A new method for the in vitro screening of inhibitors of angiotensin-converting enzyme (ACE), using the chromophore- and fluorophore-labelled substrate, dansyltriglycine.

In our search for antihypertensive plant constituents, we developed a new in vitro assay for the detection of angiotensin-converting enzyme inhibitors in plant extracts. The chromophore- and fluorophore-labelled tripeptide dansyltriglycine is used as substrate, which is cleaved by the enzyme into dansylglycine and diglycine. The product dansylglycine and unreacted substrate are separated and quantified by reversed phase high performance liquid chromatography with UV detection. This target-directed enzyme assay is very specific, highly sensitive and reproducible, and lends itself very easily to automation.