Biological activity can be predicted at a prescreening stage by using a target-accelerated combinatorial synthesis. The rate of dimerization of vancomycin analogues (see picture, X=CH=CH2, SAc) in the presence of vancomycin's targets Ac-d-Ala-d-Ala and Ac2-l-Lys-d-Ala-d-Ala correlated well with the observed biological activity. From this study three highly potent antibacterial agents effective against both vancomycin-susceptible and vancomycin-resistant bacteria strains were identified.