13C NMR spectroscopy of some third-generation cephalosporins, their synthetic intermediaries and reaction byproducts.

(13)C NMR spectroscopic data for 25 cephalosporin derivatives were assigned by combination of one- and two-dimensional experiments. The effect of the substitution at C-3, C-7 and C-4 acid group positions on the chemical shifts of the cephem nucleus is discussed.

1H and 13 C spectral assignments of 7beta-(cinnamoyl-substituted)amino-3-acetoxymethyl-cephalosporins.

The (1)H and (13)C spectroscopic data for 7beta-(cinnamoyl-substituted)amino-3-acetoxymethyl-cephalosporins were fully assigned by a combination of one- and two-dimensional experiments. Substitution on the aromatic ring and on the double-bond alpha-position of the cinnamoyl moiety has little influence on the spectroscopic properties of the 7beta-aminocephalosporanic acid parent moiety.

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.