Synthesis and antiviral activity of dihydroxycyclohexyl pyrimidine and purine carbocyclic nucleosides

The latest progress in the synthesis of carbocyclic nucleosides

This review presents the latest developments in the field of carba-nucleosides (1994-1998). Special attention is paid to the synthesis of key precursors to those carba-nucleosides that possess significant biological activities or have novel structures.

The cyclohexene ring system as a furanose mimic: synthesis and antiviral activity of both enantiomers of cyclohexenylguanine

Both enantiomers of cyclohexenylguanine were synthesized in a stereospecific way starting from the same starting material: R-(-)-carvone. Both compounds showed potent and selective anti-herpesvirus activity (HSV-1, HSV-2, VZV, CMV). The binding of both cyclohexene nucleosides in the active site of HSV-1 thymidine kinase was investigated, and a model for the binding of both enantiomers is proposed. The amino acids involved in binding of the optical antipodes are the same, but the interaction energy of both enantiomers is slightly different. This may be attributed to the interaction of the secondary hydroxyl function of the nucleoside analogues with Glu-225. Structural analysis has demonstrated the flexibility of the cyclohexenyl system, and this may be considered as an important conformational characteristic explaining the potent antiviral activity.

Synthesis and Conformational Study of 3-Hydroxy-4-(Hydroxymethyl)-1-Cyclohexanyl Purines and Pyrimidines

The cyclohexane nucleosides with a 1,4-relationship between nucleoside base and hydroxymethyl moiety were synthesized using a conjugated addition reaction of the nucleobases to ethyl 1,3-cyclohexadiene-1-carboxylate and hydroboration of the cyclohexenyl precursor. The lack of antiviral activity of the compounds was correlated with the conformation of these nucleosides as deduced from NMR and X-ray analysis.