The present invention includes novel compounds of the formula (I) wherein
X is absent or trans or cis CHCH, R.sub.1 is (C.sub.1-C.sub.10) alkyl
unsubstituted or substituted by one to three hydroxy, (C.sub.1-C.sub.10)
alkenyl unsubstituted or substituted by one to three hydroxy,
(C.sub.1-C.sub.10) alkynyl unsubstituted or substituted by one to three
hydroxy, or aryl unsubstituted or substituted by one to three hydroxy;
R.sub.2 is hydrogen, alkyl or aryl; R.sub.3 and R.sub.4 are,
independently of each other, H, halogen, or a solubilizing group, with
the provisio that at least one of R.sub.3 and R.sub.4 is halogen; and
pharmaceutically acceptable salts thereof. The invention also includes
pharmaceutically acceptable formulations of said compounds which exhibit
antibiotic activity against a wide spectrum of microorganisms including
organisms which are resistant to multiple antibiotic families and are
useful as antibacterial agents for treatment or prophylaxis of bacterial
infections, or their use as antiseptics, agents for sterilization or
disinfection.