Synthesis and Antibacterial Activity of a New Series of Tetracyclic Pyridone Carboxylic Acids

Yoshikazu Jinbo, Hirosato Kondo, Yoshimasa Inoue, Masahiro Taguchi, Hideki Tsujishita, Yasuo Kotera, Fumio Sakamoto, Goro Tsukamoto

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26 Citations (Scopus)


A series of novel tetracyclic pyridone carboxylic acids replacing the 10-position oxygen atom of 9,l-(epoxymethano)-7-fluoro-8-(4-methyl-1-piperazinyl)-5-oxo-5H-thiazolo[3,2-a]quinoline-4-carboxylic acid by imino groups (NR; R = Me, Et, c-Pr, allyl, Ph, benzyl), a sulfur atom, or a carbonyl group was prepared and evaluated for antibacterial activity and inhibitory activity on DNA gyrase isolated from E. coli KL-16. The in vitro antibacterial potency and DNA gyrase inhibitory activity were found to be in the following order: NMe ≥ O > S ≫ CO. Moreover, a methyl group was the optimal alkyl substituent at the 10-position nitrogen atom for antibacterial activity and for DNA gyrase inhibitory activity. 7-Fluoro-9,1-[(N-methylimino)methano]-8-(4-methyl-1-piperazinyl)-5-oxo-5ff-thiazolo[3,2-a]quinoline-4-carboxylic acid (10-NCH3) showed potent in vivo antibacterial activity.

Original languageEnglish
Pages (from-to)2621-2626
Number of pages6
JournalJournal of Medicinal Chemistry
Issue number18
Publication statusPublished - Jan 1 1993
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Molecular Medicine
  • Drug Discovery


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