Antimicrobial activity of E-4441, a representative azetidine quinolone.

E-4441 is a third-generation difluoroquinolone characterized by the presence in position 7 of an azetidine ring, disubstituted in position 3 by amine and methyl groups. E-4322 is another difluoroquinolone which differs from the former in having a 3-acetidinol substitution in position 7. E-4441 shows satisfactory levels of activity, both in vitro and in vivo, its activity against G(+) aerobic bacteria and anaerobic bacteria being generally notable.