Orally active cephalosporins. Part 2: Synthesis, structure–activity relationships and oral absorption of cephalosporins having a C-3 pyridyl side chain

Abstract A series of 7β-[( Z )-2-(2-aminothiazol-4-yl)-2-hydroxyiminoacetamido]cephalosporins having a pyridine ring connected through various spacer moieties at the C-3 position was designed and synthesized and evaluated for antibacterial activity and oral absorption in rats. All compounds showed potent antibacterial activity against Staphylococcus aureus , whereas antibacterial activity against Gram-negative bacteria was markedly influenced by the spacer moiety between the pyridine and cephem nucleus. Oral absorption was influenced by the position of the pyridine nitrogen as well as by the spacer moiety. Among these compounds, FR86830 ( 14 Download high-res image (104KB) Download full-size image Figure 1 . Structure of cephalosporins. ), having a 4-pyridylmethylthio moiety at the C-3 position, showed the most well balanced activity and moderate oral absorption.