Formate (l), serine (2)) formaldehyde (3), and methionine (4) each can serve as the donor of the carbon atom for the biosynthesis of the methyl group of DNA’-thymine. The utilization of formate for the biosynthesis of DNA in vitro has been reported previously (5-g), and in most instances the uptake of formate carbon under these conditions has been primarily into the methyl group of thymine (5)....

Thymine intermediate 17 has been synthesized on a multigram scale (50 g, 70 mmol) from starting sugar 1 in 15 steps in an overall yield of 73%, with only 5 purification steps. The key thymine intermediate 18 was obtained from 17 in a single step in 96% yield, whereas the key 5-methylcytosine intermediate 20 was obtained from 17 in 2 steps in 58% yield. This highly efficient large scale route ne...

Oligonucleotides containing 1-(2,4-dideoxy-beta-D-erythro-hexopyranosyl)thymine (2) and 1-(3,4-dideoxy-beta-D-erythro-hexopyranosyl)thymine (3) were synthesized on a solid support using the phosphoramidite approach. The properties of these oligonucleotides were compared with the earlier reported characteristics of oligonucleotides containing 1-(2,3-dideoxy-beta-D-erythro-hexopyranosyl) thymine ...

The paramagnetic gadolinium(III) ion is used as contrast agent in magnetic resonance (MR) imaging to improve the lesion detection and characterization. It generates a signal by changing relaxivity of protons from associated water molecules creates clearer physical distinction between molecule surrounding tissues. New gadolinium-based agents displaying larger values specifically targeted might p...

Although the immobilization of oligonucleotides (nucleic acid) on mineral surfaces is at basis different biotechnological applications, an atomistic understanding interaction nucleic acid components with titanium dioxide has not yet been achieved. Here, adsorption phosphate anion, four DNA bases (adenine, guanine, thymine, and cytosine) some entire nucleotides dinucleotides TiO2 anatase (1 0 1)...

Exposure of pyrimidines of DNA to ionizing radiation under aerobic conditions or oxidizing agents results in attack on the 5,6 double bond of the pyrimidine ring or on the exocyclic 5-methyl group. The primary product of oxidation of the 5,6 double bond of thymine is thymine glycol, while oxidation of the 5-methyl group yields 5-hydroxymethyluracil. Oxidation of the 5,6 double bond of cytosine ...

The kinetics of triplet state quenching of 3,3',4,4'-benzophenone tetracarboxylic acid (BPTC) by DNA bases adenine, adenosine, thymine, and thymidine has been investigated in aqueous solution using time-resolved laser flash photolysis. The observation of the BPTC ketyl radical anion at λ(max) = 630 nm indicates that one electron transfer is involved in the quenching reactions. The pH-dependence...