Synthesis and Antibacterial Activity of Thiazolo-, Oxazolo-, and Imidazolo[3,2-a][l,8]naphthyridinecarboxylic Acids

Hirosato Kondo, Masahiro Taguchi, Yoshimasa Inoue, Fumio Sakamoto, Goro Tsukamoto

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It is known that thiazolo[3,2-α][l,8]naphthyridine derivatives (3a) exhibit good antibacterial activity. Accordingly, several analogues of 3a, viz. oxazolo- and imidazolo[3,2-α][l,8]naphthyridine derivatives 3b and 3c, were synthesized and evaluated for antibacterial activity in vitro and for inhibitory activity against DNA gyrase of Escherichia coli K-12 C600. Compound 3a exhibited antibacterial activity comparable to that of ofloxacin and enoxacin against Gram-positive and Gram-negative bacteria and displayed antibacterial activity superior to that of 3b and 3c. The antibacterial activities of 3b and 3c decreased in that order. DNA gyrase inhibitory activities of 3a-c in E. coli K-12 C600 paralleled their in vitro antibacterial activity. It was found that enhancement of the DNA gyrase inhibitory activity of 3a was dependent on a certain feature of the sulfur atom of the thiazole ring.

Original languageEnglish
Pages (from-to)2012-2015
Number of pages4
JournalJournal of Medicinal Chemistry
Issue number7
Publication statusPublished - Jul 1990
Externally publishedYes


All Science Journal Classification (ASJC) codes

  • Molecular Medicine
  • Drug Discovery

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