Abstract: The present invention relates to new 1-substituted derivatives of 6-fluoro-7-(pyrrol-1-yl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid, their preparation and their application as drugs.The 1-substituted derivatives of 6-fluoro-7-(pyrrol-1-yl)-1,4-dihydro-4-oxoquinoline-3-carboxylic acid according to the invention correspond to the general formula I: ##STR1## in which: R represents a methyl radical, a 2-hydroxyethyl radical, a vinyl radical, a cyclopropylmethyl radical, a propyl radical, a cyclopropyl radical, a 2-fluoroethyl radical, a methylamino radical or an ethylamino radical, as well as their physiologically acceptable alkali metal or alkaline earth metal salts.They are useful as antimicrobial agents, in particular as antibacterial and fungistatic agents.

Abstract: Derivatives of inner salts of aminopyridinium hydroxide and corresponding salts thereof comprising the general formuale I and II ##STR1## in which: R.sub.1 as selected from the group consisting of a hydrogen and a radical 2-furyl-methyl-amino;R.sub.2, R.sub.4 and R.sub.6 are all selected from the group consisting of a hydrogen atom, a C.sub.1 -C.sub.1 linear or branched lower alkyl radical and a phenyl radical;R.sub.3 is selected from the group consisting of a hydrogen or a carbamyl radical;R.sub.5 represents a hydrogen; andX.crclbar. represents a monobasic anion of a pharmaceutically acceptable acid.