapies for cancer, infectious diseases, and many other diseases. However, the universality of this approach, the types of genes that can be silenced using these strategies in human cells, remain unknown to date. [Pg.1093]

Another class of molecules which are easily bound to hosts by hydrogen bonds are nucleic bases and related molecules like barbiturates (Hamilton and Little, 1990 Chang et al., 1991). The receptor arrays to bind such molecules often contain 2-acylaminopyridine units or related structures such... [Pg.109]

Calf thymus (CT) DNA was first fragmented by sonication, then purified by a standard procedure. Agarose gel electrophoresis for the sonicated CT DNA revealed a distribution in molecular weight ranging from 30 kDa to 260 kDa which is equivalent in base pairs (bp) from 40 to 400 (1 bp = 660 Da). The DNA fragments were reacted with HEDS in the presence of l-cyclohexyl-3-(2-morpholinoethyl) carbodi-imide metho-p-toluenesulfonate (CMC/jTs). Finally, the reaction mixture was gel-filtered and the macro-molecular fractions, when displayed the characteristic absorption of 260 nm of the nucleic bases, were collected. [Pg.519]

Construction of the nucleic base via a multi-step process, centered on the monosaccharide structure.104... [Pg.155]

PES has been applied to study biologically active molecules with amino groups and their constituents like nucleic bases and related compounds (e.g. adenine, guanine, thymine, cytosine, hypoxanthine and their methyl derivatives)113-120 and amino acids92,121,122 or their methyl esters123. [Pg.188]

Yeh and Falvey 1991). However, the cyclobutyl dimer of a quinone, and a dithymoquinone, also cleaves on single-electron rednction but much slower than the pyrimidine dimers (Robbins and Falvey 1993). It is truly an unresolved issue as to why the anion-radical cleavage depicted in Scheme 3.72 is so facile. Water participation can probably decrease the barrier of the cycloreversion on physiological conditions (Saettel and Wiest 2001, 2006). Besides, hydration effect is known to increase the electron affinities of nucleic bases (Scheidt et al. 1998, Kim and Schaefer 2007a, 2007b). [Pg.193]

LCA toward amino acids and nucleic bases has also been measured. Wesdemiotis and Cerda measured the alkali metal ion affinities of nucleobases in the gas phase from the dissociation of metal ion-bound heterodimers [nucleobase + B]M+, in which B represents a reference base of known affinity and M is an alkali metal. By assessing the dimer decomposition for two different internal energies, entropy is deconvoluted from enthalpy and LCA values are obtained. For guanine, cytosine, adenine, thymine and uracil, the corresponding Li+-nucleobase bond energies are as follows 57.2, 55.5, 54.1,... [Pg.213]

Nucleic Base Acidities. The N1 and N3 Acidities of Uracil. Published in J. Am Chem. Soc. 2000, 122, 6258-6262. Our progress to date involves calculations and experiments for the determination of nucleobase activities. We have learned that there is an enormous difference in the inherent stabilities of anions at the N1 (7) and N3 (8) positions in uracil (3a, Figure 1). [Pg.439]

Vanommeslaeghe K, Mignon P, Loverix S, Tourwe D, Geerlings P. Influence of stacking on the hydrogen bond donating potential of nucleic bases. J Chem Theory Comput 2006 2 1444-1452. [Pg.101]

Nucleic Bases and Other Biochemical Compounds It has been found that cytosine is physisorbed at negative potentials and chemisorbed at positive potentials on Au electrodes from 0.1 M NaCl04 and HCIO4 aqueous solutions [290]. In cyclic voltammogram... [Pg.872]

Friedel-Crafts coupling of an aromatic compound with an activated glycosyl donor is a classic, standard method for C-aryl glycoside synthesis [1,2]. Early interests were primarily centered at C-nucleoside synthesis, so that data were accumulated for the ribofuranosyl series with degradable aromatics to construct the nucleic base (Scheme 2) [5]. Equation (1)... [Pg.530]

Table 10 The Nucleic Bases, Their Proton Ionization Constants (pit,), and the Nomenclature of Their Nucleoside and Nucleotide Derivatives... Table 10 The Nucleic Bases, Their Proton Ionization Constants (pit,), and the Nomenclature of Their Nucleoside and Nucleotide Derivatives...
Since the nucleic bases are not found naturally as free bases, their coordinating properties will only be briefly summarized. It should also be pointed out that two of the potential binding atoms,... [Pg.976]

From the observations in purine and other nucleic bases (4) it appears that the components perpendicular to the direction of the HB bond are the most affected by the interactions. Unfortunately, it is difficult to secure quantitative information from observations in actual compounds because the direction of the HB interaction is not aligned with any of the principal components of the chemical shift tensors. [Pg.171]


See other pages where Nucleic bases is mentioned: [Pg.218]    [Pg.11]    [Pg.97]    [Pg.136]    [Pg.171]    [Pg.110]    [Pg.519]    [Pg.420]    [Pg.93]    [Pg.100]    [Pg.103]    [Pg.319]    [Pg.90]    [Pg.44]    [Pg.640]    [Pg.17]    [Pg.26]    [Pg.49]    [Pg.840]    [Pg.958]    [Pg.975]    [Pg.14]    [Pg.157]    [Pg.218]    [Pg.204]    [Pg.208]    [Pg.209]    [Pg.212]    [Pg.323]    [Pg.284]   
See also in sourсe #XX -- [ Pg.233 , Pg.234 ]

See also in sourсe #XX -- [ Pg.3 , Pg.41 ]

See also in sourсe #XX -- [ Pg.3 , Pg.41 ]

See also in sourсe #XX -- [ Pg.428 ]

See also in sourсe #XX -- [ Pg.61 ]




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