Thymine, electrostatic potential

Thymine, electrostatic potential map of, 1104 structure of, 1101 Thyroxine, biosynthesis of, 551 structure of. 1020 TIme-of-flight (TOP) mass spectrometry, 417-418 Titration curve, alanine, 1023 TMS, see Tetramethylsilane see Trimethylsilyl ether Tollens reagent, 701 Tollens test, 992... 

Bonaccorsi, R., A. Pullman, E. Scrocco, and J. Tomasi. 1972b. The Molecular Electrostatic Potentials for the Nucleic Acid Bases Adenine, Thymine and Cytosine. Theor. Chim. Acta 24, 51. 

As a last example of shape of electrostatic potential, we report here some results for a purinic compound, adenine (XXII). Analogous results for other nucleic acid components, thymine and cytosine, may be found in the source paper29). 

The electrostatic potentials of the nucleic acid bases [adenine (9), guanine (10), cytosine (1), and thymine (11)] were first studied in the early 1970s. Each of these molecules has several likely sites for electrophilic attack V(r)... 

Figure L Molecular topology, atomic numbering, and in-plane molecular electrostatic potential energy maps for a, 9-methylguanine (9-MeG) b, 9-methyladenine (9-MeA) c, 1-methylcytosine (1-MeC) and d, the N 1-deprotonated thymine monoanion (Thy ). Contour levels for the electrostatic potential energy maps are given in kcal/mol as in Ref. 21 and 26.

Thymidine. Under basic conditions, thymine exists as a tautomeric mixture of monoanions (29), with either N(l) or N(3) deprotonated (the N(l) deprotonated tautomer and its electrostatic potential map are Illustrated in Figure 1). Deprotonation of a thymidine residue in a polynucleotide allows the potential for metal attack at N(3). This site is contiguous to two oxo... 

Table 21.4 presents the atomic charges of adsorbed and isolated thymine obtained by the fitting of the electrostatic potential. For uracil and thymine the adsorption... 

Fig. 21.3 Two views of the optimized structure and maps of electrostatic potential of thymine adsorbed on hydrated tetrahedral and octahedral surface of kaolinite mineral (a — K(3t)NaW-TH, b - K(3o)NaW-TH) obtained at the B3LYP/6-31G(d) level of theory...

The characteristics of adsorption binding of thymine and uracil were confirmed by the maps of electrostatic potential drawn for all complexes. The isomorphic substitution and the presence of the cation in both fragments affect the electron redistribution and this influence varies based on the surface type. 

Electrostatic potential maps illustrating hydrogen bonding between thymine and adenine (a) and cytosine and guanine (b). The oxygens are red, and the nitrogens are blue. 

Bonaccorsi R, Pullman A, Scrocco E, Tomasi J (1972) The molecular electrostatic potentials for the nucleic acid bases adenine, thymine, and cytosine. Theor Chim Acta 24 51-60. doi 10.1007/BF00528310... 

Fio. 16. Electrostatic molecular potential-energy maps for thymine in the ring plane (top) and in the plane perpendicular to the ring plane and passing through atoms as indicated (bottom). 

N. K. Ray, G. Bolis, M. Shibata, and R. Rein, hit. J. Quantum Chem., Quantum Biot. Symp., 11,257 (1984). Potential Derived Point Charge Model Study of Electrostatic Interaction Energies in Some Complexes of Water with Uracil, Thymine, and Cytosine. 

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