Structural modifications and biological evaluation of 3-isoxazolylvinylcephalosporins

Structural modifications and biological evaluations of 3-isoxazolylvinylcep halosporins (I) were performed. The replacement of a hydrogen atom at the 7 -aminothiazole group by a chlorine resulted in an improvement: of the activ ity against resistant Gram-positive bacterial strains including the methici llin-resistant Staphylococcus aureus (MRSA) and the ciprofloxacin-resistant Staphylococcus aureus (CRSA). The introduction of other heterocycles such as an isothiazole or a thiadiazole in place of the isoxazole moiety gave sl ightly decreased in vitro activities. (C) 2000 Elsevier Science Ltd. All ri ghts reserved.