The relative non-toxicity of the diuretic amiloride, coupled with its selective inhibition of the protease urokinase plasminogen activator (uPA), makes this compound class attractive for structure–activity studies. Herein we substituted the C (2)-acylguanidine of C (5)-glycyl- amiloride with amidine and amidoxime groups. The data show the importance of maintaining C (5)-hydrophobicity. The C (5)-benzylglycine analogs containing either C (2) ...