Abstract: Rifamycin derivatives having antimicrobial activities, including activities against drug-resistant microorganisms are claimed in this invention. The inventive rifamycin derivatives are uniquely designed in that they have a rifamycin moiety covalently linked to a linker group through the C-3 carbon of the rifamycin moiety and the linker is, in turn covalently linked to a therapeutic moiety or antibacterial agent/pharmacophore. The therapeutic moiety can be a quinolone, an oxazolidinone, a macrolide, an aminoglycoside, a tetracycline core or a structure/pharmacophore associated with an antibacterial agent.

Abstract: The present invention relates to rifamycin 3-iminomethylenyl (—CH?N—) derivatives having antimicrobial activities, including activities against drug-resistant microorganisms. The claimed rifamycin derivative has a rifamycin moiety covalently linked to a linker through an iminomethylenyl (—CH?N—) group at the C-3 carbon of the rifamycin moiety and the linker is, in turn, covalently linked to a quinolone structure or its pharmacophore within the DNA gyrase and topoisomerase IV inhibitor family. The inventive rifamycins are novel and exhibit activity against both rifampin and ciprofloxacin-resistant microorganisms.

Abstract: Novel rifamycin derivatives of formula I (both hydroquinone and corresponding quinone (C1-C4) forms): or their salts, hydrates or prodrugs thereof, wherein: a preferred R comprises hydrogen, acetyl; L is a linker, a preferred linker group elements selected from any combination of 1 to 5 groups shown FIG. 1, provided L is not wherein R1 is H, methyl or alkyl. The inventive compounds exhibit valuable antibiotic properties. Formulations having these compounds can be used in the control or prevention of infectious diseases in mammals, both humans and non-humans. In particular, the compounds exhibit a pronounced antibacterial activity, even against multiresistant strains of microbes.

Abstract: Rifamycin derivatives having the following structure of general formula I (both hydroquinone and corresponding quinone (C1-C4) forms): or its salts, hydrates or prodrugs thereof; wherein a preferred R1 comprises hydrogen or acetyl and a prefered R2 comprises hydrogen, methyl or other lower alkyls; wherein asterik (*) denotes the carbon bearing the chiral center, wherein absolute configuration is assigned as R or S. Methods of preparation of the aforementioned rifamycin derivatives are also described. The compounds exhibit antimicrobial activities, including activities against drug-resistant microorganisms.