Yancomycin-resistant Enterococcus faecalis

Nosocomial infection caused by methicillin-resistant Staphylococcus aureus (MRSA) or vancomycin-resistant Enterococci (VRE) has become a great deal of recent concern. Although a number of cephalosporins had been synthesized in the past, few of them was effective against these resistant bacteria. Recently, TOC-39and TOC-50^3) bearing vinyl-thio linkage attached by substituted pyridines at C-3 were reported their high antibacterial activity against MRSAand E. faecalis. However, toxicological feature of the compounds prevented them from further development. Therefore, we have conducted explorative studies to find novel cephalosporin derivatives having favorable profiles with considerable activities against MRSA and VRE mainly by varying the heterocycles. In the meanwhile, Obi4) reported that methylthio linked benzothiopyrans were useful heterocycles to enhance the antibacterial activity. In this present communication, we describe that anti-