An analogue of piperonyl butoxide facilitates the characterisation of metabolic resistance.

Background: Previous work has demonstrated that piperonyl butoxide (PBO) not only inhibits microsomal oxidases but also resistance-associated esterases. The ability to inhibit both major metabolic resistance enzymes makes it an ideal synergist to enhance xenobiotics but negates the ability to differentiate which enzyme group is responsible for conferring resistance.

Results: This study examines an analogue that retains the ability to inhibit esterases but is restricted in its ability to act on microsomal oxidases, thus allowing an informed decision on resistance enzymes to be made when used in conjunction with the parent molecule.

Benzodioxole derivatives as negative effectors of plant proteases.

Previous work demonstrated that a commercial formulation of piperonyl butoxide (PBO) did inhibit the activity of some plant proteolytic enzymes. In this paper, the effect of pure PBO and nine pure PBO homologues (PBOH) appropriately synthesized toward bromelain and papain was studied in hydrocarbon solution using the bis(2-ethylhexyl)sodium sulfosuccinate (AOT) reverse micellar system. This study establishes that the majority of these compounds show, in vitro, interesting protease inhibition activities.