Biphenyl and binaphthyl peptidic compounds

Disclosed are biphenyl and binaphthyl peptidic compounds as represented by the general formulae (I), (II) and (III), wherein Ar1-Ar2 is biphenyl or binaphthyl; Q1 and Q2 are each independently selected from hydrogen, methoxy, nitro, halogen, hydroxyl, or amino; B is selected from -O-, -S-, -S(O)-, -S(O)2-, -NH-, and -N(alkyl)-; A1 and A2 are the same or different and are basic amino acid residues; each of S1, S2, S3 and S4 is either present or absent and is an independently selected amino acid residue; and wherein the other substituents are as defined herein. Also disclosed is a composition which comprises a compound as defined above or a salt thereof together with one or more pharmaceutically acceptable carriers or adjuvants. Further disclosed is the use of a compound as defined above in the preparation of a medicament for treating or preventing bacterial infection, or for the treatment or prophylaxis of HIV in a subject.