Methods for the detection and quantitation of angiotensin converting enzyme inhibitors in fermentation broths.

Two procedures are described for the detection of inhibitors of angiotensin converting enzyme (ACE). The first is a new agar-plate method useful as a screening tool. Two ACE inhibitors produced by culture A58365 were discovered using this plate test. The second method is a modification of a previously reported spectrophotometric procedure. Both procedures utilize p-nitrobenzyl-oxycarbonylglycyl-(S-4-nitrobenzo-2-oxa-1,3- diazole)-L-cysteinyl-glycine as substrate.