An International Research Journal

AJP

SSN : 0971 - 3093

Vol 26, No 8-10, November-December, 2017


Asian Journal of Physics                                                                                                    Vol. 26 No 11 & 12, 2017, 00-00


The anti-HIV Nucleoside analogue d4T (Stavudine): Solid state simulation by

DFT methods of the FT-IR and FT-Raman spectra


M Alcolea Palafoxa,b, D Kattana,b, and A Nils Kristiana

aNofima AS - the Norwegian Institute of Food, Fisheries and Aquaculture Research, Osloveien 1, 1430 Ås, Norway

bDepartamento de Química-Física I, Facultad de Ciencias Químicas,Universidad Complutense, Madrid-28040, Spain

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The theoretical and experimental vibrational study of the anti-HIV d4T (stavudine or Zerit or 3′-deoxy-2,3´-didehydro thymidine) Nucleoside Analogue was carried out. The calculated spectra were scaled by using the linear scaling equation procedure (LSE). The d4T monomer and dimers were simulated by using DFT methods. The IR spectrum was recorded in the solid state in the region 400-4000 cm-1 and the Raman spectrum was recorded in the region 0-3500 cm-1. The vibrational bands were analyzed and assigned to different normal modes of vibration by comparison with the scaled values of the different dimer forms. Thus, through this comparison, we were able to confirm that the solid state sample corresponds to dimer V. © Anita Publications. All rights reserved.

Keywords: d4T, Stavudine, anti-HIV, IR spectrum, Raman spectrum, DFT

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Asian Journal of Physics                                                                                                    Vol. 26 No 11 & 12, 2017, 00-00

 

2-Thiouracil: Influence of water in the first hydration shell and Effect of the
Sulfur Atom on the Base Pairs 2-Thiouridine-Adenosine


M Alcolea Palafox1,V K Rastogi2,3, S P Singh4 and S K Rathor3

1Departamento de Química-Fisica1. Facultad de Ciencias Químicas. Universidad Complutense. Madrid- 28040. Spain.

2R D Foundation Group of Institutions, NH-58, Kadrabad, Modinagar (Ghaziabad), India

3Indian Spectroscopy Society, KC 68/1, Old Kavinagar, Ghaziabad-201 002, India

4Department of Physics, Dr B R Ambedkar Govt Degree College, Mainpuri, India

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The crystal unit cell of 2-thiouracil (2TU) in the solid state was simulated through a tetramer form using DFT methods. The first and second hydration shells were simulated by explicit number of water molecules surrounding 2TU up to 30. The calculated spectra were compared to the experimental ones. A linear scaling procedure (LSE) was used for this task. The effect of the hydration on different parameters of the molecular structure of 2TU was analyzed. The total atomic charges were discussed. The effect of the sulfur atom on the Watson-Crick (WC) and reverse WC base pair uridine-adenosine was estimated, and the CP corrected interaction energies were calculated. A microhelix RNA:DNA was simulated with two nucleotides base pairs © Anita Publications. All rights reserved.

Keywords: 2-thiouracil, interaction energies, DFT, hydration, scaling, 2-thiouridine, uridine

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