Recently, we have introduced simplified analogs of pepstatin A, representing 'tripeptides' with two valine residues which are C-terminated by an amino alcohol moiety. In the present study, we have deleted one valine unit, yielding simple molecules-called 'valaminols'-which can be prepared in big scale under really low costs. First investigations on structure-activity relationships revealed that the most active compound is a valaminol bearing both natural substituents either at the N-terminus or at the C-terminal side chain. Its inhibitory activity fully corresponds to the activity of tripeptides, hitherto reported by us, although one valine residue has been omitted.