Investigation of 5'-Norcarbocyclic Nucleoside Analogues as Antiprotozoal and Antibacterial Agents.

Carbocyclic nucleosides have long played a role in antiviral, antiparasitic, and antibacterial therapies. Recent results from our laboratories from two structurally related scaffolds have shown promising activity against both Mycobacterium tuberculosis and several parasitic strains. As a result, a small structure activity relationship study was designed to further probe their activity and potential. Their synthesis and the results of the subsequent biological activity are reported herein.

Novel 5'-Norcarbocyclic Pyrimidine Derivatives as Antibacterial Agents.

A series of novel 5'-norcarbocyclic derivatives of 5-alkoxymethyl or 5-alkyltriazolyl-methyl uracil were synthesized and the activity of the compounds evaluated against both Gram-positive and Gram-negative bacteria. The growth of Mycobacterium smegmatis was completely inhibited by the most active compounds at a MIC99 of 67 µg/mL (mc²155) and a MIC99 of 6.7⁻67 µg/mL (VKPM Ac 1339). Several compounds also showed the ability to inhibit the growth of attenuated strains of Mycobacterium tuberculosis ATCC 25177 (MIC99 28⁻61 µg/mL) and Mycobacterium bovis ATCC 35737 (MIC99 50⁻60 µg/mL), as well as two virulent strains of M. tuberculosis; a laboratory strain H37Rv (MIC99 20⁻50 µg/mL) and a clinical strain with multiple drug resistance MS-115 (MIC99 20⁻50 µg/mL). Transmission electron microscopy (TEM) evaluation of M. tuberculosis H37Rv bacterial cells treated with one of the compounds demonstrated destruction of the bacterial cell wall, suggesting that the mechanism of action for these compounds may be related to their interactions with bacteria cell walls.