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.