While inhibitors of serine-b-lactamases are widely used in combinationtherapy with b-lactam antibiotics, there are no clinically available inhibitors associated with metallo-b-lactamases(MBLs), and so there is a need for the development of such inhibitors. This work describes your optimisationof a lead inhibitor previously identified by fragment screening of a compound library. We also reportthat thiosemicarbazide intermediates inside syntheses of these compounds are moderately potentinhibitors of this IMP-1 MBL from Pseudomonas aeruginosa. The interactions these inhibitors with theactive online site of IMP-1 were examined using in silico options.