The invention concerns agents with antibacterial activity, their production and use in the treatment of bacterial infections in animals, including man. The agents are derivatives of vancomycin-type antibiotics, of structure X—W-L-V, wherein X is hydrogen, acetyl or a lipophilic membrane-insertive element, W is a basic peptide or basic amino acid; L is a linking group and V is a glycopeptide moiety which inhibits peptidoglycan biosynthesis in bacteria.