CP6679, a new injectable cephalosporin. Part 1: synthesis and structure-activity relationships

Novel cephalosporin derivatives possessing a substituted cinnamoyl moiety at the 7 beta-position. Synthesis, structural characterization and antibacterial activity of 3-acetoxymethyl cephalosporin derivatives

Twenty 3-acetoxymethyl cephalosporin derivatives, with various cinnamoyl (3-phenyl-2-propenoyl) substituted groups at the 7beta-position, were synthesized and evaluated for antibacterial activity in vitro. Some of these cephalosporin derivatives showed good selective activity against Gram-positive bacteria. Although substitution on the aromatic ring of cinnamoyl moiety generally reduced antimicrobial activity against Staphylococcus sp. and Enterococcus sp., a hydroxy group at the para position, and particularly ortho, para di-chloro substitution, improved the activity against methicillin resistant strains of Staphylococcus aureus (MRSA). Substitution on the double bond alpha position of the cinnamoyl moiety also affected the antimicrobial activity. A cyano group attached to this position increased activity against both negative coagulase Staphylococcus and Enterococcus sp. and extended the antibacterial spectrum towards Gram-negative bacteria.

Anti-MRSA cephems. Part 2: C-7 cinnamic acid derivatives

Forty-five novel cephalosporin derivatives with activity against methicillin-resistant Staphylococcus aureus (MRSA) are described. The compounds contain novel cinnamic acid moieties at C-7 that were synthesized using a key Heck reaction followed by nucleophilic aromatic substitution reactions. The most active compound (41) displayed an MIC(90) against MRSA of 1.0 microg/mL, and a PD(50) of 0.8 mg/kg. Compound 14 was found to be very safe in a mouse model of acute toxicity.

CP6679, a new injectable cephalosporin with broad spectrum and potent activities against methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa

The antibacterial activities of CP6679, a new injectable cephalosporin with a broad antibacterial spectrum, were compared with those of other cephalosporins. CP6679 had stronger in-vitro activity than ceftazidime and cefpirome against methicillin-resistant Staphylococcus aureus(MRSA), methicillin-resistant coagulase-negative staphylococci, and Pseudomonas aeruginosa. Its activity against MRSA was eight times stronger than that of cefpirome, and it showed high binding affinity for penicillin-binding protein 2' of MRSA. Furthermore, the antibacterial activity of CP6679 against ceftazidime-resistant and imipenem-resistant P. aeruginosawas eight times stronger than that of ceftazidime and four times stronger than that of imipenem. In addition to its in-vitro activities, CP6679 showed the highest efficacy among all cephalosporins tested in murine models of systemic infection induced by MRSA or P. aeruginosa. It was more effective than vancomycin and cefpirome against respiratory tract infections induced by MRSA in mice.

Anti-MRSA cephems. Part 1: C-3 substituted thiopyridinium derivatives

Sixteen novel cephalosporin derivatives with activity against methicillin-resistant Staphylococcus aureus (MRSA) are described. The compounds were synthesized using substituted thiopyridones, generated either by cyclization of functionalized precursors, or by direct alkylation of the enolate of 2-methyl substituted pyrones. The most active compound in vitro against a strain of MRSA (A27223) displayed an MIC of 0.5 microg/mL. The most efficacious compound in vivo had a PD50 of 2.1 mg/kg.