Stereoelectronic effects of modified purine bases on the sugar conformation of nucleosides: pyrrolo[2,3-d]pyrimidines

Abstract

Steric and stereoelectronic effects of 7- and 8-substituents of 7-deaza-2′-deoxy-adenosine and -guanosine on the dynamic sugar puckering as well as on the conformation about the C(4′)–C(5′) bond have been studied. (i) The higher the electron-attracting effect of the substituents, the more the N⇌S (North⇌South) equilibrium of the pentofuranose moiety is biased towards the N-conformation. (ii) The higher the electron-withdrawing effect of the 7-substituents, the higher the γ^(+)g (+sc) rotamer population around the C(4′)–C(5′) bond. The interdependencies of the conformational equilibria of 7-deazapurine nucleosides and their influence on oligonucleotide secondary structures are discussed.

References

1. W. Saenger, Principles of Nucleic Acid Structure, Springer Verlag, New York, 1984, pp. 17–24.
2. Ref. 1, pp. 55–81.
3. J. Plavec, W. Tong and J. Chattopadhyaya, J. Am. Chem. Soc., 1993, 115, 9734.
4. J. Plavec, N. Garg and J. Chattopadhyaya, J. Chem. Soc., Chem. Commun., 1993, 1011.
5. J. Plavec, L. H. Koole and J. Chattopadhyaya, Biochim. Biophys. Meth., 1992, 25, 253.
6. L. H. Koole, H. M. Buck, A. Nyilas and J. Chattopadhyaya, Can. J. Chem., 1987, 65, 2089.
7. L. H. Koole, H. M. Buck, H. Bazin and J. Chattopadhyaya, Tetrahedron, 1987, 43, 2989.
8. L. H. Koole, J. Plavec, H. Liu, B. R. Vincent, M. R. Dyson, P. L. Coe, R. T. Walker, G. W. Hardy, S. G. Rahim and J. Chattopadhyaya, J. Am. Chem. Soc., 1992, 114, 9936.
9. J. Plavec, C. Thibaudeau, G. Viswanadham, C. Sund and J. Chattopadhyaya, J. Chem. Soc., Chem. Commun., 1994, 781.
10. C. Thibaudeau, J. Plavec, K. A. Watanabe and J. Chattopadhyaya, J. Chem. Soc., Chem. Commun., 1994, 537.
11. C. Thibaudeau, J. Plavec, N. Garg, A. Papchikhin and J. Chattopadhyaya, J. Am. Chem. Soc., 1994, 116, 4038.
12. C. Thibaudeau, J. Plavec and J. Chattopadhyaya, J. Am. Chem. Soc., 1994, 116, 6558.
13. C. Thibaudeau, J. Plavec and J. Chattopadhyaya, J. Am. Chem. Soc., 1994, 116, 8033.
14. C. Thibaudeau, J. Plavec and J. Chattopadhyaya, J. Org. Chem., 1996, 61, 266.
15. J. E. Kilpatrick, K. S. Pitzer and R. Spitzer, J. Am. Chem. Soc., 1947, 69, 2483.
16. C. Altona and M. Sundaralingam, J. Am. Chem. Soc., 1972, 94, 8205.
17. C. Altona and M. Sundaralingam, J. Am. Chem. Soc., 1973, 95, 2333.
18. H. P. M. de Leeuw, C. A. G. Haasnoot and C. Altona, Isr. J. Chem., 1980, 20, 108.
19. W. Guschlbauer and K. Jankowski, Nucl. Acids Res., 1980, 8, 1421.
20. J. van Wijk and C. Altona, PSEUROT 6.2 – A program for the conformational analysis of five membered rings, University of Leiden, July 1993.
21. C. A. G. Haasnoot, F. A. A. M. de Leeuw and C. Altona, Tetrahedron, 1980, 36, 2783.
22. E. Westhof, O. Röder, I. Croneiss and H.-D. Lüdemann, Z. Naturforsch., Teil C, 1975, 30, 131.
23. C. Hansch, A. Leo and R. W. Taft, Chem. Rev., 1991, 91, 165.
24. F. Seela, H. Rosemeyer, M. Zulauf, Y. Chen, G. Kastner and H. Reuter, Liebigs Ann. Recl., in the press.
25. T. Sato, Acta Crystallogr., Sect. C, 1984, 40, 880.
26. V. Zabel, W. Saenger and F. Seela, Acta Crystallogr., Sect. C, 1987, 43, 131.
27. H. Rosemeyer, M. Zulauf, N. Ramzaeva, G. Becher, E. Feiling, K. Mühlegger, I. Münster, A. Lohmann and F. Seela, Nucleosides Nucleotides, 1997, 16, 821.
28. H. Rosemeyer, G. Toth, B. Golankiewicz, Z. Kazimierczuk, W. Bourgeois, U. Kretschmer, H.-P. Muth and F. Seela, J. Org. Chem., 1990, 55, 5784.
29. E. Egert, H. J. Lindner, W. Hillen and M. C. Böhm, J. Am. Chem. Soc., 1980, 102, 3707.
30. D. H. Williams, Aldrichim. Acta, 1991, 24, 71.
31. D. Pörschke, Mol. Biol. Biochem. Biophys., 1977, 24, 191.
32. Ref. 1, pp. 141–143.
33. W. Hillen and H. G. Gassen, Biochim, Biophys. Acta, 1978, 518, 7.
34. W. Uhl, J. Reiner and H. G. Gassen, Nucl. Acids Res., 1983, 11, 1167.
35. W. Hillen and H. G. Gassen, Nucl. Acids Res., Spec. Supply, 1978, 149.
36. F. Seela and H. Thomas, Helv. Chim. Acta, 1995, 78, 94.
37. F. Seela, N. Ramzaeva and Y. Chen, Bioorg. Med. Chem. Lett., 1995, 5, 3049.
38. N. Ramzaeva and F. Seela, Helv. Chim. Acta, 1996, 79, 1549.
39. F. Seela and H. Thomas, Helv. Chim. Acta, 1994, 77, 897.
40. N. Ramzaeva and F. Seela, Helv. Chim. Acta, 1995, 78, 1083.
41. F. Seela and M. Zulauf, Synthesis, 1996, 726.
42. F. Seela and Y. Chen, Chem. Commun., 1996, 2263.
43. N. Ramzaeva and F. Seela, unpublished results.
44. C. Min, T. D. Cushing and G. L. Verdine, J. Am. Chem. Soc., 1996, 118, 6116.