in this paper,the molecular geometry for three tautomers of uracil and four tautomers of cytosine has been analyzed. vibrational ir spectra of the tautomers were   investigated at hf and b3lyp level using the ab initio 6-31g* and lanl2dz basis sets from the program package gaussian 98 (a.7 public domain version). the physico-chemical and biochemical properties of uracil and cytosine are one of...

In this paper,the molecular geometry for three tautomers of uracil and four tautomers of cytosine has been analyzed. vibrational IR spectra of the tautomers were   investigated at HF and B3LYP level using the AB initio 6-31G* and LANL2DZ basis sets from the program package Gaussian 98 (A.7 Public Domain version). The physico-chemical and biochemical properties of uracil and cytosine are one of...

this study is about complexes of li doped silicon carbide nanotube with thymine and cytosine ingas phase and aqueous solutions. li doped silicon carbide nanotube and its pyrimidine nucleobasecompounds were first modeled by quantum mechanical calculations in gas phase and in water.calculated binding energies indicated the stronger ability of thymine to functionalize silicon carbidenanotube than ...

The i-motif DNA, also known as i-DNA, is a non-canonical DNA secondary structure formed by cytosine-rich sequences, consisting of two intercalated parallel-stranded duplexes held together hemi-protonated cytosine–cytosine+ (C:C+) base pairs. growing interest in the i-DNA target anticancer therapy increases need for tools rapid and meaningful interpretation spectroscopic data samples. Herein, we...

The selective N-4 alkylation of cytosine plays a critical role in the synthesis biologically active molecules. This work focuses on development practical reaction conditions toward regioselective N-4-alkyl derivatives. sequence includes direct and sulfonylation at N-1 site cytosine, followed by amino using KHMDS CH2Cl2/THF mixture, providing fast efficient approach consistent with pyrimidine-ba...

X-ray photoelectron spectroscopy was used to analyze commercially available powders of thymine, uracil, cytosine, guanine, adenine, as well DNA isolated from salmon testes and RNA torula yeast. The were pressed onto a sample holder analyzed received the manufacturer. Survey spectra high-resolution O 1s, N C 1s all nucleobases are reported, including small Na contamination in cytosine. Spectra a...

application of nuclear magnetic resonance imaging (nmri) as a non-invasive and accurate imaging procedure has been widely used in recent years. meanwhile, the biological effects of magnetic fields of several tesla (t) and high energy radiofrequency (rf) is not fully known yet. because of controversy over this issue, the present research has been carried out in order to verify the effects of mag...

This study is about Complexes of Li doped silicon carbide nanotube with Thymine and Cytosine ingas phase and aqueous solutions. Li doped silicon carbide nanotube and its pyrimidine nucleobasecompounds were first modeled by Quantum mechanical calculations in gas phase and in water.Calculated binding energies indicated the stronger ability of thymine to functionalize silicon carbidenanotube than ...

We describe here the first crystalline hydrogen-bonded organic framework made from complementary guanine and cytosine nucleobases.