title: Studies on 3'-quaternary ammonium cephalosporins--III. Synthesis and antibacterial activity of 3'-(3-aminopyrazolium) cephalosporins.
abstract: The synthesis and in vitro antibacterial activity of 7 beta-[(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]cephalos porins bearing N-mono or dialkyl and carbamoyl aminopyrazolium, and five- or six-membered rings fused to the 3-aminopyrazolium methyl groups at the 3-position, are described. Aminopyrazolium methyl cephalosporins (23e, f, i), with fused saturated and unsaturated rings were especially effective against Staphylococcus strains compared to 3-amino-2-methylpyrazolium methyl cephalosporin (1). Among the cephalosporins prepared in this work, 7 beta-[(Z)-2-(2-aminothiazol-4-yl)-2-methoxyiminoacetamido]-3-(4,5, 6, 7-tetrahydro-1-pyrazolo[1,5-a]pyrimidinio)methyl-3-cephem-4-carbox ylate (23f) showed a good balance of antibacterial activity against both Gram-positive bacteria including Staphylococcus aureus and Gram-negative bacteria including P. aeruginosa. An imidazopyrazolium group at the 3-position in, for example, cephalosporin (23i) was particularly effective for improving antibacterial activity against MRSA.
authors.affiliation: New Drug Research Laboratories, Fujisawa Pharmaceutical Co., Ltd., Osaka, Japan.
authors.forename: H
authors.initials: H
authors.lastname: Ohki
authors.forename: K
authors.initials: K
authors.lastname: Kawabata
authors.forename: Y
authors.initials: Y
authors.lastname: Inamoto
authors.forename: S
authors.initials: S
authors.lastname: Okuda
authors.forename: T
authors.initials: T
authors.lastname: Kamimura
authors.forename: K
authors.initials: K
authors.lastname: Sakane
mesh_terms: D002511:Cephalosporins / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology; D009682:Magnetic Resonance Spectroscopy; D008826:Microbial Sensitivity Tests; D008956:Models, Chemical; D011550:Pseudomonas aeruginosa / Q000187:drug effects; D013211:Staphylococcus aureus / Q000187:drug effects
chemical_list: D002511:Cephalosporins