A series of beta-carbonyl substituted glutathione conjugates were prepared and evaluated as inhibitors of OvGST2. Their specificity for the parasite derived protein was assessed through comparison with their inhibition of human pi GST. Inhibition of OvGST2 has been demonstrated at low micromolar concentrations for these conjugates and selectivity for OvGST2 over human pi-GST of greater than 10-fold has been achieved. (C) 2000 Elsevier Science Ltd. All rights reserved.