Synthesis and in vitro anti-mycobacterial activity of 5-substituted pyrimidine nucleosides

Mycobacterium tuberculosis and Mycobacterium avium infections cause the two most important mycobacterioses, leading to increased mortality in patients with AIDS. Various 5-substituted 2'-deoxyuridines, uridines, 2'-O-methyluridine, 2'-ribofluoro-2'-deoxyuridines, 3'-substituted-2',3'-dideoxy uridines, 2',3'-dideoxyuridines, and 2',3'-didehydro-2',3'-dideoxyuridines were synthesized and evaluated for their in vitro inhibitory activity against M. bovis and M. avium. 5-(C-1 Substituted)-2'-deoxyuridine derivatives emerged as potent inhibitors of M. avium (MIC90 = 1-5 microg/mL range). The nature of C-5 substituents in the 2'-deoxyuridine series appeared to be a determinant of anti-mycobacterial activity. This new class of inhibitors could serve as useful compounds for the design and study of new anti-tuberculosis agents.