Beigelman and co-workers have carried out structure-activity studies on hammerhead ribozymes by substituting modified pyrimidines at various positions, where profound effects on ribozyme catalytic activity have been observed.⁽¹⁾ Pyridin-2-one Riboside phosphoramidite⁽²⁾ was found to be useful in these studies, providing alterations in syn/anti nucleobase orientation, ribose puckering, and stacking ability due to dipole changes.^1,2,[Ref: (a) Baidya, N.; Ammons, G. E.; Matulic-Adamic, J.; Karpeisky, A. M.; Beigelman, L.; Uhlenbeck, O. C. RNA1997, 3, 1135-1142. (b) Burgin, A. B., Jr.; Gonzalez, C.; Matulic-Adamic, J.; Karpeisky, A. M.; Usman, N.; McSwiggen, J. A.; Beigelman, L. Biochemistry1996, 35, 14090-14097.

Ref:

1. Beigelman, L.; Matulic-Adamic, J.; Karpeisky, A.; Haeberli, P.; Sweedler, D. Methods in Enzymology2000, 317, 39-65.
2. Matulic-Adamic, J.; Gonzalez, C.; Usman, N.; Beigelman, L. Bioorg. Med. Chem. Lett.1996, 6, 373-378.