Ten 'bisquinolones' were prepared by joining two molecules of norfloxa
cin, or 1,8-naphthyridine and benzo[c][1,8]naphthyridine derivatives,
with various aliphatic linkers. These were tested against 17 bacteria
strains but none showed more than slight activity (MIC greater than or
equal to 10 mg/l). However, a 'monoquinolone' derived from benzo[c][1
,8]naphthyridine showed greater activity than norfloxacin against a st
rain of Acinetobacter.