New streptogramin B derivatives useful as antibacterial agents and synergists for streptogramin A antibacterial agents - e.g. pyrido- or pyrimidino-pristinamyin IE derivatives

摘要

Group B streptogramin derivatives of general formula (I): wherein Ra, Rb, Rc, Rd, RSUB1/SUB, RSUB2 /SUBand Y are as defined in the description, including preparation methods and compositions containing same. Such derivatives are particularly useful as antimicrobial agents, optionally combined with at least one group A streptogramin derivative.