Base analog incorporation into

One of the lines of approach of such an investigation is the study of analogs of nucleic acid bases. The objective here is to prepare such analogs as would be incorporated into the nucleic acid molecules on the basis of their similarity to the natural species or as could interfere at some of the steps of nucleic acid biosynthesis. 

Most of the early vibration analysis was carried out using analog equipment, which necessitated the use of time-domain data. The reason for this is that it was difficult to convert time-domain data to frequency-domain data. Therefore, frequency-domain capability was not available until microprocessor-based analyzers incorporated a straightforward method (i.e.. Fast Fourier Transform, FFT) of transforming the time-domain spectmm into its frequency components. 

It has been found that 6-aminopyrazinone (Scheme 2), when incorporated as a pyrimidine base analog into an ohgonucleotide, might participate in a nonstandard base pair that retains Watson-Crick geometry [14],... 

Synthetic analogs of purine and pyrimidine bases and their derivatives serve as anticancer dmgs either by inhibiting an enzyme of nucleotide biosynthesis or by being incorporated into DNA or RNA. 

Generally, DNMT inhibitors can be divided in two big dasses. One group consists of base analogs which are incorporated into DNA and act as suidde substrates for DNMT via a covalent adduct formation. The other group acts on the free enzyme in the same way as classic enzyme inhibitors do. 

One way in which chemical compounds can induce base substitution mutation is through their incorporation into the structure of DNA itself. Thus, 5-bromodeoxyuridine (or bromouracil) can replace thymidine in DNA, where it serves as an efficient mutagenic agent.767 2-Aminopurine, an analog of adenine, pairs with thymine, just as does adenine when incorporated into DNA. 

The biosynthetic pathway to pyrimidine nucleotides is simpler than that for purine nucleotides, reflecting the simpler structure of the base. In contrast to the biosynthetic pathway for purine nucleotides, in the pyrimidine pathway the pyrimidine ring is constructed before ribose-5-phosphate is incorporated into the nucleotide. The first pyrimidine mononucleotide to be synthesized is orotidine-5 -monophosphate (OMP), and from this compound, pathways lead to nucleotides of uracil, cytosine, and thymine. OMP thus occupies a central role in pyrimidine nucleotide biosynthesis, somewhat analogous to the position of IMP in purine nucleotide biosynthesis. Like IMP, OMP is found only in low concentrations in cells and is not a constituent of RNA. 

This can be contrasted with metal ion and anion catalyses, where the metal ion, or the anion, is incorporated into the activated complex, but is regenerated after the reaction. They are thus genuine catalysts for these hydrolyses, analogous to acid catalysis, and in direct contrast to the so-called base catalysed hydrolysis. These comments are pertinent to the following problem. 

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