Chem. Pharm. Bull., 48(11),1667-1672, November 2000

Regular Articles

Studies on 8-Methoxyquinolones: Synthesis and Antibacterial Activity of 7-(3-Amino-4-substituted)pyrrolidinyl Derivatives


Katsuhiro KAWAKAMI,* Hisashi TAKAHASHI, Hitoshi OHKI, Kenichi KIMURA, Satoru MIYAUCHI, Rie MIYAUCHI, and Makoto TAKEMURA

New Product Research Laboratories I, Daiichi Pharmaceutical Co., Ltd., 16-13 Kitakasai 1-chome, Edogawa-ku, Tokyo 134-8630, Japan.

A series of 8-methoxyquinolones bearing 3-amino-4-methylpyrrolidines or 3-amino-4-fluoromethylpyrrolidines at the C-7 position was synthesized and their physicochemical and biological properties were evaluated. All of the compounds synthesized showed more potent activity than LVFX (3) against both gram-positive and -negative bacteria. Increases in lipophilicity of these compounds had desirable effects on their potency of single intravenous toxicity and pharmacokinetic profiles in animals. Among the compounds synthesized, 1-fluorocyclopropyl derivatives 17 and 20, and 7-(cis-3-amino-4-fluoromethylpyrrolidinyl) derivative 19 (DC-756h) showed negative responses in the micronucleus test in mice while 1-cyclopropyl-7-(3-aminopyrrolidinyl) derivative 16 showed a positive response. These results suggested that the introduction of a fluorine atom into the 3-aminopyrrolidinyl substituent resulted in favorable influence on genetic toxicity as well as into the N-1 cyclopropyl sub-stituent.

Key words 8-methoxyquinolone; 3-amino-4-fluoromethylpyrrolidine; micronuclei-formation; antibacterial activity; single intravenous toxicity; lipophilicity