title: Synthesis of 3- or 4-phenyl-1,8-naphthyridine derivatives and evaluation of antimycobacterial and antimicrobial activity.
abstract: A series of 3- or 4-phenyl-1,8-naphthyridine derivatives variously substituted in the positions 2, 6 and 7 were synthesized and evaluated for in vitro evaluation for their antimycobacterial activity as part of a TAACF TB screening program under the direction of the US National Institute of Health, NIAID division. Several compounds showed an interesting activity when tested at a concentration of 6.25 microg/ml against Mycobacterium tuberculosis H(37)Rv and in particular compounds 2a, 4a,d, 8a,d and 8i, exhibit a % inhibition from 91 to 99. Among these, compounds 2a, 8a and 8d appeared to have a good activity with minimum inhibitory concentrations (MICs) of 6.25 microg/ml. On the basis of the biological results, the most effective substituent in position 2 or 7 seems to be the piperidinyl group. The introduction of a morpholinyl group either in position 2 or 7 of the heterocycle ring caused a decrease in activity. The 1,8-naphthyridine derivatives were also tested in vitro for their antimicrobial activity against Staphylococcus aureus as Gram-positive bacteria and Escherichia coli as Gram-negative bacteria.
mesh_terms: D000900:Anti-Bacterial Agents / Q000138:chemical synthesis / Q000494:pharmacology*; D000995:Antitubercular Agents / Q000138:chemical synthesis / Q000494:pharmacology; D015195:Drug Design; D004926:Escherichia coli / Q000187:drug effects; D008826:Microbial Sensitivity Tests; D009169:Mycobacterium tuberculosis / Q000187:drug effects; D009287:Naphthyridines / Q000138:chemical synthesis / Q000494:pharmacology*; D013211:Staphylococcus aureus / Q000187:drug effects; D013329:Structure-Activity Relationship
chemical_list: D000900:Anti-Bacterial Agents; D000995:Antitubercular Agents; D009287:Naphthyridines