A series of dipeptides with N3-(4-methoxyfumaroyl)-L-2,3-diaminopropanoic acid (FMDP), the irreversible inhibitor of glucosamine-6-phosphate synthetase from bacteria and fungi, have been synthesized and their antibacterial and antifungal properties in vitro evaluated. The results demonstrate that these peptides inhibit the growth of a number of the tested microorganisms, especially pathogenic fungus